WO2009077209A2

WO2009077209A2 - Luminous element and lamp having a surface structure for creating visible light

Info

Publication number: WO2009077209A2
Application number: PCT/EP2008/056087
Authority: WO
Inventors: Ruppert Goihl
Original assignee: Osram Gesellschaft mit beschränkter Haftung
Priority date: 2007-12-18
Filing date: 2008-05-19
Publication date: 2009-06-25
Also published as: WO2009077209A3; DE102007060839A1

Abstract

The invention relates to a luminous element with a substrate and a structure that is arranged adjacent thereto, preferably provided with a photonic crystal, surface texturing or a lattice, said structure being designed and dimensioned such that substantially monochromatic, visible radiation can be produced. Due to suitable dimensioning, high light output can be achieved with little effort, using more recent developments, such as photonic crystals. The light output can be increased while using less energy.

Description

description

Illuminant and lamp with a surface structure for generating visible light

Technical area

The invention is based on a luminous element with a thermal emitter and a lamp with such a luminous body.

State of the art

Semiconductor light sources already offer high luminous efficiencies today. This is also evident in special applications where colored light is needed. However, semiconductor light sources typically require expensive ballasts and good cooling to avoid lowering the light output and lifetime due to an increase in junction temperatures.

In conventional thermal radiators, which form the basis of a large part of the luminous means, according to Planck's law, a considerable part of the electromagnetic radiation is emitted in a wavelength invisible to the human eye. In order to increase the efficiency of incandescent lamps, different approaches can be used. The filament temperature can be increased, which increases the proportion of visible light in the emitted light. Furthermore, by a special coating on the lamp bulb for heat recovery, the heat generated by an incandescent filament can be reflected to this. In this way, a lower energy input from the outside is necessary to bring the helix to operating temperature. A halogen incandescent lamp with such an infrared reflection coating is known from the patent DE 19701794A1. It is easy to build and inexpensive incandescent lamps, the need to increase the effectiveness, that is to increase the luminous efficacy and reduce energy consumption. One way to change the radiation behavior of a thermal emitter is the integration of this emitter in a photonic crystal having a regular structure in the size of the wavelength to be blocked, these regular structures having refractive indices which differ greatly from each other. As a result, light having a wavelength corresponding to this feature size can not propagate in the crystal, but the radiation increases in out-of-wavelength regions.

References EP 1575080A2 and US 2006 / 0071585A1 disclose incandescent filaments with a filament around which a two-dimensional or three-dimensional photonic crystal is provided. Furthermore, a relatively broadband radiation is generated in the aforementioned two documents. In the case of an applied Bragg mirror for this broadband radiation, about 40% of the infrared radiation still leaves the luminous element. Thus, the desired increase in efficiency can not be achieved with the aforementioned luminous bodies.

The document US 2003 / 0235229A1 discloses a vertical cavity surface emitting laser (VCSEL) using photonic crystals. The disadvantage here is that the emission source used is semiconductor are used, whose high production costs do not allow the use in inexpensive incandescent lamps.

Thus, there is a need for a lamp which produces predominantly white light whose luminous element allows easy installation into the lamp, in which the light is diffusely distributable or at least a considerable solid angle is illuminable, the luminous body in a simple manner to conventional voltage sources, such as 12 volts, 110 Volt, 230 volts can be connected.

Moreover, there is a need for easy-to-use light sources for colored light with good luminous efficiencies, which, because they can stabilize themselves by their resistance heating and do not require cooling, can also be used in critical environments.

Presentation of the invention

The object of the present invention is to provide a luminous element with a thermal emitter and a lamp with such luminous element, which meet the above requirements, in particular have a high luminous efficacy and in which the energy requirement is reduced. Furthermore, this should be inexpensive to produce.

This object is achieved by a luminous element, a lamp and a manufacturing method according to the independent.

According to the invention, a luminous body with a substrate and an adjacent thereto, preferably provided with a photonic crystal, a surface texturing or a lattice structure formed and dimensioned in such a way that substantially monochromatic, visible radiation can be generated. By appropriate dimensioning can be implemented with recent developments, such as photonic crystals high luminous efficiencies with little effort.

The invention further provides a luminous element with a laser cavity layer, on one side of which a thermal emitter is arranged and on the other side of which a one-dimensional photonic crystal is arranged in such a way that essentially monochromatic, visible radiation can be generated. As a result, the luminous efficacy can be increased while minimizing the required energy.

In an advantageous development, the one-dimensional photonic crystal has a plurality of dielectric layer pairs, each pair having a layer with a low refractive index and a layer with a high refractive index. As a result, a partially transmissive mirror can be provided for the desired radiation while unwanted radiation is not generated.

The thermal emitter is in one embodiment a metallic reflector layer. As a result, the thermal emitter can be formed by resistance heating with low material expenditure. In a further embodiment, the metallic reflector layer is applied to a ceramic carrier. In this case, the electrical electrical conductor formed with high electrical resistance through the ceramic or the ceramic can be used for the transmission of heat.

On the ceramic support may be provided opposite to the metallic reflector layer, a conductor for heating the metallic reflector layer. In this case, the ceramic is an electrically insulating material, but has a good thermal conductivity. Thus, there is greater scope for variation in the design of the conductor track.

In a further development of the thermal emitter is formed by a metallic coil body, so that a layer arrangement according to the invention can be applied to a conventional coil design. This application can be done either before shaping the helical body or after shaping. In the latter case, there is the advantage that the lack of deformation after the application of the layer can prevent the layer from flaking off.

Furthermore, it is preferred that a further laser cavity layer is applied to the metallic coil body opposite to the laser cavity layer. In this way, by means of radiation to both sides, the light output can be increased.

The thermal emitter is preferably formed substantially as a flat surface or substantially as a rotationally symmetric surface. In this way, a coating is possible in a simple manner. In a further embodiment, the luminous element has a substantially rectangular conductor cross-section. This favors the use of metallic conductors to perform the resistance heating.

In one embodiment, the filament is designed as a filament, so that conventional filament are replaceable for the invention.

In a further embodiment, the luminous element is embodied conically, so that an areal radiation can take place.

In an embodiment of the luminous element in a double-cone shape, the illuminance emanating from the luminous element can be increased.

The luminous element may be designed in the form of a disk, which runs perpendicular to the feed sections. In this way, it is facilitated that a planar radiation can be provided at right angles to a lamp cap.

The luminous element may have the shape of a spherical surface in sections. This facilitates a homogeneous brightening of a room area.

A resistance heating element of the thermal emitter may have meandering at least in sections, so that a large conductor length can be implemented on a small area.

The thermal emitter may be spaced to a plate having the laser cavity layer and the photonic crystal, so that higher temperatures in the thermal emitter without destruction of the layer structure can be implemented.

In a further embodiment, the thermal emitter may be applied to a plate having the laser cavity layer and the photonic crystal. As a result, the manufacturing process for planar formation of the layer structure can be facilitated.

According to the invention, a lamp with a luminous element, as described above, is also provided. This lamp has an increased light output.

Such a lamp may further comprise a lamp body, on the light-emitting region of which a converter layer is provided for converting part of the radiation into the complementary color. Thus, the production of white light is supported.

Furthermore, a gas, such as nitrogen, may be provided for oxidation protection in the lamp body.

By providing a diffuser layer a uniform blasting can be supported.

It is preferred to provide on the side opposite the one-dimensional photonic crystal between a substrate and the laser cavity layer a one-dimensional metallo-dielectric, photonic crystal of metal layers and layers with a small refractive index or particle films with a one-dimensional photonic crystal. In this way, part of the radiation can be absorbed by metal layers and the photonic crystal can simultaneously be used as a reflector. act reflector for the wavelength at which the emission of the radiator is maximum.

In one variant, a metal layer or a semiconductor layer is provided on the side opposite the one-dimensional photonic crystal between a substrate and the laser cavity layer as an emitter on a one-dimensional photonic crystal. In this case, it is preferred that the absorption in the metal layer is equal to the transmission through the reflector by the oppositely provided photonic crystal, in order to allow an optimized emission behavior. In the case of the semiconductor layer, hot electrons can form on the surface due to the formation of surface plasmons, so that the thermal equilibrium is not locally present and a blasting is possible.

There is further provided a luminous body for producing a substantially monochromatic, visible radiation with a substrate and a one-dimensional photonic crystal, to which a metal or particle layer adjoins, wherein the one-dimensional photonic crystal between the substrate and the metal or particle layer or on the to the substrate opposite side of the metal or particle layer is arranged. By appropriate design of the layers, visible light can be generated.

Particularly preferred is when the one-dimensional photonic crystal has low refractive index layers and high refractive index layers, and the thickness of the high refractive index layers is between two Low refractive index layers is twice the layer thickness as the thickness of the low refractive index layers. In this way and through the choice of material with regard to the resonance at shorter wavelengths than infrared light, the emission can be maximized.

In a further development, a luminous element for producing a substantially monochromatic, visible radiation is formed with a substrate and a partially transparent reflector layer, opposite to which a substrate is provided, wherein preferably a thicker than the partially transparent reflector layer reflector layer between the resonator and substrate is provided. By a thickness of the cavity, which is reduced compared to the designed for the emission in the infrared range cavity, an emission can take place in the visible range.

It is preferred if a one-dimensional photonic crystal is arranged as a filter for suppressing unwanted emission peaks on the partially transmissive reflector layer. In this way, the number of maxima in the spectrum that would occur without photonic crystal can be reduced.

According to a further embodiment, a luminous element for producing a substantially monochromatic, visible radiation with a substrate and a layer system is provided, which forms a one-dimensional photonic crystal and has pairs of layers of a layer of dielectric and an emitter layer, wherein the emitter layer is a volume layer is of a transition metal, a noble metal or a semiconductor or a particle layer, and the dielectric is selected to be substantially transparent to visible light at the emitter temperature. In this way, a luminous body with a simple layer structure and with diffusion processes on the surface of little importance can be implemented

The emitter layers can preferably also be used as heating elements, so that an advantageous thermal behavior can be implemented.

The emitter layer is preferably a particle layer with a metal layer for resistance heating, so that the heating and the formation of an electrical contact via the particle layer can be combined in a small space.

It is also advantageous if the emitter layer is a particle layer with metallic nanoparticles having a diameter in the range of approximately 5 nm to 1 μm, whereby a special adaptation for the emission in the visible range is present.

The substrate can be flat or have a rod-shaped core, whereby a flat or cylindrical luminous element can be realized depending on the desired application.

In a further embodiment, a luminous element is provided for generating a substantially monochromatic, visible radiation with a heatable substrate and adjacent to this provided structure, which is formed in such a way surface plasmon can emit light due to the structure. Even though Surface waves normally produce no radiation can thus be caused due to the thermally excited surface plasmons, a light emission.

The substrate metal is preferred and the structure comprises dielectric in such a way that the wave vector of the surface plasmids of the metal-dielectric interface is equal to the wave vector of the photon in the dielectric. Thus, light can be emitted.

The substrate preferably has tungsten or a coated insulator or semiconductor or ion conductor, so that use in low-voltage lamps, a thermally favorable design of the filament or a simple coating can be implemented.

The structure preferably has stripes, grids, spots or particles, whereby a simple manufacture is possible.

The formation of the structure by the vapor deposition with particles can be achieved at an irregular distance as the emitted light color white.

The particles may be coated with a dielectric, so that protection against damage by surface and volume diffusion is made.

The particles may be embedded in a dielectric to which a one-dimensional photonic crystal has been applied, thereby improving the selectivity of the radiation of the lamp. Furthermore, it is preferred if a cavity is provided between coated particles of the structure and a metal layer, so that a defined emission peak in the visible range can be realized.

There is further provided a luminous element for producing a substantially monochromatic, visible radiation with a heatable substrate and adjacent thereto provided particle lattice layer, which forms a photonic crystal, whereby a simple manufacturing process can be used.

The particle lattice layer may comprise beads of a refractory material which are coated with a dielectric, and the refractory material may have a high refractive index contrast to this dielectric, so that due to the spherical shape as the lowest energy form the coating is permanently provided.

The beads are made of tungsten in one application, and the dielectric has Al ₂ O ₃ , SiO ₂ or HfO ₂ so that widely used materials can be used with the associated low cost.

The particle lattice layer can be face centered cubic, body centered cubic or the hexagonal closest packing, so that a high absorption or emission coefficient in the visible range can be realized.

The particle lattice layer has in an embodiment spherical spaces, preferably in cubic face-centered arrangement with a small refractive index, of surrounded by a material of high refractive index. Thus, the principle of the inverse opal can be used, and destruction of the layer by diffusion can be greatly reduced.

The spheres preferably have a dielectric with a low refractive index, for example Al 2 O 3 or SiO 2, such that interconnected regions can be converted from the dielectric with a small refractive index.

There is further provided a manufacturing method for a luminous body for producing a substantially monochromatic, visible radiation with a heatable substrate and adjacent to this provided particle grid layer forming a photonic crystal, comprising the steps of a) providing a substrate, b) applying the particle lattice layer on the substrate, c) compacting the elements of the particle lattice layer, d) sintering the coating on the elements of the particle lattice layer. Thus, a simple manufacturing process can be provided.

Preferably, after step d) remaining cavities between the elements of the particle lattice layer are filled with a dielectric of low refractive index, in order to prevent destruction by surface diffusion.

The densification in step c) can be carried out by sedimentation or controlled drying of a colloidal sphere dispersion in order to permanently provide the structure.

After step b) and before step c) stripping off protruding elements of the particle lattice layer can take place in order to ensure a regular structure. Particularly advantageous embodiments can be found in the dependent claims.

Brief description of the drawings

In the following, the invention will be explained in more detail with reference to exemplary embodiments. The figures show:

1A shows a top view of a lamp with a luminous element according to the present invention, FIG. 1B shows a sectional view from the left of the lamp from FIG. 1A and FIG. 1C shows a top view of the lamp of FIG. 1A according to the present invention,

2 shows the layer structure of a first filament according to a first sub-variant of the first embodiment of the first embodiment,

3 shows the layer structure of a second luminous element according to the first sub-variant of the first embodiment of the first exemplary embodiment,

4 shows the layer structure of a third luminous element according to the first sub-variant of the first embodiment of the first exemplary embodiment,

5 shows the layer structure of a fourth filament according to the first sub-variant of the first embodiment,

6 shows the layer structure of a luminous element according to a second and third embodiment of the first sub-variant of the first embodiment, 7 shows the layer structure of a luminous element according to a fourth and fifth embodiment of the first sub-variant of the first exemplary embodiment,

8 shows the layer structure of a luminous element according to a second sub-variant of the first exemplary embodiment,

9 shows the layer structure of a luminous element according to a third sub-variant of the first exemplary embodiment,

10 shows the layer structure of a luminous element according to a fourth sub-variant of the first exemplary embodiment,

11A to 11C show details of a particle layer in the first embodiment;

12 the layer structure of a luminous element according to a first sub-variant of the second embodiment,

13 the layer structure of a luminous element according to a second sub-variant of the second exemplary embodiment,

14 the layer structure of a luminous element according to a third sub-variant of the second exemplary embodiment,

15 the layer structure of a luminous element according to a first sub-variant of the third exemplary embodiment, 16 shows the layer structure of a luminous element according to an alternative embodiment of the first sub-variant of the third embodiment,

17 the layer structure of a luminous element according to a second sub-variant of the third exemplary embodiment,

18 shows the layer structure of a luminous element according to a third sub-variant of the third embodiment,

19 the layer structure of a luminous element according to a fourth sub-variant of the third embodiment,

FIG. 20A shows a detail of the coated surface with a layer of cubic surface-centered, coated spheres according to the fourth exemplary embodiment, and FIG. 20B shows a specific embodiment of the coating from FIG. 20A, FIG.

Figs. 21A to 28B are examples of use of the luminous bodies according to the first to fourth embodiments, Figs. 21A to 21C show a first application example, Figs. 22A and 22B show a second application example of the invention, Figs. 23A and 23B show a third application example of the invention, Figs Fig. 24 shows a fourth application example of the invention, Figs. 25A and 25B show a fifth application example of the invention, Fig. 26 shows a sixth application example of the invention, Figs. 27A and 27B show a seventh application example of the invention and Figures 28A and 28B show an eighth application example of the invention.

Preferred embodiment of the invention

With the present invention, one-dimensional photonic crystals are used in such a way that, preferably exclusively, a desired, visible radiation is generated.

(Basic considerations)

No body emits more electromagnetic energy at the same temperature than a black body. This means that lamps provided with photonic crystals emit less energy overall. Due to the photonic crystals, a radiator can selectively suppress certain wavelengths. Thus, the ratio of usable radiation in the visible range to loss radiation, e.g. in the infrared range.

Photonic crystals block the propagation of radiation within a bandgap in certain spatial directions. If these crystals are suitably connected to the thermal radiator, then no radiation of the wavelengths in the locked frequency range can be emitted in the spatial directions with band gap. With obliquely incident radiation on flat layer systems, the blocked wavelength will change. On the other hand, there is no longer any effect on radiation parallel to the layers. Surface textures and grids on a thermal emitter can also enhance certain wavelengths relative to others by interacting with the surface plasmons present in the thermal emitter, for example, and thus positively alter the selectivity of the emitter. In this case, selective radiators, regardless of whether they have photonic crystals or surface structures, have very fine structures in the size range of the wavelength, for example 0.3 micrometers for visible light.

In thermal radiators, which are provided with photonic or lattice structures, the following fundamental problems occur:

The thermal radiation requires emitters which are as hot as possible, since the sum of the radiated energy is proportional to T ⁴ according to the Stefan-Boltzmann law.

- For photonic emitters, the usable radiation compared to the loss radiation can be significantly higher. For example, the ratio of usable radiation compared to the loss radiation with respect to "ordinary" thermal radiators may be better by a factor of 10. However, the emitted radiation amount at half emitter temperature is, for example, only 1/16.

- In heated bodies, diffusion processes occur, which are their physical background in the endeavor of

Have systems that increase entropy.

The speed of the processes discussed above increases with temperature, with the increasing number of voids and voids in solids different sizes of building blocks (eg atoms) of two adjacent layers and with decreasing cohesive forces. The diffusion processes can destroy these structures within a very short time (eg a few hours) and thus reset the effectiveness of the luminous element to that of a "normal" emitter.

Thus, by the inventor, by way of example, the following requirements have been made for luminous bodies / lamps according to the invention which have been optimized by photonic crystals:

- The temperature of the lamp should be as high as possible, but not higher than about 30% to 70% of the melting temperature of the material in order to substantially prevent diffusion. The reason for this is that the surface diffusion starts at about 30% of the melting temperature and the volume diffusion begins at about 45% of the melting temperature. At higher temperatures, the life of the lamp is increasingly reduced. The temperature of the photonic radiator should therefore always be lower than the temperature of "ordinary" thermal radiators with the same material and lifetime

Small irregularities or structures in materials (for example cavities, grooves or holes on the surface of the substrates, such as tungsten filaments) of the thermal radiators can not be left without special precautions.

Furthermore, structures in the metal can be destroyed very quickly by recrystallization. An example is a tungsten filament, which is caused by surface diffusion in the drove slowly to become a single crystal with crystalline surfaces.

As a result, therefore, the following provisions should be made for light sources according to the invention with good luminous efficacy and colored light:

To provide the same light output, photonic radiators should tend to have larger surface areas because the photonic crystal can not always fully compensate for the effect of the lower temperature. However, as heat losses through conduction and convection in the lamp become more and more important at lower emitter temperatures and large surfaces, the photonic emitter will very often require good vacuum insulation in the lamp. Shielding gas fillings with higher pressures slow down the destruction of the luminous element, but on the other hand lower the luminous efficacy.

Separation layers are necessary to reduce diffusion damage.

Small structures should be shaped so that their function remains even after the formation of any crystal surfaces by surface diffusion. For example, round shapes can become polygons.

A special problem area is the coating of the substrates. This can be done only in special cases before a subsequent deformation, as in the deformation, the structures can be damaged and can build up voltages that are degraded by recrystallization in later operation and the photonic Damage structure. That's why it's from Advantage if the substrates are annealed prior to coating. On the other hand, it is often impossible to subsequently coat any substrates (eg helix) evenly. For this reason, simple substrate shapes are advantageous.

The provision of one-dimensional photonic crystals also has an effect on the lamp in which such a luminous body is arranged.

Depending on the coating of the emitter, the lamp can not produce white light. The light distribution, unlike Lambert radiators, can be strongly angle-dependent.

Thus, depending on the lamp and the coating, the following peculiarities result for lamps with luminous bodies according to the invention:

a reflector, an auxiliary lens or diffuser materials should be arranged in or on the lamp housing,

Converter materials in the lamp housing for converting part of the radiation into the complementary color should be provided in or on the lamp housing,

it should be provided a contact protection, usually in the form of a lamp housing, and

it should be an oxidation protection, e.g. Vacuum or nitrogen filling, be provided for the hot components.

FIGS. 1A to 1C show views of a lamp in which a luminous element according to the invention is used. Such a lamp has a lamp 4 with a lamp base 6 with pinch seal and a reflector body 8, in which the luminous element 2 is located. In the lamp cap 6, two base pins 10a, 10b are embedded, which are connected via molybdenum foils 12a, 12b with power supply lines 14a, 14b, to which the electrical contacts of the filament 2 are fixed and the filament 2 is mechanically held.

The reflector body 8 has a reflective coating 16 on its side facing the luminous element 2 and is provided with a diffuser layer 20 at its light exit region 18, which is surrounded by the reflective coating 16, and with a converter layer 22 for converting part of the radiation into provided the complementary color. As oxidation protection for the hot components of the interior of the reflector is provided with a gas filling, for example with a nitrogen filling. Furthermore, the lamp shown in FIGS. 1A to 1C has a pump tip 24. Instead of a diffuser layer, a master lens can also be provided on the entire body.

With the luminous body 2 according to the invention, substantially visible, monochromatic light, for example with a wavelength of 400 or 500 nanometers, can be generated and emitted in a directionally directed manner.

In the carriers, i. thermal emitter or substrates, for one-dimensional photonic crystals, the following boundary conditions are to be observed.

They should consist of surfaces which are easy to coat, preferably with a flat surface, cylindrical surface, conical surface or spherical surface. The reason- bodies for receiving the one-dimensional photonic crystals are shown in FIGS. 21A to 28 and will be described in detail below. Plane and rotationally symmetric bodies can be evenly coated in PVD systems, whereby rotationally symmetric bodies are rotated.

When using wire-shaped substrates, subsequent filament winding of such wires, while retaining the coating, is difficult, in accordance with experience gained in lamp filament production. If the coating is to be applied after winding, it can no longer be uniformly applied at all points due to the shape that has now formed.

(First embodiment)

For bulbs, the following requirements apply to the thermal emitter: The total radiant energy should as far as possible be delivered in the usable wavelength range, i. for lamps in the range> 1.6 eV to about 3.3 eV). The light should be distributed so that it depends on the application, e.g. at a light spot, is bundled in the zones to be illuminated.

The emission of monochromatic light in defined angles of emission may be due to the coupling of the light to the emitter u.a. via laser-like structures with a resonator or via surface plasmons / surface phonons.

When surface waves exist at the interface between two media, the electric field strength in the media falls exponentially with the distance from the interface. fall off. In the case of photonic crystals, the amplitude of the field falls exponentially.

Similar to the surface waves at the metal / dielectric interface, surface waves may arise at the interface of a photonic crystal (e.g., a Bragg mirror). The wavelengths at which this can happen lie in the stop band of the photonic crystal, where it has a high reflectivity. Here, too, the surface waves are dependent on the angle of incidence / emission angle of the radiation. The wavelength range of the stop band can be changed for the materials to be used by adjusting the layer thicknesses. The layer thicknesses can be calculated, for example, at the Internet address http: // ab initio.mit.edu / wiki / index.php / WITH Photonic Bands.

Also on the surface of polar materials, e.g. SiC or NaCl, which are held together by ionic bonds, can be used to produce surface waves similar to metals. The same phenomena occur as with metals with surface structure, i. selective emission at certain wavelengths and angles. However, the wavelengths of surface phonon polaritons are usually in the long-wave infrared range because the lattice vibrations are sluggish.

In this case, when light from outside falls on such an interface and surface waves are generated, the absorption coefficient of the system sharply increases because the energy of the surface waves is converted into heat. Conversely, the emission coefficient increases strong when these surface waves are thermally excited.

It should be noted that in the figures the number of layer pairs and the width of the emitter are shown reduced for reasons of convenience.

(First Embodiment, First Embodiment)

In the first embodiment of the first embodiment of the present invention, the principle of the vertical cavity enhanced resonant thermal emitter (VERTE) radiator disclosed in Physical Review B72, 075127 (2005) of the American Physical Society, entitled "A resonant-cavity enhanced thermal emission "published by Ivan Celanovitch, David Perreault and John Casasakian, is used in a modified form in which the VERTE principle emitter described in the above publication has a thermal emitter, tungsten With such a radiator, infrared light having a wavelength of about 2.35 μm is emitted with relatively high coherence and with high directionality In accordance with the principle of the VCSEL laser, the US Pat US Pat. No. 20060186357.

The layer system according to the first embodiment of the first embodiment has a highly reflective substrate from the basic structure, an overlying dielectric cavity and thereon a Bragg mirror with a finite layer number. Although the structure is similar to that of the Of the US Pat. No. 20060186357, dimensions adapted to the visible range have been selected in the present invention.

The high-reflection metallic substrate is e.g. from Ag or W. At the same time the reflector acts as an emitter, because according to Kirchhoff the emission at one wavelength and direction is equal to the corresponding absorption and the absorption is the complement of the reflection to 1. The substrate thus represents a lossy mirror.

The dielectric cavity may, for example, have a thickness of approximately 0.78 μm and has a similar effect to a Fabry-Perot resonator in which the light is reflected several times between two parallel planar or curved mirrors. Each reflection on the denser medium causes a phase shift of 180 °. The reflected rays interfere with each other. By suitable mirror adjustment, a resonator mode can be amplified.

By combining the dielectric cavity with the one-dimensional photonic crystal, the wavelengths outside the resonant wavelength are suppressed, while the resonant wavelength is amplified, so that the cavity is virtually lossless.

The one-dimensional photonic crystal is designed so that λ, ie the wavelength at which the emission of the radiator is to become maximum, is in the stop band and thus represents a practically lossless mirror for λ. Nevertheless, because of the finite number of layers, a small part of the energy is transferred. The one-dimensional photonic crystal with cavity system can also be considered as a photonic crystal with a defect.

The layer thicknesses of the photonic crystal can be as already mentioned e.g. at the Internet address http: // ab-inibiύ .mit. edu / wiki / index .php / Calculated with Photon Ic Bands. Depending on the refractive index of the layers, these layer thicknesses are approximately λ / 4n for the high / low refractive index layer. For other wavelengths and materials of the thermal emitter, e.g. the number of layers can be reduced so that the transmission through the upper Bragg mirror is adapted to a possibly higher absorption in the metallic emitter.

Conventional spotlights operating according to the VERTE principle are designed for infrared radiation. For shorter wavelengths than infrared radiation, the one-dimensional photonic crystal is mathematically adjusted. A special feature of visible light is that the dielectrics of the photonic crystal should be transparent to the visible light at the operating temperature of the radiator. Si is therefore unsuitable. SiO 2, Al 2 O 3, MgO, etc. are therefore preferred for the dielectric having a low refractive index. The material of the dielectric having a "high" refractive index is preferably a metal, such as Ag, W, Mo, or ceramic, such as TiO 2, Fe 2 O 3, V 2 O 3 , Si3N ₄ , etc. The cavity can be made of the same material as the low-refracting dielectric, eg, Al ₂ O _3. The layer thickness d of the cavity is adjusted in accordance with the wavelength λ, at which the emission of the radiator is to become maximum and is dependent on the Refractive index n _reso n _ato rM _ed i _u m of the cavity preferably about m * λ / (2n _Resonat orMedium) r where m is an integer.

In a conventional radiator according to the VERTE principle, a metallic lossy reflector is needed, which still has a very high reflection at the wavelength λ with a defined small loss factor. The loss in the lower reflector and the cavity should be so large that it corresponds to the radiated energy through the upper reflector (critical coupling). However, in the case of the reflector for the considerably shorter wavelengths of visible light, the requirements are lower because the radiated bandwidth may be greater. The purely metallic reflector used in conventional spotlights according to the VERTE principle can therefore be replaced by the following alternatives in the first embodiment of the first exemplary embodiment:

first sub-variant: Adapting the spotlight according to the VERTE principle to the emission of visible light, the substrate may have a deviating from a metallic body design

second sub-variant: metallo-dielectric, photonic crystal One or more thin metal layers absorb part of the radiation and can also act as an emitter when heated, the photonic crystal simultaneously acting as a reflector for wavelength λ.

third sub-variant: Particle films combined with a one-dimensional photonic crystal The particle films emit or absorb a defined part of the radiation, while the Bragg mirror takes over the task of reflection.

fourth sub-variant: a thin metal layer as an emitter on a one-dimensional photonic crystal,

fifth sub-variant: one-dimensional photonic crystal (reflector) and a semiconductor with a suitable electric band gap.

(First Sub-Variant of First Embodiment of First Embodiment)

Hereinafter, the first to fourth sub-variants of the first embodiment of the first embodiment will be explained in more detail. FIGS. 2 to 5 show the layer structure for the luminous element according to this first sub-variant of the first exemplary embodiment of the invention, and FIGS. 21a to 29c show a first to eighth application example for the luminous elements with a layer structure according to the invention.

Each luminous element according to FIGS. 2 to 5 has the basic structure in which a thermal emitter with a high reflection coefficient is provided with an active layer on which there is a layer system which has layers of alternatingly high and low refractive index. This layer order implements the following basic function:

The thermal emitter would emit radiation as a Planckian radiator in a wide wavelength range. Due to the provided active layer, which is preferably a dielectric medium and which has a predetermined Has layer thickness, builds up a standing wave, which corresponds to a corresponding electromagnetic field. This electromagnetic field interacts with the actual quantum source in the thermal emitter (plasmons, molecular dipoles, lattice waves, or others), coupling the quantum well to the existing electromagnetic field. As a result, only synchronously with the existing electromagnetic field radiation can be emitted, that is synchronous with the frequency corresponding to the size of the active layer.

In this first sub-variant of the first exemplary embodiment of the present invention, the layer system is provided on the side of the active layer opposite the thermal emitter, which can act as a Bragg mirror in the form of a partially transmissive mirror.

For the function of such a luminous body is important that the two sides of the active layer are provided with a good mirror. This can be implemented, for example, by a metallic surface on the thermal emitter on one side. In the case of the one-dimensional photonic crystal of the layer system on the other side, there is a partially transmissive mirror which has a high reflectivity (for example 99%) for the desired radiation.

Thus, in contrast to the prior art, as reproduced in the aforementioned Physical Review, no infrared radiation is reflected, but visible light. The layers of the luminous element are designed in such a way that a part of the visible Ren radiation from the laser exits and can be used in this way.

In FIGS. 2 and 3, the thermal emitter has a metallic reflector layer 26 applied to a resistance heating element, which has a high reflection coefficient. The reflectance is preferably more than 90%, for which a high surface quality is necessary.

In FIGS. 4 and 5, the thermal emitter is part of a metallic filament, whereby both the resistance heating and the reflection function are converted by this filament. In all four examples, the active layer is preferably a laser cavity layer whose thickness depends on the wavelength and is, for example, 170 nanometers. It is preferred that the thickness of the cavity layer is about λ / 4, where λ is the wavelength at the bandgap. The material used is preferably a transparent material with the lowest possible absorption rate and a defined permeativity.

The refractive index of this laser cavity layer should be small. To reduce the loss of a laser cavity layer, this can also be designed in two layers. The thickness of the laser cavity layer determines the wavelength of the light emitted from the luminous element, which is based on the electromagnetic field, which represents a half-wave of the radiation. The layer system is a one-dimensional photonic crystal and has layers with alternately high and then low refractive index. The layer with high For example, refractive index applied to the thermal emitter may be made of silicon or diamond and may have a thickness of, for example, 35 nanometers. The low refractive index layer which adjoins the high refractive index layer may, for example, be made of silicon dioxide and have a thickness of, for example, 80 nanometers. With respect to a bandgap at a wavelength λ, it is preferable to select the thickness of the layers each about λ / 4.

A multiplicity of these double layers are located on the active layer in FIGS. 2 to 5. The layer system is similar to the layer thickness and the material selection of an infrared reflection layer in conventional lamps. This layer reflects light, which attenuates interference of certain wavelengths. The layer thickness is adapted to the desired wavelength. For visible light, a thickness range of 30 to 150 nanometers has proved to be favorable. Due to the similarity to the infrared reflection layer, the layer system can be manufactured on IRC (infrared coating) coating systems.

FIG. 2 shows the cross section through a luminous element, in which the metallic reflector layer 26 is applied to a ceramic substrate 28, which is produced, for example, from Al 2 O 3, AlN or other substances. The reflector layer 26 is heated by resistance heating by the ceramic carrier 28 to a certain temperature, for example to 1200 Kelvin. The ceramic carrier is made of a material with a high electrical derstand, for example SiC, and can therefore be connected directly to a power supply.

On the metallic reflector layer 26 is applied as the active layer, the laser cavity layer 30, on which the layer system 32 is made of a respective high-refractive-index layer 32a and a low-refractive-index layer 32b.

In the luminous element according to FIG. 3, the thermal emitter comprises the metallic reflector layer 26, which, for example, is made of tungsten, silver, molybdenum, nickel, iron or the like, as in the first exemplary embodiment, and the ceramic carrier, which is produced, for example, from Al 2 O 3, AlN or others , on.

On the ceramic carrier, a conductor track 36 is provided on the side opposite the metallic reflector layer 26, over which the resistance heating is carried out. The ceramic carrier 34 is an electrically insulated material with good thermal conductivity. The conductor track 36 has a sufficient length and a sufficient cross-section to carry out the resistance heating. As in this first example, the laser cavity layer 30 and the layer system 32 with layers of high refractive index and with layers of low refractive index are located on the metallic reflector layer 26. With the first and second examples, a luminaire for relatively high voltages is disclosed.

The luminous element according to FIGS. 4 and 5 is a luminous element for relatively lower voltages. In this case, the thermal emitter is replaced by a metallic body, in particular from gangsten or precious metal, preferably formed by a helix 38, through which the heating function and the reflection function is implemented. It is preferred if the helix 38 is made of molybdenum or tungsten. On the helix 38, as in the implementation in FIGS. 2 and 3, there is a laser cavity layer 30 and a layer system 32.

In the coating method, it is advantageous if a luminous body is provided in which the layer system 32 does not chip off during mechanical deformation. This can be implemented advantageously in particular when the coil 38 is wound from a metal strip and then the coating process is carried out. Alternatively, first the coating of the helix 38 can be made and then the luminous body can be formed.

In the case of the luminous element according to FIG. 5, a laser cavity layer 30 and a layer system 32 are respectively applied to the opposite sides of the filament 38. As an alternative to the helix, another metallic body of transition metal or noble metal, for example molybdenum, Ag, W, may also be provided as substrate and emitter. With such a coating, the luminous efficacy of the luminous element increases. On the other hand, the safety requirements increase against the chipping of the layer system from the helix. The laser cavity has a thickness of preferably approximately one quarter of the wavelength, which is to become maximum at the emission of the radiator, while the layers of the layer system 32 preferably have a thickness which is d = λ / n, where λ is the Wavelength to be maximized at the emission of the radiator, and n is the number of the double layer.

In the second to fifth subvariants of the first embodiment of the first embodiment, as in the first sub-variant, a layer system 32 of high refractive index layers and low refractive index layers is provided on a laser cavity layer 30. However, the structure on the opposite side of the laser cavity layer to the one-dimensional photonic crystal differs.

Second Sub-Variant of First Embodiment of First Embodiment

6, a second sub-variant of the first embodiment of the first embodiment is shown. In this sub-variant is a radiator for a wavelength λ at which the emission of the beam is to be maximum, in the visible range, wherein a me- tallo-dielectric photonic crystal is used as a lossy emitter. The substrate 40 may be metallic at low supply voltage, for example from W. At higher supply voltage, it is preferably electrically insulating or provided with a high electrical resistance, for example, the substrate is ceramic. In question are electrically insulating ceramics such as Al ₂ O ₃ or AlN. The emitter is then heated only via thin metal layers on the substrate 40. In this case, high supply voltages can be used. Finally, ceramics with high electrical resistances at operating temperature can be used, for example, ion conductors. Correspondingly high supply voltages must then be selected. Ideally, the substrate is coated on both sides with both the one-dimensional crystal and the laser cavity layer in order to reduce the losses.

On the substrate 40 is a one-dimensional metallo-dielectric photonic crystal 41 with a band gap at λ, wherein the layer thicknesses are about λ / 4n. In this one-dimensional metallo-dielectric photonic crystal is a layer sequence of a layer 41a with a low refractive index, for example of Al2O3, and a metal layer 41b whose thickness is smaller than the skin depth and whose material is preferably a transition metal.

The opposite end faces of the layers of the one-dimensional metallo-dielectric photonic crystal 41 are provided with the electrical contacts 42 for these emitter layers. Optionally, these are also provided for the substrate during resistance heating.

For the high refractive index layer 32b, TiO _{2 is} preferably used, while for the low refractive index layer, preferably Al ₂ O ₃ is used.

It is provided an electrical contacting of the emitter layers and optionally also the substrate for resistance heating.

Third Third Variant of First Embodiment of First Embodiment

The structure of the third sub-variant of the first embodiment of the first embodiment corresponds to the in Fig. 6 shown construction of the second sub-variant of the first embodiment of the first embodiment. In contrast to the latter, however, in the third sub-variant, the metal layers are replaced by particle layers. The particle diameter is below the wavelength λ, at which the emission of the radiator should be maximum.

(Fourth sub-variant of the first embodiment of the first embodiment)

FIG. 7 shows the fourth sub-variant of the first embodiment of the first exemplary embodiment, in which, instead of the one-dimensional metallo-dielectric photonic crystal, a thin metal layer 43 is provided as emitter on a one-dimensional photonic crystal 44. The upper reflector 32 and the laser cavity layer 30 correspond to the configuration in the second and third subvariants.

On the substrate 40, the one-dimensional photonic crystal 44 having a bandgap at the wavelength λ is provided in such a manner that the high refractive index layer 32a is in contact with the substrate 40 and is followed by the low refractive index layer 32b the latter also being adjacent to the metal layer 43. The metal layer 43 is made of transition or noble metal having a thickness that is so large that the absorption in the metal layer is equal to the transmission through the upper reflector 32. The electrical contact 42 establishes the electrical connection to the substrate 41 and / or to the metal layer 43.

Fifth Sub-Variant of First Embodiment of First Embodiment

The structure of the fourth sub-variant is modified in the fifth sub-variant so that instead of the metal layer 43, a semiconductor layer is used, which acts as an active medium. Thus, between the substrate 40 and the laser cavity layer 30 there is a one-dimensional photonic crystal and a suitable semiconductor. Although, in principle, the thermal pumping of a laser medium is not possible because it can not be produced in the active medium at thermal equilibrium because of the Bolzmann distribution. Due to the formation of surface plasmons, however, hot electrons can form on the surface. The thermal equilibrium is then temporarily absent locally. In this way, replacement of the purely metallic reflector in the VERTE principle can now be converted to visible light when irradiated.

Second Embodiment of First Embodiment

From the document Coherent thermal emission from one-dimensional photonic crystals, BJ Lee, CJ. Fu, ZM Zhang, Applied Physics Letters 87, 071904 (2005) shows a layer system consisting of a layer of the polar material SiC on a one-dimensional photonic crystal. The band gap of the one-dimensional photonic crystal is designed to coincide with the wavelength at which SiC surface chenwellen form in the form of phonons. This is the case, inter alia, at about 11 microns. Because of the formation of surface waves, a monochromatic emission of heat radiation results and this only at certain emission angles. By adjusting the SiC layer thickness, the emission can be maximized.

Such a layer system is, as shown in Fig. 8 in cross section, adapted for visible light. It should be noted that the representation is not true to scale lent and the number of layers of the photonic crystal is shown reduced. More specifically, on a substrate 40 according to the first embodiment of the first embodiment, a one-dimensional photonic crystal 45 having a low refractive index dielectric 41a adjacent to the substrate 40 and a high refractive index dielectric 41b at the opposite end portion is deposited. The thickness of this layer of high index nielectric 41b is approximately λ / 8 * n, which is also the thickness of said layer of low refractive index dielectric 41a. Between the layers of the low refractive index dielectric 41a in the photonic crystal 45 are the layers of the high refractive index dielectric 41b as double layers.

On the opposite side of the substrate of the one-dimensional photonic crystal, a metal or particle layer 43 is provided according to the first embodiment of the first embodiment with a thickness between 10 and 500 nm. The metal or particle Layer 43 is driven via an electrical contact 42.

On the opposite side of the substrate, preferably also a one-dimensional photonic crystal with a metal or particle layer are arranged.

For the shorter wavelengths of visible light according to the invention compared to the infrared range, the structure in the aforementioned document is adapted accordingly, wherein instead of SiC, a polar material with resonances at shorter wavelengths is used for the metal or particle layer 43. Metals such as Ag and, because of the temperature resistance, transition metals such as W can be used. The bandgap of the underlying photonic crystal 45 is matched by correspondingly thinner layers. The dielectric having a high refractive index is a ceramic, for example, as in the first embodiment of the first sub-variant, while comparable materials can likewise be used for the second dielectric with the first embodiment of the first sub-variant.

The heating of the layer system according to the second sub-variant is preferably carried out by conductive substrates and the metal or particle layer.

Third Embodiment of First Embodiment

In Fig. 9, a layer system according to the third embodiment of the first embodiment is not shown to scale and with a reduced layer number of the photonic crystal. This layer system is similar to a layer system for infrared radiation from the document "Design and fabrica- tion of planar multilayer structures with coherent thermal emission characteristics", BJ Lee and ZM Zhang, Journal of Applied Physics 100, 063529 (2006).

Although the structure is similar to that of the second embodiment of the first embodiment, but requires fewer layers in the one-dimensional photonic crystal.

In contrast to the second embodiment, the one-dimensional photonic crystal 46 is deposited on a substrate 43 which was SiC in the above-mentioned literature but is adapted to the visible light in the present invention. The band gap of the photonic crystal in this literature source is the phonon absorption band of the SiC in the infrared region. Upon absorption of incident radiation or thermal emission, surface waves with corresponding consequences are formed at the interface of the photonic crystal to SiC.

In the third embodiment of the first embodiment, the layer structure of both the photonic crystal 46 and the metal or particle layer is modified for shorter wavelengths. In this case, the stop band of the photonic crystal was adjusted by correspondingly thinner layers as in the second embodiment of the first embodiment. The stopband then lies with the resonances in the visible range. More specifically, on the substrate 40, which may be provided according to the first aspect of the first embodiment, one is already in the The first embodiment described metal or particle layer 43, the thickness of which is preferably in the range of about 10 to 500 nm and which is connected via electrical contacts 42. Provided on this metal or particle layer 43 is the one-dimensional photonic crystal 46 with low refractive index layers 46a and high refractive index layers 46b, with the high refractive index layers 46b on the opposite sides in a thickness of approximately λ / 8n. however, are provided between the double-thickness small-refractive-index layers 46a and the thickness of the low-refractive-index layers 46a is also about λ / 8n.

The substrate material should support plasmons in the visible wavelength range. This is basically in

Metals of the case, preferably Ag and Au, due to the low melting temperature and transition metals can be used. It should be noted that the dielectric

Function of some metals excludes a suitability due to excessive damping. Alternatively, bulk plasmas in particle layers can be a solution.

Thus, even in the third variant of the first embodiment, a visible light emitter is obtained.

Fourth Embodiment of First Embodiment

In Fig. 10, a layer system according to the fourth embodiment of the first embodiment is not shown to scale and with a reduced layer number of the photonic crystal. This layer system is similar to another layer system for infrared radiation, which is also described in the document "Design and fabrication of planar multilayer structures with coherent thermal emission characteristics", BJ Lee and ZM Zhang, Journal of Applied Physics 100, 063529 (2006) is.

The layer system according to the fourth embodiment of the first embodiment has a cavity acting as a resonator 47, between two reflector layers, a thick reflector layer 48 between the resonator 47 and provided in accordance with the preceding embodiments substrate 40 and a thin reflector layer 49 on the of the Substrate 40 facing away from, is arranged, wherein the one thin reflector layer 48 has a certain transmission due to their smaller thickness. The layer system according to the fourth embodiment of the first embodiment corresponds to a Fabry-Perot system, so that a design should also be done accordingly. The reflector layers 48, 49 are preferably made of silver. The thickness of the partially transmissive thin reflector layer 49 is preferably in the range of 10 to 20 nm, more preferably about 15 nm, while the substantially opaque reflector layer 48 has the function of a substrate, and preferably has a thickness in the range of about 1 to 2 μm. The thin reflector layer 49 preferably emits approximately Η of the radiation of the resonator 47 and the thick reflector layer 48 reflects the remaining ¹ ^ of the radiation. The electrical contact with both the thick and the the thin reflector layer 48, 49 takes place via electrical contacts 42.

Because the thin reflector 49 is relatively unselective, several maxima occur over a wide range in the spectrum. The maximum transmission and absorption in the substrate takes place at a thickness D of the resonator 47 of approximately

d = m * λ / (2n _{ResonatorMedlum} )

where n is the refractive index of _RESO natorMedium Resonatormedi- killed, λ the wavelength at which the emission of the radiator is to be maximal, and m is an integer.

For the inventive adaptation of the structure from the above-mentioned document to the visible range, the dimensions of the resonator 47 for which, for example, dielectrics with a low refractive index and a high melting temperature, for example Al ₂ O ₃ or MgO, are reduced. For the material of the reflector layers 48, 49, other noble metals than silver can be used. Alternatively, transition metals such as W can be used. The quality factor for the different reflection values of the mirrors has to be adapted. In order to suppress the unwanted emission peaks, a one-dimensional photonic crystal (not shown in FIG. 10) may be applied to the thin reflection layer 49 as a filter.

Depending on the substrate used, the thick reflector layer 48 should not be used, so that in this case the resonator 47 may be applied directly to the substrate 40. As in the case of the second sub-variant of the first exemplary embodiment, in the case of the third and fourth sub-variants of the first exemplary embodiment, the respectively identical layer arrangements can be provided on the opposite side of the substrate 40.

Second Embodiment

In the document "1D Metallo-Dielectric Photonic Crystals as Selective Emitters for Thermophotovoltaic Applications," Arvind Narayanaswamy, James Cybulski, Gang Chen, CP738, Thermophotovoltaic Generation of Electricity, Sixth Conference is presented a layer system that is a selective emitter in the infrared and This visible radiator is used in an adapted form in the second exemplary embodiment, as shown in Figures 11, 12 and 13A to 13C.

This layer system has, for example, 11 pairs of layers each having an emitter and a dielectric. According to the invention, both materials have a dielectric function suitable for the visible wavelength range, and the contrast of the refractive indices of the two layers should be sufficient for the emission of visible light.

For the visible range, silver or a semiconductor with a large band gap, for example SiC, as the emitter layer and, for example, Al ₂ O ₃ as the dielectric, are used in the above document. Although mentioned in the cited document, the application in the light bulb sector and it is because silver with its low melting point only low emitter temperatures allows for the applications in the visible range, for example SiC designates, but it is assumed by the inventor of the present invention that in certain cases SiC is not optimally suitable for visible wavelengths. In contrast to silver, SiC is a material that holds together by ionic bonds and supports surface waves (phonons) at wavelengths in the infrared range. For the visible wavelength range, according to the invention, particle layers are regarded as an alternative to the noble metals, to SiC and to other semiconductors.

The layer system from the above-mentioned document amplifies the emission of radiation in the desired, eg visible, wavelength range in comparison to the remaining, eg infrared, wavelength range, between which there is a transition wavelength range. The location of this transition from low to high emission can be adjusted by the choice of material and the thickness of the layers of the layer system. When using silver as the emitter layer with a thickness of 10 nm and of Al ₂ O ₃ as a dielectric, the emissivity increases very sharply from a wavelength of about 700 nm up to a wavelength of about 400 nm.

Due to the emitter layer being very thin, the thickness being significantly smaller than the skin depth of silver, which is 120 nm at a wavelength of 470nm, the emission coefficient becomes due to interference effects in the layer relative to the normally thicker emitter layers obtained using a Silver plate can be, for example, lmm, reinforced, in the visible range to five times. The effect of the remaining layers of the photonic crystal, the emission - A l -

suppressed by unwanted long-wave radiation. Therefore, the top emitter layer is not affected by the photonic crystal, while deeper layers are more "filtered".

Such a one-dimensional emitter system has, among other things, the advantage of a simple layer structure, a heatability of the thin emitter layers with corresponding contacting directly via the electrical resistance and little significance of surface diffusion processes in comparison with e.g. to surface-structured luminous bodies. Surface diffusion processes proceed faster than volume diffusion processes at the same temperature and material. Surface diffusion allows emitters to be destroyed faster.

As shown for example in the document "Microstructured Radiators", Philippe Ben-Abdallah, Final Report of the ESA study, it may also make sense that the above layer system consists of more than two types of material. For example, as shown in this document, the combination of one or more emitters, for example, made of metal or semiconductor, with one or more dielectric layers acting as non-emitters is possible. The layer sequence may also be irregular, such as, for example, the layer sequence emitter-non-emitterl-emitter-non-emitter2-non-emitter2.

According to a further alternative, instead of providing a continuous emitter layer, a layer with partially isolated particles may be applied. For particles with diameters which are in the range of the wavelength and can be smaller than the wavelength, light plasmons (Mie plasmon) can be formed when light is irradiated, which become particularly strong near the plasmon resonance frequency of the particle. The plasmon vibrations cancel out after about 10 ^{~ 13} s due to the loss of material. The radiation energy is converted into heat, whereby the absorption coefficient increases at this wavelength. The underlying mechanism has been known since Gustav Mie. With programs such as "FDDT-Solutions®" (finite-difference time-domain algorithm from Lumerical Solutions, Inc.), the optimal diameters for the imaginary wavelengths can be determined, in which the absorption and thus according to Kirchhoff At higher degrees of coverage (greater than a percolation threshold of approximately 50%), these layers become electrically conductive throughout and can thus be heated directly by resistance heating, but the layer consists of individual layers Partially interconnected particles and islands The particles may be incorporated into a dielectric, ie, after vapor deposition of the particles, they are covered by a dielectric layer.

The diameter of the particles or the layer thickness is in the range of less than 1 nm to about 500 nm. The particles can be given a round shape by annealing after the vapor deposition. The shape and size of the particles has an influence on the resonance frequency and the resonance width of the plasmons. There is thus a possibility of optimizing the emission characteristic of the emitter layer for the visible region.

Liu and Luke P. Lee, Nano Letters 2005 Vol. 1-5, a similar layer of 20 nm size silver particles is shown which are regularly deposited at a given distance on the substrate by a special process. Depending on the particle spacings, absorption maxima result, e.g. at wavelengths of 400 nm. This means that the average particle spacing, which depends on the coverage density in simple vapor deposition, is also important for the emission properties of the film.

Particle layers in glass are also used for polarizers. However, elongated particles are preferred for this purpose.

As already mentioned, instead of the conventional continuous emitter layers of, for example, silver, particle layers can be used, which is illustrated below with reference to the sectional views of FIGS. IIA, IIB and HC. In these figures, respective particle layers 124 are provided between two dielectric layers 126. In the particle layers 124 125 particles 127 are provided in a dielectric. These particles 127 are preferably metallic nanoparticles with a diameter in the range of approximately 5 nm to 1 μm, which are made, for example, of a noble metal or a superalloy. are transition metal. Particle distance and diameter optimized for optimal emission in the visible light range.

The dielectric 125 has a low refractive index with respect to the highest possible contrast with the refractive index of the particles 127, so that the material of the dielectric layer 126 should have a high refractive index.

FIG. IIA shows a state of the particle layer 124 in which the percolation threshold has not yet been reached. To achieve the percolation threshold, the entire layer system should e.g. be heated from the substrate. In FIG. IIB, the percolation threshold is exceeded in the depth of the drawing, so that an electrical contact is established via the particle layer 124.

In HC, a modification has been made in the particle layer, so that the modified particle layer 124a now has the particle layer 124 with particles 127 of Fig. HA, on one side of a thin metal layer 128, preferably with a thickness in the range of 5 to 30 nm, is applied. This metal layer 128 can also be used for resistance heating, so that such a modified particle layer is connected to the electrical contact.

The abovementioned layer systems are preferably produced by alternately vapor-depositing a substrate, for example by means of a PVD method, with the emitter layer and the dielectric layer. A layer system according to the invention as described above is produced as follows:

In a first step, a substrate made of a material having a high melting point, a dielectric such as Al ₂ O 3, HfO ₂ , ZrO ₂ , MgO, etc., or an el. Conductor, such as tungsten, TiB 2 is provided. The substrate may include electrical traces in or on the surface with which it is brought to operating temperature by el. Resistance heating. The substrate has at least the thickness and mechanical strength required by the further manufacturing process, for example a thickness of 0.5 to 1 mm. The shape of the substrate is adapted to the possibility of uniform coating. Examples are simple surfaces, such as flat surfaces and cylinders, or, for example, spherical surfaces.

In a second step, the substrate is vapor-deposited with the layer system of emitter and dielectric.

As the emitter material either suitable metals or semiconductors with sufficient bandgap are used. Suitable metals from this point of view are silver or gold, but their low melting point is unfavorable. While other metals, such as e.g. W, Mo, Ni, V, unfavorable dielectric data. However, these can be compensated by the use of a suitable percolation film. Semiconductors with a sufficient bandgap are, for example, SiC, TiO 2, ZnO (with a bandgap of approximately 3.3 eV), titanates, ZrO 2, zirconates. The layer thickness is about 10 nm.

The dielectric may, for example, comprise or consist of Al ₂ O ₃ , diamond, MgO, Si ₃ N ₄ , AlN, HfO ₂ . A However, a prerequisite is that the dielectric is still transparent to visible light emitter at a temperature of eg 1000 ⁰ C. In other words, the dielectric should have an even larger electrical bandgap than the emitter. Furthermore, the refractive index should be very different from that of the emitter. The layer thickness of the dielectric is approximately 100 to 300 nm.

The number of layer pairs is preferably about 10 layer pairs.

In the case where the emitter layers of the one-dimensional photonic crystal itself are to be used as heating elements, the contacting of the layers takes place. For this purpose it is preferred if the contacting sites of the emitter layers are exposed, as e.g. can be achieved by masks during coating. The contact point is finally covered with a thicker conductor layer, which is sufficiently robust to connect them, for example by laser welding with the electrical supply see.

Subsequently, the electrical leads are mounted, which can also have the function of a carrier of the emitter in the lamp. The emitter with the leads is then mounted in the glass vessel, for example. The lamp vessel, which has power supply lines to the emitter, is either cleaned and evacuated or finally filled with a protective gas, for example N ₂ . The shielding gas fulfills similar tasks as with tungsten luminous bodies: it, for example, reduces the vaporizing emitter material during operation, but causes additional heat losses.

(First sub-variant of the second embodiment)

Fig. 12 shows a sectional view through a planar luminous element according to the first sub-variant of the second embodiment.

In this sub-variant, a layer system of emitter layer 144 and dielectric 146 is provided on a substrate 140 which, depending on the substrate material, may optionally be provided with a conductor track 141 for substrate heating, for example as described in the first exemplary embodiment. The emitter layers 144 are used as electrical conductors and are formed as a volume layer or percolation layer. Contacting of the emitter layers 144 occurs via electrical contacts 142 of e.g. refractory metal, which are connected to power supply lines 148, preferably consisting of Mo wire, of which branch off in the case of provided conductor tracks power supply lines 149 for supplying the conductor track 142.

For reasons of clarity, the number of layer pairs is reduced to three, and the effective luminous area F of the luminous element is shown shortened.

The lower side of the substrate 140 or the printed conductor 142 is preferably coated like the upper side.

Second Second Variant of Second Embodiment Fig. 13 shows a sectional view through a cylindrical luminous element according to the second sub-variant of the second embodiment.

In this sub-variant, a substrate 160 as a rod-shaped core having a preferred thickness of about 1 mm is made of an insulator material, such as a metal substrate. AI2O3 provided. On top of this, a cylindrical dielectric layer having a preferred thickness in the range of approximately 100 to 300 nm is located on cylindrical emitter layers 164 having a preferred diameter of 10 nm. The electrical contact 162 on the opposite sides represents both the voltage supply to the substrate 160 also with the emitter layers 164 ago. Each of the electrical contacts 162 is provided with a power supply 169.

For the other properties of the second sub-variant, reference is made to the first sub-variant.

Third Third Variant of Second Embodiment

14 shows a sectional view through a cylindrical luminous body according to the third sub-variant of the second exemplary embodiment.

This differs from the second sub-variant shown in Fig. 13 in that the substrate is a rod-shaped core having a preferred thickness of 1 mm from a high resistance electrical conductor 170 at operating temperature, for example, SiC or Na-β-Al ₂ O 3 and that the electrical contacting 172 are connected to power supply lines 179 and to the substrate 170 and at the end face of the emitter layer 164 mounted on the substrate.

For the other properties of the third sub-variant, in particular also to the dielectric layer and the emitter layer, reference is made to the second sub-variant.

In a modification of the third sub-variant of the second embodiment, instead of the rod-shaped core 170, a planar core is provided as a substrate with a preferred thickness of approximately 1 mm. Thus, the emitter layers and dielectric layers are also planar with the aforementioned materials and thicknesses.

(Third Embodiment)

It is known in the art that structured surfaces on certain materials can produce selective, coherent, and highly directed thermal radiation. This is described, for example, in the following articles: Highly directional radiation generated by a tungsten thermal source, M. Laroche, C. Arnold, F. Marquier, R. Carminati, J. Greffet, S. Collin, N. Bardou, L Pelouard, Optics Letters Vol. 19, 2005 and Thermal Stability of micro-structured selective tungsten emitters, C.Schlemmer et al., Conference paper Thermophotovoltaic Generation of Electricity: 5th Conference The radiation is often similar to that of a conventional laser, making it generally unsuitable for general lighting purposes In addition, operation at operating temperatures above approximately 0.35 times the melting temperature has a negative effect on the surface structure itself made of thermally very resistant materials, such as tungsten.

The reason for this is seen, for example, in the "Optical Studies of Periodic Microstructures in Polar Materials," in which at the interface between two media, such as a metal and a dielectric, such as air or glass, electrical "surface currents" or charge density waves in the form of so-called surface plasmon polaritons can arise. These waves arise from a combined oscillation of the electromagnetic field and the surface charges in the metal. In the case of a smooth metal surface, which is coated with a dielectric, with a suitable excitation electromagnetic waves run parallel to this interface and cancel after a few femtoseconds again.

In contrast to the case of lossless total reflection at the interface to a optically thinner material, the surface waves in the absorbing materials, especially in the metal, are attenuated, converting energy to heat. The surface waves thus greatly increase the absorption coefficient of the material at the existing wavelength and at the angle of incidence. According to Kirchhoff's law of radiation, the corresponding emission coefficient increases with increasing absorption coefficient, which is advantageous for lamps. The surface waves can not normally generate radiation due to their parallel to the surface wave vector. In addition, due to conservation of momentum, all the impulse and energy of the surface plasmone should be exchanged with the photon, which is usually not the case on smooth metal surfaces. On the other hand, the surface plasmons can be thermally excited, which in principle could cause a light emission.

The complex wave vector | k _SP | the surface plasmons of the plane interface of metal and dielectric is:

in which

λ is the wavelength of the light or plasmone,

ε _{D is} the dielectric constant of the dielectric,

ε _{M is} the complex dielectric constant of the metal.

The wave vector of the photon in the dielectric is

_2π I-

The proportion of particles parallel to the interface is

where Θ is the incident or emission angle of the light. Thus, normally k _SP > k _Px , whereby, unlike ε _D > l, no light can be generated. In this context, reference is made to the Kretschmann-Raether configuration for excitation of the plasmons.

However, when the surface is patterned, for example, by a metal grid vapor-deposited on the metal surface or by a low-coverage carrier, by island films or otherwise, these surface waves penetrate into these structures. The wave vector is complemented by a structure dependent component so that the momentum of the plasmon and the photon can match. Charges build up in the structures. These structures can then act like antennas and radiation can be emitted, which increases the emission of the metal.

The wave vector of the surface plasmons of the structured interface between metal and dielectric is:

where n is an integer and a represents the structural constant of the surface.

If the surface plasmons can emit light with the wavelength λ due to the surface structures, k _Px = k _x should be.

On the other hand, these structures can mediate the efficient coupling between the surface waves and the waves radiated by radiators, thereby creating a coherent generate radiation. Recesses of the structure can, with appropriate alignment with the emitted wave, ie coupled to the polarization, act like cavities. This is described, for example, in the article Thermal emission and design in one-dimensional periodic metallic photonic crystal slabs, David LC Chan, Marin Soljacic, JD Joannopoulos, Physical Review E 74, 2006. The electric field component should be perpendicular to the structure, ie, for example perpendicular to the space between two balls of the particle layer. The surface plasmons have resonances as a function of the structure size. The emission spectrum is thus not uniform, but has peaks. This does not immediately produce "white light" as with ordinary thermal radiators, but the spectrum can even be monochromatic.

The strength of the emission also depends on the plasmon resonance frequency in the emitter. This further enhances the selectivity of the radiation. The plasmon resonance frequency is also material-dependent. For structures in the wavelength range, the plasmon resonance also depends on the structure size. Because the emission also depends on the angle of incidence of the radiation (angle Θ), the light source is also not a Lambert radiator, i. that the radiance is not constant in all directions. This may be for the lamp, i. directed light sources, be beneficial or can be compensated by scattering elements.

As a result, a luminous body according to the invention with a structured surface satisfies the following requirements, wherein these requirements according to the invention are contrasted with developments in the prior art:

a) There should be sufficient mechanical stability despite structures in the range of approximately 0.5 μm. The present invention uses self-supporting substrates that are easy to coat because of their simple surface shape.

In contrast to the present invention, US2006 / 0001344 shows an incandescent filament which is folded so that cavities are formed between the filament elements or the filament legs form the photonic crystal, so that the emitted radiation can become selective. The surface of the helix may additionally be provided with regularly arranged holes, which are also intended to increase the emission in the visible by coupling out the surface plasmons. It is disadvantageous that the structures should be self-supporting and therefore the structure is destroyed by a deformation at the latest during operation, which manifests itself in the form of a sagging helix. In addition, the production of the surface holes according to this prior art in practice is very complex. The holes can be quickly destroyed again by the surface diffusion.

b) The structures should be easy to produce. In the present invention, construction methods are used which allow a "one-dimensional" production of the emitter, ie that, for example, a carrier substrate is provided with particles or layers, this coating being carried out essentially by application Although flat surface can be considered as a two-dimensional structure, but this is inexpensive to produce.

In contrast to the present invention, US2003 / 0132705 shows a three-dimensional structure of crosswise stacked wires arranged in a regular lattice structure. The disadvantage is the complex production of the 3D crystal.

The US2006 / 0071585 shows inter alia emitters consist of two- and three-dimensional photonic crystals, the production of which is complicated.

c) The surface should be adapted to the annealing temperature, the emitters should have a relatively large surface, so that even at low annealing temperatures still enough light is generated.

Photonic filaments have a filigree structure that is sensitive to mechanical, thermodynamic, chemical and electrical loads. At elevated temperature, there is increased diffusion in the material and on the surface. Impurities in the lamp, for example O ₂ , can easily damage fine surface structures, eg due to oxidation. The frequently used electrical resistance heating requires sufficient cross sections. Because, for these reasons, the operating temperature of the photonic filament should be kept relatively low, ie, at about 30 to 70% of the temperature of a common filament of the same material, the surface should be of maximum size to minimize the loss of light output after exposure to light Stefan- Boltzmann law proportional to the fourth power of the Tepmerpatur, at least partially compensate.

US2005 / 0168147 shows filaments connected to photonic structures, with the disadvantage that the radiating surface is relatively small. In US2006 / 0071585, among other things coated with one-dimensional photonic crystals filaments are shown, the disadvantages occur as in US2005 / 0168147.

d) It should as far as possible the entire emitter surface be exploited in order to increase the efficiency of the lamp.

Both US2005 / 0168147 and US2006 / 0001344 contain photonic structures that can only affect radiation in a very small angular range. The largest part of the radiation of the filament is therefore not more selective than that of a conventional gray body with the same temperature as tungsten.

e) Converter layers are to be installed in order to convert the monochromatic or the non-white light into the desired spectrum as required. In the case of incorporation of scattering layers, which can be used to obtain sufficiently diffuse radiation instead of a partially coherent beam, part of the energy is lost again.

f) The structure should be protected from damage by surface and volume diffusion. This is achieved, inter alia, on the one hand by the lowest possible operating temperature, but which requires a particularly large surface, and on the other hand by diffusion barriers, eg in the form of HfO ₂ . Regarding the Diffusion barriers are referred to the document "Thermal stability of micro-structured selective tungsten emitter", C. Schmalmer et al., Conference paper Thermophotovoltaic Generation of Electricity: 5th Conference.

Document US2005 / 0160964 shows a lamp with a photonic filament produced by the coating of a spherical particle carrier. The result is a three-dimensional photonic crystal with spheres of the materials Si, SiO 2 or metals or the inverse form thereof, such as spherical holes in a matrix. Although the production of this emitter is simple, but there are some disadvantages. In the case of the coating of only one wire, it is to be assumed that the lamp has a low light output owing to the small surface area, as described above. On the other hand, the structure in the helix production can be damaged. From the fact that the emitter material consists of, for example, metal or other spheres that are in direct contact with each other, in addition to the lack of flexibility in the geometry results in a porous body as the final product. More specifically, the balls are approximated to contact by the capillary forces and then sintered. As a result, no three-dimensional photonic crystals can be produced in which the spherical surfaces are at a defined distance from each other. The porosity arises because in operation, the surface diffusion processes lead to a rapid change of the body to destruction. Since the balls are not protected by diffusion barriers, the subsequent Filling the remaining cavities with a dielectric does not completely eliminate this problem.

g) The heat losses in the lamp are to be kept low, it should be noted that the annealing temperature of the emitter is relatively low. Although energy is saved by the fact that the photonic emitter radiates more selectively than an ordinary incandescent filament and therefore emits less IR radiation, on the other hand the heat loss through convection and heat conduction is more significant than with a conventional incandescent lamp. This requires relatively low filling pressures for the shielding gas or a vacuum. Also, the spotlight should not unnecessarily lose heat due to its suspension in the lamp. Finally, as far as possible all heated surfaces should be coated in order to prevent losses due to infrared radiation.

h) It is a suitable emitter material to use, since the position of the plasmon resonance is material-dependent. The resonant frequency can be shifted further away from the visible range, for example, by a high refractive index of the dielectric and by polarizable d electrons of the emitter material into the red region. Precious metals such as gold, silver (the plasmon resonance is at about 420 nm here) have pronounced plasmon resonances in the visible range and are therefore to be preferred. Unfortunately, these have relatively low melting points, so that as a compromise, for example, transition metals, such as Mo, W or conductive ceramics come into question. FIGS. 15 to 19 show first to fourth subvariants of the third embodiment, which will be described below.

(First Sub-Variant of Third Embodiment)

FIGS. 15 and 16 show luminous bodies according to the first and second embodiments of the first sub-variant of the third exemplary embodiment. The basic idea of the first sub-variant is to provide a heatable carrier with strips, grids or dots by means of coating or etching.

The processing requires a fine, for example photolithographic, mask. The metallic support is coated, for example, with photoresist and then exposed, for example, by means of a holographic process. This results in interference patterns that are used in the later etching or coating process as a mask.

The support can be solid, for example, or consist of a coated insulator or semiconductor conductors or ion conductors with relatively high electrical resistance.

In the case of the solid carrier, for example, this has relatively massive tungsten and this is directly electrically heated. As a result, it is particularly suitable for low-voltage lamps.

In the case of a coated insulator, for example, Al ₂ O ₃ , ATI, AlN, ZrO ₂ may be used. The insulator has insulated tracks for heating, the can be used directly as a heating layer depending on the supply voltage directly.

When using (doped) semiconductors or ion conductors with a relatively high electrical resistance, for example, perovskites, titanium oxides, SiC are used. The carrier is then coated again with the structure and, for example, can be used directly as an electrical conductor due to its high electrical resistance. The shape of the carrier, which may be a flat surface, for example, allows a simple coating.

In Fig. 15, the first embodiment of the first sub-variant of the third embodiment is shown in which a carrier 220 made of, for example, Al 2 O 3, which is preferably about 1 mm thick, a tungsten layer 222 with a preferred thickness of about 1 micron on both sides of Carrier 220 is applied. The two sides of the tungsten layer are connected via a via 224. On the tungsten layer 222 are vapor-deposited elevations 226, so-called dips, at a distance a of approximately 0.1 to 1 μm and with a height in the micrometer range, in such a way that they are distributed in a grid pattern on the surface. On the elevations 226 and the tungsten layer, a dielectric 228 is applied, which preferably has a thickness of about 10 to 20 nm and in which the materials HfO ₂ , AI2O3 and MgO can be used.

The materials of the first embodiment may be modified as mentioned above. Fig. 16 shows the second embodiment of the first sub-variant of the third embodiment in the form of a sectional view through an etched surface. In this case, on a support 230 made of an insulator such as AI2O3, which is preferably between 0.5 to 1 mm thick and was corrugated etched and coated, a metal layer 232 of, for example, W, Mo in a thickness of about 1 micron and a Structure size of 100 to 500 nm applied. On the metal layer 232 is a diffusion layer 238, preferably with a thickness of approximately 20 nm.

Both the tungsten layer 222 of the first embodiment and the metal layer 232 of the second embodiment are supplied with voltage via the respective layers associated electrical feed lines 239, preferably in the form of Mo contact pins.

Second Sub-Variant of Third Embodiment

It is vaporized a similar carrier with particles. In this case, the coverage density can be selected so that isolated particles having a mean distance a of approximately 50 nm to 0.5 μm (see FIG. 17) arise as a function of the wavelength on the carrier. The diameter and distance of the particles are decisive for the emission. Due to the rather irregular distance, the emitted light color is rather white. With lower coverage density, the average distance increases. The individual particles partially form isolated, approximately spherical nanoparticles. In addition, the particles may be covered with a dielectric such as Al 2 O 3, MgO, HfO 2. This is the structure before Destruction protected by surface diffusion. If no dielectric is applied, on the other hand, the plasmon resonance frequency may advantageously increase.

Alternatively, according to a method as described in the document "High-Density Silver Nanoparticle Film with Temperature-Controllable Interparticle Spacing for a Tunable Surface Enhanced Raman Scattering Substrate", Yu Lu, Gang L. Liu and Luke P. Lee, Nano Letters 2005 Vol.5, no. 1 5-9, the particles are defined at regular intervals. However, the manufacturing costs for lamp products could be a problem.

Fig. 17 is a sectional view of the particle-coated surface. In this case, a non-conductor, a semiconductor or an ion conductor having a sufficiently high electrical resistance as a function of the supply voltage is provided as the carrier 240. On both sides there is a metal layer 242, such as Mo. This can be surface-structured as in the first sub-variant. On the metal layer 242, a particle film 246 of eg Mo, W, TaC is applied with a diameter of the particles in the range of 10 to 1000 nm, above which a dielectric layer 248, preferably of Al2O3, MgO, HfO ₂ , can be arranged.

Third Third Variant of Third Embodiment

In the third sub-variant of FIG. 18, an emitter coated with particles or other gratings, for example according to the second sub-variant, additionally provided on both sides with a one-dimensional photonic crystal 254.

The background to this is that surfaces provided with surface structures generate in practice infrared radiation. In certain cases, however, a light source of a particular light color may be desired. In order to improve the selectivity of the radiation of the lamp in these cases, the above emitter can be additionally provided with a layer system which represents a photonic crystal. The photonic crystal consists of alternating layers of high and low refractive index materials. The layer thicknesses are approximately λ / 4 * n, where λ is the blocked wavelength. The one-dimensional photonic crystal can suppress the spontaneous emission of the unwanted wavelengths.

In Fig. 18, on the structure of the second sub-variant in Fig. 17, the dielectric 258 is applied in such a manner that the metal-layer, particle-film and dielectric substrate 258 has a constant thickness. On the Dielelektrikum 258, which should have the smallest possible refractive index and preferably has Al2O3, the one-dimensional photonic crystal 254 is added, which preferably has some 10 pairs of layers.

The contacting of the metal layers takes place in the second and third sub-variants of the third embodiment as in the first sub-variant of the third embodiment.

(Fourth sub-variant of the third embodiment) In the fourth sub-variant, completely isolated particles are used to exploit the Mie resonance or to form an additional cavity.

In the paper "Monochromatic polarized coherent emitter by surface plasmons and a cavity", A. Battula, SC Chen, Physical Review B 74, 2006, an emitter system is presented which exhibits an emission peak using silver as the material at around 550 nm. This is achieved by metallic lattices, which are separated by an air cavity from a one-dimensional photonic crystal.The lattice interstices form thereby converging or diverging channels.

Even if the geometry is too complex for a lamp-technically usable emitter, this can be approximated. Instead of the grids, spherical particles could be used. Also in the transmission through the particle layer comparable surface plasmons can be excited. The cavity should be formed by a dielectric of small refractive index, eg SiO ₂ , Al ₂ O ₃ , MgO. The one-dimensional photonic crystal under the cavity can be replaced, as in the "VERTE" system according to the first embodiment example, by a metal or by a layer system consisting of higher melting constituents than InSb / SiO ₂ , for example Cr ₂ O. ₃ , Fe ₂ O ₃ , HfO ₂ or TiO ₂ for the high refractive index material and SiO ₂ , Al ₂ O ₃ , Y ₂ O ₃ , MgO for the low refractive index material The spherical particles may be deposited by, for example, sedimentation and then be sintered. Alternatively, the cavity can be dispensed with or made thinner. The particle diameters can also be changed, from a particle diameter D, which is the same as the wavelength λ, to a few 10 nm. At the nanoparticles, the passing light wave can lead to charge shifts, which also interact with the environment, eg a metallic substrate , whereby the emission coefficient can be changed. The calculation can be done according to the Mie theory and using the internet addresses MieCalc, http: // www. lightsca ttering. de / MieCalc / index. html and in terms of FDTD Solutions, http: / / www. εirnul opti it. de / scftware / fdtdso lurions / index. ml.

Such a luminous body is shown in FIG. 19, wherein a layer 262 in the form of a metal layer or a one-dimensional photonic crystal is applied to an electrical resistance body 260 of, for example, SiC or W for heating. The photonic crystal may have about 40 alternating layer pairs of, for example, MgO / TiO with a single layer thickness of about 50 nm. A cavity 264 of, for example, MgO having a thickness of, for example, about 200 nm is applied to the layer 262. On the cavity 264 are coated particles 266 of, for example, W having a preferred outer diameter of approximately 200 nm, the coating of, for example, MgO having a thickness of 2 to 10 nm being applied thereto.

According to this fourth sub-variant, three-dimensional photonic crystals can be produced where the ball surfaces have a defined distance from each other. However, this variant is simple and inexpensive to produce by particle technology. More specifically, in the present invention, emitters are made by a simple "one-dimensional process", for example, by coating.

(Fourth Embodiment)

In the literature under "Thermal emission by photonic micron-textured" surfaces (see also http://arxiv.org/g/abs/physics/0505165yl), Jones TK Wan and CT Chan presents a particulate-layered tungsten carrier Particle layers consist of approximately 0.3 μm diameter tungsten spheres positioned over the planar tungsten carrier to span a cubic surface centered grating, and one or more such grating layers may be applied to the tungsten carrier, the emitter being the electromagnetic emitter The tungsten spheres close to the surface of the tungsten carrier form a photonic crystal, and the crystal has a bandgap in the infrared, so that the photonic crystal is directly adjacent to the emitter, suppressing spontaneous emission in the blocked wavelength range. With a layer thickness of one or two (111) fcc layers (cubic surface-centered layers) already significantly reduce the emission of long-wave light relative to short-wave light. For example, with an applied layer, the absorption coefficient at wavelengths is in the range of 1.6 eV to 3 eV, which corresponds to the visible light, has risen from approx. 50% to approx. 75 to 95% compared to the tungsten carrier without a layer. As an alternative to this cubic face centered structure, other structures with regard to other crystal classes or crystal systems are also conceivable, for example cubic space centered or hexagonal close packing.

The preparation of these structures is similar as described in the document "Monodispersed Colloidal Spheres: Old Materials with New Applications", By Younan Xia, Byron Gates, Yadong Yin, and Yu Lu, Advanced Materials 2000, 12, no. 10 is called. As a coating method, among other things, the self-organization of the beads is possible.

The advantages of this embodiment are the following:

1. The material may consist essentially of tungsten, which has corresponding advantages, such as a high temperature resistance, existing manufacturing know-how.

2. The photonic crystal is applied as a particle layer, which simplifies the manufacturing process with respect to other three-dimensional photonic crystals.

3. In the case of customary structured luminous bodies, there is a greater deformation or destruction due to diffusion, in particular surface diffusion, and due to recrystallization in operation in comparison to this embodiment. For example, "surface grid" in tungsten are within a few hours, for example within 125 hours, destroyed at 1000 ⁰ C. Further details on this are the article "Thermal static C.Schlemmer et al., conference paper on Thermophotovoltaic Generation of Electricity: 5th Conference: At high temperatures, diffusion processes occur that cause the surface of a body to expand to a certain extent The thermodynamic driving force is the reduction of the free enthalpy of the body, but in this embodiment it is spheres of tungsten, which already have approximately their lowest energy macroscopic form and which are relatively permanently separated by the diffusion barrier coating During operation, as long as they do not touch each other, they also remain approximately spheres or polyhedra, whereby it can happen that over time the homogeneous coating changes and, for example, grains form.

The required cubic surface centered lattice shape, as closest possible packing of spheres, allows easy placement of the spheres by e.g. Sediment. However, there are a variety of variants of the densest packing. By means of suitable measures, however, face-centered cubic arrangements of the tungsten spheres, which correspond approximately to the size and shape of the natural opal structure, can be produced.

The inventor strives for the following production possibilities of the cubic surface-centered layer:

During sedimentation, the spheres are "slurried" or a colloid is formed in a liquid with suspending agents, for example, and this colloid is then sedimented by gravity on the tungsten carrier is in the articles "THE COMPLETE PHOTONIC BAND CAP IN INVERTED OPALS: HOW CAN WE PROVE IT EXPERIMENTALLY?", DJ Norris * and Yu. A. Vlasov, NEC Research Institute, Inc. 4 Independence Way Princeton, NJ 08540 USA; Monomeric Colloidal Spheres: Old Materials with New Applications, By Younan Xia, Byron Gates, Yadong Yin, and Yu Lu, Advanced Materials 2000, 12, no. 10; Lecture "Production of Opverse Opals by Self-Organization", Dr. Holger Winkler, Dr. Ralf Anseimann, Dr. Josef Bauer, Dr. Ralf Glausch, Corinna Weigandt, Rene Schneider (MERCK KGaA, Darmstadt), Dr. Götz P. Hellmann, Dr. Ing. Tilmann Ruhl, Peter Spann (Deutsches Kunststoff-Institut, Darmstadt), Dr. Franco Laeri (TU Darmstadt, Institute of Applied Physics) in "Controlled Self-Organization for Future Technical Applications Expert discussion, analysis, outlook" by VDI Technology Center and Jörg Schilling " Production and Optical Properties of 2D and 3D Photonic Crystals from Macroporous Silicon ", Dissertation, p.15.

In the controlled drying of colloidal sphere dispersions, a colloid, ie a dispersion of eg small tungsten beads in liquid, is prepared with the coated tungsten beads and dried. It is also possible, for example, tungsten wires (today's helical wires) pull through such a colloid solution, as in the article: "Contributions of nanotechnology to increase functionality and density in electronics", Werner Prost, University of Duisburg-Essen, Faculty of Engineering, Semiconductor Tech - nik / Semiconductor Technology, in "Controlled Self-Organization for Future Technical Applications In the vertical deposition technique, the balls are pulled up by capillary forces on the liquid surface on the wire, and when the wire is pulled out of the colloid, the cubic-surface-centered structure is formed by evaporation Capillary forces compress the structure until it touches the balls, whereas in the patent US2005 / 0160964 a coating of the balls is lacking.Further information on the above-mentioned production possibility can be found in the lecture "Production of inverse opals by self-organization". Holger Winkler, dr. Ralf Anselmann, dr. Josef Bauer, dr. Ralf Glausch, Corinna Weigandt, Rene Schneider (MERCK KGaA, Darmstadt), dr. Götz P. Hellmann, Dr. med. Tilmann Ruhl, Peter Spahn (German Plastic Institute, Darmstadt), Dr. med. Franco Laeri (TU Darmstadt, Institute of Applied Physics) in "Controlled Self-Organization for Future Technical Applications Expert Discussion, Analysis, Outlook" from the VDI Technology Center.

The latter reference is also the preparation of a liquid phase (ligand technology) and to remove the spray of the colloid solution on the support and drying.

Hereinafter, the configuration and the production of the luminous bodies according to the invention will be described according to the fourth embodiment.

At the beginning, the starting materials are marked in more detail. Carrier consists as possible of a body with a relatively easy-to-coat surface, such as a plane or cylindrical, spherical or conical surfaces. The carrier can also be a wire. The material of the carrier is preferably tungsten or another refractory metal or an electrically conductive ceramic.

The spheres, which are preferably made of tungsten or a high refractive index contrast refractory material to the dielectric, with a diameter of about 0.3 μm may be e.g. by plasma spraying and subsequent sieving, a "polyol process", as described, for example, under http://Info.Tuwien.ac.at/nano- materials / or the Stöber method in accordance with the article SiO2 spheres with cores Gold nanoparticles: "Synthesis and optical properties of gold-labeled silica particles", LIZ-MARZAN LM; PHILIPSE A.P., Journal of Colloids and Interface Science 1995, vol. 176 are generated.

Diameter fluctuations and shape deviations can not be avoided and change the light output. However, even with non-round particles, the essential physical quantities, e.g. alternating thickness of the low-refractive dielectric layer and thickness of the metal layer in the propagation direction of a photon, comparable.

The balls, which are preferably formed of tungsten, are highly likely to have a defined distance from one another and from the carrier. The balls can be embedded eg in the dielectric vacuum. Because this makes manufacturing practical for obvious reasons would make impossible, the cavities between the "free-floating" balls in the production later with a dielectric such as AI2O3, SiO ₂ , HfO _2, for example, by a CVD method are filled.It is therefore preferable, the balls themselves with a very thin The layer thickness corresponds to half the distance of the spheres from each other.This layer also reduces during operation the surface diffusion between the spheres that would destroy the structure.The coating can be, for example, by vapor deposition or In order to achieve the highest possible contrasts in the refractive index, the refractive index n of the dielectric should be small, but the melting point should be high, and therefore it is preferable to use Al ₂ O ₃ (n = 1.6, melting temperature 2045 ⁰⁾ for the dielectric C), SiO ₂ (n =

1.46, melt temp. about 1600 ⁰ C), HfO ₂ (n = 2, Schmelztemp.

Approximately 2700 ⁰ C), Y ₂ O ₃ (n = l, 85, Schmelztemp approx. 2400 ° C) MgO

(n = l, 7, Schmelztemp. about 2800 ⁰ C), Gd ₂ O ₂ (n = l, 75, Schmelztemp. 2350 ° C) and ZrO ₂ (n = 2, Schmelztemp. 2700 ° C).

As a material for coating the tungsten particles, a material having a high dielectric constant and refractive index may also be suitable because of the small thickness of the layer, e.g. a perovskite. In this case, the high refractive index volumes will touch.

Since the permeability of the dielectric is not equal to that at vacuum in the article Thermal emission by photonic micro-textured surfaces (see also http://arxiv.org/abs/physics/0505165vl), Jones TK Wan and CT Chan is, should the geometric sizes of the photonic crystal can be adjusted accordingly.

Due to the high operating temperature of the luminous body, pure tungsten structures would be produced in a short time, e.g. due to surface diffusion, destroy. This is the same process that occurs during sintering of the tungsten material as from the powder and is desired. These processes can be considerably slowed down by a suitable coating of the tungsten balls. The voids remaining between the balls (vacuum) may also be e.g. be filled by CVD. Further surface diffusion is thus suppressed.

The preparation of a suitable solution with the balls may e.g. in the form of a colloid. In this case, in a suitable medium, such. Water, the balls are held by auxiliaries in the balance. Between the balls with each other and the medium, forces acting to cause the balls to be arranged regularly, e.g. Surface charges and capillary forces.

The entire luminous body can be produced as follows:

To produce the carrier, for example, a tungsten wire can be drawn as is known, a tungsten plate made of powder can be sintered, or a ceramic carrier can be sintered and optionally provided with conductor tracks for resistance heating. The side of the support to be coated with the cubic surface-centered layer is vapor-deposited with a thin tungsten layer of, for example, 2 μm. The coated tungsten spheres are applied in a thin layer on the tungsten carrier. The balls can be slurried in a colloid.

If necessary, the overhanging balls can be removed by a knife which is passed over the layer at a distance. As known from the literature, the influence of a larger number of layers is small. The coated luminaire would at a

Number of layers of, for example, 128 layers in the visible range and in the infrared range emit slightly more light than in just one layer.

The compacting of the balls takes place on the support by e.g. Gravitation (sedimentation), as explained above.

The sintering of the coating of the balls is carried out by baking. In the process, a cubic surface-centered grid is formed with the tungsten spheres, which are separated from one another by a thin layer of the coating. With a long sintering time, the dielectric separation layer may become too thin, so that the initial layer thickness should be increased accordingly.

Optionally, the remaining voids between the spheres can be filled with a low refractive index dielectric, but this decreases the refractive index contrast.

FIG. 20A shows a section of the coated surface of a luminous element according to the fourth exemplary embodiment of the invention, wherein the layer has cubic surface-centered coated tungsten spheres 340. The coated tungsten particles are sintered to each other and to the carrier 342.

The carrier 342 is formed by a tungsten layer on an insulating or conductive ceramic or by a solid tungsten carrier, e.g. is heated directly by passage of current formed. The thin tungsten layer on an insulating ceramic makes it possible to heat the layer later directly with a supply voltage that would be higher than that of a solid, electrically conductive carrier.

Hereinafter, this luminaire will be described with reference to a concrete embodiment in FIG. 2OB. The carrier 342 has the insulating ceramic Al 2 O 3 324 a, on which a tungsten layer 342 b of preferably 1 μm thick is applied. On this are the sintered tungsten balls 340. The electrical contact is made via contacts 344.

However, the present embodiment may be modified in the form of an inverse opal.

Inverse opal structures will, as it is from the article "THE COMPLETE PHOTONIC BAND CAP IN INVERTED OPALS: HOW CAN WE PROVE IT EXPERIMENTALLY?", DJ Norris * and Yu. According to Vlasov NEC Research Institute, Inc. 4 Independence Way Princeton, NJ 08540, USA, "a great deal of potential is attributed to possible complete photonic bandgaps, so it may be useful to make the balls to be joined not tungsten but either one or more With a low refractive index such as Al2O3 or SiO 2 exist, which later interconnected areas of the dielectric with small refractive index or consist of a dielectric with a low refractive index with an overlying layer of a few nm of a material having a high refractive index, for example Cr ₂ θ3, HfO ₂ , TiO ₂ or a metal. As a result, later all dielectric cores remain separated.

The following steps can be used to produce such an inverse opal

First, the carrier is manufactured as described above. Then the balls are applied in a thin layer on the carrier. The balls can be slurried in a colloid. If necessary, stripping the protruding balls by a knife, which is guided over the layer at a predetermined distance. Subsequently, the spheres are compacted on the support by e.g. Gravity (sedimentation), as described above. Then sintering of the balls is performed by annealing, forming a cubic surface centered grid with the balls. Optionally, the remaining voids between the spheres can then be infiltrated with a high refractive index dielectric or with a metal.

As a result, a photonic crystal is obtained on the substrate having cubic surface centered spherical space having a small refractive index and surrounded by regions of high refractive index. This photonic crystal can have a complete band gap for the infrared region and thus completely block the infrared radiation of the substrate. Because the balls are not hollow, Thus, the dielectric is removed as in other examples, the destruction of the layer is slowed by diffusion at the high operating temperatures.

Due to their simple layer structure, the emitters described above according to the first to fourth exemplary embodiments allow a relatively inexpensive production. If the lamp is to produce colored light, this is also possible due to the monochrome nature of the emitters. Otherwise, converter layers are required.

In the case of the luminous bodies according to the preceding embodiments, the selectivity of the radiation is greater than in the case of tungsten filaments, as a result of which there is the possibility of saving energy, in particular in the case of colored incandescent lamps. With the present invention, further layer systems for the concept of lamp can be used with a one-dimensional photonic crystals.

(Variants for the shape of the thermal emitter)

For an implementation of the present invention according to the first to fourth embodiments are suitable for the thermal emitter in particular planar surfaces and rotationally symmetric surfaces, such as cylindrical surfaces, spherical surfaces, conical surfaces and others. Application examples of such a configuration of the luminous element are given below with reference to FIGS. 21A to 28B.

FIGS. 21A to 21C show a luminous element according to a first example of application, wherein in FIG. 6A a side view from the left, in FIG. 21B a Front view, in Figure 21C is a perspective view of the lamp 50 is shown.

In the first application example, the power supply lines 14a, 14b, which are shown in FIG. 1B, are directly adjacent to the incandescent filament itself. It is preferable to provide the filament 52 and not the power leads 14a, 14b with a layer system according to the first to fourth embodiments.

Figures 22A and 22B show a cone-shaped like luminous body, from the center of the power supply 14b and from the edge portion on the outer circumference, the power supply 14a emerges. FIG. 22A shows a plan view of the luminous element 2, and FIG. 22B shows a view from the left of the luminous element. While in the first application example, there is a cylindrical radiation characteristic, in the second example of application the surface is radiated.

Figures 23A and 23B show a luminous body 60 according to the third embodiment, wherein in Figure 23A is a view from the left, in Figure 23B a plan view has been reproduced. Here, the luminous element 60 is formed as the lateral surface of a double cone, wherein a large surface can be provided in a small space.

FIG. 24 shows a luminous element 64 in accordance with a fourth example of use. Here, the luminous element 64 is designed as a surface with a meandering active region 66. As a result of this meander-shaped active region 66, a long printed conductor is made possible on a small surface, so that a high level of light is achieved Luminous efficacy and a high temperature can be maintained. Again, it is preferred that the region of the power supply lines 14a, 14b has neither the active layer, nor the layer system. FIG. 24 shows a front view of the luminous element 64.

FIGS. 25A and 25B show a luminous element 70 which has a substantially disc-shaped active region 72, from which the current supply lines 14a, 14b emerge. FIG. 25A shows a plan view and FIG. 25B shows a perspective view from the front right of the luminous element 70.

FIG. 26 shows a luminous element 76 according to the sixth example of application. In this case, advantageously the structure according to the second embodiment is used. More precisely, FIG. 26 shows a plan view of the luminous element 76. Conductor tracks 36 are applied meander-shaped on the ceramic carrier 34 and can be connected to the power supply lines 14a, 14b via connection surfaces 78a, 78b. On the ceramic support 34 is the metallic reflector layer 26 and the laser cavity layer 30 and then the layer system 32 according to the previous embodiments. In such an embodiment, it is advantageous that the coating of a flat surface with the ceramic carrier 34 as the base material can be carried out and the conductor track 36 is formed thereon.

FIGS. 27A and 27B as well as FIGS. 28A and 28B show a seventh and eighth application example of the present invention, the embodiment according to FIG. 3. More specifically, the conductor track 36 from FIG. replaced element that is provided at a predetermined distance from the ceramic carrier 34.

FIG. 27A shows a luminous element 84 with a conductor track 86 and a layer arrangement 88, which are spaced from each other by a distance b. 27A shows a top view of the filament 84. In the layer arrangement 88, the ceramic carrier 34, the metallic reflector layer 26, the laser cavity layer 30 and the layer arrangement 32 are provided.

In the eighth application example from FIGS. 28A and 28B, the luminous element 94 is provided with a resistance heating element 96 and a spherical layer arrangement 98, wherein in FIG. 28A a view from the left and in FIG. 28B a plan view of the luminous element 94 are provided. The resistance heating element 96 is connectable via power supply lines 14a, 14b with molybdenum foils 12a, 12b and generates heat which is absorbed by the layer arrangement 98, which can be fastened to the lamp base via a rod-shaped holding element 100.

As in the seventh application example, the layer arrangement of the eighth application example starting from the resistance heating element 96 has a ceramic carrier 34, a metallic reflection layer 26, a laser cavity layer 30 and the layer arrangement 32 of the application of FIG.

Due to the increased distance between track and

Ceramic carrier in the seventh and eighth application example may be due to the conductor track an increased temperature vorge- will see. It is favorable if the lamp according to the invention is filled with a gas, by means of which the heat transport from the resistance heating element 96 or from the conductor 86 to the corresponding layer arrangement is optimized.

The designs of the layers of the luminous element according to the present invention can also be carried out, for example, with the aid of perturbation theory given given refractive indices or depending on the characteristic impedance of the metallic reflector, as indicated in the article of the Physical Review on pages 2 and 3. In comparison with the laser described there, the quality requirement in the present invention is lower, but the feature sizes are smaller because of the considerably shorter wavelength.

Hereinafter, the possible light output of a photonic radiator according to the present invention will be examined.

It is assumed that the filament of a halogen incandescent lamp reaches a temperature of 3000 Kelvin in this case. The radiant power is calculated according to the Stefan Boltzmann law as follows

P = C - Z - A - \ T _emitter - ^ ENVIRONMENT) W \

Assuming that

W σ = 5.8e ^~ m ² - K ⁴ and ε is about 0.42 for tungsten at 3000 Kelvin and a wavelength of 500 nanometers, resulting in neglecting the ambient radiation

p o. in 'W m ^~

When the photonic filament is heated to 1500 Kelvin, it radiates at 0.46 of tungsten at 1500K and a wavelength of 500 nanometers at 0.46

--2 ^*

This results in a power ratio of

1,4 -10 ⁵

The portion which falls within the visible wavelength range is only about 10% for a halogen coil, while the photonic coil according to the present invention, when properly designed, emits nearly 100% of the light in the visible range. Thus, the radiant power at the resonance wavelength and tungsten as the carrier increases thirteen times.

As a result, it can be stated that under these circumstances the photonic helix produces approximately the same radiation power in the visible range at only 1500 Kelvin. As a result, less than 10% of the electric power is required with a luminaire and a lamp according to the present invention, and the luminous efficiency has increased tenfold. According to the invention, a luminous element and a lamp are provided with a luminous element, wherein a thermal emitter is arranged on one side of a laser cavity layer and on the other side a one-dimensional photonic crystal, so that substantially monochromatic, visible radiation can be generated. As a result, the light output can be increased with reduced energy consumption.

According to the invention, a luminous body is provided with a substrate and a structure provided adjacent thereto, preferably provided with a photonic crystal, a surface texturing or a grating, which is designed and dimensioned in such a way that essentially monochromatic, visible radiation can be generated. intended. By appropriate sizing can be with recent developments, such as. photonic crystals implement high luminous efficiencies with little effort. It can increase the light output with reduced energy input.

Claims

claims

A luminous body having a substrate and a structure provided adjacent thereto, preferably provided with a photonic crystal, a surface texturing or a grating, which is designed and dimensioned in such a way that essentially monochromatic, visible radiation can be generated.

2. luminous body (2) with a laser cavity layer (30), on one side of which a thermal emitter (28; 34, 36; 38) is arranged and on the other side of which a one-dimensional photonic crystal (32) is arranged in such a manner, that substantially monochromatic, visible radiation can be generated.

3. A luminaire according to claim 2, wherein said one-dimensional photonic crystal (32) comprises a plurality of dielectric layer pairs (32a, 32b) each having a high refractive index layer (32a) and a low refractive index layer (32b).

4. The luminous element according to claim 2 or 3, wherein the thermal emitter has a metallic reflector layer (26).

5. The luminous element according to claim 4, wherein the metallic reflector layer (26) is applied to a ceramic carrier (28).

6. A luminous element according to claim 5, wherein on the ceramic carrier (34) opposite to the metallic reflector layer (26) a conductor track (36) is provided for heating the metallic reflector layer.

7. A luminous element according to claim 2 or 3, wherein the thermal emitter is formed by a metallic coil body (38).

8. A luminous element according to claim 7, wherein on the metallic coil body (38) opposite to the laser cavity layer (30) a further laser cavity layer (30) is applied.

9. A luminous element according to claim 2, wherein on the side opposite the one-dimensional photonic crystal (32) side between a substrate and the laser cavity layer (30) a one-dimensional metallo-dielectric photonic crystal (42) of metal layers and layers with low refractive index or particle films is provided with a one-dimensional photonic crystal.

10. The luminous element as claimed in claim 2, wherein a metal layer (43) or a semiconductor layer is provided as an emitter on a one-dimensional photonic crystal (44) on the side opposite the one-dimensional photonic crystal (32) between a substrate and the laser cavity layer (30) is.

11. A luminous body for producing a substantially monochromatic, visible radiation with a substrate and a one-dimensional photonic crystal (45, 46), to which a metal or particle layer (43) adjoins, wherein the one-dimensional photonic crystal (45, 46). is arranged between the substrate and the metal or particle layer (43) or on the side of the metal or particle layer (43) opposite the substrate (40).

The luminous body of claim 11, wherein the one-dimensional photonic crystal (45, 46) has low refractive index layers and high refractive index layers, and the thickness of the high refractive index layers between two low refractive index layers is twice the layer thickness as the thickness of the layers small refractive index.

13. A luminous element for producing a substantially monochromatic, visible radiation with a substrate and a partially transparent reflector layer, opposite to which a substrate is provided, preferably a thicker compared to the partially transparent reflector layer (49) reflector layer (48) between the resonator (47 ) and substrate (40) is provided.

14. A luminous element according to claim 13, wherein on the partially transparent reflector layer, a one-dimensional photonic crystal is arranged as a filter for suppressing unwanted emission peaks.

15. Illuminant for producing a substantially monochromatic, visible radiation with a substrate (140, 160) and a layer system which forms a one-dimensional photonic crystal and layer pairs of a layer of dielectric (126, 146, 166) and an emitter layer (124, 144, 164), wherein the emitter layer is a bulk layer of a transition metal, a noble metal or a semiconductor or a particle layer and the dielectric is selected to be substantially transparent to visible light at the emitter temperature.

16. The luminous element according to claim 15, wherein the emitter layers are used as heating elements.

17. The luminous element according to claim 15, wherein the emitter layer is a particle layer with a metal layer for resistance heating.

18. A luminous element according to claim 15, wherein the emitter layer is a particle layer with metallic nanoparticles having a diameter in the range of about 5 nm to lμm.

19. Luminaire according to one of claims 15 to 18, wherein the substrate is flat or has a rod-shaped core

20. Illuminant for producing a substantially monochromatic, visible radiation with a heatable substrate (220, 230, 240) and adjacent thereto provided structure (226, 232, 246,, 266) formed in such a manner that surface plasmons can emit light due to the structure.

21. A luminaire according to claim 20, wherein the substrate comprises metal and the structure dielectric in such a way that the wave vector of the surface plasmids of the interface between metal and dielectric is equal to the wave vector of the photon in the dielectric.

22. The luminous element according to claim 20, wherein the substrate

(220, 230) comprises tungsten or a coated insulator or semiconductor or ionic conductor.

The luminaire of claim 20, wherein the structure (226, 232, 246, 266) comprises stripes, grids, spots or particles.

24. A luminous element according to claim 20, wherein the structure is formed by the vapor deposition with particles (246).

25. Luminaire according to claim 24, wherein the particles

(246) are coated with a dielectric (248)

26. A luminous element according to claim 24, wherein the particles

(246) are embedded in a dielectric (258) a one-dimensional photonic crystal (254) is deposited.

27. The luminous element as claimed in claim 20, wherein a cavity (264) is provided between coated particles (266) of the structure and a metal layer (262)

28. A luminous element for producing a substantially monochromatic, visible radiation with a heatable substrate (342) and adjacent to this provided particle grid layer, which forms a photonic crystal.

The luminaire of claim 28, wherein the particle lattice layer comprises spheres (340) of a refractory material coated with a dielectric and the refractory material has a high refractive index contrast to that dielectric.

30. A luminous element according to claim 29, wherein the beads

(340) are made of tungsten and the dielectric has AL ₂ O ₃ , SiO ₂ or HfO ₂ .

31. Luminaire according to one of claims 28 to 30, wherein the particle lattice layer is face-centered cubic, cubic body-centered or the hexagonal closest packing.

32. The luminous element as claimed in claim 28, wherein the particle lattice layer has spherical spaces, preferably in bulk. a face-centered, small refractive index array surrounded by a high refractive index material.

33. The luminous element according to claim 32, wherein the spheres (342) comprise a dielectric with a low refractive index, for example Al 2 O 3 or SiO 2.

34. Illuminating element according to one of the preceding claims, wherein the thermal emitter is formed as a substantially flat surface or as a substantially rotationally symmetrical surface.

35. The luminous element as claimed in one of the preceding claims, wherein the luminous element (50; 56; 60; 64; 70; 76) has a substantially rectangular conductor cross-section.

36. The luminous element according to one of the preceding claims, which is designed as a filament (50).

37. The luminous element according to one of the preceding claims, which is conical (56).

38. The luminous element according to one of the preceding claims, which is designed as a double cone (60).

39. A luminous element according to one of the preceding claims, which is in the form of a disc (72) which extends perpendicular to the feed sections (14a, 14b) is formed.

40. The luminous element according to one of the preceding claims, which has the shape of a spherical surface (98) at least in sections.

41. The luminous element according to one of the preceding claims, wherein a resistance heating element (66) of the thermal

Emitters has at least partially meander shape.

42. A luminous element according to claim 2 or 3, wherein the thermal emitter (86) is spaced from a plate having the laser cavity layer (30) and the photonic crystal.

43. A luminous element according to claim 2 or 3, wherein the thermal emitter (36) is applied to a plate comprising the laser cavity layer and the photonic crystal.

44. Lamp with a luminous element according to one of the preceding claims.

45. The lamp as claimed in claim 44 having a lamp body, on whose light-emitting region a converter layer (22) is provided for converting part of the radiation into the complementary color.

46. The lamp according to claim 44, which is filled for oxidation protection with a gas, for example nitrogen

47. The lamp of claim 45 with a diffuser layer

(20) provided between the lamp housing and the converter layer.

48. A manufacturing method for a luminous body for producing a substantially monochromatic, visible radiation with a heatable substrate (342) and adjacent to this provided particle grid layer forming a photonic crystal, comprising the steps of a) providing a substrate (342) , b) applying the particle lattice layer to the substrate, c) compacting the elements (340) of the particle lattice layer, d) sintering the coating on the elements of the particle lattice layer.

49. The method of claim 48, wherein after step d) remaining cavities between the elements (340) of the particle lattice layer are filled with a dielectric of small refractive index

50. A luminous element according to claim 48 or 49, wherein the compaction in step c) takes place by sedimentation or controlled drying of a colloidal sphere dispersion.

51. A luminous element according to any one of claims 48 to 50, wherein after step b) and before step c) stripping protruding elements of the particle lattice layer takes place.