By doping an organic compound functioning as an electron donor (hereinafter referred to as donor molecules) into an organic compound layer contacting a cathode, donor levels can be formed between respective LUMO (lowest unoccupied molecular orbital) levels between the cathode and the organic compound...http://www.google.fr/patents/US7141817?utm_source=gb-gplus-shareBrevet US7141817 - Light emitting device
