An N-I-P type photovoltaic device includes a multi-layered body of N-doped semiconductor material which has an amorphous, N doped layer in contact with the amorphous body of intrinsic semiconductor material, and a microcrystalline, N doped layer overlying the amorphous, N doped material. A tandem device...http://www.google.fr/patents/US5977476?utm_source=gb-gplus-shareBrevet US5977476 - High efficiency photovoltaic device
