STABLE PHOTOVOLTAIC DEVICES AND METHOD OF PRODUCING SAME

摘要

An amorphous semiconductor photovoltaic device having improved long term efficiency stability. The improved stability is achieved by grading the band gap energy of a portion of the photo-responsive layer of the device. The widest band gap energy portion of the photo-responsive layer is disposed nearest the light-incident surface of the device. The band gap gradation may be smooth or stepped, and may be accomplished by varying the composition of the source materials during deposition of the photo-responsive layer.