Hydrogenated amorphous silicon carbide(a-SiC:H) with δ-doped boron layers was chosen as window material in order to enhance the conversion efficiency of amorphous silicon(a-Si:H) PIN-solar cells. High efficiency, 9.34%, was obtained in a-SiC:H/a-Si:H hetrojunction solar cells. This efficiency is 1.7% higher than that of a-Si:H homojunction cell. Improvement of the conversion efficiency in hetrojunction structures is due to the large optical gap of a-SiC:H. We performed the reverse bias annealing(RBA) treatment for both hetero-and homojunction solar cells at various temperatures. The conversion efficiency of a-SiC:H/a-Si:H solar cell was increased up to 10% by RBA at 210℃, which is attributed to the increase of active dopants in doped layers and of μγ product in the undoped layer.
