Investigation of the high efficiency microcrystalline silicon solar cell

Control of the minute structure of doped hydrogenated microcrystalline silicon (/spl mu/c-Si:H) and intrinsic /spl mu/c-Si:H was investigated in order to improve the output properties of /spl mu/c-Si:H-related solar cells. The output parameters of /spl mu/c-Si:H solar cells, especially the open circuit voltage (Voc) and fill factor (F.F.) can be improved by controlling the axis of the /spl mu/c-Si:H grains of both layers. The discontinuity of the doped and photovoltaic layer may cause a reduction in the path density of the leak current, and this contributes to an improvement of the Voc and F.F. of solar cells. Based on the developed structure, the fabrication conditions of a hydrogenated amorphous silicon (a-Si:H)//spl mu/c-Si:H stacked solar cell were optimized, and an initial efficiency of 12.6% was obtained. In addition, an integrated type a-Si:H//spl mu/c-Si:H stacked solar cell mini-module was also fabricated as a trial, and normal operation was basically confirmed.