17.7% efficiency large area multicrystalline silicon solar cell using screen-printed metallization technique

This paper describes the development of an industrial processing sequence that employs the screen printing and firing for large area multicrystalline silicon (mc-Si) solar cells. A record high efficiency mc-Si solar cell of 17.7%; cell area: 232.5 cm/sup 2/ has been achieved using Kyocera's original cast mc-Si material. The diffusion length of mc-Si material was improved after cell processing especially at the region that had low diffusion length by gettering or passivation effects. The diffusion length after cell processing was about 270 /spl mu/m, and this value corresponds to the value estimated internal quantum efficiency curve of PC-1D simulation very well. The photovoltaic module has been fabricated using 48 cells that have average efficiency of 17.2% with this type of cell. The record module efficiency of 15.7% has been achieved.