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 cm² 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 μm, 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.