High efficiency silicon solar cells fabricated by catalytic chemical vapor deposition (Cat-CVD) Technology

This is to demonstrate recent progress of Cat-CVD technology, particularly for application to high efficiency crystalline silicon (c-Si) solar cells. Surface recombination velocity (SRV) of c-Si, which is one of major factors deciding efficiency of solar cells, can be lowered to 1.5 cm/s or less by coating c-Si surface with Cat-CVD silicon-nitride (SiNx)/amorphous- silicon (a-Si) stacked layers. The value is extremely low compared with ones obtained by other conventional technologies. Phosphorus (P) atoms can be also doped into c-Si at temperatures as low as 80°C with using species generated by catalytic reaction of P-related gases in Cat-CVD apparatus. Degradation of c-Si quality by heating process, which limits the efficiency of c-Si solar cells, can be avoided by this low temperature doping process. All these facts encourage us to use Cat-CVD technology for fabrication of high efficiency c-Si solar cells. © The Vacuum Society of Japan 2012.