Minority carrier lifetime in polycrystalline silicon solar cells studied by photoassisted Kelvin probe force microscopy

We have proposed a method to evaluate minority carrier lifetime through photovoltage measurements by photoassisted Kelvin probe force microscopy and have applied it to characterize a polycrystalline silicon solar cell. The results indicate that the lifetime significantly decreases in the vicinity of a grain boundary of the polycrystalline material. The photovoltage distribution around the grain boundary is also discussed by considering a contribution of both the intrinsic surface potential and the lifetime. (C) 2008 American Institute of Physics.