Spatially resolved photoconductivity of polycrystalline silicon

摘要

Spatially resolved photoconductivity measurements are used to deduce information describing majority carrier current flow and minority carrier grain boundary recombination in solar grade polycrystalline silicon. Relative to the bulk silicon diffusion velocity, grain boundary recombination velocity of SGB = 0.28 is measured. Measurements using two superposed light sources show intensity dependent nonlinear recombination processes at the grain boundary. Numerical calculations of grain boundary recombination velocity are presented that clarify the microscopic origin of these nonlinearities.