Minority-Carrier Diffusion and Recombination in CdZnS/CuInSe2 Solar Cells

Minority-carrier diffusion has been investigated in as-grown CdZnS/CuInSe₂ solar cells. Capacitance-voltage (C-V) and photoconductivity measurements are combined to determine diffusion and interface recombination processes. Diffusion lengths of about 2 μm and a small interface recombination velocity are determined from biased photoconductivity, biased spectral response, and photoluminescence studies. Photoluminescence studies also indicate that a much lower interface recombination velocity occurs at the CdZnS/CuInSe₂ interface than that at a bare CuInSe₂ surface.