Diffusion length measurements on electrodeposited CuInSe2 cells

Polycrystalline thin films of p-type CuInSe2 (thickness about 1 μm) have been prepared by an electrodeposition method. Heterojunction devices of the forms of CdS(low resistivity)/CdS(high resistivity)/CuInSe2 and ZnO(low resistivity)/CdS(high resistivity)/CuInSe2 were fabricated for both electrical and optical measurements. Experiments were specifically carried out to determine the diffusion length of minority carriers in the p-type CuInSe2. It was observed that the diffusion length in CuInSe2 films treated in Ar (with the CdS prepared by a chemical bath deposition method) was generally greater than the length for films treated in vacuum under similar conditions.