Composition Measurements related to the CU2S-ZNXCD1-XS Heterojunction

Composition of zinc and cadmium have been measured for three key regions related to the formation of Cu2S on Zn x Cd1_x X by aqueous ion exchange. These are the ion_exchange solution, the resulting Cu2S, and the Zn x Cd1_x S near the Cu2S_Zn x Cd1_x interface. It is found that the participation of zinc in the ion_exchange reaction is incomplete. Zinc is thus retained in the p_n junction region, and is found mainly in the Zn x Cd1_x S just under the interface. This phenomenon helps to account for certain differences between electro_optical properties of Cu2S/CdS and Cu2S/Zn x Cd1_x S solar cells.