Photovoltaic properties of five II-VI heterojunctions

Five heterojunction systems, involving the II-VI compounds CdSe, CdTe, ZnSe, and ZnTe, have been prepared using the close-spaced vapor transport method. Current transport through these heterojunctions was found to be dominated by recombination at the interface. Using a collection function, introduced to describe the voltage dependence of the collection of photogenerated carriers, diffusion potentials were determined, and from them values of the electron affinity of CdSe (4.53 eV) and ZnTe (3.73 eV) relative to CdTe (4.28 eV).