Photovoltaic properties of n-CdSe/p-ZnTe heterojunctions

Measurements of the diffusion potential, depletion layer width, and bias dependence of quantum efficiency for n-CdSe/p-ZnTe heterojunctions are used to construct a band diagram for the junction and to propose a current transport model. A new value of the electron affinity of CdSe is indicated by measurements of the open-circuit voltage at low temperatures and high intensities. The saturation current density J0 is controlled by a thermal activation energy of 0.8 eV, corresponding to electron flow to the interface where recombination occurs through interface states. Performance as photovoltaic cells is limited by the short diffusion length of holes in CdSe.