Interface properties of a CdTe-ZnTe heterojunction

A vapour phase epitaxial layer of ZnTe was grown on (111), (110) and (100) planes of In-doped n-CdTe substrates. The I-V characteristics of the CdTe-ZnTe heterojunction show that the generation and recombination currents and the diffusion current are controlled by the interface states of the junction. The frequency-dependence and temperature-dependence of the C-V characteristics of the heterojunction were studied. The results show that the band bending is 1.06 eV. The length of the transition region is found to be 0.004 mu m toward the n-CdTe side and 4.81 mu m toward the ZnTe side, which means that the situation is as if an n + -p junction had been formed. The interface state density has been found to be 7.5*10 13 cm -3 . An attempt was made to draw the complete band diagram of the heterojunction.