Effects of heat treatment on the surface carrier density in p-type CdTe

The purpose of this study is to investigate the mechanism in which the carrier density of p-CdTe:P decreases due to heat treatment. By successive etching of a heat-treated sample, the carrier density profile resulting from carrier loss near the surface was found to be a real effect. Further experiments with varying cadmium and phosphorus vapor pressures indicate that compensation occurs through the formation of PCd anti-site donors. Observation of the reverse reaction by annealing a sample of p-CdTe:P with CdTe powder after first annealing in vacuum, shows that it does occur but at a much slower rate than the formation of the PCd defects