Photoluminescence of CdSe: Evidence for selective etching of donor states

Abstract

Photoluminescence of n-type CdSe at 1.8 K and above is used to investigate the effect of photoelectrochemical etcing on the impurity distribution near the semiconductor surface. The results suggest that shallow donor states are removed from the surface preferentially, and hence the surface becomes relatively intrinsic following that surface treatment. The model of nonuniform charge flow is invoked to explain this phenomenon.