PHOTOLUMINESCENCE STUDIES IN ZNXCD1-XTE SINGLE-CRYSTALS

The crystalline quality of ZnxCd1 xTe single crystals prepared by a modified Bridgman method with 0<x<0.05 has been analyzed using photoluminescence. The spectrum of a typical sample is dominated by lines originating from the recombination of free and bound excitons. Lines due to free excitons in their ground and first excited states are observed in both the pure CdTe and the mixed crystals. Excitons bound to Cd vacancies are observed in the pure CdTe crystal but not in the mixed crystal. Weaker and broader features appearing at energies below the exciton emission range were associated with transitions involving free-to-bound and bound-to-bound levels. The origin of the various lines in the spectra was deduced from the detailed measurements of the dependence of the spectrum on temperature and excitation intensity. © 1990, American Vacuum Society. All rights reserved.