Photoluminescence spectra of Cl-doped CdTe crystals

A detailed analysis of photoluminescence (PL) spectra has been done to identify the origins of PL emissions in solution-grown CI-doped CdTe crystals. In the exciton emission region, a sharp peak at 1.590 eV and a broad peak at 1.586 eV are observed in the Cl-doped CdTe crystals and their intensities are enhanced with increasing amount of Cl. On the basis of the temperature-dependence measurements: the two features are attributed to the recombination of excitons bound to two different accepters. From the variations in the PL spectra of the Cl-doped CdTe crystals before and after Cd annealing, it is demonstrated that the feature at 1.590 eV is associated to exciton bound to complex acceptor formed with a Cd vacancy and two Cl donors (V-Cd-2Cl(Te)), and the feature at 1.586 eV is associated to exciton bound to another Cl-related complex acceptor of(V-Cd-Cl-Te). The ionization energies for (V-Cd-2Cl(Te)) and (V-Cd-Cl-Te) complex acceptors are found to be about 45 and 120 meV, respectively. (C) 1998 Published by Elsevier Science B.V. All rights reserved.