Low-temperature Photoluminescence Studies of CdTe Thin Films Deposited on CdS/ZnO/Glass Substrates

Abstract

The CdTe photoluminescence spectra of CdTe/CdS/ZnO heterojunctions annealed in the presence of CdCl 2 have been analyzed in the 4.7-100K temperature range. The analysis has been performed for laser excitation power between 0.01 mW and 30 mW. The analysis showed that the photoluminescence spectrum in the 1.1-1.6 eV region consists of a defect band (1.437 eV) having complex structure and revealing well contoured LO phonon replicas and bound exciton annihilation in the 1.587-1.593 eV region. The band analysis has been carried out by deconvoluting the spectra. It has been shown that the defect band consists of two elementary bands and their phonon replica. An "unusual" temperature dependence of the defect band has been found.