The copper influence on the PL spectra of CdTe thin film as a component of the CdS/CdTe heterojunction

The influence of annealing in the presence of CdCl2 and a thin copper layer deposited onto CdTe on the photoluminescence spectra of CdTe, as a component of CdS/CdTe heterojunction, has been studied for two excitation wavelengths: 0.337 μm and 0.6328 μm. The behavior of the PL was studied as a function of the measurement temperature and excitation intensity. At 0.6328 μm excitation, the interface PL consists of a known 1.43X band, and the chloride annealing enhances radiative transitions at 1.536 eV. The intensity of the 1.536 eV transitions increases when Cu is present. The PL of as-deposited CdTe films prepared in the presence of oxygen has the 1.45X band attenuated when excited with 0.337 μm excitation wavelength.