Efectos de la variación de la energía de excitación en los espectros de fotoluminiscencia de películas de CdTe

We report the photoluminescence spectra of CdTe polycrystalline thin films at 10 K as a fuction of the exciting photon energy in the 1.62-1.72 eV range, using a Ti-Sapphire laser as the exciting light. Our preliminary results indicate that the ratio associated to the maximum intensity of the bound exciton band (I_E) to the corresponding associated to the defect band (I_D) shows a resonant increment in the range between 1.62-1.65 eV of the excitation photon energy. This behavior is attributed to the efficient emission of LO-photons during the thermalization process of the created photocarriers in their corresponding bands. Moreover, as a result an increase also of bound excitons to Cd vacancies is also observed. We have also identified in the non-resonance region two deep levels associated to the defects band, through the deconvolution in a double structure of this band.