CdTe solar cells were activated by using Argon, Argon-CHClF2 and Argon-Oxygen-CHClF2 gas mixtures respectively. The solar cells structures ZnO/CdS/CdTe were grown onto commercial indium tin oxide. Both ZnO and CdS thin films were deposited using rf-sputtering. The CdS layer, grown in Argon atmosphere, was not intentionally treated before the CdTe thin film was deposited using a conventional closed space sublimation technique. The influence of different gas mixtures annealing in the illuminated and darkness J-V curves, EQE and photoluminescence spectra are shown and discussed for each experiment. (C) 2013 Published by Elsevier Ltd.