We present the results concerning photovoltaic materials CuIn_1-xGa_xSe₂ thin films, which were obtained by close-spaced vapor transport “CSVT”. The influence of the iodine pressure on the growth of CuIn_1-xGa_xSe₂ thin films was studied. The thin films were characterized by Energy Dispersive Spectrometry (EDS), Scanning Electron Microscope (SEM), hot point probe method, X-Ray Diffraction (XRD), Photoluminescence, and Optical response (Photoconductivity). At high pressure, the deposition rate was very important. The films were relatively thick and homogeneous with large grains dimensions. These films are formed of crystals placed in a preferential orientation depending on the plan (112). At low pressure, the films were thin and inhomogeneous with relatively small grains. These films of crystals didn’t have preferential orientation.