The structural, optical and electrical properties of CdSxxTe1-x1-x thin films prepared by co_evaporation of powders of CdS and CdTe ha ve been studie d by x_ray diffraction, atomic force microscopy and optical transmittance spectr a measurements. Results show that the as_deposited CdSxxTe1-x1 -x thi n films are homogeneous, adherent and compact on the glass slides substrates wit hout pinhole and that their conductivity is n_type for x≥05 and p_type fo r xxTe1-x1-x thin f ilms are pol ycrystalline and show highly preferential orientation. The predominant direct op tical transitions were observed and the variation of the optical energy gap E gg is nonlinear with x. Given the values of lattice parameter and opt ical energy gap, the exact composition of the phase change at x=025 has been determined. The films are of a cubic phase for x025. After annealing there is no change in the structure of the films with a slight decrease in optical energy gap. Finally, a new structure of CdS/CdTe/Z nTe/ZnTe:Cu/Au solar cells with a CdSxxTe1-x1-x buffer l ayer has been proposed.