Thin films of Bi2 (Se1-xTex)3 system, where x = 0%, 50% and 100%, were deposited from the previously prepared bulk alloys using vacuum thermal evaporation technique. The crystal structure was studied by X-ray diffraction (XRD) analysis. XRD analysis shows that the prepared samples are polycrystalline single-phase materials. Some physicochemical characteristics such as density, compactness, molar volume, mean coordination number, and free volume percentage have been derived based on the calculated density and theoretical equations. The thermal behavior of the samples was recorded using Differential scanning calorimetric (DSC) and Thermogravimetry (TGA) techniques. From DSC thermograms, the peak crystallization temperature (Tc,p), and the melting temperature (Tm) were determined. The thickness of the films, their optical constants, and optical band gaps were calculated from transmission and reflection spectra.