Thin films of Bi 2 Se 3 , Bi 2 Se 2.9 Te 0.1 , Bi 2 Se 2.7 Te 0.3 and Bi 2 Se 2.6 Te 0.4 are prepared by compound evaporation. Micro structural, optical and electrical measurements are carried out on these films. X-ray diffraction pattern indicates that the as-prepared films are polycrystalline in nature with exact matching of standard pattern. The composition and morphology are determined using energy dispersive X-ray analysis and scanning electron microscopy (SEM). The optical band gap, which is direct allowed, is 0.67eV for Bi 2 Se 3 thin films and the activation energy is 53meV. Tellurium doped thin films also show strong optical absorption corresponding to a band gap of 0.70–0.78eV. Absolute value of electrical conductivity in the case of tellurium doped thin film shows a decreasing trend with respect to parent structure.