INFLUENCE OF FILM THICKNESS ON OPTICAL ABSORPTION AND ENERGY GAP OF THERMALLY EVAPORATED CdS 0.1 Se 0.9 THIN FILMS

摘要

CdS 0.1 Se 0.9 samples with different film thicknesses have been evaporated on ultrasonically cleaned glass substrates in a vacuum of about 8.2x10 -4 Pa. The film thickness was estimated using multiple-beam Fizeau fringes in reflection. The optical properties of the prepared films were studied by transmittance and reflectance measurements and the integrated absorptance (A UV and A VIS ) in the ultraviolet and in the visible regions were calculated and correlated with film thickness. The dependence of absorption coefficient on wavelength as well as the energy gap was found to be affected by film thickness.