Structural Optical and Electrical Properties of Bi-Sb-Se

The aim of the present work The present thesis is mainly devoted to: 1- Investigate the structure of Bi40-xSbxSe60 (x = 4 12 20 28 and 36 at. %) using X-ray diffraction. 2- Study the transmittance with respect to wavelength by using IR spectroscopy. 3- Study the transmittance with respect to wavelength using the ultraviolet/visible spectrophotometer and determination the optical constants and energy gap of bulk Bi40-xSbxSe60 samples. 4- Study the compositional dependence of the activation energy by d.c dark conductivity. 5- Study the compositional dependence of the a.c conductivity and dielectric constants.