Study of Some Optical Properties for Different Composition Bismuth -Antimony Thin Films

BiSb, Bi2Sb and BiSb2 alloys were prepared by direct melting of weight from elements, which was followed by quenching then the alloy used to prepared on quartz substrates by using the thermal vacuum evaporation technique at room temperature. The optical characteristics of the prepared thin films have been investigated by UV-VIS spectrophotometer (UV-1650PC Shimadzu) in the wavelength range (200-900 nm), also were determined by FTIR recorder spectrometer model Shimadzu were used to measure the transmission and absorption spectra of (Bi-Sb) alloy thin film deposited on quartz substrate in spectral range (400–4000 cm-1). The films has an indirect allow electronic transitions and optical energy gap (Eg) has increased from 0.063 eV to 0.081eV by modification Bismuth Antimony ratio. The optical properties of the BiSb, Bi2Sb, BiSb2 thin films were studied which include their absorbance and transmittance. The films were found to exhibit low transmittance, high absorbance in the visible, and near infrared region.