Optical Characteristics of Amorphous Se-Ge-Ag Thin Films

Abstract

Abstract Detailed studies on impurity dependence of the optical structural properties have been carried out on Se-Ge-Ag thin film samples prepared by thermal evaporation technique. The effect of the addition of varying amounts of silver in concentrations from 5 to 15 molar percent to Se-Ge system were analyzed systematically under the room temperature. The optical transmission and reflection spectra of these films were measured in the range of 300–900 nm. The mechanism of the optical absorption follows the rule of forbidden non-direct transition. The band gap Eg, determined from plots of both (αhν)1/2 and (e//r)versus hν, was found to increase with the increase of the Ag contents in the sample. Real and imaginary parts of the dielectric constant are determined and it showed apparently little change with impurity doping in the sample. The results are discussed in terms of the structure of Se-Ge-Ag films in terms of structure factor. From the reflectance and transmittance studies of the thin films of Se-Ge-Ag system, it may be concluded that the refractive index η decreases, while the value of the extinction coefficient k increases with photon energy.   Keywords: Chalcogenide glasses, amorphous semiconductor, quenching technique, optical properties Cite this Article Niraj Kumar Sharma, Srivastava KK. Optical Characteristics of Amorphous Se-Ge-Ag Thin Films. Trends in Opto-Electro & Optical Communications. 2016; 6(3): 33–38p.