Compositional studies of optical parameters in (Ag₃AsS₃)x(As₂S₃)₁₋x (x = 0.3; 0.6; 0.9) thin films

Abstract

(Ag₃AsS₃)x(As₂S₃)₁₋x (x = 0.3; 0.6; 0.9) thin films were deposited onto a silica substrate by rapid thermal evaporation. The amount of Ag-rich crystalline phase precipitates on the surfaces of the films increases with Ag₃AsS₃ content. It has been shown that the absorption edge spectra are described by the Urbach rule. The temperature behaviour of absorption spectra was studied, the temperature dependences of energy position of absorption edge and Urbach energy were also investigated. The influence of compositional disordering due to Ag₃AsS₃ introduction into As₂S₃ on the optical parameters of (Ag₃AsS₃)x(As₂S₃)₁₋x thin films were analyzsed. The spectral, temperature and compositional behaviour of refractive index for (Ag₃AsS₃)x(As₂S₃)₁₋x thin films were studied.