Optical properties of chalcogenide (As2S1.5Se1.5)0.99:Sn0.01 thin films

Abstract

In this work, we carried out measurements of optical constants (refractive index n, ab- sorption coefficient α, extinction coefficient k, optical band gap E ) from transmission spectrum at strong and medium absorption regions on a thin film arsenic As-S-Se-Sn system prepared by a conventional melt-quenching technique. Photostructural transformations in amorphous films of (As S Se ) :Sn (x = 0.01 at %) were investigated. The value of the photoinduced changing refractive index and band gap were obtained Δn = 0.10 (±0.02); ΔE = 0.07 (±0.01) eV. The refractive index and optical band gap before and after light exposure at λ = 700 nm is n = 2.52÷2.62 (±0.02) and E = 2.09÷2.16 (±0.01) eV.