Effect of KI/AgI on the thermal and optical properties of the GeS2–In2S3 chalcogenide glasses

GeS2–In2S3–KI/AgI chalcohalide glasses were prepared by traditional melt-quenching method and the glass-forming region was determined. The dependence of glass properties on composition as formula of (100 − x)(0.75GeS2–0.25In2S3) − x(In2S3–KI/AgI) was investigated. The allowed indirect transition of samples was calculated according to the classical Tauc equation. The results show that 50 mol% AgI can be introduced in the glassy matrix while only 40 mol% of KI can be incorporated in the GeS2–In2S3–KI glass system. GeS2–In2S3–AgI glass system has larger density, higher refractive index and better thermal stability, while GeS2–In2S3–KI glass system has shorter visible cut-off wavelength and higher optical band gap.