Research on the novel GeSe2–In2Se3–KBr chalcohalide optic glasses

(1 − x)(0.75GeSe2–0.25In2Se3) − x(1/3In2Se3–2/3KBr) (x = 0, 0.15, 0.3, 0.45, 0.525) chalcohalide glasses were prepared by traditional melt-quenching method and its glass-forming region was determined. The physical, thermal and optical properties of the GeSe2–In2Se3–KBr ternary glass system are reported. The results show that the GeSe2–In2Se3–KBr glass system has relatively high glass transition temperature (Tg = 286–335 °C) and good thermal stability. With increasing KBr content from 0 to 35 mol%, a blue-shift from 750 to 620 nm at the visible absorbing cutting-off edge is observed. The red-shifting of the transmission cutting-off edge at the long-wave IR band occurs linearly with increasing KBr. The allowed direct transition and indirect transition of samples were calculated according to the classical Tauc equation. The direct optical band gaps and indirect optical band gaps were in the range from 1.649 to 1.931 eV and 1.513 to 1.863 eV, respectively.