Electronic structure and optical property of As2(Te1−xSx)3 and As2(Te1−xSex)3 crystals

► We grew single crystals of S- and Se-incorporated As2Te3 by using vertical Bridgman method. ► The electronic structure and optical property of As2(Te1−xSx)3 and As2(Te1−xSex)3 series compounds have been characterized by thermoreflectance measurements in a wide energy range of 0.7-6 eV. ► Composition-dependent structural phases and band-edge transition energies for the As2(Te1−xSx)3 and As2(Te1−xSex)3 series compounds are respectively determined.