Temperature dependence of the optical properties of thin Ge-Se-In films

Abstract This paper deals with the properties of the glasses and thin films from multi-component chalcogenide prepared by co-evaporation technique. The thin chalcogenide layers from the Ge 30 Sе 70−x In x system were deposited by thermal co-evaporation of bulk glasses from Ge-Se system and In 2 Se 3 . Using X-ray microanalysis it was found that the film compositions are close to the expected ones. The refractive index, n , and the optical band gap, E g opt , were determined by spectral ellipsometric measurements. The thin film's structure was investigated by Raman spectroscopy. The temperature coefficients of the linear thermal expansion, α l and the band gap, β Eg were determined. Decrease of the values of α l from 2.49 × 10 −4  K −1 to 4.55 × 10 −5  K −1 and β Eg from −1.3 × 10 −3  eV·K −1 to −0.7 × 10 −3  eV·K −1 was observed when indium content in the thin films was increased from 0 to 17 at.%.