Materials for Optical Sensors of X-ray Irradiation Based on (GaxIn1 – x)2Se3 Films

(GaxIn1-x)2Se3 films with 0.1 ≤ x ≤ 0.4 were deposited by the thermal evaporation technique. As-deposited (GaxIn1-x)2Se3 films were irradiated using the wideband radiation of a Cu-anode X-ray tube at different exposure times. The spectral dependences of the refractive index and extinction coefficient are measured by the spectral ellipsometry technique. The optical transmission spectra of X-ray irradiated (GaxIn1-x)2Se3 films are studied for various irradiation times. Parameters of the Urbach absorption edge for X-ray-irradiated (GaxIn1-x)2Se3 thin films are determined and compared with those of non-irradiated films. The spectral dependences of the refractive indices of non-irradiated and X-ray-irradiated (GaxIn1-x)2Se3 films are described in the framework of the model developed by Cauchy, Sellmeier, Wemple, and DiDomenico, as well as by the optical-refractometric relation. The detailed variation of the parameters of the Wemple–DiDomenico model for non-irradiated and X-ray-irradiated (GaxIn1-x)2Se3 films has been analyzed. The perspective of applications of (GaxIn1-x)2Se3 films as the materials for optical sensors of X-rays is discussed.