Laser–induced changes in the optical characteristics of amorphous films оf the As–Sb-S System

Abstract

The optical transmission spectra of amorphous As40-xSbxS60 films with small antimony content (x=0, 0.8, 1.6, 4, 6) prepared by the thermal evaporation of glasses of corresponding compositions have been measured over the whole 400- 750 nm spectral range. It is established that the laser irradiation and annealing of films leads to an absorption edge shift into the long-wave spectral region. The values of pseudoforbidden gap width Eg and refractive index n of films have been determined. The parameters of a single-oscillator model (oscillator energy E0, dispersion energy Ed, and effective coordination number per cation Nc) for the studied films are estimated. The maximum changes in optical characteristics are found for As36Sb4S60 films. Changes in the optical parameters of films are caused by structural transformations taking place in them under the irradiation and annealing. Keywords: chalcogenide