Optical studies of (AsSe)100−x Sb x thin films

Abstract

Thin arsenic-selenium-antimony films (AsSe)100−x Sb x (x=0,5,10,15 mol.%) have been deposited on glass substrates by vacuum thermal evaporation (VTE) and pulsed laser deposition (PLD) techniques from the corresponding bulk glassy materials. The refractive index and the film thickness have been determined from the optical transmission spectra by modified Swanepoel method. The optical band gap calculated using the Tauc’s approximation showed a narrowing as a function of the increased Sb content from 1.74 eV to 1.53 eV in the VTE films and from 1.64 eV to 1.42 eV in the PLD films. The refractive index of the Sb-doped films strongly increased with the Sb content and reached the largest value for the PLD films. The results verify that both techniques are suitable for deposition of thin glassy films with high optical quality.