Modification of Some Optical and Mechanical Properties of Amorphous As-S-Se Thin Films by Copper Introduction

In this research experimental investigation of the influence of copper introduction on some relevant parameters in As-S-Se amorphous thin films is performed. Copper is introduced into As-2(S0.5Se0.5)(3) amorphous thin film in concentration of 3 at.%. Samples of As-2(S0.5Se0.5)(3) and Cu-3(As-2(S0.5Se0.5)(3))(97) amorphous thin films are prepared by the vacuum thermal evaporation technique from previously synthesized bulk samples. Envelope method is applied for the determination of the optical constants, using the transmission and reflection spectra. The dispersion of the refractive index is discussed in terms of the single oscillator model proposed by Wemple-DiDomenico. Values of absorption coefficients in the high absorption region are discussed according to Tauc's law. Instrumented indentation testing is performed, using the Berkovich geometry indenter, for obtaining the value of nano-hardness. All the determined parameters have shown the increase with introduction of copper into amorphous thin film.