Study the effect of aluminum impurities on the structural and optical properties of (As2Se3) thin films Prepared By Thermal Evaporation Technique

Abstract

:- In this research studied the most important changes in the structural and optical properties for (As₂Se₃)thin films with (1 ,2 and 3) wt % of aluminum impurities. Using method the thermal evaporation technique on the glass substrate at room temperature. Thin films were prepared with thickness (400±20)nm, deposition rate was (1±0.05)nm/s. The structure measurement through X-ray diffraction (XRD) analyses shows the structure of (As₂Se₃) films before and after doping are amorphous. Field Emission Scanning Electron Microscopy (FESEM) appear somewhat homogeneous surface for films. The optical measurement show that (As₂Se₃) films have indirect energy gap and decreasing with the increasing of doping (1.74 -1.4) eV. The optical constants are investigated such as absorption coefficient (?), refractive index (n) for the wavelengths in the range (300-1100) nm, before and after doping processes.