Effect of Composition on The Structural, Morphology, and Optical Properties of AgSb(S_xSe_1-x)₂Thin Films

Abstract

Quenching method was used to prepare alloys of the AgSb(SxSe1-x)2 quaternary compound with different sulfur content. AgSb(SxSe1-x)2 thin films with different sulfur concentration were prepared at room temperature 303K on glass substrate using pulsed laser deposition under vacuum of 10−2 bar, thickness of ∼100nm. The structure of the prepared alloys and thin films were examined by x-ray diffraction. The results declared that all the prepared compounds have polycrystalline with cubic structure whereas the deposited AgSb (SxSe1-x)2 thin films were amorphous. Atomic Force Microscopy revealed that the average grain size decreases while roughness exhibit to increase in non-regular manner with the increase of sulfur concentration. The absorbance and the transmittance were provided from- visible spectrophotometer measurements in the wavelength range (300-1100nm). The results showed that the prepared thin films have indirect allowed band gap which showed absorbable increase with the increase of sulphur content, indeed the optical energy gap increase from 1.1 to 1.7 eV with the increase of sulphur content while all the optical constants (the refractive index n, the extinction coefficient k and real and imaginary parts of dielectric constants εr, εi all declared reduction with the increase of sulfur concentration.