Effect of substrate temperature on the microstructural and optical properties of chemical molecular beam deposited sb2s3 flms

Abstract

In this work, SbxSy thin flms were grown on glass substrates for the frst time using the chemical molecular beam deposition method in the atmospheric pressure hydrogen fow. The structural, morphological and optical properties of SbxSy thin flms grown at diferent substrate temperatures of 300 °C, 350 °C, 400 °C and 450 °C were studied. XRD results showed that the SbxSy thin flms grown at diferent substrate temperatures have an orthorhombic crystal structure. Phase analysis indicated a weakening of Sb-S bonds with increasing substrate temperature. Also, the grain sizes of all obtained thin flms ranged from 0.5 to 3 µm. The increase in temperature caused the grains to grow and the spaces between them to increase. Optical experiments reveal that as the substrate temperature increases, the optical band gap energy of the flms increases from 1.52 eV to 1.73 eV, as well as an increase in the Urbach energy from 0.11 eV to 0.44 eV. The experimental values of the band gap for Sb2S3 flms are near the optimum value for photovoltaic conversion.