Study on Structural and Optical Properties of Sb2S3 and CdI2 Composite Thin Films Deposited by Thermal Vapor Deposition

Thin films of Sb2S3 and CdI2 composites were deposited by thermal vapor deposition method on a glass substrate. The structural and optical properties have been investigated as a function of the film thickness. Three samples were deposited with thickness of 160 nm, 210 nm and 380 nm. The samples were characterized by X-ray diffraction (XRD), UV-visible (UV-Vis) absorption spectroscopy and photoluminescence (PL) spectroscopy. The XRD result confirms the orthorhombic structure of Sb2S3 peaks. The bigger crystals are formed with the increase of the thickness of the film. The band gaps of the deposited composite thin films were found to be in range 2.17-1.48 eV and suggest the possibility of band gap tunability in the visible region with the changing the thickness of the film. The PL study reveals the intense emission due to band to band recombination with emission in the red region corresponding to trap states.