Structural, optical and electrical characterization of selenium sulphide nanostructured thin film

Thin film of selenium sulphide (Se₇₅S₂₅) has been prepared using inert-gas consolidation (IGC) method and micro-structural, optical and electrical measurements were carried out on the film. Scanning electron microscopy (SEM) studies show that the deposited film is well adherent and grains are uniformly distributed over the surface of the substrate. X-ray diffraction (XRD) analysis shows that the film is polycrystalline nature with single phase and crystallizes in the orthorhombic structure. The field emission transmission electron microscope (FETEM) revealed the uniform dispersion and an average particle size of 20 nm. Analysis of the optical absorption data indicates that the optical band gap E_opt of this film obeys Tauc's relation for the allowed non-direct transition with energy gap is 2.48 eV. Electrical conduction measurements also show the presence of two distinct phases of the materials and characteristic changes in transport properties due to the nanosize of the materials.