Preparation and study of structural and optical properties of chemical bath deposited copper indium diselenide thin films

Copper indium diselenide thin films of different thicknesses were prepared by the chemical bath deposition technique onto well-cleaned glass substrates at room temperature. The thickness of the deposited films has been determined by gravimetry. The structural characterization was carried out by X-ray diffraction and scanning electron microscopic studies. These studies confirm the polycrystalline nature of the films with chalcopyrite structure. The structural parameters such as lattice constants, axial ratio, tetragonal distortion, crystallite size, dislocation density and number of crystallites per unit area have been evaluated. The composition of the various constituents in CuInSe2 films has been determined by energy dispersive X-ray analysis. The optical properties have been studied in detail in the wavelength range 4000-14500 Angstrom and the optical band gap has been found to be direct and allowed.