Investigation of properties the copper sulfide thin films prepared from different copper salts

Abstract

Copper sulfide (CuS) thin films were prepared on commercial glass substrates by Chemical Bath Deposition (CBD) method using solution of different copper salts at 50 °C temperature for seven hours. Different anions of copper salts that is crucial for the properties of the films affect the precipitation mechanism and growth rate. For this reason, the effect of the different copper salts on the properties of CuS thin films was investigated and discussed. The influence of the different copper salts in the chemical bath was determined by means of optical transmission of the thin films in the wavelength range of 400–1100 nm taken at room temperature. Next, using these data, the optical band gap values Eg, the extinction coefficient k, the refractive index n, and the real ε1 and imaginary parts ε2 of the dielectric constant were calculated. The crystallographic structure of CuS thin films were analyzed with an X-ray diffractometer (XRD). XRD analysis was revealed the polycrystalline and hexagonal phase of CuS thin films. The surface roughness of the films were measured by AFM. The surface roughness of the thin films was different despite the same deposition time.