Preparation and Characterization of Polycrystalline CdS Thin Films Deposited by Chemical Bath Deposition


MATERIALS FOCUS, vol.7, no.3, pp.351-355, 2018 (Peer-Reviewed Journal) identifier

  • Publication Type: Article / Article
  • Volume: 7 Issue: 3
  • Publication Date: 2018
  • Doi Number: 10.1166/mat.2018.1525
  • Journal Name: MATERIALS FOCUS
  • Page Numbers: pp.351-355
  • Çanakkale Onsekiz Mart University Affiliated: Yes


Cadmium sulfide (CdS) thin films are deposited on microscope glass substrates at 82 +/- 2 degrees C for 1 h using chemical bath deposition technique. Deposited films are annealed at 350 degrees C for 1 h in air atmosphere. Their structural, morphological, compositional analysis and optical properties are studied by X-ray diffraction (XRD), scanning electron microscope (SEM), energy dispersive X-ray spectroscopy (EDS) and UV-Vis spectrophotometer, respectively. The XRD patterns show that both deposited and annealed CdS films have hexagonal structure with preferred orientation along the (0 0 2) plane. The grain size of the deposited film increases with annealing. The optical properties of the films are determined by measuring transmittance and absorbance spectra which are used to evaluate the optical band gap, refractive index, real and imaginary parts of dielectric constant. The band gap of the film decreases from 2.06 eV to 1.95 eV with annealing. Currentvoltage (IV) measurements are also carried out in the dark for as-grown and annealed films. The electrical conductivity of the film increases from 2.12 x 10 (11) (Omega cm)(1) to 2.02 x 10 1 (10) (Omega cm)(1) after heat treatment. An increment in electrical conductivity of the film after annealing process can be attributed to an increase in electron density and mobility, as well as an increment in grain size