Effects of different annealing atmospheres on the properties of cadmium sulfide thin films

• Compactness and smoothness of the films were enhanced after sulfur annealing.
• Micro-strain values of some films were improved after sulfur annealing.
• Dislocation density values of some films were improved after sulfur annealing.
• Band gap values of the films were improved after sulfur annealing.

Cadmium sulfide (CdS) thin films were prepared on glass substrates by using chemical bath deposition (CBD) technique. The effects of different annealing atmospheres (air and sulfur) on the structural, morphological and optical properties of CdS thin films were studied at three different pH values. Compactness and smoothness of the films (especially for pH 10.5 and 11) enhanced after sulfur annealing. pH value of the precursor solution remarkably affected the roughness, uniformity and particle sizes of the films. Based on the analysis of X-ray diffraction (XRD) patterns of the films, micro-strain and dislocation density values of the sulfur-annealed films (pH 10.5 and 11) were found to be lower than those of air-annealed films. Air-annealed films (pH 10.5, 11 and 11.5) exhibited higher transmittance than sulfur-annealed films in the wavelength region of 550–800 nm. Optical band gap values of the films were found between 2.31 eV and 2.36 eV.

The effects of different annealing atmospheres (air and sulfur) on the structural, morphological and optical properties of CdS thin films were studied at three different pH values.Figure optionsDownload as PowerPoint slide