Abstract
Good quality CdS films were deposited on glass substrates by the simple and inexpensive SILAR (Successive Ionic Layer Adsorption and Reaction) technique from aqueous solutions having different S:Cd ratios (1:1, 3:1, 5:1 and 7:1). The annealing induced changes in the structural, surface morphological, elemental and optical properties were studied and reported. The X-ray diffraction studies revealed that a transformation from cubic or mixed phase to the pure hexagonal phase was caused by the annealing process at 350 °C and the degree of crystallinity was enhanced very much due to annealing. The recrystallization induced by the annealing process improved the S/Cd ratio in the films and thereby made the films to acquire good stoichiometry suitable for photovoltaic applications. The annealed films were found to have better transmittance (>85 %) in the visible region and enhanced optical band gap (2.50 eV)..
Keywords
CdS thin films, SILAR, Annealing, Structural and optical properties, Elemental analysis, Stoichiometry.
Citation
V. SENTHAMILSELVI, K. SARAVANAKUMAR, R. ANANDHI, A. T. RAVICHANDRAN, K. RAVICHANDRAN, Effect of annealing on the stoichiometry of CdS films deposited by SILAR technique, Optoelectronics and Advanced Materials - Rapid Communications, 5, 10, October 2011, pp.1072-1077 (2011).
Submitted at: Aug. 15, 2011
Accepted at: Oct. 20, 2011