Chemical deposition of CdS films: structure,RBS, PIXE,optical and photoelectrochemical solar cell studies

CdS semiconductor films have been chemically prepared from a basic solution containing CdSO₄, thiourea and NH₄OH. X-ray diffraction studies have revealed the presence of polycrystalline mixed cubic and hexagonal phases of CdS in the deposit. The surface topography has been identified by SEM analysis and found to be non-uniform and spongy. Rutherford Backscattering Spectrometry (RBS) analysis gave the Cd to S ratio as 1.016 whereas that of Proton Induced X-ray Emission (PIXE) analysis gave the Cd to S ratio as 0.905. The band gap of the CdS film has been estimated from optical absorption studies and found to be 2.46 eV. The CdS/S^2–, S₂ ^2– interface has been characterized in order to identify the charge transfer process. Finally, Photoelectrochemical Solar Cells (PESCs) have been fabricated with cell configuration Ti/CdS/S^2–, S₂ ^2–/Pt and the results have been discussed.