Study the structural and optical properties of pure and Aluminum doped CdS thin films prepared by chemical bath deposition method

Abstract

This research deals with the preparation of pure and   Aluminum doped CdS thin films by chemical bath deposition method, with a thickness of (450±20) nm and preparation temperature of (75ᵒC). The results of XRD showed that the films had a polycrystalline hexagonal structure. The preferred orientation was along (002) plane. The average c rystallite size increasing with increasing of dopant concentration. The results of (AFM) showed that the roughness and (RMS) value were increased with doping. Results of (SEM) showed that the films were uniformly distributed and homogenous. The optical properties were studied by recording the absorption and transmittance spectra of the wavelength range (300-1100) nm, it was found that absorbance increased and transmittance decreased with increasing doping. It was also found that the absorption coefficient increased with increasing of dopant concentration  , optical energy gap found of pure and   Aluminum doped CdS thin films with different percentages of (0 , 2.5, 5 , 7.5)%were(2.89 , 2.85 , 2.79 , 2.81 )eV respectively.