Abstract

Thin films of CdS and Al-doped CdS have been successfully deposited on glass substrates by using a CBD technique and their properties were investigated. The structural analysis confirmed the hexagonal structure of CdS with preferential orientation along (002) planes. Crystallite sizes decreases with Al content. The AFM images of the films show changes in morphology with increase the dopant concentration. Raman scattering were composed of fundamental longitudinal optical (LO) modes and their multi-phonon process. Transmittance, reflectance, refraction index and extinction coefficient were studied to extract the optical properties variation upon Al doping. The increase of the lattice strain due to Al doping modifies the optical properties of the films. The energy band gap was found to increase from 2.3 to 2.6 eV with increase in Al content. The doping also affects the photoluminescence properties of CdS crystal structure, causing a shift towards shorter wavelengths of the peaks of Al-doped films.