Effect of Immersion Time on Crystallinity and Optical Properties of CdTe Thin Films

This study examined the influence of immersion periods in nanoparticles suspension of cadmium telluride (CdTe) prepared by pulsed laser ablation on the structural and optical properties of deposited thin films with a thickness range of 300 to 420 nm. X-ray diffraction (XRD) showed a polycrystalline structure with enhanced crystallinity and an increase in crystallite size from 19 to 21.6 nm with increasing immersion time from 1 to 4 h. Atomic force microscopy (AFM) showed increases in particle diameter and surface roughness with increasing deposition time. These changes were linked with the development of optical absorbance of the deposited films; in addition, the energy gap narrowed from 2.82 to 2.62 eV. Fourier transform infrared spectroscopy (FTIR) confirms the formation of the CdTe structure. These variations make the thin films more suitable for various applications.