Effect of deposition temperature on structural, optical properties and configuration of CdSe nanocrystalline thin films deposited by chemical bath deposition

Abstract

CdSe nanoparticle thin films were deposited on glass substrates by the chemical bath deposition (CBD) method at low deposition temperature ranging from room temperature up to 50°C while the pH of the bath was kept constant at 12.1. The structural and morphological variation were investigated by X-ray diffraction (XRD) and scanning electron microscopy (SEM) technique. The energy band gap and optical properties were characterized by the absorbance spectra. Rutherford backscattering spectroscopy (RBS) analysis reveals the excess of Cd rather than Se in depth profile along the thin film thickness. The prepared CdSe nanoparticles have cubic structure and by increasing the temperature the deposited films become continues, homogeneous and tightly adherent. The results also revealed that by increasing the deposition temperature from room temperature up to 50°C, the band gap decreases from 3.52eV up to 1.84eV.