The effect of the annealing temperature on the properties of electrodeposited CdZrS thin films

Abstract The electrodeposition procedure was carried out utilizing a two-electrode system on fluorine-doped tin oxide (FTO) glass substrates, with the as-prepared and various annealing temperatures for cadmium zirconium sulfide (CdZrS) thin films. On the synthesized thin films, the structural, surface morphology, elemental composition, surface roughness, and optical properties of the resulting films were studied by characterization techniques such as x-ray diffraction (XRD), scanning electron microscopy (SEM), energy dispersive spectrometry (EDS), scanning probe microscopy (SPM), and ultraviolet-visible spectroscopy (UV–vis) techniques. The XRD results revealed that CdZrS thin films exhibit the cubic phase. The crystallite size of the films fluctuated with an increase in annealing temperature. The SEM images show the hexagonal shape and white rod-like structures on the surface of the films. The EDS results confirmed the presence of all the expected elements for Cd, Zr, and S forming the desired compound of CdZrS. The surface roughness of the films decreased with an increase in annealing temperature from 250 °C–550 °C in the range of 36.67-21.81 nm compared to the as-prepared film. The UV–vis measurements show that the absorbance decreases with an increase in annealing temperature and the energy bandgap increased from 2.22–2.31 eV at 250 °C–450 °C and suddenly decreased to 2.25 eV at 550 °C. To maximize charge transport, light transmission, and solar device efficiency, the optimal window layer material for n -type thin films should have small, compatible crystallite sizes, low surface roughness, minimal absorbance, and a carefully chosen energy bandgap.