Characterization of CdS1−xSex thin films by chemical bath deposition technique

Abstract

The cadmium sulfo selenide CdS1−xSex thin films were chemical bath deposited in aqueous media onto coated glass substrates. As-deposited CdS1−xSex thin films were annealed at 350°C in air for 30min. The structural, morphological, compositional and optical properties of deposited CdS1−xSex thin films were studied using X-ray diffractometer (XRD), scanning electron microscopy (SEM), Energy dispersive analysis by X-ray (EDAX), and UV-Vis-NIR spectrophotometer respectively. X-ray diffraction patterns of CdS1−xSex thin films reveal the polycrystalline nature and hexagonal structure. The microstructural parameters such as crystallite size (D), micro strain (ɛ), and dislocation density were calculated and found to depend on compositions. The surface morphology and grain size are found to be influenced with the annealing temperature. The presence of Cd, S and Se of the CdS1−xSex thin films and the composition of CdS1−xSex thin film are estimated by EDAX analysis. The optical transmittance and absorption spectra were recorded in the range 400–2500nm. The band gap of the CdS1−xSex thin films is found to decrease from 2.5eV to 1.75eV.