A facile and low cost strategy to synthesize Cd1−xZnxSe thin films for photoelectrochemical performance: effect of zinc content

Abstract

In the present work, we report a facile chemical route for the deposition of Cd_1−xZn_xSe thin films using a simple, self-organized arrested precipitation technique (APT). The effect of Zn content on optical, structural, morphological, compositional and photoelectrochemical properties in Cd_1−xZn_xSe thin films was investigated. The optical properties and band gap profile of Cd_1−xZn_xSe thin films were varied with respect to Zn content. The estimated direct optical band gap was found to be in the range of 1.77 to 1.98 eV. X-ray diffraction (XRD) studies revealed that the films were nanocrystalline in nature with a pure cubic crystal structure and the calculated crystallite size lies in the range 36.5 to 66.3 nm. Scanning electron microscopy (SEM) demonstrates that the surface morphology can be improved with incorporation of Zn into the CdSe lattice. Compositional analysis of all samples was carried out using energy dispersive X-ray spectroscopy (EDS) and X-ray photoelectron spectroscopy (XPS), which confirms the stoichiometric deposition of Cd_1−xZn_xSe thin films. J–V characteristics of all samples were studied in sulphide/polysulphide redox electrolyte. A high efficiency of 0.68% was observed due to lower crystallite size and higher surface area. These results show that by varying Zn content in Cd_1−xZn_xSe thin films, the photoelectrochemical performance can be enhanced.