Optimization of the properties of CdxZn1-xS films prepared by chemical bath deposition at low Cd2+ concentrations

Abstract

Abstract CdxZn1-xS thin films were deposited on glass substrates by chemical bath deposition (CBD) in solutions containing cadmium sulfate, zinc sulfate, thiourea, ammonia sulfate and ammonia. The effect of low Cd2+ concentration on the film properties was systematically studied by experiments and simulations, while the film properties were greatly improved by optimizing the concentration ratios of different solutions. The SEM results show that the films have optimal homogeneity and denseness at a Cd2+ concentration of 0.007 M. Also, XRD results at this concentration indicate that the films have better crystallinity. The optical characterization results illustrate that the transmittance of the films is up to 90% at 500 nm-800 nm, and the band gap value of the films varies from 3.05 eV to 3.72 eV when the Cd2+ concentration is 0.001-0.009 M. Finally, the performance of the CdxZn1-xS buffer layer prepared under low Cd2+ concentration conditions was simulated by SCAPS software, and the conversion efficiency was as high as 24.36%.