Structural, morphological, vibrational, optical, and nonlinear characteristics of spray pyrolyzed CdS thin films: Effect of Gd doping content

Abstract

This paper reports the preparation of cadmium sulfide (CdS) thin films using a nebulizer spray pyrolysis technique by varying gadolinium content in the range of 0–5 wt.%; their characterization is also described. In this study, the effect of Gd concentration on structure, vibrational, optical linear, and nonlinear properties is investigated. The XRD examination of undoped and Gd-doped CdS films shows the crystalline nature toward the (002) plane. Other important parameters, such as crystalline size (D), strain (ϵ), and dislocations density (δ), were evaluated by XRD, and these results are thoroughly discussed. The SEM studies show the morphology of grains. It was observed that the size of grains increased with an increase in doping concentration. Owing to Gd doping in CdS, the optical energy gap is observed to be lower than that of pure film, which is in the range of 2.416–2.283 eV. The linear and nonlinear properties of CdS: Gd films indicated that Gd doping affected optical properties. The observed enhancement in opto-electrical properties, changes in crystalline quality, and optical property enhancements are caused by an increase in Gd doping concentration.