Tuning the Optical and Electric Properties of CdS/ZnO Nanocomposites via Controlling ZnO Composition

In the present work, nanoparticles of CdS and ZnO were synthesized using the coprecipitation method, and their respective composites were formed using an ultrasonic technique with varying ZnO concentrations. The effect of ZnO concentration enhancement on the structural, electrical, and optical properties of CdS/ZnO composites has been studied. The X‐ray spectroscopy and Raman spectroscopy confirm the formation of CdS and ZnO nanoparticles and their composites. X‐ray diffraction spectroscopy (XRD) has been used to study the structural properties of CdS, ZnO nanoparticles, and their composites. The coexistence of the planes corresponds to both CdS and ZnO nanoparticles in the XRD diffractogram of nanocomposites, confirming the formation of the composites. Linear absorption properties of the material are studied with the help of UV–Visible (UV–Vis) spectroscopy and photoluminescence spectroscopy (PL). The bandgap of nanoparticles and their respective composites has been studied using Tauc's Plots. The bandgap calculated from the UV–Vis spectra first increases and then decreases with a rise in ZnO concentration in the composites discussed in UV–Vis section. The KEITHLEY 6517A electrometer is used to study the electrical properties of these materials, which show a rise in current with an enhancement in ZnO concentration at a fixed voltage. The results obtained from the current–voltage characteristics are in good agreement with the UV–Vis spectroscopy analysis. In this work, we tuned the optical properties of CdS/ZnO nanocomposites can be tuned by varying the ZnO composition in the nanocomposites. Moreover, the composites have enhanced visible light adsorption capacity, which extends their use in photocatalytic applications. Findings from various characterizations are consistent with each other.