ENGINEERING OPTO-ELECTRONIC PROPERTIES OF CUO-ZNO NANOCOMPOSITE THIN FILMS FOR DUAL-FUNCTIONAL APPLICATIONS IN PHOTOVOLTAICS AND PHOTOCATALYSIS

Abstract

The opto-electronic properties of metal oxide nanocomposites are highly tunable through compositional control, enabling their application across diverse fields. This study presents a facile chemical bath deposition method to fabricate CuO-ZnO thin films with varying precursor concentrations (0.2M - 0.8M). UV-Vis spectroscopy revealed that the optical bandgap could be engineered from 3.5eV down to 2.2eV, with the 0.4M concentration exhibiting optimal characteristics: the narrowest bandgap, highest absorbance across the visible spectrum, and favourable film thickness. These properties are critically dissected for two key applications. The enhanced visible light absorption and ideal band alignment suggest superior performance as a photoactive layer in low-cost photovoltaic cells. Concurrently, the narrow bandgap and promoted charge separation at the CuO-ZnO p-n junction position this same 0.4M film as an efficient visible-light-driven photocatalyst for environmental remediation. This work demonstrates the successful design of a single, versatile nanomaterial with high potential for advancing both clean energy generation and water purification technologies.