Electrodeposition of ZnO thin films at low temperature: effects of deposition potential on properties for ZnO/CuO heterojunction solar cells

In this study, we investigate the electrochemical deposition of Zinc Oxide (ZnO) thin films as a cost-effective and easily implementable technique to harness its promising semiconductor properties. Various parameters can be adjusted to achieve ZnO thin films with desired structural, morphological, and optical characteristics. In particular, we focus on the deposition potential as a critical parameter. The ZnO thin films were electrodeposited at a low temperature of 55 degrees C, with varying deposition potentials ranging from - 1.2 to - 1.4 V/SCE. Our experimental findings reveal the profound influence of the deposition potential on the structural and morphological properties of the ZnO thin films, as confirmed by X-ray diffraction (XRD) and scanning electron microscopy (SEM) analyses. Additionally, a significant impact on the optical properties was observed, with the band gap energy shifting from 3.25 to 3.31 eV. The film thicknesses exhibited variations from 0.14 to 0.79 mu m in response to changes in the deposition potential. To complement our experimental investigations, we conducted simulations using the Solar Cell Capacitance Simulator in One Dimension (SCAPS-1D) software. Specifically, we explored the feasibility of utilizing these electrodeposited ZnO thin films as window layers in ZnO/CuO heterojunctions for photovoltaic applications. The results demonstrate promising energy conversion efficiencies of 9.13, 9.08 and 9.07% for ZnO thin films deposited at - 1.2, - 1.3, and - 1.4 V/SCE respectively, at the low temperature of 55 degrees C. Overall, our study underscores the significance of optimizing the deposition potential for tailoring the properties of ZnO thin films, rendering them well-suited for applications in photovoltaic devices.