Optimizing zinc concentration in spray -deposited zinc oxide (ZnO) thin films for enhanced properties and application in Cu2ZnSnS4/ZnO heterojunction device

This study investigates the synthesis and optimization of zinc oxide (ZnO) thin films through the cost-effective spray pyrolysis technique, utilizing varying molar concentrations of zinc acetate precursor. The unique hierarchical morphology of the ZnO thin film with a zinc concentration of 0.2 M, comprising nanoflakes connected by nanowires, is explored for its superior properties, including a hexagonal wurzite structure, enhanced transparency, and a blue shift in absorbance spectra. Structural, optical, and morphological analyses reveal the promising characteristics of the 0.2 M specimen, making it a potential candidate for applications in optoelectronics, microelectronics, and solar cells. Furthermore, the optimized ZnO thin film is employed as an antireflective layer and heterojunction partner in a CZTS/ZnO thin film heterojunction device. The diode behavior observed in the current-voltage characteristics emphasizes the rectifying properties of the CZTS/ZnO heterojunction, opening avenues for further optimization and enhanced device performance in electronic and optoelectronic applications. This research contributes to the ongoing efforts in transitioning towards sustainable energy sources by providing insights into the fabrication of efficient and cost-effective thin film heterojunction devices.