Optimization of Post-Annealing Temperature of RF Magnetron-Sputtered ZnO Thin Films for Enhancing Performances of UV Photodetectors

In this study, we examined the surface morphology and crystal structure of RF-sputtered ZnO thin films that were annealed at various temperatures. Also, we fabricated UV photodetectors with an Au-ZnO-ITO sandwich structure, utilizing the thin films annealed at 600 °C. The surface roughness of the film initially increases and then decreases as the annealing temperature rises, and the crystalline quality improves with an increase in the annealing temperature. Due to the Schottky heterojunction formed by the Au-semi contact, the fabricated UV photodetector exhibits a responsivity of 7.91 mA W −1 under 405 nm UV light. And the device demonstrates high response stability and rapid response sensitivity, with a swift rise time of 80 ms at a light intensity of 2.56 mW cm −2 .