Gaining effect of flower-like ZnO nanowire arrays on the responsivity performance of Cu2O/ZnO heterojunction photodetector

In recent years, many studies have shown that nanostructures have an excellent gain effect on the performance of photodetectors (PDs). In this paper, Cu2O and ZnO was prepared by electrochemical and magnetron sputtering methods respectively, then the ZnO nanowire arrays (NWAs) were grown on Cu2O/ZnO PD by hydrothermal method. After growing ZnO nanowires (NWs), the responsivity of the Cu2O/ZnO PD was increased by about 16 times, and the absorption of light by PD was also greatly improved, indicating that the introduction of the NWs can effectively improve the absorption and utilization of the light by the Cu2O/ZnO PD. Moreover, the built-in electric field of Cu2O/ZnO can effectively separate electron-hole pairs and inhibit their recombination. The detection sensitivity of Cu2O/ZnO/ZnO NWs PD is increased by nearly 5 times, which proves that ZnO NWs have a remarkable improvement for heterojunction PDs.