Self-powered narrowband p-NiO/n-ZnO nanowire ultraviolet photodetector with interface modification of Al₂O₃

All inorganic, self-powered, narrowband, and rapid response p-NiO/n-ZnO nanowire (NW) ultraviolet (UV) photodetectors were fabricated and investigated with Al₂O₃ as an interface modification layer. Al₂O₃ films grown by atomic layer deposition can greatly suppress the surface defects on ZnO NWs and improve the p-NiO/n-ZnO NW interface. The photo-response of the photodetector in the 430-500 nm wavelength range was greatly inhibited and the full-width at half-maximum of the response spectrum was less than 30 nm. A large responsivity of 1.4 mA/W was achieved under a 380 nm UV irradiation (0.36 mW/cm²) at zero bias and the response time of the device was less than 0.04 s. Such a simple interface modification method might promote the developing of ZnO NW based narrowband photodetectors.