Self-Powered ZnO Nanowire UV Photodetector Integrated With GaInP/GaAs/Ge Solar Cell

This letter reports the fabrication of a ZnO nanowire (NW) ultraviolet (UV) metal-semiconductor photodetector (MS-PD) integrated with a GaInP/GaAs/Ge triple-junction (TJ) solar cell. The ZnO NW MS-PD can detect UV light <;370 nm. The TJ solar cell transforms solar light to electrical power and provides a bias of 2.5 V to enhance the response of the detector. At this bias, the UV-to-visible (370 to 500 nm) rejection ratio of the ZnO NW MS-PD is ~218 and the measured responsivity is 3.39 × 10^-4 A/W. In addition, the dynamic response of the ZnO NW MS-PD under the UV light illumination of 370 nm is stable and reproducible with an ON/OFF current ratio of ~1000.