Preparation and Photodetection Property of ZnO Nanorods/ZnCo2O4 Nanoplates Heterojunction

Heterojunction-type nanostructures based on ZnO nanomaterials are one of the important candidates for constructing high-performance ultraviolet (UV) photodetectors. In this work, a novel ZnO nanorods/ZnCo2O4 nanoplates heterojunction was designed and prepared, and the electrical properties and photodetection properties of the as-prepared heterojunction were investigated. ZnCo2O4 nanoplates were constructed into uniform thin film on ITO glass substrate using oil/water interface self-assembly. Next, ZnO nanorod arrays with uniform orientation and proper density were grown on ZnCo2O4 nanoplates thin film using hydrothermal method with the help from ZnO seed layer. As a result, high-quality ZnO nanorods/ZnCo2O4 nanoplates heterojunction was achieved. This heterojunction has a high rectification ratio of 673.7. Under reverse bias, this heterojunction has a light-dark current ration of more than two orders of magnitude. The UV-visible rejection ratio of this heterojunction is 29.4, which indicates its selective detection of UV light. These results effectively prove the potential of this ZnO nanorods/ZnCo2O4 nanoplates heterojunction in constructing high-performance UV photodetectors.