Optimizing performance of Cu2O/ZnO nanorods heterojunction based self-powered photodetector with ZnO seed layer

The Cu2O films were electrodeposited on ZnO nanorod arrays (NRs) and the Cu2O/ZnO NRs heterojunctions were formed. The optical-electronic response of the heterojunctions was investigated. The diameter size and crystal quality of ZnO NRs were modified by the seed layer. ZnO NRs with good crystal quality were obtained on the 0.5% Al doped ZnO seed layer film (named as AZO (0.5%)). The devices based on the Cu2O/ZnO NRs heterojunction exhibit excellent stability and reproducibility of the self-powered photoresponse properties. The device with AZO (0.5%) seed layer demonstrates the high photoresponsivity of 60-70 mA/W in the violet and blue light with a fast response speed at zero applied bias.