A Self-Powered High-Performance UV Photodetector Based on Core-Shell GaN/MoO3-x Nanorod Array Heterojunction

Self-powered UV photodetectors are highly desirable for applications in space communications and environmental monitoring. However, most self-powered UV photodetectors exhibit unimpressive performance in weak signal detection. Herein, a self-powered UV photodetector based on the core-shell GaN/MoO3-x nanorod array (NRA) heterojunction system is demonstrated. Homogeneous MoO3-x layers are deposited on GaN NRAs by a simple one-step physical vapor deposition method. The photodetector device shows an ultrahigh specific detectivity of 2.7 x 10(15) Jones at 355 nm without any power supply. Further analyses reveal a responsivity of 160 A W-1 and a high UV-vis rejection ratio (R-355 nm/R-400 nm) of 2.0 x 10(4) under zero bias. The self-powered device also has a fast response speed with a rise/fall time of 73/90 mu s. As a result, the self-powered photodetector, featuring ultrahigh detectivity and responsivity along with fast response, exhibits great potential for applications in next-generation UV detection. The core-shell NRA structure heterojunction design provides a valuable direction for realizing nanoscale self-powered UV photodetectors.