Optimizing growth of ZnO nanowire networks for high-performance UV detection

Abstract The response speed and photo-to-dark current ratio are critical indicators of ZnO based UV photodetectors. Here we found the response speed and photo-to-dark current ratio of ZnO nanowire UV photodetectors could be well optimized by tuning the entanglement and density of ZnO nanowires grown on SiO 2 pillars through a catalyst-free chemical vapor deposition process. The best performance of ZnO nanowire based UV photodetectors could be achieved at a growth time of 3 min. After the optimized period of growth, ZnO nanowire UV photodetector presents a rise time of 0.45 s and a decay time of 0.06 s, with a high photocurrent to dark current ratio of 10 2 . The fast tuning of nanowire-nanowire junction barrier height contributes to the enhanced response speed of the ZnO nanowire UV photodetectors, while the high photo-to-dark current ratio is attributed to the sparse ZnO distribution and also multi-channel structures. We believe this work would greatly boost the application of ZnO NWs in nanoelectronics and optoelectronics.