Research On ZnO Growth Without Catalyst And UV Photodetector Performance

Zinc oxide?ZnO?,a II-VI semiconductor,which is a direct wide band-gap?3.4 eV at room temperature?material with also a relatively large exciton binding energy?60 meV?,has recently attracted global interest,especially in its nanostructure structure.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 SiO₂ 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?Better than the constant temperature time of 30min in previous articles?.After the optimized period of growth,ZnO nanowire UV photodetector presents a rise time of 0.45s and a decay time of 0.06s,with a high photocurrent to dark current ratio of10².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.At the same time,we also carried out the nanodiamond and zinc oxide nanowire composite experiment.Through the simple method to make nanodiamond and zinc oxide nanowires form heterojunction between,greatly enhance the zinc oxide-based UV detector in all aspects of performance.We believe these work would greatly boost the application of ZnO NWs in nanoelectronics and optoelectronics.