Morphology modification of ZnO nanosheets and ZnO nanorods via thermal dissipation system for UV photoresponse improvement

In this study, a ZnO seed layer is annealed via a thermal dissipation annealing (TDA) system combined with an infrared lamp and cold plate to prevent defect formation. ZnO NRs grown on a seed layer that was subjected to the TDA method (ZnO NR3s) provide higher ZnO NR densities and lower defect densities than ZnO NRs grown on a ZnO seed layer that was annealed via a furnace (ZnO NR2s). In terms of photoresponse properties, ZnO NR3s exhibit a higher photocurrent, increased photosensitivity and photoresponsivity by factors of 6 and 3, respectively, and a faster rise time constant, compared to ZnO NR2s. Therefore, the UV photodetector that was fabricated by TDA treated ZnO NRs exhibited extremely improved responses rate, sensitivity, responsivity, and photocurrent stability. These finding indicate that the proposed approach is a realistic and useful fabrication method for ZnO-based high-performance optoelectronic devices.