A Study on the UV Photoresponse of Hydrothermally Grown Zinc Oxide Nanorods With Different Aspect Ratios

We report on the effect of the aspect ratio of zinc oxide (ZnO) nanorods (NRs) prepared by the hydrothermal process. It was found that increasing the precursor molar amount resulted in the decrease of the aspect ratio of ZnO NRs. Furthermore, the aspect ratios showed a significant effect on the structural and optical properties of the prepared ZnO NRs. The ZnO NRs were fabricated into a metal-semiconductor-metal (MSM) UV photodetector. The performances of the prepared MSM ZnO NRs were also studied, and the high aspect ratio showed that the highest responsivity had a value of 33 A/W at a bias voltage of 5 V and a wavelength of 380 nm. The responsivity, rise time, and full time of the prepared ZnO NRs showed a trend of behavior as the molar amount of the precursor was varied.