High-Performance UV Photodetectors Based on 1-D Ag/ZnO Nanostructures with a Simple Photochemical Process at Room Temperature

High-quality one-dimensional (1-D) zinc oxide (ZnO) nanorods (NRs) were successfully manufactured via the low-cost hydrothermal method synthesis solution route. Furthermore, well-aligned nanostructures with silver nanoparticles (Ag NPs) were successfully adsorbed on the ZnO surface in a silver nitrate (AgNO3) aqueous solution via a simple photochemical way under ultraviolet (UV) light irradiation at room temperature. FE-SEM, HR-TEM, and XRD patterns of the hydrothermally as-grown NR arrays exhibited the hexagonal wurtzite structure with a single crystal property and preferentially oriented along the c-axis direction. The ZnO photodetectors (PDs) with and without adsorbed Ag NPs were labeled the Ag@ZO-1 and Ag@ZO-0 NR arrays, respectively. The dark currents ( $\text{I}_{\text {dark}}{)}$ of Ag@ZO-0 and Ag@ZO-1 PDs were $4.9\times 10^{-{8}}$ and $7.0\times 10^{-{9}}$ A, with photocurrents ( $\text{I}_{\text {ph}}{)}$ under UV light illumination of $1.30\times 10^{-{6}}$ and $1.34\times 10^{-{5}}$ A, respectively at 1 V. The Ag@ZO-1 PDs (1914) show better $\text{I}_{\text {ph}}/\text{I}_{\text {dark}}$ ratios compared with the Ag@ZO-0 PDs (26.53). Overall, the Ag@ZO-1 samples displayed outstanding UV-sensing performance and better photoresponse compared with the Ag@ZO-0 samples. The designed device can detect UV light emanating from Internet-of-Thing applications and even people in the surrounding environment, particularly their skin aging, skin cancer, cataract disease, and deoxyribonucleic acid mutation.