High-Performance UV Photodetectors Based on 1-D Ag/ZnO Nanostructures With a Simple Photochemical Process at Room Temperature
Yen‐Lin Chu, Sheng‐Joue Young, Yu-Jhih Chu, Yi-Hsing Liu, Tung-Te Chu
Abstract
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 ( <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$\text{I}_{\text {dark}}{)}$ </tex-math></inline-formula> of Ag@ZO-0 and Ag@ZO-1 PDs were <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$4.9\times 10^{-{8}}$ </tex-math></inline-formula> and <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$7.0\times 10^{-{9}}$ </tex-math></inline-formula> A, with photocurrents ( <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$\text{I}_{\text {ph}}{)}$ </tex-math></inline-formula> under UV light illumination of <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$1.30\times 10^{-{6}}$ </tex-math></inline-formula> and <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$1.34\times 10^{-{5}}$ </tex-math></inline-formula> A, respectively at 1 V. The Ag@ZO-1 PDs (1914) show better <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$\text{I}_{\text {ph}}/\text{I}_{\text {dark}}$ </tex-math></inline-formula> 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.