Multifunctional Au-ZnO Plasmonic Nanostructures for Enhanced UV Photodetector and Room Temperature NO Sensing Devices

Abstract

In this study we report the enhancement of UV photodetection and wavelength tunable light induced NO gas sensing at room temperature using Au-ZnO nanocomposites synthesized by a simple photochemical process. Plasmonic Au-ZnO nanostructures with a size less than the incident wavelength have been found to exhibit a localized surface plasmon resonance (LSPR) that leads to a strong absorption, scattering and local field enhancement. The photoresponse of Au-ZnO nanocomposite can be effectively enhanced by 80 times at 335 nm over control ZnO. We also demonstrated Au-ZnO nanocomposite's application to wavelength tunable gas sensor operating at room temperature. The sensing response of Au-ZnO nancomposite is enhanced both in UV and visible region, as compared to control ZnO. The sensitivity is observed to be higher in the visible region due to the LSPR effect of Au NPs. The selectivity is found to be higher for NO gas over CO and some other volatile organic compounds (VOCs), with a minimum detection limit of 0.1 ppb for Au-ZnO sensor at 335 nm.

One-Dimensional Zinc Oxide Nanomaterials for Application in High-Performance Advanced Optoelectronic Devices

“…In addition, functional devices consisting of a noble metal (e.g., Au [132,133] and Ag [134][135][136][137]) coated on semiconductor nanostructures have inspired extensive research effort. Such devices can realize superior optoelectronic properties to those without a metal coating because their LSPR effect leads to strong scattering and absorption of incident light, efficient separation of photogenerated electron-hole pairs, and rapid transport of charge carriers at the metal/semiconductor interface.…”

Insights into non-noble metal based nanophotonics: exploration of Cr-coated ZnO nanorods for optoelectronic applications

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Efficient Auger Charge-Transfer Processes in ZnO

“…It is also nontoxic, sustainable, and cheap and can be readily synthesized with high quality as bulk crystals and thin films and in various nanostructured morphologies [12][13][14][15][16][17]. All these attributes make ZnO a very promising material for a wide range of applications including light-emitting diodes and lasers [18,19], gas sensors [20], solar cells [21], and photodetectors [22] and as transparent conductive oxide in displays [23,24]. In addition to that, ZnO is much more resistant to radiation damage than other common semiconductor materials, such as Si, GaAs, CdS, and even GaN.…”