Multifunctional dumbbell-shaped ZnO based temperature-dependent UV photodetection and selective H2 gas detection

In this article, a single step, chemically synthesized dumbbell-shaped ZnO microcrystal has been utilized to fabricate UV photodetectors and highly selective H-2 gas sensors. The structural, morphological, chemical states and optical properties were investigated via using various characterization tools. The dumbbell-shaped morphology acquires 1.2-1.4 mu m length and diameters of 300-400 nm respectively. The temperature-dependent photodetection and gas sensing characteristics has been studied in the temperature range 298.15-433.15 K respectively. The maximum relative change in photoresponse and gas sensor response has been found at 358.15 K. The rise time and fall time have been reduced from similar to 2.4 sec to similar to 1.0 sec and similar to 3.1 sec-similar to 2.2 sec respectively in the applied temperature range. Such behavior is attributed to the increasing desorption rate with a higher operating temperature. The maximum sensor response towards H-2 was found to be similar to 20% for 100 ppm concentration at an operating temperature of 358.15 K. (C) 2020 Hydrogen Energy Publications LLC. Published by Elsevier Ltd. All rights reserved.