Hydrogen sensing performance of a Pd nanoparticle/Pdfilm/GaN-based diode

A new Pd nanoparticle (NP)/Pd film/GaN-based Schottky diode-type hydrogen sensor is fabricated and studied. Pd NPs are formed using a proper photochemical approach based on a drop of PdCl2 solution and UV illumination. Experimentally, excellent hydrogen sensing performance, including an extremely high sensing response (4.2 x 10(6)@1% H-2/air gas) with a very low detection limit (<= 0.8 ppm H-2/air) is obtained at 25 degrees C. This is mainly caused by the enhanced surface area/volume ratio of the Pd NPs and the catalytic reactivity of the Pd film. Furthermore, the studied device exhibits sensitive responses to humid ambiences at 25 degrees C. Therefore, based on the reported benefits and relatively simple process flow, the studied device is a promising high-performance hydrogen sensor. (C) 2017 Elsevier B.V. All rights reserved.