Improved GaN based Hydrogen Sensors

Abstract

To improve the conventional GaN based hydrogen sensor devices, catalytically active Pt nanonetworks were applied to active gate area of AlGaN/GaN HEMT, and surface roughening of active area in nonpoalar a-plane and semipolar GaN diode by using Photoelectrochemical etching was employed. When the active gate region of an AlGaN/GaN sensor is functionalized with platinum nanostructures that contain a larger surface area offering more active sites for hydrogen molecules to be adsorbed, the drain current response was dramatically improved. Also, the extended rough surface of the diodes showed improved hydrogen detection sensitivity due to the presence of more available adsorption sites, resulting in effective variations of the Schottky barrier height.