8.1.3 Influence of Oxygen Impurities on the CO/H2 Selectivity of GaN Based Gas Sensors

R. M. Pradad, A. Gurlo, R. Riedel, O. Merdrignac-Conanec, M. Hübner, N. Barsan & U. Weimar
We report on the influence of oxygen impurities on the gas sensing properties of gallium nitride based chemiresistors, once prepared by using synthesized GaN from nitridation of Ga2O3 and once by using a commercial GaN. Time dependencies of the resistance for untreated- and ammonia treated-GaN sensors exposed to carbon monoxide (CO) and hydrogen (H2) in pure nitrogen at 530 °C is investigated. The untreated GaN sensors show high response towards both CO and H2 whereas...