8.1.3 Influence of Oxygen Impurities on the CO/H2 Selectivity of GaN Based Gas Sensors
- 14th International Meeting on Chemical Sensors - IMCS 2012
2012-05-20 - 2012-05-23
- 8.1 Chemical Sensors based on III-V Semiconductors
- R. Prasad, A. Gurlo, R. Riedel - Technische Universitaet Darmstadt, Fachbereich Material- und Geowissenschaften (Germany), O. Merdrignac-Conanec - Laboratoire Verres et Céramiques, UMR CNRS 6512, Université de Rennes 1 (France), M. Hübner, N. Barsan, U. Weimar - Tübingen University, Faculty of Science, Chemistry Department (Germany)
- 667 - 669
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 for ammonia treated GaN sensors the sensitivity towards CO is dramatically reduced. The decrease in CO sensor response for ammonia treated GaN sensors is attributed to a decrease in the wt.% of contaminated oxygen in as synthesized- and commercial-GaN after their treatment in dry ammonia.