Hydrogen sensing properties of a Pt-oxide-GaN Schottky diode

Yan Ying Tsai, Kun Wei Lin, Huey-Ing Chen, I-Ping Liu, Ching Wen Hung, Tzu Pin Chen, Tsung Han Tsai, Li Yang Chen, Kuei Yi Chu, Wen-Chau Liu

Research output: Contribution to journalArticle

18 Citations (Scopus)

Abstract

The interesting hydrogen sensing properties of a Pt-oxide-GaN metal-oxide-semiconductor-type Schottky diode are comprehensively studied and demonstrated. In the hydrogen-containing environment, the shift in current-voltage curves and decrease in turn-on voltage are found to be caused by the lowering of Schottky barrier height. Also, the corresponding series resistance is decreased from 191.8 (in air) to 155.3 Ω (for a 9970 ppm H2/air gas) at 30°C. As the carrier gas is replaced by a nitrogen gas, a significant variation of 0.32 V and 19.56 Ω in the turn-on voltage Von and series resistance Rs values, respectively, is obtained at 30°C, even at an extremely low hydrogen concentration of 4.3 ppm H2/N2. Since the oxygen atoms will be dissolved on the Pt metal surface and react with hydrogen atoms by the formation of hydroxyl and water, the number of adsorbed hydrogen atoms on the Pt surface is reduced. Moreover, the shorter response time constant and the larger initial rate of current density variation are found even at room temperature.

Original languageEnglish
Article number024515
JournalJournal of Applied Physics
Volume104
Issue number2
DOIs
Publication statusPublished - 2008 Aug 12

All Science Journal Classification (ASJC) codes

  • Physics and Astronomy(all)

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