Selective-hydrogen sensing at room temperature with Pt-coatedInN nanobelts

• Published in: Applied physics letters 2008-11, Vol.93 (20), p.202109-202109-3
• Main Authors: Lim, Wantae, Wright, J. S., Gila, B. P., Pearton, S. J., Ren, F., Lai, Wei-Ta, Chen, Li-Chyong, Hu, Ming-Shien, Chen, Kuei-Hsien
• Format: Article
• ISSN: 0003-6951; 1077-3118
• DOI: 10.1063/1.3033548

The hydrogen sensing characteristics of multiple InN nanobelts grown by metalorganic chemical vapor deposition were investigated. Pt-coated InN sensors could selectively detect hydrogen at the tens of ppm level at 25 ° C , while uncoated InN showed no detectable change in current when exposed to hydrogen under the same conditions. Upon exposure to various concentrations of hydrogen (20-300 ppm) in N 2 ambient, the relative resistance change increased from 1.2% at 20 ppm H 2 to 4% at 300 ppm H 2 . Approximately 90% of the initial InN resistance was recovered within 2 min by exposing the nanobelts to air. Temperature-dependent measurements showed larger resistance change and faster response at high temperature compared to those at room temperature due to increase in catalytic dissociation rate of H 2 as well as diffusion rate of atomic hydrogen into the Pt/InN interface. The Pt-coated InN nanobelt sensors were operated at low power levels ( ∼ 0.5   mW ) .