title: Suspended GaN nanowires as NO2 sensor for high temperature applications.
abstract: We propose a gas sensor operable over a wide temperature range and using suspended GaN nanowires functionalized with Pt-Pd. The sensor is batch-fabricated by directly integrating the GaN nanowires onto batch-processed silicon microelectrodes in parallel. The high thermal stability of the sensor originates from a large band gap of GaN nanowires that enables the detection of NO2 gas at an elevated temperature of up to 350 °C without a decrease in responsiveness. Exposed to NO2 at 100-1000 ppm at 350 °C, the sensor shows a linear increment in relative response with respect to the change in gas concentration. The sensor results in a two- to four-fold increase in responsiveness to NO2 at 100 ppm compared to NH3 at 100 ppm and CO2 at 1000 ppm. The nanowires suspended over a substrate provide increased surface area that could interact with gas molecules for enhanced responsiveness, and prevent any unnecessary interactions between the nanowires and the substrate.
authors: School of Mechanical Engineering, Yonsei University, 50 Yonsei-ro, Seodaemun-gu, Seoul 120-749, Republic of Korea.
authors: Jaesam
authors: J
authors: Sim
authors: Kwanoh
authors: K
authors: Kim
authors: Soonho
authors: S
authors: Song
authors: Jongbaeg
authors: J
authors: Kim