Suspended AlGaN/GaN HEMT NO2 Gas Sensor Integrated with Micro-heater

Jianwen Sun, Robert Sokolovskij, Elina Iervolino, Zewen Liu, Pasqualina M. Sarro, Guoqi Zhang*

*Corresponding author for this work

Research output: Contribution to journalArticleScientificpeer-review

17 Citations (Scopus)
13 Downloads (Pure)


We developed an AlGaN/GaN high electron mobility transistor (HEMT) sensor with a tungsten trioxide (WO3) nano-film modified gate for nitrogen dioxide (NO2) detection. The device has a suspended circular membrane structure and an integrated micro-heater. The thermal characteristic of the Platinum (Pt) micro-heater and the HEMT self-heating are studied and modeled. A significant detection is observed for exposure to a low concentration of 100 ppb NO2 /N2 at ∼300 °C. For a 1 ppm NO2 gas, a high sensitivity of 1.1% with a response (recovery) time of 88 second (132 second) is obtained. The effects of relative humidity and temperature on the gas sensor response properties in air are also studied. Based on the excellent sensing performance and inherent advantages of low power consumption, the investigated sensor provides a viable alternative high performance NO2 sensing applications. It is suitable for continuous environmental monitoring system or high temperature applications.

Original languageEnglish
Article number8856274
Pages (from-to)997-1004
Number of pages8
JournalJournal of Microelectromechanical Systems
Issue number6
Publication statusPublished - 1 Dec 2019

Bibliographical note

Green Open Access added to TU Delft Institutional Repository ‘You share, we take care!’ – Taverne project
Otherwise as indicated in the copyright section: the publisher is the copyright holder of this work and the author uses the Dutch legislation to make this work public.


  • GaN
  • HEMT
  • micro-heater
  • NO sensor
  • WO


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