PMC – Exhaust Gas Sensors for Automotive Antipollution Systems

Authors: Yacine Halfaya, Chris Bishop, Ali Soltani, Suresh Sundaram, Vincent Aubry, Paul L. Voss, Jean-Paul Salvestrini, and Abdallah Ougazzaden

Impact Factor: 2.478

Investigation of the Performance of HEMT-Based NO, NO2 and NH3 Exhaust Gas Sensors for Automotive Antipollution Systems

ABSTRACT:

We report improved sensitivity to NO, NO2 and NH3 gas with specially-designed AlGaN/GaN high electron mobility transistors (HEMT) that are suitable for operation in the harsh environment of diesel exhaust systems. The gate of the HEMT device is functionalized using a Pt catalyst for gas detection.

We found that the performance of the sensors is enhanced at a temperature of 600 °C, and the measured sensitivity to 900 ppm-NO, 900 ppm-NO2 and 15 ppm-NH3 is 24%, 38.5% and 33%, respectively, at 600 °C.

We also report dynamic response times as fast as 1 s for these three gases. Together, these results indicate that HEMT sensors could be used in a harsh environment with the ability to control an anti-pollution system in real time.

Keywords: AlGaN/GaN heterostructure, HEMT transistor, NOx and NH3, automotive exhaust line, gas sensor.