Impact of the Sensor Temperature on Low Acetone Concentration Detection Using AlGaN/GaN HEMTs

Ali Ahaitouf (1) , Yacine Halfaya , Suresh Sundaram (1) , Simon Gautier , Paul Voss (1) , Jean-Paul Salvestrini (1) , Abdallah Ougazzaden (1)

1 Georgia Tech Lorraine [Metz]

In this work, we report on AlGaN/GaN HEMT sensors for acetone concentration below 100 ppm and in a broad range of the sensor temperature varying from RT to 300 • C. At RT, in presence of acetone, a smooth and monotonic decrease of the current is observed with a rather large response of 15 µA/ppm and with large response time (several minutes) and memory effect. At high temperature (300 • C), a current decrease is first observed just after the acetone injection and then followed by an increase which saturates and stabilizes at a constant value. In order to clarify this unexpected behaviour, a detailed study of the sensors response versus the temperature and acetone injection flow has been carried out. The outcome of this investigation is that a competition between the current variations induced by both the sensor and gas flow temperature difference from one side and acetone dipolar moment from the other side can explain this transient. Our study highlights that AlGaN/GaN HEMTs-based sensors allow for very sensitive acetone detection at both room and high temperature. Nevertheless, care must be taken during the characterization and operation of such sensors especially at high operating temperature. On the other hand, high temperature operation helps to improve the sensor response suppress the memory effect.

Mots clés: HEMT; AlGaN/GaN; acetone; temperature; drain current; sensor; sensing; transistor

Domaines: Sciences de l'ingénieur [physics]

Ali Ahaitouf, Yacine Halfaya, Suresh Sundaram, Simon Gautier, Paul Voss, et al.. Impact of the Sensor Temperature on Low Acetone Concentration Detection Using AlGaN/GaN HEMTs. 7th International Electronic Conference on Sensors and Applications, Nov 2020, 2020, ⟨10.3390/engproc0010005⟩. ⟨hal-03120961⟩