AlGaN/GaN Heterostructure Field Effect Transistors for High Temperature Hydrogen Sensing with Enhanced Sensitivity

AlGaN heterostructure field effect transistors (HFETs) have demonstrated superior sensitivity for high temperature hydrogen sensing. The sensitivity of HFETs at high temperatures under 1000 ppm or higher H₂ concentrations is more than three orders higher than that of Schottky diodes. The device sensitivity peaks at the gate bias of threshold voltage and at the drain bias of knee voltage in sensing gas.