A hydrogen sensor based on a metamorphic high electron mobility transistor (MHEMT)

A hydrogen sensor based on a metamorphic high electron mobility transistor (MHEMT) is fabricated and investigated. It is found that the applied gate–source voltage plays an important role in sensor performance. A highest sensing response is found to be 68% at the applied gate–source voltage of −0.6 V under exposing to a 1% H2/air. While the applied gate–source voltage is fixed at 0 V, the large magnitude of drain current variation of 1.8 mA is observed. However, the higher current variation accompanies higher power consumption. Thus, a trade-off between the sensor performance and power consumption should be considered.