AlGaN/GaN high electron mobility transistor for various sensing applications: A review

AlGaN/GaN high electron mobility transistors (HEMTs) demonstrate exceptional properties desired for sensing regime applications due to their extraordinary chemical stability, non-toxicity, surface amenable to functionalization, high surface charge sensitivity and high temperature endurance. This report provides a comprehensive review on the AlGaN/GaN HEMT based solid-state microsensors used for detection of gases, biomarkers, ions and high energy radiation which has application in environmental, clinical and water quality monitoring besides medical research. The material properties and fabrication aspects are highlighted first and then sensing mechanisms for different applications and various device design advancements during past decades in literature are discussed along with the modelling and simulation perspectives. There are some reports which discuss AlGaN/GaN HEMT for a particular application only and thus there was a need for a review which discusses various aspects and applications in one study to render an overall bird's eye view of potential of this material system.