A review on H2 sensors based on FET

Highly selective, sensitive, and fast hydrogen sensing technology is becoming increasingly important in the processes of production, transportation, and usage of hydrogen energy. Field-effect transistor (FET) is the basic element of modern IC. When serving as a gas sensor, FET poses advantages of small size, high sensitivity, and low power consumption. This article reviews the latest developments in FET hydrogen sensors based on channel materials from traditional silicon, III-V compound semiconductors to novel channel materials carbon nanotubes, graphene, and two-dimensional black phosphorus. Firstly, the structure of FET sensors was investigated. Then the sensitive materials severing as gate were reviewed and efforts to improve the performance was summarized. Then, we discuss the sensitive materials that are currently available, with a focus on the interaction mechanisms between hydrogen and the sensitive materials. Lastly, methods to enhance sensor performance by modifying the physical and chemical properties of the sensitive materials are presented. Finally, the article provides an outlook on the future development of FET type hydrogen gas sensing.