Gas Sensing Properties of Indium-Oxide-Based Field-Effect Transistor: A Review

Excellent stability, low cost, high response, and sensitivity of indium oxide (In O ), a metal oxide semiconductor, have been verified in the field of gas sensing. Conventional In O gas sensors employ simple and easy-to-manufacture resistive components as transducers. However, the swift advancement of the Internet of Things has raised higher requirements for gas sensors based on metal oxides, primarily including lowering operating temperatures, improving selectivity, and realizing integrability. In response to these three main concerns, field-effect transistor (FET) gas sensors have garnered growing interest over the past decade. When compared with other metal oxide semiconductors, In O exhibits greater carrier concentration and mobility. The property is advantageous for manufacturing FETs with exceptional electrical performance, provided that the off-state current is controlled at a sufficiently low level. This review presents the significant progress made in In O FET gas sensors during the last ten years, covering typical device designs, gas sensing performance indicators, optimization techniques, and strategies for the future development based on In O FET gas sensors.