Oxygen‐assisted recoverable hydrogen sensor based on sensing gate field effect transistor with ppb‐level detection ability

Abstract The rise in gas leakage incidents underscores the urgent need for advanced gas‐sensing platforms with ultra‐low concentration detection capability. Sensing gate field effect transistor (FET) gas sensors, renowned for the gas‐induced signal amplification without directly exposing the channel to the ambient environment, play a pivotal role in detecting trace‐level hazardous gases with high sensitivity and good stability. In this work, carbon nanotubes are employed as the conducting channel, and yttrium oxide (Y 2 O 3 ) is utilized as the gate dielectric layer. Noble metal Pd is incorporated as a sensing gate for hydrogen (H 2 ) detection, leveraging its catalytic properties and unique adsorption capability. The fabricated carbon‐based FET gas sensor demonstrates a remarkable detection limit of 20 × 10 –9 for H 2 under an air environment, enabling early warning in case of gas leakage. Moreover, the as‐prepared sensor exhibited good selectivity, repeatability, and anti‐humidity properties. Further experiments elucidate the interaction between H 2 and sensing electrode under an air/nitrogen environment, providing insights into the underlying oxygen‐assisted recoverable sensing mechanism. It is our aspiration for this research to establish a robust experimental foundation for achieving high performance and highly integrated fabrication of trace gas sensors.