A bottom-gate modulated carbon-based field-effect transistor for room-temperature H₂S detection with complete recovery

A bottom-gate-modulated carbon-based FET is developed for room-temperature H 2 S detection. • Complete recovery is achieved by purely electrical activation without external assistance. • The sensor shows favorable selectivity and stability for miniaturized, integrated sensing applications. Increasing attention has been paid to the detection of hazardous gases under room-temperature operating conditions. To address this, this work proposes a novel strategy based on a bottom-gate modulated carbon-based field-effect transistor (FET) for efficient room-temperature H₂S sensing. The FET-type gas sensor was constructed by integrating ZnWO₄/WO₃ composites with the carbon nanotube channel. It was found that applying a −1.5 V bottom-gate bias effectively modulates the surface electronic states of the sensing material, leading to significantly enhanced device performance: a response time of 28 s and a recovery time of 92 s toward 10 ppm H₂S at room temperature, enabling both rapid response and complete recovery. Furthermore, the sensor exhibits a favorable concentration-dependent response within 1–10 ppm, while maintaining high selectivity, consistent reproducibility, and durable long-term stability (maximum response fluctuation <7.1% over 15 days). The performance enhancement is primarily attributed to the gate-bias-facilitated regeneration of adsorbed oxygen species on the material surface. This work not only provides an innovative approach for room-temperature, low-power H₂S detection but also offers a new pathway toward the development of miniaturized and integratable gas sensors. Download: Download high-res image (227KB) Download: Download full-size image