Field Effect Transistors With Semiconductor-Sensitized Gate for High-Sensitivity Hydrogen Detection

The increasing popularity of hydrogen ( $\text{H}_{{2}}{)}$ energy has led to a growing demand for highly sensitive and reliable $\text{H}_{{2}}$ sensors. In this work, we present a field effect transistor (FET) $\text{H}_{{2}}$ gas sensor with a semiconductor-sensitized gate and achieved low subthreshold swing and significant current modulation effect. The FET-based sensor demonstrated excellent $\text{H}_{{2}}$ sensitivity, with a response of 62.8–250-ppm $\text{H}_{{2}}$ gas at 180 °C. An equivalent model of the sensor was also established to study the sensing mechanism behind the FET-based $\text{H}_{{2}}$ sensor. The results suggest that the interaction of the gas-sensitive film with $\text{H}_{{2}}$ molecules leads to a change in the potential of the floating gate (FG), which in turn modulates the channel current and allows the sensor to detect different $\text{H}_{{2}}$ concentrations. The proposed structure of the FET-based gas sensor offers significant potential for improving the sensitivity of $\text{H}_{{2}}$ detection.