High Selectivity Hydrogen Gas Sensor Based on WO3/Pd-AlGaN/GaN HEMTs
Van Cuong Nguyen1, Ho-Young Cha1, Hyungtak Kim1
1School of Electronic and Electrical Engineering, Hongik University, Seoul 04066, Republic of Korea.
Sensors (Basel, Switzerland)
|April 13, 2023
Summary
This study presents a novel high-temperature hydrogen gas sensor using AlGaN/GaN HEMTs functionalized with Pd and WO3. The sensor demonstrates excellent sensitivity and selectivity for hydrogen detection in complex gas mixtures at elevated temperatures.
Area of Science:
- Materials Science
- Semiconductor Physics
- Chemical Sensing
Background:
- High-temperature hydrogen gas sensing is crucial for various industrial applications.
- Aluminum Gallium Nitride/Gallium Nitride (AlGaN/GaN) High Electron Mobility Transistors (HEMTs) offer potential for robust sensor platforms.
- Developing selective and sensitive hydrogen sensors for complex environments remains a challenge.
Purpose of the Study:
- To investigate the performance of AlGaN/GaN HEMTs as hydrogen gas sensors operating at high temperatures.
- To enhance hydrogen gas sensing selectivity using palladium (Pd) and tungsten oxide (WO3) functionalization.
- To evaluate the sensor's response and selectivity in a mixed gas environment at elevated temperatures.
Main Methods:
- Fabrication of AlGaN/GaN HEMT-based sensors.
- Functionalization of the HEMT gate area with a 10 nm Palladium (Pd) catalyst layer.
- Deposition of a thin Tungsten Oxide (WO3) layer on the Pd catalyst for enhanced selectivity.
- Testing sensor performance at high temperatures (150-250 °C) with various gases including hydrogen (H2), nitrogen dioxide (NO2), methane (CH4), carbon dioxide (CO2), ammonia (NH3), and hydrogen sulfide (H2S).
Main Results:
- The sensor exhibited a high sensitivity of 658% towards 4% H2 at 200 °C.
- The sensor demonstrated minimal response to other tested gases (NO2, CH4, CO2, NH3, H2S) at high temperatures.
- Over the temperature range of 150 °C to 250 °C, the sensor's response to 10 ppm H2 was significantly higher (at least eight times) than its response to other gases.
Conclusions:
- The developed AlGaN/GaN HEMT sensor functionalized with Pd and WO3 is highly sensitive and selective for hydrogen detection at high temperatures.
- The sensor's ability to differentiate hydrogen in a complex gas environment makes it suitable for demanding industrial applications.
- This technology offers a promising solution for reliable high-temperature hydrogen monitoring.
Keywords:
gallium nitridehigh electron mobility transistorhydrogen sensorpalladium catalystselectivitytungsten trioxideMore Related Videos
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