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Title [SPECIAL ISSUE] High Performance NO2 Gas Sensor Based on Pd-AlGaN/GaN High Electron Mobility Transistors with Thin AlGaN Barrier
Authors Cuong Van Nguyen; Hyungtak Kim
Page pp.170-176
ISSN 1598-1657
Keywords Palladium; platinum; gallium nitride; nitrogen dioxide sensor; high electron mobility transistor
Abstract We investigated the performance of NO2 gas sensors based on AlGaN/GaN high electron mobility transistors (HEMT) with 10 nm AlGaN barrier. The sensors were designed to operate in μA range to reduce power consumption and realize good sensing performance. The gate area of the HEMT sensor was functionalized using a Pd and Pt catalyst layer for NO2 detection to compare the performance between Pd and Pt catalysts. Pd-functionalized sensors demonstrated better sensing characteristics compared with Pt-functionalized sensors. When the sensors were exposed to 100 ppm of NO2 at 300 oC, the relative sensitivity of 53 % was measured with the response time and recovery time of 136 s and 196 s, respectively. Also, the sensor shows a significant change of drain current for 30 s exposure time in different concentrations from 10 to 100 ppm NO2. These results suggest that Pd-AlGaN/GaN HEMT sensors with a thin barrier can be the great choice to detect NO2 gas and they could be used in the harsh environment in real-time condition.