Pt-AlGaN/GaN HEMT-Sensor for Hydrogen Sulfide (H2S) Detection

Sokolovskij, Robert; Iervolino, E.; Zhao, Changhui; Santagata, F.; Wang, Fei; Yu, Hongyu; Sarro, P.M.; Zhang, Guo Qi

doi:10.3390/proceedings1040463

Cited by 4 publications

(5 citation statements)

References 7 publications

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“…AlGaN layers with 30% Al concentration contain 5-10 times higher channel sheet densities compared with GaAs or InP HEMTs. By functionalizing the gate area of an HEMT sensor for sensing materials, the AlGaN/GaN sensors have been demonstrated for H 2 [21], CO [22]- [24], NO [25], [26], NO 2 [26]- [28], NH 3 [25], [29], [30], CH 4 [31], H 2 S [32], [33], and C 2 H 2 [34]. So far, very few results of acetone detection with AlGaN/GaN devices have been reported [35].…”

Section: Introductionmentioning

confidence: 99%

Characterization of an Acetone Detector Based on a Suspended WO₃-Gate AlGaN/GaN HEMT Integrated With Microheater

Sun¹,

Sokolovskij²,

Iervolino³

et al. 2019

IEEE Trans. Electron Devices

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A suspended AlGaN/GaN high electron mobility transistor (HEMT) sensor with a tungsten trioxide (WO 3 ) nanofilm modified gate was microfabricated and characterized for ppm-level acetone gas detection. The sensor featured a suspended circular membrane structure and an integrated microheater to select the optimum working temperature. High working temperature (300 • C) increased the sensitivity to up to 25.7% and drain current change I DS to 0.31 mA for 1000-ppm acetone in dry air. The transient characteristics of the sensor exhibited stable operation and good repeatability at different temperatures. For 1000-ppm acetone concentration, the measured response and recovery times reduced from 148 and 656 to 48 and 320 s as the temperature increased from 210 • C to 300 • C. The sensitivity to 1000-ppm acetone gas was significantly greater than the sensitivity to ethanol, ammonia, and CO gases, showing low cross-sensitivity. These results demonstrate a promising step toward the realization of an acetone sensor based on the suspended AlGaN/GaN HEMTs.

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Section: Introductionmentioning

confidence: 99%

Characterization of an Acetone Detector Based on a Suspended WO₃-Gate AlGaN/GaN HEMT Integrated With Microheater

Sun¹,

Sokolovskij²,

Iervolino³

et al. 2019

IEEE Trans. Electron Devices

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“…The depth (d) of the gate-recessed region after etching was about 6 nm. More details about the two-step gate recess technique [45] and the AlGaN/GaN sensors can be found in our earlier publications [20], [28], [48]- [52].…”

Section: Methodsmentioning

confidence: 99%

“…Gallium nitride (GaN) based sensors have been drawing attention due to their unique properties, such as high thermal resistance and chemical stability [16]. Compared to AlGaN/GaN Schottky diode sensors [17]- [19], AlGaN/GaN high electron mobility transistor (HEMTs) sensors provide several advantages: higher current changes [20], lower theoretical detection limits [21] and the modulated sensitivity by changing the gate bias [23]. AlGaN/GaN heterostructures exhibit great potential for the development of a high performance sensing platform, due to the high carrier density two-dimensional electron gas (2DEG) at the interface, which is sensitive to the changes in surface potential [24].…”

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confidence: 99%

Enhanced Sensitivity Pt/AlGaN/GaN Heterostructure NO₂ Sensor Using a Two-Step Gate Recess Technique

et al. 2021

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Based on our proposed precision two-step gate recess technique, a suspended gate-recessed Pt/AlGaN/GaN heterostructure gas sensor integrated with a micro-heater is fabricated and characterized. The controllable two-step gate recess etching method, which includes O 2 plasma oxidation of nitride and wet etching, improves gas sensing performance. The sensitivity and current change of the AlGaN/GaN heterostructure to 1-200 ppm NO 2 /air are increased up to about 20 and 12 times compared to conventional gate device, respectively. The response time is also reduced to only about 25 % of value for conventional device. The sensor has a suspended circular membrane structure and an integrated micro-hotplate for adjusting the optimum working temperature. The sensitivity (response time) increases from 0.75 % (1250 s) to 3.5 % (75 s) toward 40 ppm NO 2 /air when temperature increase from 60 • C to 300 • C. The repeatability and cross-sensitivity of the sensor are also demonstrated. These results support the practicability of a high accuracy and fast response gas sensor based on the suspended gate recessed AlGaN/GaN heterostructure with an integrated micro-heater. Index Terms-AlGaN/GaN, gate recess, gas sensor, NO 2 . I. INTRODUCTION R ECENTLY, there have been growing concerns about environment pollution, such as photochemical smog and acid rain, was caused by the growing nitrogen dioxide (NO 2 ) emission mainly from combustion of automotive exhaust [1], [2], industrial processes [3]. Especially, the monitoring of

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“…Compared with Schottky diode sensors, the transistor-based sensors usually have a larger sensing current and a higher signal-to-noise ratio. Especially for AlGaN/GaN based HEMT [12,13], due to the presence of two-dimensional electron gas (2DEG), the response current is even larger than mA level.…”

Section: Introductionmentioning

confidence: 99%

Impact of high temperature H2 pre-treatment on Pt-AlGaN/GaN HEMT sensor for H2S detection

Zhang

Sokolovskij

Chen

et al. 2019

Sensors and Actuators B: Chemical

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In this paper, a method to extend the detection range of hydrogen sulfide (H2S) gas sensor is demonstrated. The sensor is based on AlGaN/GaN high electron mobility transistors (HEMTs) with Pt gate. It is observed that the as-fabricated devices exhibited sensing signal saturation at 30 ppm H2S exposure in dry air. A pre-treatment using H2 pulses in dry air ambient at 250 ºC was applied to extend the detection range of the sensor. The H2 treated H2S gas sensor was able to detect a higher H2S concentration up to 90 ppm at 250 ºC without complete saturation.

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Pt-AlGaN/GaN HEMT-Sensor for Hydrogen Sulfide (H2S) Detection

Cited by 4 publications

References 7 publications

Characterization of an Acetone Detector Based on a Suspended WO₃-Gate AlGaN/GaN HEMT Integrated With Microheater

Characterization of an Acetone Detector Based on a Suspended WO₃-Gate AlGaN/GaN HEMT Integrated With Microheater

Enhanced Sensitivity Pt/AlGaN/GaN Heterostructure NO₂ Sensor Using a Two-Step Gate Recess Technique

Impact of high temperature H2 pre-treatment on Pt-AlGaN/GaN HEMT sensor for H2S detection

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Pt-AlGaN/GaN HEMT-Sensor for Hydrogen Sulfide (H2S) Detection

Cited by 4 publications

References 7 publications

Characterization of an Acetone Detector Based on a Suspended WO3-Gate AlGaN/GaN HEMT Integrated With Microheater

Characterization of an Acetone Detector Based on a Suspended WO3-Gate AlGaN/GaN HEMT Integrated With Microheater

Enhanced Sensitivity Pt/AlGaN/GaN Heterostructure NO₂ Sensor Using a Two-Step Gate Recess Technique

Impact of high temperature H2 pre-treatment on Pt-AlGaN/GaN HEMT sensor for H2S detection

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Characterization of an Acetone Detector Based on a Suspended WO₃-Gate AlGaN/GaN HEMT Integrated With Microheater

Characterization of an Acetone Detector Based on a Suspended WO₃-Gate AlGaN/GaN HEMT Integrated With Microheater