Methane detection using Pt-gated AlGaN/GaN high electron mobility transistor based Schottky diodes

Abstract

Pt-gated AlGaN/GaN high electron mobility transistor based Schottky diodes were employed to detect methane. A detection sensitivity >100 was obtained for the diodes under reverse bias, and this was one order of magnitude higher than the sensitivity of the diodes operated under forward bias. A new method to extract the response time was demonstrated by taking the derivative of diode current, allowing a reduction in the sensor response time by 80%. Methane sensing experiments were conducted at different temperatures, and an Arrhenius plot of the data determined an activation energy of 57 kJ/mol for the sensing process.

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

“…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].…”

A comprehensive review of gallium nitride (GaN)-based gas sensors and their dynamic responses

“…They used a Pt anode in a GaN-based Schottky diode sensor to detect methane (CH 4 ). 47 Methane is a hazardous, odorless, and colorless gas with a lower explosive limit and an upper explosive limit of 5.3% and 14.3%, respectively, at room temperature. When exposed to 10 000 ppm CH 4 at 400 °C (673 K), the device exhibited a sensitivity of 1 under the reverse-bias condition, much higher than that under the forward-bias condition.…”

Suspended AlGaN/GaN HEMT NO2 Gas Sensor Integrated With Micro-heater

“…Finally, the 2DEG does not interact with the analytes but is sensitive to surface states. By functionalizing the gate area of a HEMT sensor for different analytes, such as enzymes, polyimides, or metals, sensitivity to H 2 [7], NO 2 [9], NH 3 [9], [10], methane (CH 4 ) [11], pH [12], urea [13], glucose [14], chloride ion [15], heavy metal [16], and DNA [17] have been reported. As for most of chemical sensing, as shown in numerous experimental works and theoretical considerations, the important parameters such as selectivity, sensitivity, and response time of gas sensors can be improved by increasing the surface temperature.…”