Comprehensive Analytical Modeling of AlGaN/GaN based Heterostructure Gas Sensor

Authors Bhaskar Roy1,3, Ritam Dutta2, Md. Aref Billaha4, Soumya Basak5

1Dept. of Electronics & Communication Engineering, Brainware University, Kolkata 700125, India

2Dept. of ECE, Surendra Institute of Engineering & Management, West Bengal 734009, India

3Dept. of AEIE, Asansol Engineering College, Asansol 713305, India

4Dept. of ECE, Asansol Engineering College, Asansol 713305, India

5Wipro Autonomous System & Robotics Lab, Bangalore, Karnataka 560100, India

Issue Volume 13, Year 2021, Number 3
Dates Received 10 January 2021; revised manuscript received 14 June 2021; published online 25 June 2021
Citation Bhaskar Roy, Ritam Dutta, Md. Aref Billaha, Soumya Basak, J. Nano- Electron. Phys. 13 No 3, 03010 (2021)
PACS Number(s) 07.07.Df
Keywords Volatile organic compounds, Heterostructure (7) , 2D electron gas, Polarisation, Gas sensing.

Currently we are facing major problem regarding the environmental pollution due to industry-emitting gases and industrial waste, which can induce environmental hazards and causes serious health problems for human beings. So, volatile organic compounds (VOCs) sensors have generated a lot of attention from researchers over the last decade. As acetone is among the VOCs that extensively used for all research laboratories, industries and human consumables, thus, acetone concentration level monitoring is beneficial for biomedical and environmental research. The Schottky diode AlGaN/GaN heterostructure has therefore been analytically modeled to effectively detect acetone. As a consequence of spontaneous and piezoelectric polarization, the inbuilt high density 2DEG produced over at the interface of AlGaN/GaN is highly sensitive to surface state alterations. Owing to the polarity of acetone, the electrostatic potential of the AlGaN surface is amended when the sensing device is introduced to acetone (dipole moment ( 2.9 Dy). This potential alteration leads the 2D electron gas to be modified and hence the current to change. The TCAD tool is used to simulate the Schottky diode sensor and I-V curves generated at various temperatures for different gas concentration levels.From the I-V curves the sensitivity is determined with a biasing voltage of 0.5 V at an elevated temperature of 450 K, around 72 % response in the presence of 100 ppm gas is being recorded as this model estimates the sensing properties. It is also observed that the sensitivity saturates after 450 K hence the optimum operating temperature of 450 K is determined and the device also demonstrates good linearity and response at different temperatures. The sensitivity changes as per the change in surface coverage which is ultimately increases due to the increase in gas concentration up to certain limit. Hence the reliance of the area surface coverage on the various gas concentrations has been taken into account.

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