Publications Repository - Gdańsk University of Technology

This work demonstrates a graphene/AlGaN/GaN sensing device with two-dimensional electron gas (2DEG) toward nitrogen dioxide (NO2), tetrahydrofuran, and acetone detection under UV light irradiation. We propose combining measurements of the DC characteristics with a fluctuation-enhanced sensing method to provide insight into the gas detection mechanisms in the synergistic structure of highly stable GaN and gas-sensitive graphene. Both DC and low-frequency noise studies reveal the impact of UV irradiation (275 nm) on the GaN-based field-effect transistor (FET). Gas detection improves under UV light with higher differentiability between selected concentrations of inorganic (NO2) gas and the possibility of discrimination between weakly adsorbing organic species (tetrahydrofuran and acetone). Time-domain experiments confirm the stability and reversibility of sensor (short-time and long-time) responses and reduced time drift after employing UV light. Features observed in the 1/f noise spectra may indicate the high impact of the irradiation on the trapping states in the GaN-based heterostructure, which further modulates the fluctuations of the channel carriers in our device. Our findings broaden the view on AlGaN/GaN heterostructures modulated with a graphene gate for gas sensing purposes, including strongly binding inorganic gas and weakly adsorbing organic species.

Authors

• Katarzyna Drozdowska link open in new tab ,
• Sergey Rumyantsev,
• prof. dr hab. inż. Janusz Smulko link open in new tab ,
• dr inż. Andrzej Kwiatkowski link open in new tab ,
• Pavlo Sai,
• Paweł Prystawko,
• Aleksandra Krajewska,
• Grzegorz Cywiński