NO₂ Detection and Real-Time Sensing with Field-Effect Transistors

Abstract

The huge impact of nitrogen dioxide (NO 2 ) emission on public health and the environment is motivating extensive scientific and technological research in the field of NO 2 sensing. Field-effect transistors have emerged as a sensitive and reliable technology for monitoring air quality, due to their amplified sensor response. In this review article, the NO 2 detection mechanism with field-effect transistors is discussed. The origin is charge trapping at the gate dielectric, yielding a threshold voltage shift. The dynamic response can be described by an analytical model. Implementation in a sensor protocol allows for the fabrication of a functional demonstrator. The sensor, based on a ZnO field-effect transistor, is capable of detecting concentrations as low as 40 ppb of NO 2 in real-time. The sensor operates in ambient air, and apart from drying, no further precautions are taken, showing that the fabricated sensor is selective for NO 2 . The results reviewed in this paper set a precedent for sensing with field-effect transistors.

Physisorption-Based Charge Transfer in Two-Dimensional SnS2 for Selective and Reversible NO2 Gas Sensing

“…8 Optical methods predominately rely on the unique optical fingerprints of NO2 gas molecules including their chemiluminescent emission and infrared light absorption wavelengths, which result in high selectivity NO2 sensing.…”

“…[8][9][10][11][12] Instead, electrochemical 4 sensing of NO2, which relies on the electrochemical reduction of NO2 in the presence of noble catalysts, is a low-cost approach. 13 Nevertheless, such sensors have cross-talk with active gas species such as hydrogen and their operation lifetime are relatively short.…”

Performance improvement of organic field-effect transistor based nitrogen dioxide gas sensor using biocompatible PMMA/silk fibroin bilayer dielectric

“…To monitor and control the air quality, sensitive and reliable NO 2 sensors are imperative [1][2][3]. So far, a great amount of researches on NO 2 sensors have been reported.…”

“…So far, a great amount of researches on NO 2 sensors have been reported. The general methods to realize NO 2 sensing can be mainly summarized as: (1) introducing sensitive materials, i.e. conducting polymer, metal oxide, graphene and nanostructure materials, as detective layers, (2) optimizing interfacial properties of gas detection layer in sensor devices, (3) designing new architecture of sensor devices [4][5][6][7].…”

The effect of metal-buffer bilayer drain/source electrodes on the operational stability of the organic field effect transistors

“…This is because of their attractive potentials such as low fabrication cost, large-area processing, and flexibility [1][2][3][4][5]. So far applications such as light emitting [6,7], sensing [8][9][10], logic-gate [11], and photo-switching [12,13] have been developed using these transistors. However, some practical difficulties such as high threshold voltage (V TH ), low field effect mobility (μ eff ) and limited operational stability currently hindering wide application of the OFETs.…”