A novel three-dimensional Ag nanoparticles/reduced graphene oxide microtubular field effect transistor sensor for NO₂ detections

Abstract

A novel three-dimensional (3D) microtubular NO2 field effect transistor (FET) sensor has been fabricated from 2D reduced graphene oxide (rGO) nanosheets decorated with Ag nanoparticles, by applying the self-roll-up technique. The electrical properties of 2D and 3D Ag NP/rGO FET sensors have been investigated and compared. Finally, the performance of the 3D sensors has been demonstrated, where the preliminary results show that our 3D Ag NP/rGO FET NO2 sensor exhibits a relatively fast response (response time of 116 s) to 20 parts per million NO2 with a response of 4.92% at room temperature at zero bias voltage and 2 V source–drain bias voltage. Moreover, characteristics of our 3D Ag NP/rGO FET sensors, e.g. response, response and recovery times, have been demonstrated to be tuned by adjusting the applied source–drain and gate biases. Compared to the 2D geometry, our 3D geometry occupies less device area, but with the same sensing area. This study provides a new way to optimize sensing device performance, and promotes its development for miniaturized and integrated gas-sensing applications for indoor health and safety detection, outdoor environmental monitoring, industrial pollution monitoring and beyond.

Graphene‐Based Heterostructure Composite Sensing Materials for Detection of Nitrogen‐Containing Harmful Gases

“…Ag NP/rGO [111] FET [64] He et al prepared intercalated γ-Bi 2 MoO 6 /graphene nanosheet composites. BMO/GNCs-8-160 based sensor had outstanding gas sensing performance.…”

NO2-Affinitive Conjugated Polymer for Selective Sub-Parts-Per-Billion NO2 Detection in a Field-Effect Transistor Sensor

“…Gas sensors based on field-effect transistors (FETs) have drawn much attention due to their capability to provide a multi-parameter response, such as the charge carrier mobility, on/off current ratio, threshold voltage, and bulk conductivity, for accurate interpretation. − There are several types of FET gas sensors depending on the applied semiconductors: inorganic semiconductors, carbon materials, layered materials, organic semiconductors, and organic–inorganic hybrid materials. − For instance, an FET based on metal oxide, which is regarded as one of the most traditional gas-sensing materials, can detect target gases by chemical interaction with the adsorbed oxygen ions in metal oxide . However, the operating temperature in the metal oxide sensor is relatively high, and thus, reducing the temperature to room temperature is a target goal. , On the other hand, two-dimensional (2D) materials such as graphene or MoS 2 can be used to fabricate room-temperature-operating gas sensors. , However, the operating principle typically depends on the charge transfer (CT) between active layers and physisorbed gas molecules. , For this reason, target gas molecules are limited to dipolar gases (i.e., NO 2 and NH 3 ), and the selectivity is generally low. Conjugated polymers (CPs) are desirable active layers for developing wearable gas sensors. , Although field-effect mobilities of CPs are relatively low, recently developed diketopyrrolopyrrole (DPP) polymers exhibiting high mobility could be an alternative for the highly sensitive FET-based gas sensors .…”

“…6,10 However, the operating principle typically depends on the charge transfer (CT) between active layers and physisorbed gas molecules. 11,12 For this reason, target gas molecules are limited to dipolar gases (i.e., NO 2 and NH 3 ), and the selectivity is generally low. Conjugated polymers (CPs) are desirable active layers for developing wearable gas sensors.…”

Two-Dimensional Field-Effect Transistor Sensors: The Road toward Commercialization

“…Gas detection, especially the air pollutions associated with toxic ammonia (NH 3 ) and nitrogen dioxide (NO 2 ), plays a vital role in environmental protection, , ecological safety, and human health. , Gas sensing of the 2D FET sensors relies on the redox reactions between target gases and the sensing surface. For instance, the changes in FET channel conductivity are related to the redox properties of gas molecules (left panel in Figure a) .…”