A Novel Three-Dimensional Ag nanoparticles/rGO Microtubular Field Effect Transistor Sensor for NO₂Detections

Abstract：A novel three-dimensional (3D) microtubular NO₂FET sensor has been fabricated from the two-dimensional (2D) reduced graphene oxide (rGO) nanosheets decorated with Ag nanoparticles, by applying the self-roll up technique. The electrical properties of 2D and 3D FET Ag NPs/rGO sensors have been investigated and compared. Finally, the performance of the 3D sensors has been demonstrated, where the preliminary results shown that our 3D FET Ag NPs/rGO NO₂sensor exhibit a relative fast response (response time of 116 s) to 20 part per million (ppm) NO₂with a response of 4.92 % at room temperature at zero bias voltage and 2 V source-drain bias voltage. Moreover, the characteristics of our 3D FET Ag NPs/rGO 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 2D geometry, our 3D geometry occupied less device area, but with the same sensing area. This study would provide a new way to optimize sensing devices performance, and promote its developments for miniaturized and integrated gas sensing applications for indoor health and safety detections, outdoor environmental monitoring, industrial pollution monitoring and beyond.