The Effect of Thin Film Fabrication Techniques on the Performance of rGO Based NO2 Gas Sensors at Room Temperature

Abstract

Reduced graphene oxide (rGO) has attracted enormous interest as a promising candidate material for gas detection due to its large specific surface areas. In our work, rGO films were fabricated on a large scale using dip-coating and spin-coating methods for the detection of nitrogen dioxide (NO2) gas at room temperature. The influence of different test environments on the sensing performance, including the test atmosphere, gas flow and gas pressure was evaluated. The response time of the dip-coating method was 573 s with a long recovery period of 639 s and for the spin-coating method, the response time and recovery time was 386 s and 577 s, respectively. In addition, the spin-coated sensor exhibited high selectivity to NO2, with the response increasing by more than 20% (for 15 ppm NO2) as compared with that for HCHO, NH3, and CH4. Our results indicated that the spin coating method was more suitable for rGO-based gas sensors with higher performance.

Enhanced Gas Sensing Characteristics of a Polythiophene Gas Sensor Blended with UiO‐66 via Ligand Functionalization

“…Moreover, the sensitivity of the U-NH 2 /P3HT blend film to 100 ppm NO 2 gas was twice that of the home P3HT film (Figure 4i). Indeed, the sensor proposed in this study demonstrates superior performance in terms of high-sensitivity behavior compared to NO 2 gas sensors presented in other studies [33][34][35][36][37][38][39][40][41][42][43][44][45] (Table S1, Supporting Information).…”

Improved NO2 Gas-Sensing Performance of an Organic Field-Effect Transistor Based on Reduced Graphene Oxide-Incorporated Nanoporous Conjugated Polymer Thin Films

“…With excellent reproducibility, an OFET sensor based on the nanoporous P3HT/rGO (89/11, w/w %) composite film exhibited the highest detection response of 61.3% to 10 ppm NO 2 , a significant improvement compared to the OFET sensors based on a nanoporous P3HT film (∼24.2%) and nonporous P3HT/PS/rGO (89/11, w/w %) composite film (∼17.7%). In addition, the sensor exhibited excellent sensing properties with a limit of detection (LOD) of under 500 ppb and a fast response and recovery time of 62 and 145 s, respectively, which are superior to those (responsivity = ∼30%, LOD = ∼500 ppb, response/recovery time = ∼200/∼300 s) of previously reported NO 2 sensors operated at room temperature. ,− …”

Reliable Lift‐Off Patterning of Graphene Dispersions for Humidity Sensors

“…[3][4][5] Graphene provides large surface-to-volume ratios, high electrical conductivity, and low noise levels, which altogether constitute beneficial conditions for gas sensing. [6][7][8][9] Dispersion-based graphene, [10][11][12] in particular, is interesting due to lowcost and scalable device fabrication via different deposition methods, such as inkjet printing, [13][14][15] spin-coating [7,8,16,17] or Langmuir-Blodgett [18][19][20] deposition. Nevertheless, different deposition methods are accompanied by film structure and homogeneity challenges, which translate into device performance and reproducibility issues.…”

“…These agglomerates form highly conductive localized regions that reduce the total active sensor area. This has been shown to have a negative impact on the sensor sensitivity, [13,17,21] response time, [17] and reproducibility of response, [17] and highlights the importance of homogeneous graphene flake films to achieve efficient sensors.…”