Improved chemiresistor gas sensing response by optimizing the applied electric field and interdigitated electrode geometry

Improving the sensing performance of chemiresistive gas sensors is largely material-centric, but further studies are needed to optimize the performance of electrode interfaces and interdigitated electrode structures (IDEs) geometry. Hence, we systematically optimize IDEs geometry (spacing between fingers (Sf), finger width (Wf) and number of fingers (Nf)) using methane (100 ppm) selective nanomaterial. This study provides some fascinating findings: Changing the dimensions of Sf/Wf to 50-300 mu m/20-75 mu m in a constant device area increased sensing response by 1.2/1.54 times, possibly due to increased grain-to-grain contacts in sensing material/potential barrier between electrode and sensing material. Moreover, changing Nf from 2 to 44 and from 44 to 74 resulted in a 2.42-fold improvement and a 3.91-fold decrease in the sensing response, respectively. It can attribute to changes in the base charge density because it affects the contribution of charge carriers due to methane gas adsorption. This research opens the door for fabricating low-power highly sensitive gas sensors that can also be integrated into the Internet of Things.

Automated summary

Improving the performance of chemiresistive gas sensors involves optimizing both the material and the electrode interfaces and interdigitated electrode structures (IDEs) geometry. In this study, the IDEs geometry (spacing between fingers, finger width, and number of fingers) was systematically optimized using a methane selective nanomaterial. The findings showed that changing the dimensions of the IDEs led to improved sensing response, with an increase of 1.2/1.54 times when adjusting the finger spacing/finger width, and a 2.42-fold improvement and a 3.91-fold decrease in sensing response when changing the number of fingers. This research opens up possibilities for fabricating low-power highly sensitive gas sensors that can be integrated into the Internet of Things.