Analytical modeling of the sensing parameters for graphene nanoscroll-based gas sensors

Abstract

Graphene nanoscrolls (GNSs) as a new category of quasi one dimensional (1D) materials belong to the carbon-based nanomaterials, which have recently captivated the attention of researchers. The latest discoveries of the outstanding characteristics of GNSs in terms of their structural and electronic properties such as, high mobility, controllable band gap, tunable core size, high mechanical strength, high sensing capability and large surface-to-volume ratio make them a great candidate for nanoelectronic devices in future work. Due to the importance and critical role of nanoscale sensors and biosensors in medical facilities and human life, using promising materials like graphene and graphene nanoscrolls has widely attracted the interest and attention of researchers to achieve better accuracy and sensitivity in these devices. Up until now, the majority of surveys conducted previously have focused on experimental studies for sensors. Therefore, there is a lack of analytical models in comparison to experimental surveys. In order to start and understand the modeling of gas sensor structure, the field effect transistor (FET)-based structure has been employed as a basic model for a gas detection sensor. The graphene nanoscroll conductance has been affected under exposure to the NH₃ gas molecules. The adsorption of NH₃ gas concentration on the GNSs surface which is caused by a chemical reaction between NH₃ and the GNSs. Therefore it makes the changes in the GNS conductance and current–voltage characteristics of the proposed GNS based gas sensor. This phenomenon is considered as the sensing mechanism with proposed sensing parameters. The I–V characteristics of a GNS-based sensor have been proposed as a criterion to detect the effect of gas adsorption. Finally, in order to verify the accuracy of the proposed model, the results are compared with the existing experimental works.