An analytical approach to evaluate the performance of graphene and carbon nanotubes for NH₃ gas sensor applications

Abstract

SummaryCarbon, in its variety of allotropes, especially graphene and carbon nanotubes (CNTs), holds great potential for applications in variety of sensors because of dangling π-bonds that can react with chemical elements. In spite of their excellent features, carbon nanotubes (CNTs) and graphene have not been fully exploited in the development of the nanoelectronic industry mainly because of poor understanding of the band structure of these allotropes. A mathematical model is proposed with a clear purpose to acquire an analytical understanding of the field-effect-transistor (FET) based gas detection mechanism. The conductance change in the CNT/graphene channel resulting from the chemical reaction between the gas and channel surface molecules is emphasized. NH3 has been used as the prototype gas to be detected by the nanosensor and the corresponding current–voltage (I–V) characteristics of the FET-based sensor are studied. A graphene-based gas sensor model is also developed. The results from graphene and CNT models are compared with the experimental data. A satisfactory agreement, within the uncertainties of the experiments, is obtained. Graphene-based gas sensor exhibits higher conductivity compared to that of CNT-based counterpart for similar ambient conditions.

Unified bandgap engineering of graphene nanoribbons

“…When combined with non‐equilibrium Arora distribution function (NEADF) as used for graphene , and CNT it can make predictions for both ballistic and quantum transport . Similarly, transformation to bilayer GNR and application to gas sensors can proceed on those lines . Both CNTs and GNRs are also expected to find applications in sensor technology .…”

“…Similarly, transformation to bilayer GNR and application to gas sensors can proceed on those lines . Both CNTs and GNRs are also expected to find applications in sensor technology . Complete landscape of graphene folding into CNT and GNR is described in the forthcoming book .…”

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

“…In this model, the gate voltage changes while the channel is exposed to gas. 68,69 It can be seen clearly that by increasing the temperature, the current value increases too. The performance of the GNSbased gas sensor is evaluated by the current-voltage characteristics before exposure to the gas and aer exposure to NH 3 gas.…”

Electronic Nose: Recent Developments in Gas Sensing and Molecular Mechanisms of Graphene Detection and Other Materials

“…The p-and n-type semiconducting behavior can be detected by applying and modulating gate voltage. Among all gas molecules considered, the absorption of the NH 3 molecule can enhance conductance [46]. In the case of CO and NO molecules, the charge transfer towards graphene is observed, thus the conductivity of the sensor is increased [47].…”