Analyzing the electronic and conductive characteristics of zigzag graphene nanoribbons upon NOx and N2O Adsorption: An ab-initio study

Abstract

Achieving a cleaner and more sustainable environment relies on the precise identification and elimination of toxic gases. Addressing this imperative, our current study utilizes a symmetric zigzag graphene nanoribbon (ZGNR)-based sensor device to effectively detect gases from the NOx family at low concentrations. The ZGNR serves as the channel element within a simulated sensing device, with its electrodes connected to a variable direct voltage (d.c) source. The performance of the device is validated by monitoring changes in adsorption energy, charge transfer, dipole moment, recovery time and conductance. The manuscript utilizes non-equilibrium Green’s function (NEGF) theory and density functional theory (DFT). These theories serve as the foundation for electronic structure calculations, supplemented by the application of the Landauer-Büttiker equation for computing electrical characteristics.Three common gasses namely NO, NO2, and N2O have been taken into consideration for ZGNR-based sensor device detection. Notably, the suggested sensor device exhibits a higher sensor response (S= 4.63) and a selectivity of about 21% for NO gas. This is likely due to the high adsorption energy (-1.07 eV), and large dipole moment (4.86×10−30Cm) that substantiate larger charge transfer (-0.14e) as compared to NO2 and N2O.Meanwhile, the ZGNR sensor device shows great gas sensing performances, including excellent selectivity, repeatability (due to small recovery time of 103.00 and 0.01 microseconds), and stability. It can therefore be explored as a sensor device that is comparable as well as superior to various carbon-based chemical entities of both 1D and 2D nanomaterials.