Defect and functionalized graphene for supercapacitor electrodes

•Defected and functionalized N-graphene sheets have been analysed within DFT framework.•Single and Double Vacancy defects in have been investigated for their possible application as supercapacitor electrodes.•Significant acceptor-type energy levels observed near the fermi level predicting the p-type behavior of defected graphene.•Portrays remarkable increase in electrical conductivity of single vacancy functionalized graphene.

The structural, electronic and transport properties of defected (single vacancy and double vacancy) and nitrogen functionalized graphene sheets have been analysed within the framework of Density Functional Theory (DFT) and non-equilibrium Green's function (NEGF) formalism for their possible application as supercapacitor electrodes. Formation energy calculations reveal the increasing stability of defect with nitrogen functional doping concentration at its edges. The extracted electronic properties reveal the presence of acceptor-type energy levels at Fermi level in the defected and functionalized sheets. Transport studies portray remarkable increase in electrical conductivity of graphene sheet after the formation of single vacancy defect and its functionalization. Especially, the Single Vacancy Trimerized pyridine-type defect (SVT) configuration has demonstrated superior thermodynamic stability as well as electrical conductance in comparison to all the other configurations.

Graphical abstractSchematic model of DVT sheet device model and Current-Voltage (I-V) phenomenon in pristine graphene, SV, SVM, SVD and SVT defected sheets.Figure optionsDownload full-size imageDownload as PowerPoint slide