Effect of Strain on Quantum Capacitance of Two Dimensional Intrinsic Graphene

Abstract

In this article, effect of strain on quantum capacitance of 2D intrinsic graphene has been investigated and the theoretical basis of its evolution has been formulated. The variation of quantum capacitance with applied strain has extensively been studied. It is observed that quantum capacitance not only depends on magnitude of applied strain but also depends on its direction. Under anisotropic strain field, the expression of quantum capacitance is calculated from density of states (DOS) using anisotropic dispersion energy in tight-binding approximation (TBA). This anisotropy in strain field causes accumulation of charge carriers in graphene without external bias and generates energy band gap. The strain-tunable band gap is introduced in the expression of quantum capacitance that would help to control the performance of high speed graphene devices by tuning the band gap applying anisotropic strain and would open up the possibility of designing new kind of graphene based field effect devices with very thin gate dielectric.