Quantum Capacitance of Hybrid Graphene Copper Nanoribbon

Abstract

Quantum capacitance of hybrid graphene copper nanoribbon (HGCN) has been calculated using first principle density functional theory (DFT). Compared to an infinite sheet of graphene on copper substrate, a HGCN width below 3 nm shows significant enhancement of quantum capacitance suggesting a possible application for energy storage devices. On the other hand, electronic chip interconnect application is limited above this critical 3 nm width because of a large total capacitance. It has been observed that enhancement of quantum capacitance occurs due to the weakening of electron-electron interaction and Fermi velocity modulation. In this work, the origin of such quantum capacitance enhancement has been studied for HGCN using ab-initio DFT calculation with possible effect at nanoribbon width higher than 3 nm. Moreover, an approximate semi-empirical analytic equation based model has been proposed describing the quantum capacitance enhancement of such quasi-one dimensional graphene-copper hybrid structure.