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. © The Author Graphene since its inception, 1 has attracted attention due to its exotic mechanical strength 2 along with high electrical 1,3,4 and thermal 5,6 conductivities. Graphene, one atom thick sp 2 hybridized hexagonal carbon sheet, has been proposed for FET, 7 energy storage devices, 8 sensors 9-11 and also for photonic devices 12,13 in its two-dimensional form. Owing to the superior electrical and thermal conductivity, graphene has been at the point of interest for semiconductor chip interconnect for better signal propagation and extensive thermal management. Especially, the planar graphene sheet in its quasi-onedimensional form of nanoribbon, also known as graphene nanoribbon (GNR), is of paramount interest for interconnect technology.14 Existing interconnect technology favors copper nanowire (Cu-NW) for high signal integrity and excellent thermal management. However, as the technology node scales down to 7 nm and below, the long electron mean free path (∼40 nm) of Cu-NW results in severe surface scattering, Joule heating, electromigration and void formation, making it questionable for future technology interconnect options. 15,16 Therefore, it is extremely important to assess the performance of such Cu-NW or any other alternative material compatible with nanoscale technology nodes. Considering the electrical and thermal characteristics of both Cu-NW and GNR at the nanoscale, graphene-coated Cu-NW (G/Cu-NW), has recently shown potential as an alternative to Cu-NW for the following three reasons: a) electronic interconnects are buried under dielectrics where graphene acts as a Cu diffusion barrier layer, 17,18 b) low-cost large area CVD graphene growth has been developed and well understood 19,20 where graphene growth process includes annealing of Cu foil which eventually reduces vacancies and impurities and increases electrical conductivity, 21 and c) graphene provides a heat spreading path for the interconnect in addition to contributing to electronic conduction. 5,22The graphene-copper heterostructure is f...

Effective Room-Temperature Ammonia-Sensitive Composite Sensor Based on Graphene Nanoplates and PANI

“…8 Meanwhile, with the consideration of the need for cheap, fast and efficient sensors, semiconductor-based gas sensors have been developed quickly. 9 As an emerging 2-D material, graphene has attracted much attention worldwide for its large specific surface area 10 and excellent electrical properties. 11,12 However, no material can be satisfactorily applied in any field, especially in complex scenarios.…”

Density functional theory studies on graphene/h-boron nitride hybrid nanosheets for supercapacitor electrode applications

“…12,13 Meanwhile, electron energy density in graphene originates from the p-electrons at individual k-points of the bare carbon (C) atom. This electron energy density in graphene can further be enhanced by establishing valence defects, 14,15 functional groups, [16][17][18] doping heteroatoms, [19][20][21] inducing tensile strength, 22 multi-layer stacking, 23 surface rippling, and hybrid structure formation with or without altering the orientation of nanolayers. [24][25][26] These alterations impact the geometry and electronic properties, which ultimately improve the electron energy density of the material.…”

Fabrication and Characterization of Graphene Oxide/Polyaniline Electrode Composite for High Performance Supercapacitors

“…It has high specific surface area and excellent conductivity, and its planar two-dimensional structure makes the microstructure more plentiful than other carbon materials, such as carbon fibers and carbon nanotubes. [14][15][16][17][18] Graphene is regarded as one of the most suitable electrode materials for supercapacitors. 19,20 However, the characteristics of the two-dimensional large π conjugation system of graphene make it easy to stack and reunite in the preparation process, so that the high specific surface area cannot be fully utilized when serving as an electrode material for supercapacitors.…”