Quantum Capacitance of Graphene Sheets and Nanoribbons

TL;DR

This paper develops semi-analytical models to calculate the quantum capacitance of graphene sheets and nanoribbons, incorporating effects like electron-hole puddles, temperature, and finite-size edge effects, aligning well with experimental observations.

Contribution

It introduces comprehensive models that include puddles, temperature, and edge effects for quantum capacitance in graphene and nanoribbons, advancing understanding of their electronic properties.

Findings

Quantum capacitance models agree with experimental data.

Temperature influences quantum capacitance near charge neutrality.

Edge effects significantly impact nanoribbon capacitance.

Abstract

In this chapter, semi-analytical models for the calculation of the quantum capacitance of both monolayer and bilayer graphene and its nanoribbons, are presented. Since electron-hole puddles are experimental facts in all graphene samples, they have been incorporated in our calculations. The temperature dependence of the quantum capacitance around the charge neutrality point is also investigated and the obtained results are in agreement with many features recently observed in quantum capacitance measurements on both monolayer and bilayer graphene devices. Furtheremore, the impact of finite-size and edge effects on the quantum capacitance of graphene nanoribbons is studied taking into account both the edge bond relaxation and third-nearest-neighbour interaction in the band structure of GNRs.