Aspects of electron transport in zigzag graphene nanoribbons

TL;DR

This paper explores electron transport in zigzag graphene nanoribbons using NEGF formalism, analyzing how conductance and other properties depend on atomic structure and temperature, highlighting the importance of electron contribution to thermoelectric performance.

Contribution

It applies NEGF formalism to ZGNRs considering potential wells, revealing how atomic structure influences transport properties and thermoelectric figure of merit.

Findings

Electron and thermal conductance increase with more atoms.

Transport properties significantly depend on the number of atoms per unit cell.

Electron contribution enhances the figure of merit above crossover temperature.

Abstract

We investigate the aspects of the electron transport in the zigzag graphene nanoribbons (ZGNRs) using the non-equilibrium Green's function (NEGF) formalism. The latter is an esoteric tool in mesoscopic physics and using this tool the analysis is performed by considering the potential well within the system. Within this potential well, the dependence of the transmission coefficient, local density of states (LDOS) and the electron transport properties on the number of atoms per unit cell is discussed. We observe that the electron and thermal conductance increases with the increase of the number of atoms. In addition to these, the figure of merit which depends on these transport properties has also been studied and we find that the electrons' contribution to enhance the figure of merit is important above the crossover temperature.