Diluted chirality dependence in edge rough graphene nanoribbon field-effect transistors

TL;DR

This study examines how structural imperfections like edge roughness affect the performance of graphene nanoribbon transistors, revealing that such imperfections diminish chirality effects and categorize GNRs into wide and narrow types with distinct electronic properties.

Contribution

It demonstrates that edge roughness reduces chirality dependence in GNRFETs and introduces a classification based on width, providing insights for device design and understanding non-idealities.

Findings

Edge roughness dilutes chirality dependence.

GNRs can be classified into wide (semi-metallic) and narrow (semiconducting).

Device performance is affected by width modulation and surface steps.

Abstract

We investigate the role of various structural nonidealities on the performance of armchair-edge graphene nanoribbon field effect transistors (GNRFETs). Our results show that edge roughness dilutes the chirality dependence often predicted by theory but absent experimentally. Instead, GNRs are classifiable into wide (semi-metallic) vs narrow (semiconducting) strips, defining thereby the building blocks for wide-narrow-wide all-graphene devices and interconnects. Small bandgaps limit drain bias at the expense of band-to-band tunneling in GNRFETs. We outline the relation between device performance metrics and non-idealities such as width modulation, width dislocations and surface step, and non-ideality parameters such as roughness amplitude and correlation length.