Strongly modulated transmissions in gapped armchair graphene nanoribbons with sidearm or on-site gate voltage

TL;DR

This paper introduces dual-structure field-effect transistors using gapped armchair graphene nanoribbons with sidearms or on-site gate voltages, enabling controllable conduction windows within the band gap for potential electronic applications.

Contribution

It presents a novel dual-structure design for graphene nanoribbon transistors that achieves tunable conduction windows and robust switching behavior within the band gap.

Findings

Conduction peaks appear inside the gap with single sidearm or gate.

Dual structures broaden peaks into conduction plateaus.

Conduction windows are controllable by structural parameters.

Abstract

We propose two schemes of field-effect transistor based on gapped armchair graphene nanoribbons connected to metal leads, by introducing sidearms or on-site gate voltages. We make use of the band gap to reach excellent switch-off character. By introducing one sidearm or on-site gate to the graphene nanoribbon, conduction peaks appear inside the gap regime. By further applying two sidearms or on-site gates, these peaks are broadened to conduction plateaus with a wide energy window, thanks to the resonance from the dual structure. The position of the conduction windows inside the gap can be fully controlled by the length of the sidearms or the on-site gate voltages, which allows "on" and "off" operations for a specific energy window inside the gap regime. The high robustness of both the switch-off character and the conduction windows is demonstrated and shows the feasibility of the proposed dual structures for real applications.