Graphene Thickness-Graded Transistors with Reduced Low-Frequency 1/f Noise

TL;DR

This paper presents a novel graphene transistor design with thickness grading that achieves high mobility and significantly reduced 1/f noise, advancing the understanding of noise mechanisms in graphene devices.

Contribution

It introduces a thickness-graded graphene transistor structure that maintains high mobility while lowering low-frequency noise, revealing noise origins related to doping and density of states.

Findings

High electron mobility comparable to single-layer graphene

Lower 1/f noise levels in thickness-graded devices

Noise reduction linked to doping and density of states differences

Abstract

We demonstrate graphene thickness-graded transistors with high electron mobility and low 1/f noise (f is a frequency). The device channel is implemented with few-layer graphene with the thickness varied from a single layer in the middle to few-layers at the source and drain contacts. It was found that such devices have electron mobility comparable to the reference single-layer graphene devices while producing lower noise levels. The metal doping of graphene and difference in the electron density of states between the single-layer and few-layer graphene cause the observed noise reduction. The results shed light on the noise origin in graphene.