Electrical and Noise Characteristics of Graphene Field-Effect Transistors: Ambient Effects and Noise Sources

TL;DR

This study systematically investigates the low-frequency noise and ambient effects on graphene transistors, revealing that noise mainly originates from the graphene layer and is significantly affected by aging and environmental exposure.

Contribution

It provides a comprehensive experimental analysis of noise sources and aging effects in graphene transistors, highlighting differences from silicon-based devices.

Findings

Noise primarily from graphene layer, not contacts

Aging increases noise due to reduced mobility and contact resistance

Noise behavior varies with gate bias and charge neutrality point

Abstract

We fabricated a large number of single and bilayer graphene transistors and carried out a systematic experimental study of their low-frequency noise characteristics. A special attention was given to determining the dominant noise sources in these devices and the effect of aging on the current-voltage and noise characteristics. The analysis of the noise spectral density dependence on the area of graphene channel showed that the dominant contributions to the low-frequency electronic noise come from the graphene layer itself rather than from the contacts. Aging of graphene transistors due to exposure to ambient for over a month resulted in substantially increased noise attributed to the decreasing mobility of graphene and increasing contact resistance. The noise spectral density in both single and bilayer graphene transistors either increased with deviation from the charge neutrality point or depended weakly on the gate bias. This observation confirms that the low-frequency noise characteristics of graphene transistors are qualitatively different from those of conventional silicon metal-oxide-semiconductor field-effect transistors.