Effect of Spatial Charge Inhomogeneity on 1/f Noise Behavior in Graphene

TL;DR

This study investigates how spatial charge inhomogeneity affects 1/f noise in graphene, revealing unexpected noise reduction near the Dirac point in both single and bilayer graphene, with different behaviors.

Contribution

It provides new insights into the noise behavior in graphene near the Dirac point, highlighting the role of spatial charge inhomogeneity in both SLG and BLG.

Findings

Noise decreases near the Dirac point in SLG.

BLG shows similar noise reduction with different gate dependence.

Spatial charge inhomogeneity influences 1/f noise behavior.

Abstract

Scattering mechanisms in graphene are critical to understanding the limits of signal-to-noise-ratios of unsuspended graphene devices. Here we present the four-probe low frequency noise (1/f) characteristics in back-gated single layer graphene (SLG) and bilayer graphene (BLG) samples. Contrary to the expected noise increase with the resistance, the noise for SLG decreases near the Dirac point, possibly due to the effects of the spatial charge inhomogeneity. For BLG, a similar noise reduction near the Dirac point is observed, but with a different gate dependence of its noise behavior. Some possible reasons for the different noise behavior between SLG and BLG are discussed.