Suspended Graphene: a bridge to the Dirac point

TL;DR

This paper reports on the fabrication of suspended graphene devices that minimize environmental disturbances, enabling detailed study of intrinsic properties near the Dirac Point, revealing high mobility and reduced charge inhomogeneity.

Contribution

It introduces a method to create suspended graphene devices that allow exploration of intrinsic electronic properties close to the Dirac Point with minimal environmental interference.

Findings

Charge inhomogeneity reduced by nearly tenfold.

Mobility exceeds 100,000 cm2/Vs near the Dirac Point.

Access to intrinsic properties of graphene close to the Dirac Point.

Abstract

The recent discovery of methods to isolate graphene, a one-atom-thick layer of crystalline carbon, has raised the possibility of a new class of nano-electronics devices based on the extraordinary electrical transport and unusual physical properties of this material. However, the experimental realization of devices displaying these properties was, until now, hampered by the influence of the ambient environment, primarily the substrate. Here we report on the fabrication of Suspended Graphene devices and on studies of their electrical transport properties. In these devices, environmental disturbances were minimized allowing unprecedented access to the intrinsic properties of graphene close to the Dirac Point (DP) where the energy dispersion of the carriers and their density-of-states vanish linearly giving rise to a range of exotic physical properties. We show that charge inhomogeneity is reduced by almost one order of magnitude compared to that in Non-Suspended Graphene devices. Moreover, near the DP, the mobility exceeds 100,000 cm2/Vs, approaching theoretical predictions for evanescent transport in the ballistic model.