Surface resistivity of hydrogenated amorphous carbon films: Existence of intrinsic graphene on its surface

TL;DR

This study measures the surface resistivity of hydrogenated amorphous carbon films and finds evidence of intrinsic graphene on their surface, which could impact future graphene applications and material understanding.

Contribution

It provides experimental evidence of intrinsic graphene on amorphous carbon surfaces, revealing a low sheet resistance comparable to defect-free graphene.

Findings

Sheet resistance as low as 7.5 kΩ/sq near the peak

Presence of a sharp ambipolar peak near zero gate voltage

Existence of intrinsic graphene on amorphous carbon surfaces

Abstract

Surface resistivity of hydrogenated amorphous carbon films was measured as a function of the applied electrical field. The measured dependence shows a sharp ambipolar peak near zero gate voltage. Furthermore, we found that in some samples sheet resistance at the peak is as low as 7.5 k{\Omega}/sq. This value is the same order of magnitude as the sheet resistance of a defect free graphene monolayer. Therefore a conclusion is made that an intrinsic graphene with dimensions of at least millimeters exist on the surface of amorphous carbon films. These results can open new perspectives not only for graphene applications, but also for better understanding of this unique material.