Friction force microscopy: a simple technique for identifying graphene on rough substrates and mapping the orientation of graphene grains on copper

TL;DR

Friction force microscopy (FFM) provides a simple, rapid, and non-destructive method to identify graphene on various substrates, map its orientation, and study growth processes at high resolution.

Contribution

This paper demonstrates the effectiveness of FFM for identifying graphene and mapping its crystallographic orientation on copper and other substrates, offering a new tool for 2D material research.

Findings

FFM can distinguish graphene from substrates on rough surfaces.

FFM accurately maps graphene's crystallographic orientation.

The technique is applicable to other 2D materials and substrates.

Abstract

At a single atom thick, it is challenging to distinguish graphene from its substrate using conventional techniques. In this paper we show that friction force microscopy (FFM) is a simple and quick technique for identifying graphene on a range of samples, from growth substrates to rough insulators. We show that FFM is particularly effective for characterising graphene grown on copper where it can correlate the graphene growth to the three-dimensional surface topography and map the crystallographic orientation of the graphene nondestructively, reproducibly and at high resolution. We expect FFM to be similarly effective for studying graphene growth on other metal/locally crystalline substrates, including SiC, and for studying growth of other two-dimensional materials such as molybdenum disulphide and hexagonal boron nitride.