Determining Graphene Adhesion via Substrate-regulated Morphology of Graphene

TL;DR

This paper presents an analytic model linking graphene morphology on patterned substrates to its adhesion properties, enabling indirect measurement of adhesion through observable morphological transitions.

Contribution

The study introduces a quantitative model correlating graphene morphology with adhesion, substrate stiffness, and layer number, revealing a sharp transition at a critical adhesion value.

Findings

Graphene exhibits two distinct morphologies depending on adhesion.

A critical adhesion value causes a sharp morphological transition.

The model enables indirect measurement of graphene adhesion.

Abstract

Understanding the adhesion between graphene and other materials is crucial for achieving more reliable graphene-based applications in electronic devices and nanocomposites. The ultra-thin profile of graphene, however, poses significant challenge to direct measurement of its adhesion property using conventional approaches. We show that there is a strong correlation between the morphology of graphene on a compliant substrate with patterned surface and the graphene-substrate adhesion. We establish an analytic model to quantitatively determine such a strong correlation. Results show that, depending on the graphene-substrate adhesion, number of graphene layers and substrate stiffness, graphene exhibits two distinct types of morphology: I) graphene remains bonded to the substrate and corrugates to an amplitude up to that of the substrate surface patterns; II) graphene debonds from the substrate and remains flat on top of the substrate surface patterns. The sharp transition between these two types of graphene morphology occurs at a critical adhesion between the graphene and the compliant substrate material. These results potentially open up a feasible pathway to measuring the adhesion property of graphene.