Substrate-regulated morphology of graphene

TL;DR

This paper presents a theoretical framework to predict and control the morphology of graphene on substrates with periodic grooves, revealing how surface roughness and bonding energy influence conforming or flat states, with potential for device design.

Contribution

The study introduces a general energy minimization framework to analyze substrate-regulated graphene morphology, including snap-through instability phenomena.

Findings

Graphene morphology depends on substrate roughness and bonding energy.

Morphology can switch abruptly between conforming and flat states.

Framework enables precise control of graphene shape for device applications.

Abstract

We delineate a general theoretical framework to determine the substrate-regulated graphene morphology through energy minimization. We then apply such a framework to study the graphene morphology on a substrate with periodic surface grooves. Depending on the substrate surface roughness and the graphene-substrate interfacial bonding energy, the equilibrium morphology of graphene ranges from 1) closely conforming to the substrate, to 2) remaining flat on the substrate. Interestingly, in certain cases, the graphene morphology snaps between the above two limiting states. Our quantitative results envision a promising strategy to precisely control the graphene morphology over large areas. The rich features of the substrate-regulated graphene morphology (e.g., the snap-through instability) can potentially lead to new design concepts of functional graphene device components.