Controlling the nanoscale rippling of graphene with SiO2 nanoparticles

TL;DR

This study demonstrates how SiO2 nanoparticles can be used to controllably induce and modify nanoscale rippling in graphene, enabling reversible and dynamic control of its local morphology for potential electronic applications.

Contribution

It introduces a novel method of using SiO2 nanoparticles to induce and reversibly control nanoscale rippling in graphene, advancing strain engineering techniques.

Findings

Graphene transferred onto SiO2 nanoparticles shows controllable corrugation.

Annealing modifies the graphene membrane's strain and morphology.

AFM tips can reversibly lift suspended graphene regions.

Abstract

The electronic properties of graphene can be significantly influenced by mechanical strain. One practical approach to induce strain in graphene is to transfer this atomically thin membrane onto pre-patterned substrates with specific corrugation. The possibility to use nanoparticles to impart extrinsic rippling to graphene has not been fully explored yet. Here we study the structure and elastic properties of graphene grown by chemical vapour deposition and transferred onto a continuous layer of SiO2 nanoparticles with diameters of around 25 nm, prepared on Si substrate by Langmuir-Blodgett technique. We show that the corrugation of the transferred graphene and thus the membrane strain can be modified by annealing at moderate temperatures. The membrane parts bridging the nanoparticles are suspended and can be reversibly lifted by the attractive forces between an atomic force microscope tip and graphene. This allows the dynamic control of the local morphology of graphene nanomembranes.