Dynamic strain in gold nanoparticle supported graphene induced by focused laser irradiation

TL;DR

This study investigates how focused laser irradiation induces reversible dynamic strain in graphene supported on gold nanoparticles, revealing differences from graphene on SiO2 and potential for high-temperature sensor applications.

Contribution

It demonstrates that laser-induced strain in graphene on gold nanoparticles is reversible and does not cause permanent damage, unlike in graphene on SiO2, advancing understanding of graphene-plasmonic nanostructure interactions.

Findings

Laser irradiation causes reversible hydrostatic strain in graphene on gold NPs.

Higher laser intensity increases doping and defects in graphene on SiO2.

Graphene on gold NPs remains stable under repeated laser exposure.

Abstract

Graphene on noble-metal nanostructures constitutes an attractive nanocomposite with possible applications in sensors or energy conversion. In this work we study the properties of hybrid graphene/gold nanoparticle structures by Raman spectroscopy and Scanning Probe Methods. The nanoparticles (NPs) were prepared by local annealing of gold thin films using focused laser beam. The method resulted in a patterned surface, with NPs formed at arbitrarily chosen microscale areas. Graphene grown by chemical vapour deposition was transferred onto the prepared, closely spaced gold NPs. While we found that successive higher intensity (6 mW) laser irradiation increased gradually the doping and the defect concentration in SiO2 supported graphene, the same irradiation procedure did not induce such irreversible effects in the graphene supported by gold NPs. Moreover, the laser irradiation induced dynamic hydrostatic strain in the graphene on Au NPs, which turned out to be completely reversible. These results can have implications in the development of graphene/plasmonic nanoparticle based high temperature sensors operating in dynamic regimes.