Optimising the visibility of graphene and graphene oxide on gold with multilayer heterostructures

• Published in: Nanotechnology Vol. 29; no. 27; p. 275205
• Main Authors: Velický, Mat j, Hendren, William R, Donnelly, Gavin E, Katzen, Joel M, Bowman, Robert M, Huang, Fumin
• Format: Journal Article
• Language: English
• Published: England IOP Publishing 06.07.2018
• Subjects: Au substrate; graphene; graphene oxide; optical contrast; visibility
• ISSN: 0957-4484; 1361-6528
• DOI: 10.1088/1361-6528/aabec1

Metals have been increasingly used as substrates in devices based on two-dimensional (2D) materials. However, the high reflectivity of bulk metals results in low optical contrast (<3%) and therefore poor visibility of transparent mono- and few-layer 2D materials on these surfaces. Here we demonstrate that by engineering the complex reflectivity of a purpose-designed multilayer heterostructure composed of thin Au films (2-8 nm) on SiO2/Si substrate, the optical contrast of graphene and graphene oxide (GO) can be significantly enhanced in comparison to bulk Au, up to about 3 and 5 times, respectively. In particular, we achieved ∼17% optical contrast for monolayer GO, which is even 2 times higher than that on bare SiO2/Si substrate. The experimental results are in good agreement with theoretical simulations. This concept is demonstrated for Au, but the methodology is applicable to other metals and can be adopted to design a variety of high-contrast metallic substrates. This will facilitate research and applications of 2D materials in areas such as plasmonics, photonics, catalysis and sensors.