Epitaxial Graphene on 4H-SiC (0001) as a Versatile Platform for Materials Growth: Mini-Review

Abstract

Material growth on a dangling-bond-free interface such as graphene is a challenging technological task, which usually requires additional surface pre-treatment steps (functionalization, seed layer formation) to provide enough reactive sites. Being one of the most promising and adaptable graphene-family materials, epitaxial graphene on SiC, due to its internal features (substrate-induced n-doping, compressive strain, terrace-stepped morphology, bilayer graphene nano-inclusions), may provide pre-conditions for the enhanced binding affinity of environmental species, precursor molecules, and metal atoms on the topmost graphene layer. It makes it possible to use untreated pristine epitaxial graphene as a versatile platform for the deposition of metals and insulators. This mini-review encompasses relevant aspects of magnetron sputtering and electrodeposition of selected metals (Au, Ag, Pb, Hg, Cu, Li) and atomic layer deposition of insulating Al2O3 layers on epitaxial graphene on 4H-SiC, focusing on understanding growth mechanisms. Special deliberation has been given to the effect of the deposited materials on the epitaxial graphene quality. The generalization of the experimental and theoretical results presented here is hopefully an important step towards new electronic devices (chemiresistors, Schottky diodes, field-effect transistors) for environmental sensing, nano-plasmonics, and biomedical applications.

Computational Appraisal of Silver Nanocluster Evolution on Epitaxial Graphene: Implications for CO Sensing

“…Apart from the intrinsic properties of Ag nanoparticles, from the technological point of view, it is imperative to ensure the reproducible and uniform growth of Ag nanostructures on large-area substrates, which is a key prerequisite for boosting their utility for real applications. A novel tendency is the exploration of atomically flat substrates, such as monolayer epitaxial graphene (MEG) on SiC . Indeed, in contrast to roughened substrates, MEG can act as a defectless support for the highly controlled and ordered arrangement of Ag nanoislands, thereby preventing possible spatial inhomogeneity effects induced by the undesired interaction between Ag species and structural imperfections.…”

“…A novel tendency is the exploration of atomically flat substrates, such as monolayer epitaxial graphene (MEG) on SiC. 18 Indeed, in contrast to roughened substrates, MEG can act as a defectless support for the highly controlled and ordered arrangement of Ag nanoislands, thereby preventing possible spatial inhomogeneity effects induced by the undesired interaction between Ag species and structural imperfections. Concomitantly, it is challenging to perform growth on dangling bond-free surfaces such as MEG in order to gain new properties and benefit from them in both fundamental and applicational aspects.…”

Investigation of the Morphology and Electrical Properties of Graphene Used in the Development of Biosensors for Detection of Influenza Viruses

“…However, this technique also cannot fully avoid the issues of inhomogeneity of graphene quality. Apart from perfect monolayer graphene, there are typical inclusions of bilayer and multilayer graphene [ 18 , 19 ]. Typically, the grown samples are composed of 85% monolayer graphene and 15% bilayer graphene that is represented by small bilayer patches (inclusions) of various sizes.…”

“…Typically, the grown samples are composed of 85% monolayer graphene and 15% bilayer graphene that is represented by small bilayer patches (inclusions) of various sizes. It is reasonable to assume that the unsaturated edges of these inclusions may create extra nucleation ions [ 18 ]. More information about the intrinsic properties of the epitaxial graphene on SiC can be extracted from the analysis of the Raman mapping data [ 19 ].…”

Silver nanoparticle array on weakly interacting epitaxial graphene substrate as catalyst for hydrogen evolution reaction under neutral conditions

“…As one of the most prominent graphene family representatives, epitaxial graphene has all key attributes of free-standing graphene (FSG) but exhibits higher reactivity compared to FSG, which originates from substrate-induced n-doping and compressive strain of the SiC-supported graphene layer. 26 The enhanced binding affinity of epitaxial graphene to external adsorbates may trigger the formation of a larger number of stable early stage nuclei (compared to FSG) during metal deposition, making the growth process controllable (tunable morphology of NPs over a wider range) from the technological point of view.…”