Identifying suitable substrates for high-quality graphene-based heterostructures. (8th February 2017)

• Record Type: Journal Article
• Authors: Banszerus, L; Janssen, H; Otto, M; Epping, A; Taniguchi, T; Watanabe, K; Beschoten, B; Neumaier, D; Stampfer, C
• Is Part Of: 2D materials. Volume 4:Number 2(2017)
• Publication Date: 2017-02-08
• Subjects: graphene -- substrate -- Raman spectroscopy -- high quality; Graphene -- Periodicals; Materials science -- Periodicals; Nanostructured materials -- Periodicals; 620.115
• DOI: 10.1088/2053-1583/aa5b0f
• Languages: English
• ISSNs: 2053-1583

Abstract

Abstract: We report on a scanning confocal Raman spectroscopy study investigating the strain-uniformity and the overall strain and doping of high-quality chemical vapour deposited (CVD) graphene-based heterostuctures on a large number of different substrate materials, including hexagonal boron nitride (hBN), transition metal dichalcogenides, silicon, different oxides and nitrides, as well as polymers. By applying a hBN-assisted, contamination free, dry transfer process for CVD graphene, high-quality heterostructures with low doping densities and low strain variations are assembled. The Raman spectra of these pristine heterostructures are sensitive to substrate-induced doping and strain variations and are thus used to probe the suitability of the substrate material for potential high-quality graphene devices. We find that the flatness of the substrate material is a key figure for gaining, or preserving high-quality graphene.