Oxidising and carburising catalyst conditioning for the controlled growth and transfer of large crystal monolayer hexagonal boron nitride. (20th January 2020)

• Record Type: Journal Article
• Authors: Babenko, Vitaliy; Fan, Ye; Veigang-Radulescu, Vlad-Petru; Brennan, Barry; Pollard, Andrew J; Burton, Oliver; Alexander-Webber, Jack A; Weatherup, Robert S; Canto, Barbara; Otto, Martin; Neumaier, Daniel; Hofmann, Stephan
• Is Part Of: 2D materials. Volume 7:Number 2(2020)
• Publication Date: 2020-01-20
• Subjects: hexagonal boron nitride -- large crystal -- monolayer -- chemical vapor deposition -- 2D materials -- transfer -- encapsulation; Graphene -- Periodicals; Materials science -- Periodicals; Nanostructured materials -- Periodicals; 620.115
• DOI: 10.1088/2053-1583/ab6269
• Languages: English
• ISSNs: 2053-1583

Abstract

Abstract: Hexagonal boron nitride (h-BN) is well-established as a requisite support, encapsulant and barrier for 2D material technologies, but also recently as an active material for applications ranging from hyperbolic metasurfaces to room temperature single-photon sources. Cost-effective, scalable and high quality growth techniques for h-BN layers are critically required. We utilise widely-available iron foils for the catalytic chemical vapour deposition (CVD) of h-BN and report on the significant role of bulk dissolved species in h-BN CVD, and specifically, the balance between dissolved oxygen and carbon. A simple pre-growth conditioning step of the iron foils enables us to tailor an error-tolerant scalable CVD process to give exceptionally large h-BN monolayer domains. We also develop a facile method for the improved transfer of as-grown h-BN away from the iron surface by means of the controlled humidity oxidation and subsequent rapid etching of a thin interfacial iron oxide; thus, avoiding the impurities from the bulk of the foil. We demonstrate wafer-scale (2″) production and utilise this h-BN as a protective layer for graphene towards integrated (opto-)electronic device fabrication.