title: Catalyst Interface Engineering for Improved 2D Film Lift-Off and Transfer.
abstract: The mechanisms by which chemical vapor deposited (CVD) graphene and hexagonal boron nitride (h-BN) films can be released from a growth catalyst, such as widely used copper (Cu) foil, are systematically explored as a basis for an improved lift-off transfer. We show how intercalation processes allow the local Cu oxidation at the interface followed by selective oxide dissolution, which gently releases the 2D material (2DM) film. Interfacial composition change and selective dissolution can thereby be achieved in a single step or split into two individual process steps. We demonstrate that this method is not only highly versatile but also yields graphene and h-BN films of high quality regarding surface contamination, layer coherence, defects, and electronic properties, without requiring additional post-transfer annealing. We highlight how such transfers rely on targeted corrosion at the catalyst interface and discuss this in context of the wider CVD growth and 2DM transfer literature, thereby fostering an improved general understanding of widely used transfer processes, which is essential to numerous other applications.
authors.affiliation: Department of Engineering, University of Cambridge , Cambridge CB3 0FA, United Kingdom.
authors.forename: Ruizhi
authors.initials: R
authors.lastname: Wang
authors.affiliation: Center for Nanostructured Graphene (CNG), DTU Nanotech, Technical University of Denmark , DK-2800, Kongens Lyngby, Denmark.
authors.forename: Patrick R
authors.initials: PR
authors.lastname: Whelan
authors.affiliation: Department of Engineering, University of Cambridge , Cambridge CB3 0FA, United Kingdom.
authors.forename: Philipp
authors.initials: P
authors.lastname: Braeuninger-Weimer
authors.affiliation: Department of Engineering, University of Cambridge , Cambridge CB3 0FA, United Kingdom.
authors.forename: Stefan
authors.initials: S
authors.lastname: Tappertzhofen
authors.affiliation: Department of Engineering, University of Cambridge , Cambridge CB3 0FA, United Kingdom.
authors.forename: Jack A
authors.initials: JA
authors.lastname: Alexander-Webber
authors.affiliation: Department of Engineering, University of Cambridge , Cambridge CB3 0FA, United Kingdom.|Cambridge Graphene Centre, University of Cambridge , 9 JJ Thomson Avenue, Cambridge CB3 0FA, United Kingdom.
authors.forename: Zenas A
authors.initials: ZA
authors.lastname: Van Veldhoven
authors.affiliation: Department of Mechanical Engineering, Massachusetts Institute of Technology , Cambridge, Massachusetts 02139, United States.
authors.forename: Piran R
authors.initials: PR
authors.lastname: Kidambi
authors.affiliation: Center for Nanostructured Graphene (CNG), DTU Nanotech, Technical University of Denmark , DK-2800, Kongens Lyngby, Denmark.
authors.forename: Bjarke S
authors.initials: BS
authors.lastname: Jessen
authors.affiliation: Center for Nanostructured Graphene (CNG), DTU Nanotech, Technical University of Denmark , DK-2800, Kongens Lyngby, Denmark.
authors.forename: Timothy
authors.initials: T
authors.lastname: Booth
authors.affiliation: Center for Nanostructured Graphene (CNG), DTU Nanotech, Technical University of Denmark , DK-2800, Kongens Lyngby, Denmark.
authors.forename: Peter
authors.initials: P
authors.lastname: Bøggild
authors.affiliation: Department of Engineering, University of Cambridge , Cambridge CB3 0FA, United Kingdom.
authors.forename: Stephan
authors.initials: S
authors.lastname: Hofmann
keywords: 2D materials; CVD; catalyst; graphene; h-BN; transfer