Introducing Overlapping Grain Boundaries in Chemical Vapor Deposited Hexagonal Boron Nitride Monolayer Films

Author(s)
Bernhard C, Bayer, Sabina Caneva, Timothy J. Pennycook, Jani Kotakoski, Clemens Mangler, Stephan Hofmann, Jannik C. Meyer
Abstract

We demonstrate the growth of overlapping grain boundaries in continuous, polycrystalline hexagonal boron nitride (h-BN) monolayer films via scalable catalytic chemical vapor deposition. Unlike the commonly reported atomically stitched grain boundaries, these overlapping grain boundaries do not consist of defect lines within the monolayer films but are composed of self-sealing bilayer regions of limited width. We characterize this overlapping hBN grain boundary structure in detail by complementary (scanning) transmission electron microscopy techniques and propose a catalytic growth mechanism linked to the subsurface/bulk of the process catalyst and its boron and nitrogen solubilities. Our data suggest that the overlapping grain boundaries are comparatively resilient against deleterious pinhole formation associated with grain boundary defect lines and thus may reduce detrimental breakdown effects when polycrystalline h-BN monolayer films are used as ultrathin dielectrics, barrier layers, or separation membranes.

Organisation(s)
Physics of Nanostructured Materials
Journal
ACS Nano
Volume
11
Pages
4521-4527
No. of pages
7
ISSN
1936-0851
DOI
https://doi.org/10.1021/acsnano.6b08315
Publication date
05-2017
Publication status
Published
Peer reviewed
Yes
Austrian Fields of Science 2012
103018 Materials physics, 103042 Electron microscopy
Keywords
hexagonal boron nitride, grain boundary, chemical vapor deposition, aberration-corrected scanning transmission electron microscopy, 2D materials, MONO LAYER, 2-DIMENSIONAL MATERIALS, ELECTRONIC-PROPERTIES, STACKING ORDER, GROWTH, GRAPHENE, DEFECTS, DOMAINS, NUCLEATION, COPPER
Portal url
https://ucris.univie.ac.at/portal/en/publications/introducing-overlapping-grain-boundaries-in-chemical-vapor-deposited-hexagonal-boron-nitride-monolayer-films(c22ff788-1701-45b3-86f8-915a1a16c5dd).html