Thermal and transport properties of pristine single-layer hexagonal boron nitride : a first principles investigation
Illera, Sergio (Institut Català de Nanociència i Nanotecnologia)
Pruneda, Miguel (Institut Català de Nanociència i Nanotecnologia)
Colombo, Luciano (Institut Català de Nanociència i Nanotecnologia)
Ordejon, Pablo (Institut Català de Nanociència i Nanotecnologia)

Date:	2017
Abstract:	Molecular dynamics is used in combination with density functional theory to determine the thermal transport properties of the single-layer hexagonal boron nitride (SL h-BN) from ab initio calculations. Within this approach, the possible anisotropy in the thermal conductivity of SL h-BN was studied. For samples with finite length (of the order of 20 nm), we find a significant dependence of the conductivity on the transport direction. We make a direct comparison of the results obtained for two-dimensional (2D) layers and for nanoribbons with similar size, and show that, as a consequence of edge scattering, the ribbon geometry induces a significant decrease in the conductivity, and produces a strong change in the anisotropy. For the zigzag and armchair transport directions, the dependence of the thermal conductivity on the system length was also obtained, as well as its value in the 2D bulk limit case. A very small anisotropy was found for the limit of long samples, in contrast with the finite length ones. This is explained analyzing the dependence of the average square group velocities on the transport direction and the phonon frequency.
Grants:	European Commission 676598 Ministerio de Economía y Competitividad FIS2015-64886-C5-3-P Ministerio de Economía y Competitividad SEV-2013-0295 Agència de Gestió d'Ajuts Universitaris i de Recerca 2014/SGR-301
Rights:	Tots els drets reservats.
Language:	Anglès
Document:	Article ; recerca ; Versió acceptada per publicar
Subject:	DFT, Molecular Dynamics ; Anisotropy thermal conductivity ; Single-layer ; Hexagonal boron nitride
Published in:	Physical review materials, Vol. 1, issue 4 (Sep. 2017) , art. 44006, ISSN 2475-9953

DOI: 10.1103/PhysRevMaterials.1.044006

Preprint 20 p, 1.8 MB

Postprint 20 p, 2.7 MB

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Research literature > UAB research groups literature > Research Centres and Groups (research output) > Experimental sciences > Catalan Institute of Nanoscience and Nanotechnology (ICN2)
Articles > Research articles
Articles > Published articles