Direct band-gap crossover in epitaxial monolayer boron nitride
| Autor: | Alex Summerfield, Guillaume Cassabois, Christopher J. Mellor, Peter H. Beton, Pierre Valvin, Bernard Gil, Laurence Eaves, Sergei V. Novikov, Tin S. Cheng, C. T. Foxon, Thomas Pelini, Christine Elias |
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| Přispěvatelé: | Laboratoire Charles Coulomb (L2C), Université de Montpellier (UM)-Centre National de la Recherche Scientifique (CNRS), Nanostructures quantiques propriétés optiques (NQPO), Université de Montpellier (UM)-Centre National de la Recherche Scientifique (CNRS)-Université de Montpellier (UM)-Centre National de la Recherche Scientifique (CNRS), Faculty of Engineering [Nottingham], University of Nottingham, UK (UON), School of Physics and Astronomy [Nottingham], ANR-11-LABX-0014,GANEX,Réseau national sur GaN(2011) |
| Jazyk: | angličtina |
| Rok vydání: | 2019 |
| Předmět: |
0301 basic medicine
Photoluminescence Materials science Science General Physics and Astronomy 02 engineering and technology Two-dimensional materials Epitaxy Article General Biochemistry Genetics and Molecular Biology law.invention 03 medical and health sciences chemistry.chemical_compound law Boron nitridewideband gap semiconductors2D Materialsvan der Waals epitaxy Monolayer Graphite lcsh:Science Nanoscale materials Multidisciplinary Graphene business.industry General Chemistry 021001 nanoscience & nanotechnology 030104 developmental biology chemistry Boron nitride [PHYS.COND.CM-GEN]Physics [physics]/Condensed Matter [cond-mat]/Other [cond-mat.other] [PHYS.COND.CM-MS]Physics [physics]/Condensed Matter [cond-mat]/Materials Science [cond-mat.mtrl-sci] Optoelectronics Direct and indirect band gaps lcsh:Q 0210 nano-technology business Molecular beam epitaxy |
| Zdroj: | Nature Communications, Vol 10, Iss 1, Pp 1-7 (2019) Nature Communications Nature Communications, Nature Publishing Group, 2019, 1 (1), pp.1. ⟨10.1038/s41467-019-10610-5⟩ |
| ISSN: | 2041-1723 |
| DOI: | 10.1038/s41467-019-10610-5⟩ |
| Popis: | Hexagonal boron nitride is a large band-gap insulating material which complements the electronic and optical properties of graphene and the transition metal dichalcogenides. However, the intrinsic optical properties of monolayer boron nitride remain largely unexplored. In particular, the theoretically expected crossover to a direct-gap in the limit of the single monolayer is presently not confirmed experimentally. Here, in contrast to the technique of exfoliating few-layer 2D hexagonal boron nitride, we exploit the scalable approach of high-temperature molecular beam epitaxy to grow high-quality monolayer boron nitride on graphite substrates. We combine deep-ultraviolet photoluminescence and reflectance spectroscopy with atomic force microscopy to reveal the presence of a direct gap of energy 6.1 eV in the single atomic layers, thus confirming a crossover to direct gap in the monolayer limit. Insulating hexagonal boron nitride (hBN) is theoretically expected to undergo a crossover to a direct bandgap in the monolayer limit. Here, the authors perform optical spectroscopy measurements on atomically thin epitaxial hBN providing indications of the presence of a direct gap of energy 6.1 eV in the single atomic layer. |
| Databáze: | OpenAIRE |
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