%0 Journal Article
%T Direct band-gap crossover in epitaxial monolayer boron nitride
%+ Laboratoire Charles Coulomb (L2C)
%+ Nanostructures quantiques propriétés optiques (NQPO)
%+ Faculty of Engineering [Nottingham]
%+ School of Physics and Astronomy [Nottingham]
%A Elias, Christine
%A Valvin, Pierre
%A Pelini, Thomas
%A Summerfeld, Alex
%A Mellor, Chris
%A Cheng, T.S.
%A Eaves, L.
%A Foxon, C.T.
%A Beton, Peter
%A Novikov, Sergei
%A Gil, Bernard
%A Cassabois, Guillaume
%< avec comité de lecture
%Z L2C:19-098
%@ 2041-1723
%J Nature Communications
%I Nature Publishing Group
%V 1
%N 1
%P 1
%8 2019-06-14
%D 2019
%R 10.1038/s41467-019-10610-5
%K Boron nitridewideband gap semiconductors2D Materialsvan der Waals epitaxy
%Z Physics [physics]/Condensed Matter [cond-mat]/Other [cond-mat.other]
%Z Physics [physics]/Condensed Matter [cond-mat]/Materials Science [cond-mat.mtrl-sci]Journal articles
%X 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 unex- plored. 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 tech- nique 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 6.1eV in the single atomic layers, thus confirming a crossover to direct gap in the monolayer limit.
%G English
%2 https://hal.science/hal-02156532/document
%2 https://hal.science/hal-02156532/file/s41467-019-10610-5.pdf
%L hal-02156532
%U https://hal.science/hal-02156532
%~ CNRS
%~ L2C
%~ MIPS
%~ UNIV-MONTPELLIER
%~ ANR
%~ UM-2015-2021