Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Band gap measurements of monolayer h-BN and insights into carbon-related
  point defects   Being a flexible wide band gap semiconductor, hexagonal boron nitride (h-BN)
has great potential for technological applications like efficient deep
ultraviolet light sources, building block for two-dimensional heterostructures
and room temperature single photon emitters in the ultraviolet and visible
spectral range. To enable such applications, it is mandatory to reach a better
understanding of the electronic and optical properties of h-BN and the impact
of various structural defects. Despite the large efforts in the last years,
aspects such as the electronic band gap value, the exciton binding energy and
the effect of point defects remained elusive, particularly when considering a
single monolayer. Here, we directly measured the density of states of a single
monolayer of h-BN epitaxially grown on highly oriented pyrolytic graphite, by
performing low temperature scanning tunneling microscopy (STM) and spectroscopy
(STS). The observed h-BN electronic band gap on defect-free regions is
$(6.8\pm0.2)$ eV. Using optical spectroscopy to obtain the h-BN optical band
gap, the exciton binding energy is determined as being of $(0.7\pm0.2)$ eV. In
addition, the locally excited cathodoluminescence and photoluminescence show
complex spectra that are typically associated to intragap states related to
carbon defects. Moreover, in some regions of the monolayer h-BN we identify,
using STM, point defects which have intragap electronic levels around 2.0 eV
below the Fermi level.

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The categories of this paper are: gr-qc
33
The categories of this paper are: plasm-ph
37
The categories of this paper are: supr-con
20
The categories of this paper are: acc-phys
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The categories of this paper are: math
11
The categories of this paper are: hep-lat
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The categories of this paper are: q-fin
28
The categories of this paper are: alg-geom
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The categories of this paper are: hep-ex
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The categories of this paper are: adap-org
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The categories of this paper are: comp-gas
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The categories of this paper are: hep-th
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The categories of this paper are: mtrl-th
31
The categories of this paper are: ao-sci
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The categories of this paper are: dg-ga
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The categories of this paper are: solv-int