Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Large-Area Aiming Synthesis of WSe2 Monolayers   The monolayer transition metal dichalcogenides have recently attracted much
attention owing to their potential in valleytronics, flexible and low-power
electronics and optoelectronic devices. Recent reports have demonstrated the
growth of large-size 2-dimensional MoS2 layers by the sulfurization of
molybdenum oxides. However, the growth of transition metal selenide monolayer
has still been a challenge. Here we report that the introduction of hydrogen in
the reaction chamber helps to activate the selenization of WO3, where
large-size WSe2 monolayer flakes or thin films can be successfully grown.

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The categories of this paper are: patt-sol
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The categories of this paper are: nucl-ex
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The categories of this paper are: gr-qc
0
The categories of this paper are: hep-ph
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The categories of this paper are: hep-lat
28
The categories of this paper are: alg-geom
31
The categories of this paper are: ao-sci
12
The categories of this paper are: nucl-th
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The categories of this paper are: bayes-an
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The categories of this paper are: econ
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The categories of this paper are: atom-ph
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The categories of this paper are: eess
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The categories of this paper are: chem-ph
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The categories of this paper are: hep-ex
27
The categories of this paper are: comp-gas
3
The categories of this paper are: physics