Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Black Phosphorus-Monolayer MoS2 van der Waals Heterojunction P-N Diode   Phosphorene, an elemental 2D material, which is the monolayer of black
phosphorus, has been mechanically exfoliated recently. In its bulk form, black
phosphorus shows high carrier mobility (~10000 cm2/Vs) and a ~0.3 eV direct
bandgap. Well-behaved p-type field-effect transistors with mobilities of up to
1000 cm2/Vs, as well as phototransistors, have been demonstrated on few-layer
black phosphorus, showing its promise for electronics and optoelectronics
applications due to its high hole mobility and thickness-dependence direct
bandgap. However, p-n junctions, the basic building blocks of modern electronic
and optoelectronic devices, have not yet been realized based on black
phosphorus. In this paper, we demonstrate a gate tunable p-n diode based on a
p-type black phosphorus/n-type monolayer MoS2 van der Waals p-n heterojunction.
Upon illumination, these ultra-thin p-n diodes show a maximum photodetection
responsivity of 418 mA/W at the wavelength of 633 nm, and photovoltaic energy
conversion with an external quantum efficiency of 0.3%. These p-n diodes show
promise for broadband photodetection and solar energy harvesting.

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The categories of this paper are: hep-ex
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The categories of this paper are: eess
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The categories of this paper are: math-ph
20
The categories of this paper are: acc-phys
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The categories of this paper are: cs
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The categories of this paper are: nucl-th
37
The categories of this paper are: supr-con
32
The categories of this paper are: atom-ph
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The categories of this paper are: plasm-ph
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The categories of this paper are: q-bio
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The categories of this paper are: mtrl-th
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The categories of this paper are: econ
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The categories of this paper are: q-alg
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The categories of this paper are: physics
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The categories of this paper are: patt-sol
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The categories of this paper are: funct-an