Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Wavelength-Controlled Photocurrent Polarity Switching in BP-MoS$_2$
  Heterostructure   Layered two-dimensional van der Waals (vdW) semiconductors and their
heterostructures have been shown to exhibit positive photoconductance (PPC) in
many studies. A few recent reports have demonstrated negative photoconductance
(NPC) as well that can enable broadband photodetection besides multi-level
optoelectronic logic and memory. Controllable and reversible switching between
PPC and NPC is a key requirement for these applications. This report
demonstrates visible-to-near infrared wavelength-driven NPC and PPC, along with
reversible switching between the two, in an air stable, high mobility,
broadband black phosphorus (BP) field effect transistor (FET) covered with a
few layer MoS$_2$ flake. The crossover switching wavelength can be tuned by
varying the MoS$_2$ bandgap through its flake thickness and the NPC and PPC
photoresponsivities can be modulated using electrostatic gating as well as
laser power. Recombination-driven NPC and PPC allows for reversible switching
at reasonable time scales of a few seconds. Further, gate voltage-dependent
negative persistent photoconductance enables synaptic behavior that is
well-suited for optosynaptic applications.

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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: econ
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The categories of this paper are: supr-con
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The categories of this paper are: quant-ph
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The categories of this paper are: nucl-th
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The categories of this paper are: gr-qc
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The categories of this paper are: bayes-an
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The categories of this paper are: dg-ga
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The categories of this paper are: funct-an
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The categories of this paper are: cmp-lg
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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: q-alg
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The categories of this paper are: nlin
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The categories of this paper are: stat