Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Polyhydrogenated Graphene - Excited State Dynamics in Photo- and
  Electroactive 2D-Domains   Understanding the phenomenon of intense photoluminescence in carbon materials
such as hydrogenated graphene, graphene nanoribbons, etc. is at the forefront
of investigations. In this study, six different types of hydrogenated graphene
(phG) produced from different starting materials, were fully characterized in
terms of structure and spectroscopy. Comprehensive photoluminescence lifetime
analyses of phGs were conducted by combining time-correlated single-photon
counting spectroscopy with steady-state fluorescence spectroscopy and
femtosecond transient absorption spectroscopy. The conclusion drawn from these
assays is that graphene islands with diameters in the range from 1.1 to 1.75 nm
reveal band gap photoluminescence between 450 and 800 nm. As a complement, phGs
were implemented in hybrids with water-soluble electron accepting
perylenediimides (PDI). By virtue of mutual {\pi}-stacking and charge transfer
interactions with graphene islands, PDIs assisted in stabilizing aqueous
dispersion of phG. Implicit in these ground state interactions is the formation
of 300 ps lived charge separated states once photoexcited.

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The categories of this paper are: gr-qc
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The categories of this paper are: hep-th
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The categories of this paper are: dg-ga
11
The categories of this paper are: hep-lat
10
The categories of this paper are: q-bio
30
The categories of this paper are: q-alg
16
The categories of this paper are: stat
29
The categories of this paper are: funct-an
9
The categories of this paper are: nlin
22
The categories of this paper are: chao-dyn
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The categories of this paper are: math-ph
27
The categories of this paper are: comp-gas
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The categories of this paper are: nucl-ex
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The categories of this paper are: patt-sol
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The categories of this paper are: cs
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The categories of this paper are: econ