Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Direct Patterning of Colloidal Quantum-Dot Thin Films for Enhanced and
  Spectrally Selective Out-Coupling of Emission   We report on a template-stripping method for the direct surface patterning of
colloidal quantum-dot thin films to produce highly luminescent structures with
feature sizes less than 100 nm. Through the careful design of high quality
bulls-eye gratings we can produce strong directional beaming (10{\deg}
divergence) with up to six-fold out-coupling enhancement of spontaneous
emission in the surface-normal direction. A transition to narrow single-mode
lasing is observed in these same structures at thresholds as low as 120
{\mu}J/cm2. Furthermore, making use of the size-tunable character of colloidal
quantum dots, we demonstrate spectrally selective out-coupling of light from
mixed quantum-dot films. Our results provide a straightforward route towards
significantly improved optical properties of colloidal quantum-dot assemblies.

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The categories of this paper are: bayes-an
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The categories of this paper are: hep-ex
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The categories of this paper are: astro-ph
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The categories of this paper are: nucl-ex
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The categories of this paper are: alg-geom
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The categories of this paper are: nlin
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The categories of this paper are: q-fin
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The categories of this paper are: supr-con
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The categories of this paper are: nucl-th
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The categories of this paper are: eess
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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: math
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The categories of this paper are: dg-ga
0
The categories of this paper are: hep-ph
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The categories of this paper are: ao-sci