TY - JOUR
T1 - Picosecond energy transfer and multiexciton transfer outpaces Auger recombination in binary CdSe nanoplatelet solids
AU - Rowland, Clare E.
AU - Fedin, Igor
AU - Zhang, Hui
AU - Gray, Stephen K.
AU - Govorov, Alexander O.
AU - Talapin, Dmitri V.
AU - Schaller, Richard D.
N1 - Funding Information:
This work was performed, in part, at the Center for Nanoscale Materials, a US Department of Energy, Office of Science, Office of Basic Energy Sciences User Facility under Contract No. DE-AC02-06CH11357. C.E.R. acknowledges support by a National Science Foundation Graduate Research Fellowship under Grant No. DGE-0824162. D.V.T. acknowledges support by the NSF MRSEC Program under Award Number DMR 14-20709 and thanks the II-VI Foundation and Keck Foundation. H.Z. and A.O.G. acknowledge support by the US Army Research Office under grant number W911NF-12-1-0407 and the Volkswagen Foundation (Germany).
Publisher Copyright:
© 2015 Macmillan Publishers Limited. All rights reserved.
PY - 2015/5/1
Y1 - 2015/5/1
N2 - Fluorescence resonance energy transfer (FRET) enables photosynthetic light harvesting, wavelength downconversion in light-emitting diodes (LEDs), and optical biosensing schemes. The rate and efficiency of this donor to acceptor transfer of excitation between chromophores dictates the utility of FRET and can unlock new device operation motifs including quantum-funnel solar cells, non-contact chromophore pumping from a proximal LED, and markedly reduced gain thresholds. However, the fastest reported FRET time constants involving spherical quantum dots (0.12-1 ns; refs,) do not outpace biexciton Auger recombination (0.01-0.1 ns; ref.), which impedes multiexciton-driven applications including electrically pumped lasers and carrier-multiplication-enhanced photovoltaics. Few-monolayer-thick semiconductor nanoplatelets (NPLs) with tens-of-nanometre lateral dimensions exhibit intense optical transitions and hundreds-of-picosecond Auger recombination, but heretofore lack FRET characterizations. We examine binary CdSe NPL solids and show that interplate FRET (â 1/46-23 ps, presumably for co-facial arrangements) can occur 15-50 times faster than Auger recombination and demonstrate multiexcitonic FRET, making such materials ideal candidates for advanced technologies.
AB - Fluorescence resonance energy transfer (FRET) enables photosynthetic light harvesting, wavelength downconversion in light-emitting diodes (LEDs), and optical biosensing schemes. The rate and efficiency of this donor to acceptor transfer of excitation between chromophores dictates the utility of FRET and can unlock new device operation motifs including quantum-funnel solar cells, non-contact chromophore pumping from a proximal LED, and markedly reduced gain thresholds. However, the fastest reported FRET time constants involving spherical quantum dots (0.12-1 ns; refs,) do not outpace biexciton Auger recombination (0.01-0.1 ns; ref.), which impedes multiexciton-driven applications including electrically pumped lasers and carrier-multiplication-enhanced photovoltaics. Few-monolayer-thick semiconductor nanoplatelets (NPLs) with tens-of-nanometre lateral dimensions exhibit intense optical transitions and hundreds-of-picosecond Auger recombination, but heretofore lack FRET characterizations. We examine binary CdSe NPL solids and show that interplate FRET (â 1/46-23 ps, presumably for co-facial arrangements) can occur 15-50 times faster than Auger recombination and demonstrate multiexcitonic FRET, making such materials ideal candidates for advanced technologies.
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U2 - 10.1038/nmat4231
DO - 10.1038/nmat4231
M3 - Article
AN - SCOPUS:84939949618
VL - 14
SP - 484
EP - 489
JO - Nature Materials
JF - Nature Materials
SN - 1476-1122
IS - 5
ER -