Spectrally Resolved Ultrafast Exciton Transfer in Mixed Perovskite Quantum Wells

Research output: Contribution to journalArticle

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Abstract

Solution-processed perovskite quantum wells have been used to fabricate increasingly efficient and stable optoelectronic devices. Little is known about the dynamics of photogenerated excitons in perovskite quantum wells within the first few hundred femtoseconds-a crucial time scale on which energy and charge transfer processes may compete. Here we use ultrafast transient absorption and two-dimensional electronic spectroscopy to clarify the movement of excitons and charges in reduced-dimensional perovskite solids. We report excitonic funneling from strongly to weakly confined perovskite quantum wells within 150 fs, facilitated by strong spectral overlap and orientational alignment among neighboring wells. This energy transfer happens on time scales orders of magnitude faster than charge transfer, which we find to occur instead over 10s to 100s of picoseconds. Simulations of both Förster-type interwell exciton transfer and free carrier charge transfer are in agreement with these experimental findings, with theoretical exciton transfer calculated to occur in 100s of femtoseconds. ©

Original languageEnglish (US)
Pages (from-to)419-426
Number of pages8
JournalJournal of Physical Chemistry Letters
Volume10
Issue number3
DOIs
StatePublished - Feb 7 2019

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Excitons
Perovskite
Semiconductor quantum wells
excitons
quantum wells
Charge transfer
charge transfer
Energy transfer
energy transfer
optoelectronic devices
Optoelectronic devices
alignment
Spectroscopy
LDS 751
perovskite
electronics
spectroscopy
simulation

All Science Journal Classification (ASJC) codes

  • Materials Science(all)
  • Physical and Theoretical Chemistry

Cite this

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Spectrally Resolved Ultrafast Exciton Transfer in Mixed Perovskite Quantum Wells. / Scholes, Gregory D.

In: Journal of Physical Chemistry Letters, Vol. 10, No. 3, 07.02.2019, p. 419-426.

Research output: Contribution to journalArticle

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AU - Scholes, Gregory D.

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