Spectrally Resolved Ultrafast Exciton Transfer in Mixed Perovskite Quantum Wells

Andrew H. Proppe, Madeline H. Elkins, Oleksandr Voznyy, Ryan D. Pensack, Felipe Zapata, Lucas V. Besteiro, Li Na Quan, Rafael Quintero-Bermudez, Petar Todorovic, Shana O. Kelley, Alexander O. Govorov, Stephen K. Gray, Ivan Infante, Edward H. Sargent, Gregory D. Scholes

Research output: Contribution to journalArticlepeer-review

32 Scopus citations

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

All Science Journal Classification (ASJC) codes

  • Materials Science(all)
  • Physical and Theoretical Chemistry

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