Semiconductor Nanoplatelet Excimers

Benjamin T. Diroll, Wooje Cho, Igor Coropceanu, Samantha M. Harvey, Alexandra Brumberg, Nicholas Holtgrewe, Scott A. Crooker, Michael R. Wasielewski, Vitali B. Prakapenka, Dmitri V. Talapin, Richard D. Schaller*

*Corresponding author for this work

Research output: Contribution to journalArticlepeer-review

40 Scopus citations


Excimers, a portmanteau of "excited dimer", are transient species that are formed from the electronic interaction of a fluorophore in the excited state with a neighbor in the ground state, which have found extensive use as laser gain media. Although common in molecular fluorophores, this work presents evidence for the formation of excimers in a new class of materials: atomically precise two-dimensional semiconductor nanoplatelets. Colloidal nanoplatelets of CdSe display two-color photoluminescence resolved at low temperatures with one band attributed to band-edge fluorescence and a second, red band attributed to excimer fluorescence. Previously reasonable explanations for two-color fluorescence, such as charging, are shown to be inconsistent with additional evidence. As with excimers in other materials systems, excimer emission is increased by increasing nanoplatelet concentration and the degree of cofacial stacking. Consistent with their promise as low-threshold gain media, amplified spontaneous emission emerges from the excimer emission line.

Original languageEnglish (US)
Pages (from-to)6948-6953
Number of pages6
JournalNano letters
Issue number11
StatePublished - Nov 14 2018


  • Excimer
  • amplified spontaneous emission
  • nanoplatelet
  • photoluminescence
  • two-dimensional

ASJC Scopus subject areas

  • Bioengineering
  • Chemistry(all)
  • Materials Science(all)
  • Condensed Matter Physics
  • Mechanical Engineering


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