Reversible tunability of the near-infrared valence band plasmon resonance in Cu2- xSe nanocrystals

Dirk Dorfs, Thomas Härtling, Karol Miszta, Nadja C. Bigall, Mee Rahn Kim, Alessandro Genovese, Andrea Falqui, Mauro Povia, Liberato Manna*

*Corresponding author for this work

Research output: Contribution to journalArticlepeer-review

340 Scopus citations

Abstract

We demonstrate that colloidal Cu2 - xSe nanocrystals exhibit a well-defined infrared absorption band due to the excitation of positive charge carrier oscillations (i.e., a valence band plasmon mode), which can be tuned reversibly in width and position by varying the copper stoichiometry. The value of x could be incrementally varied from 0 (no plasmon absorption, then a broad peak at 1700 nm) to 0.4 (narrow plasmon band at 1100 nm) by oxidizing Cu 2Se nanocrystals (upon exposure either to oxygen or to a Ce(IV) complex), and it could be incrementally restored back to zero by the addition of a Cu(I) complex. The experimentally observed plasmonic behavior is in good agreement with calculations based on the electrostatic approximation.

Original languageEnglish (US)
Pages (from-to)11175-11180
Number of pages6
JournalJournal of the American Chemical Society
Volume133
Issue number29
DOIs
StatePublished - Jul 27 2011

ASJC Scopus subject areas

  • Catalysis
  • Chemistry(all)
  • Biochemistry
  • Colloid and Surface Chemistry

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