On the origin of photoluminescence in silicon nanocrystals: Pressure-dependent structural and optical studies

Daniel C. Hannah, Jihua Yang, Paul Podsiadlo, Maria K.Y. Chan, Arnaud Demortière, David J. Gosztola, Vitali B. Prakapenka, George C. Schatz, Uwe Kortshagen, Richard D. Schaller

Research output: Contribution to journalArticle

93 Citations (Scopus)

Abstract

A lack of consensus persists regarding the origin of photoluminescence in silicon nanocrystals. Here we report pressure-dependences of X-ray diffraction and photoluminescence from alkane-terminated colloidal particles. We determine the diamond-phase bulk modulus, observe multiple phase transitions, and importantly find a systematic photoluminescence red shift that matches the X conduction-to-Λ valence transition of bulk crystalline silicon. These results, reinforced by calculations, suggest that the efficient photoluminescence, frequently attributed to defects, arises instead from core-states that remain highly indirect despite quantum confinement.

Original languageEnglish
Pages (from-to)4200-4205
Number of pages6
JournalNano letters
Volume12
Issue number8
DOIs
Publication statusPublished - Aug 8 2012

Keywords

  • Quantum dot
  • X-ray diffraction
  • diamond anvil cell
  • nanocrystal
  • photoluminescence
  • pressure
  • silicon

ASJC Scopus subject areas

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

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  • Cite this

    Hannah, D. C., Yang, J., Podsiadlo, P., Chan, M. K. Y., Demortière, A., Gosztola, D. J., Prakapenka, V. B., Schatz, G. C., Kortshagen, U., & Schaller, R. D. (2012). On the origin of photoluminescence in silicon nanocrystals: Pressure-dependent structural and optical studies. Nano letters, 12(8), 4200-4205. https://doi.org/10.1021/nl301787g