Origin of low quantum efficiency of photoluminescence of InP/ZnS nanocrystals

Roza Shirazi, Andras Kovacs, Dennis Dan Corell, Claudia Gritti, Anders Thorseth, Carsten Dam-Hansen, Paul Michael Petersen, Beata Kardynal

Research output: Contribution to journalJournal articleResearchpeer-review

Abstract

In this paper, we study the origin of a strong wavelength dependence of the quantum efficiency of InP/ZnS nanocrystals. We find that while the average size of the nanocrystals increased by 50%, resulting in longer emission wavelength, the quantum efficiency drops more than one order of magnitude compared to the quantum efficiency of the small nanocrystals. By correlating this result with the time-resolved photoluminescence we find that the reduced photoluminescence efficiency is caused by a fast growing fraction of non-emissive nanocrystals while the quality of the nanocrystals that emit light is similar for all samples. Transmission electron microscopy reveals the polycrystalline nature of many of the large nanocrystals, pointing to the grain boundaries as one possible site for the photoluminescence quenching defects.
Original languageEnglish
JournalJournal of Luminescence
Volume145
Pages (from-to)936-939
ISSN0022-2313
DOIs
Publication statusPublished - 2013

Keywords

  • InP/ZnS
  • Nanocrystals
  • Efficiency
  • Colloidal
  • Photoluminescence

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