Size and Dopant Dependent Single Particle Fluorescence Properties of Graphene Quantum Dots

Somes K. Das, Chi Man Luk, William E. Martin, Libin Tang, Doo Young Kim, Shu Ping Lau, Christopher I. Richards

Research output: Journal article publicationJournal articleAcademic researchpeer-review

34 Citations (Scopus)


The emissive properties of both doped and nondoped graphene quantum dots (GQDs) with sizes ranging from 3 to 11 nm were analyzed at the single particle level. Both doped and nondoped GQDs are a composite of particles exhibiting green, red, or NIR fluorescence on excitation at 488, 561, and 640 nm, respectively. Nitrogen-doped GQDs (N-GQDs) with diameters ranging from 3.4 to 5.2 nm show a larger proportion of particles with NIR emission as compared to nondoped particles. Doping of GQDs also resulted in changes in the photostability and the fluorescence intermittency seen in single GQD particles. While milliseconds to seconds time scale blinking was regularly observed for red-emitting nondoped GQDs, nitrogen doping significantly reduced blinking. Both doped and nondoped particles also exhibit moderate size dependent photophysical properties.
Original languageEnglish
Pages (from-to)17988-17994
Number of pages7
JournalJournal of Physical Chemistry C
Issue number31
Publication statusPublished - 6 Aug 2015

ASJC Scopus subject areas

  • Electronic, Optical and Magnetic Materials
  • Energy(all)
  • Surfaces, Coatings and Films
  • Physical and Theoretical Chemistry

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