Characteristic Excitation Wavelength Dependence of Fluorescence Emissions in Carbon "quantum" Dots

Fabrizio Messina, Alice Sciortino, Gregory E. Lecroy, Ya-Ping Sun, Ping Wang, K. A. Shiral Fernando, Christopher E. Bunker, Alice Sciortino

Risultato della ricerca: Article

27 Citazioni (Scopus)

Abstract

Carbon "quantum" dots (CDots), generally defined as small carbon nanoparticles with various surface passivation schemes, have emerged to represent a rapidly advancing and expanding research field. CDots are known for their bright and colorful fluorescence emissions, where the colorfulness is associated with the emissions being excitation wavelength dependent. In this work, CDots with 2,2′-(ethylenedioxy)bis(ethylamine) (EDA) for surface functionalization were studied systematically by using steady-state and time-resolved fluorescence methods. The observed fluorescence quantum yields are strongly excitation wavelength dependent, and the dependence apparently tracks closely the observed absorption profile of the EDA-CDots, whereas the excitation wavelength dependence of observed fluorescence lifetimes is much weaker, obviously decoupled from the quantum yields. Mechanistically, the presence of two sequential processes immediately following the photoexcitation of CDots leading to fluorescence is used to rationalize these effects, and the experimental results seem better explained by attributing one of the two processes to be primarily responsible for the characteristic excitation wavelength dependence. Significant implications of the mechanistic probing to the understanding of CDots as a new class of quantum dot-like fluorescent nanomaterials are discussed, and so are further challenges and opportunities.
Lingua originaleEnglish
pagine (da-a)28180-28186
Numero di pagine7
RivistaJOURNAL OF PHYSICAL CHEMISTRY. C
Volume121
Stato di pubblicazionePublished - 2017

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All Science Journal Classification (ASJC) codes

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

Cita questo

Messina, F., Sciortino, A., Lecroy, G. E., Sun, Y-P., Wang, P., Fernando, K. A. S., Bunker, C. E., & Sciortino, A. (2017). Characteristic Excitation Wavelength Dependence of Fluorescence Emissions in Carbon "quantum" Dots. JOURNAL OF PHYSICAL CHEMISTRY. C, 121, 28180-28186.