Berlin 2018 – wissenschaftliches Programm
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BP: Fachverband Biologische Physik
BP 9: Postersession I
BP 9.28: Poster
Montag, 12. März 2018, 17:30–19:30, Poster A
Studying the fluorescence properties of graphene quantum dots — •Maren Sakowski1, Stefan Fasbender1, Ralf Kühnemuth2, Bekir Bulat2, Claus Seidel2, and Thomas Heinzel1 — 1Experimental Condensed Matter Physics, Heinrich-Heine-University Dusseldorf — 2Molecular Physical Chemistry, Heinrich-Heine-University Dusseldorf
Fluorescent graphene quantum dots (GQDs) are prepared by thermal decomposition of citric acid and diethylentriamine slightly modifying the method of Qu et al. [1]. The particles are purified with HPLC and the fluorescence properties are studied using fluorescence spectroscopy, UV-vis, fluorescence correlation spectroscopy (FCS) and time-correlated single photon counting (TCSPC). The GQDs show an absorption maximum around 360 nm with an emission maximum around 450 nm (25 % quantum yield) and a second absorption maximum around 480 nm with an emission maximum around 560 nm (6 % quantum yield). TCSPC reveals a fluorescence lifetime of 9.92 ns at 360 nm excitation and 1.78 ns at 480 nm excitation. The Stokes radius is identified to be 0.6 nm using FCS.
[1] Qu et al., Light: Science & Applications, 2015, 4, e364