White-light emission of blue-luminescent graphene quantum dots by europium (III) complex incorporation
In: Carbon, Jg. 124 (2017-11-01), S. 479-485
Online
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Zugriff:
Traditionally, graphene quantum dots are prepared by fragmentation of graphene sheets into the nanoscale particles of controlled sizes followed by band gap adjustment by doping with electron-donating elements. Our novel synthetic aqueous arc discharge process has been developed to produce the blue-luminescent graphene quantum dots (bGQDs). The resulting bGQDs are ∼15 nm in diameter and the amount of oxygen-including functional groups can be controlled to 27.4% and 30.8% at 1 and 4 A of a current level, respectively. The presence of a band gap is confirmed by using scanning tunneling microscopy/spectroscopy (STM/STS). Additionally, we investigated the effect of oxygen doping levels on the band gap by photoluminescence (PL) behaviors and a density functional theory (DFT). The PL emission is red-shifted from 397 to 425 nm corresponding to the amount of oxygen-including functional groups in bGQDs and the DFT calculation confirms the decrease in a band gap from ∼2.0 to ∼1.7 eV due to electron donation from oxygen. In addition, our quantum dots have promising applications for practical use in optoelectronics devices. For example, tris-dibenzoylmethane mono-1,10-phenanthroline-europium (III) (Eu III DP) is incorporated with bGQDs for white-light emission and is shown to be successfully fabricated into light-emitting polymer films.
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White-light emission of blue-luminescent graphene quantum dots by europium (III) complex incorporation
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Autor/in / Beteiligte Person: | Song, Youngjun ; Jun Hong Park ; Ying Shirley Meng ; Joon Kyo Seo ; Kim, Sejung ; Heller, Michael J. |
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Zeitschrift: | Carbon, Jg. 124 (2017-11-01), S. 479-485 |
Veröffentlichung: | Elsevier BV, 2017 |
Medientyp: | unknown |
ISSN: | 0008-6223 (print) |
DOI: | 10.1016/j.carbon.2017.08.021 |
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