Department of Chemistry, Indiana University, Bloomington, Indiana 47405, USA.
Nano Lett. 2010 Jul 14;10(7):2679-82. doi: 10.1021/nl101474d.
Electronic relaxation in photoexcited graphenes is central to their photoreactivity and their optoelectrical applications such as photodetectors and solar cells. Herein we report on the first ensemble studies of electronic energy relaxation pathways in colloidal graphene quantum dots with uniform size. We show that the photoexcited graphene quantum dots have a significant probability of relaxing into triplet states and emit both phosphorescence and fluorescence at room temperature, with relative intensities depending on the excitation energy. Because of the long lifetime and reactivity of triplet electronic states, our results could have significant implications for applications of graphenes.
电子弛豫在光激发石墨烯中对其光反应性及其光电应用（如光探测器和太阳能电池）至关重要。在此，我们报告了胶体石墨烯量子点中电子能量弛豫途径的首次整体研究，这些量子点具有均匀的尺寸。我们表明，光激发的石墨烯量子点有很大的概率弛豫到三重态，并在室温下发射磷光和荧光，相对强度取决于激发能量。由于三重态电子态的长寿命和反应性，我们的结果可能对石墨烯的应用有重要意义。
