National Laboratory of Solid State Microstructures and School of Physics, Nanjing University , Nanjing 210093, China.
ACS Nano. 2013 Dec 23;7(12):10654-61. doi: 10.1021/nn4053342. Epub 2013 Nov 23.
We have performed the first single-particle spectroscopic measurements on individual graphene quantum dots (GQDs) and revealed several intriguing fluorescent phenomena that are otherwise hidden in the optical studies of ensemble GQDs. First, despite noticeable differences in the size and the number of layers from particle to particle, all of the GQDs studied possess almost the same spectral lineshapes and peak positions. Second, GQDs with more layers are normally brighter emitters but are associated with shorter fluorescent lifetimes. Third, the fluorescent spectrum of GQDs was red-shifted upon being aged in air, possibly due to the water desorption effect. Finally, the missing emission of single photons and stable fluorescence without any intermittent behavior were observed from individual GQDs.
我们对单个石墨烯量子点（GQDs）进行了首次单粒子光谱测量，并揭示了一些在集合 GQDs 的光学研究中隐藏的有趣荧光现象。首先，尽管各个颗粒在尺寸和层数上存在明显差异，但所有研究的 GQDs 都具有几乎相同的光谱线形状和峰值位置。其次，层数更多的 GQDs 通常是更亮的发射器，但荧光寿命更短。第三，GQDs 在空气中老化后荧光光谱发生红移，可能是由于水脱附效应。最后，从单个 GQDs 观察到单光子的缺失发射和稳定荧光，没有任何间歇行为。
