State Key Laboratory on Integrated Optoelectronics, College of Electronic Science and Engineering, Jilin University, 2699 Qianjin Street, Changchun, 130012, China.
Nanoscale. 2017 Sep 14;9(35):13042-13051. doi: 10.1039/c7nr03570e.
Carbon dots (CDs) have emerged as novel fluorescent probes due to their remarkable optical properties; however, red emission is still rare, has a relatively low efficiency, and its mechanism remains ambiguous. Herein, relatively efficient red-emission CDs based on p-phenylenediamine were prepared through various solvothermal means, where the highest quantum yield approached 41.1% in n-amyl alcohol, which was the most efficient quantum yield reported to date. Various structural characterizations were performed and confirmed that the red emission originated from the molecular states consisting of a nitrogen-containing organic fluorophore. The CDs were dispersed in different organic solvents and showed tunable emission, evolving from green to orange-red in aprotic solvents and a red emission in protic solvents. Further solvent correlation studies indicated that the hydrogen bond effect between the CDs and solvents was the main mechanism leading to the spectral shift. Accordingly, solid-state luminescent CDs-polymers were fabricated, which also demonstrated continuously tunable emission properties. This work opens a new window for recognizing the generation of tunable and red-emission CDs.
碳点 (CDs) 由于其显著的光学性质而成为新型荧光探针; 然而，红色发射仍然很少见，效率相对较低，其机制仍不清楚。本文通过各种溶剂热方法制备了基于对苯二胺的相对高效的红色发射 CD，其在正戊醇中的量子产率最高接近 41.1%，这是迄今为止报道的最高效率的量子产率。进行了各种结构表征，并证实红色发射源于由含氮有机荧光团组成的分子态。CD 在不同的有机溶剂中分散，并表现出可调谐的发射，从非质子溶剂中的绿色到橙色-红色，以及质子溶剂中的红色发射。进一步的溶剂相关研究表明，CDs 与溶剂之间的氢键作用是导致光谱位移的主要机制。因此，制备了固态发光 CDs-聚合物，其也表现出连续可调谐的发射性质。这项工作为认识可调谐和红色发射 CDs 的产生开辟了新的窗口。
