碳点光致发光机理的新见解:进展与展望

Insights into photoluminescence mechanisms of carbon dots:advances and perspectives

碳点由于其优异的光学性能、高生物相容性和低毒性,在生物成像、发光二极管和传感等许多领域具有潜在的应用价值.它们的光致发光机制已经得到了广泛的研究,了解这一机制对于指导可调谐光致发光碳点的合成和促进其应用具有重要意义.然而,光致发光的内在机制尚不清楚,由于粒子结构的不同,尚未找到统一的机制.本综述概括了碳点的类别,指出了它们的结构多样性,概述了与结构差异有关的三种类型的发光机制:内部因素主导发射(包括共轭效应、表面态和二者的协同效应)、外部因素主导发射(包括分子态和环境效应)和交联增强发射,并简要介绍了碳点的光学应用.最后,对发光机制研究的发展前景进行了讨论,指出了未来工作的主要挑战和发展方向.

Carbon dots(CDs) are potentially useful in many areas such as bioimaging, light-emitting diodes, and sensing because of their excellent optical properties, high biocompatibility, and low toxicity.Knowledge of their photoluminescence(PL) mechanisms, which have been widely studied, is of significance in guiding the synthesis and promoting applications of CDs with tunable PL emissions. However,the intrinsic mechanism of PL emission remains unclear, and a unified mechanism has not been found because of differences in particle structures. This review generalizes the categories of CDs, noting their structural diversity. Three types of PL mechanism pertaining to structural differences are outlined: internal factors dominated emission(including the conjugation effect, the surface state, and the synergistic effect), external factors dominated emission(including the molecular state and the environment effect),and crosslink-enhanced emission. Optical applications of CDs are also briefly mentioned. Finally, the prospects for research into PL mechanisms are discussed, noting the remaining challenges and directions for future work.