The photoluminescence mechanism in carbon dots （graphene quantum dots, carbon nanodots, and polymer dots）： Current state and future perspective

目前，光致发光(PL ) 的实际机制荧光灯碳点(CD ) 仍然是在研究人员之中的开的争论。因为 CD 的变化，为这些种碳材料总结 PL 机制是高度重要的；那么做能指导有效合成线路和新奇应用程序的开发。这评论将集中于 CD 的 PL 机制。三种类型荧光灯 CD 被包含：graphene 量点(GQD ) ，碳 nanodots (CND ) ，和聚合物点(PD ) 。四合理 PL 机制被证实了：被碳核心决定的量监禁效果或结合的 -domains, ；表面状态，它由碳脊梁和连接的化学的组的杂交坚定；分子状态，它完全坚定由荧光灯分子在 CD 的表面或内部上连接了；并且提高交叉连接的排放(C ) 效果。为 CD 给一篇彻底的摘要，范畴和合成线路，以及化学 / 物理的性质，简短预先被介绍。

At present, the actual mechanism of the photoluminescence （PL） of fluorescent carbon dots （CDs） is still an open debate among researchers. Because of the variety of CDs, it is highly important to summarize the PL mechanism for these kinds of carbon materials; doing so can guide the development of effective synthesis routes and novel applications. This review will focus on the PL mechanism of CDs. Three types of fluorescent CDs were involved： graphene quantum dots （GQDs）, carbon nanodots （CNDs）, and polymer dots （PDs）. Four reasonable PL mechanisms have been confirmed： the quantum confinement effect or conjugated 7x-domains, which are determined by the carbon core; the surface state, which is determined by hybridization of the carbon backbone and the connected chemical groups; the molecule state, which is determined solely by the fluorescent molecules connected on the surface or interior of the CDs; and the crosslink- enhanced emission （CEE） effect. To give a thorough summary, the category and synthesis routes, as well as the chemical/physical properties for the CDs, are briefly introduced in advance.