Hydrogen Bond-Induced Flexible and Twisted Self-Assembly of Functionalized Carbon Dots with Customized-Color Circularly Polarized Luminescence

Abstract

Circularly polarized luminescence (CPL) is widely applied in optical data storage, quantum computing and backlights in three-dimensional (3D) displays. Carbon dots (CDs) exhibit competitive optical properties, in addition to excellent resistance to photo- and chemical-bleaching after carbonization. Combining the superior optical performance with polarization peculiarities through hierarchical structure engineering is imperative for the development of CDs. Here, oriented assembly was driven by hydrophobic interactions of aromatic ligands, which participated in the surface-ligand post-modification process on ground-state chiral carbon core. Furthermore, the residual chiral amides on CDs formed multi-hydrogen bonds during gradual aggregation, causing the assembled materials to form asymmetric bending structure. Superficial ligands interfered with optical dynamics of exciton radiation transition and promoted the excited state of the assembled materials to achieve a circularly polarized signal. The linkage ligands successfully overcame the frequent phenomenon of aggregation-induced quenching and contributed further to the formation of self-supporting films by assembly and facilitated chiral optical expression. The full-color and white CPL were manipulated by simply regulating the functional groups on the ligands. Finally, based on the stable chiral powder phosphors, large chiral flexible films and multicolor chiral light-emitting diodes were constructed which provide feasible materials and technical support for flexible 3D displays.