Onion-like multicolor thermally activated delayed fluorescent carbon quantum dots for efficient electroluminescent light-emitting diodes

作者：Yuxin Shi, Yang Zhang, Zhibin Wang, Ting Yuan, Ting Meng, Yunchao Li, Xiaohong Li, Fanglong Yuan, Zhan’ao Tan, Louzhen Fan · 发表于：Nature Communications · 年份：2024 · DOI：10.1038/s41467-024-47372-8 · 被引用次数：74 · 研究领域：Carbon and Quantum Dots Applications、Organic Light-Emitting Diodes Research、Nanocluster Synthesis and Applications

Abstract Carbon quantum dots are emerging as promising nanomaterials for next-generation displays. The elaborate structural design is crucial for achieving thermally activated delayed fluorescence, particularly for improving external quantum efficiency of electroluminescent light-emitting diodes. Here, we report the synthesis of onion-like multicolor thermally activated delayed fluorescence carbon quantum dots with quantum yields of 42.3–61.0%. Structural, spectroscopic characterization and computational studies reveal that onion-like structures assembled from monomer carbon quantum dots of different sizes account for the decreased singlet-triplet energy gap, thereby achieving efficient multicolor thermally activated delayed fluorescence. The devices exhibit maximum luminances of 3785–7550 cd m −2 and maximum external quantum efficiency of 6.0–9.9%. Importantly, owing to the weak van der Waals interactions and adequate solution processability, flexible devices with a maximum luminance of 2554 cd m −2 are realized. These findings facilitate the development of high-performance carbon quantum dots-based electroluminescent light-emitting diodes that are promising for practical applications.