近日，北京师范大学范楼珍团队研究了外量子效率超过20%的发光二极管的对称硼桥碳量子框架。相关论文发表在2025年7月28日出版的《美国化学会杂志》上。

生态友好型溶液处理量子点的发展在大面积显示应用的电致发光二极管（LED）的制造中起着重要作用。然而，这些环保设备的效率仍然明显低于基于重金属的最先进替代品。

研究组展示了无金属碳基量子材料：对称硼桥联碳量子框架（sym-B-CQFs），该框架由四个二苯并[fg,op]并四苯块体组成，这些块体通过硼原子连接，形成了一个刚性的非平面共轭框架。sym-B-CQFs具有1.04 × 10⁶ s^-1的反向系统间交叉率（k_RISC）和98±0.6%的总光致发光量子产率。实验和理论分析表明，由对称硼桥形成的非平面框架导致了边界轨道在不同块上的交替分布，使得单线态和三重态激发态之间存在较小的能隙；这反过来又增加了k_RISC。

基于sym-B-CQFs的溶液可处理LED表现出创纪录的20.4%的外部量子效率（EQE）和低效率滚降（EQE = 18.0%，1000 cd m^-2）。研究组预计这些高性能碳基LED非常适合下一代大面积显示器。

附：英文原文

Title: Symmetric Boron-Bridged Carbon Quantum Frameworks for Light-Emitting Diodes with over 20% External Quantum Efficiency

Author: Ting Yuan, Guimin Zhao, Diandong Tang, Xianzhi Song, Jiameng Du, Zhaoxi Yu, Yang Zhang, Laizhi Sui, Xiaohong Li, Yunchao Li, Lin Shen, Fanglong Yuan, Wei Jiang, Louzhen Fan

Issue&Volume: July 28, 2025

Abstract: The development of eco-friendly solution-processed quantum dots plays an important role in the fabrication of electroluminescent light-emitting diodes (LEDs) for large-area display applications. However, the efficiency of these eco-friendly devices is still significantly lower than that of heavy metal-based state-of-the-art alternatives. Herein, we demonstrate metal-free carbon-based quantum materials: symmetric boron-bridged carbon quantum frameworks (sym-B-CQFs) composed of four dibenzo[fg,op]tetracene blocks bonded by boron atoms to form a rigid nonplanar conjugated framework. The sym-B-CQFs can deliver high-efficiency delayed fluorescence with a reverse intersystem crossing rate (kRISC) of 1.04 × 106 s–1 and 98 ± 0.6% total photoluminescence quantum yield. Experimental and theoretical analyses reveal that the nonplanar frameworks, originating from symmetric boron-bridges, lead to an alternate distribution of the frontier orbitals on different blocks and result in a small energy gap between the singlet and triplet excited states; this, in turn, increases kRISC. Solution processable LEDs based on sym-B-CQFs exhibit a record-high external quantum efficiency (EQE) of 20.4% and low efficiency roll-off (EQE = 18.0% at 1000 cd m–2). We anticipate that these high-performance carbon-based LEDs are highly suitable for next-generation large-area displays.

DOI: 10.1021/jacs.5c10746

Source: https://pubs.acs.org/doi/abs/10.1021/jacs.5c10746