北京师范大学袁方龙团队报道了用于多色、明亮、高效电致发光二极管的单固态发射碳量子点。相关研究成果于2024年12月9日发表在《德国应用化学》。

基于量子点（QDs）的色彩可调电致发光二极管（LEDs），正迅速成为下一代全彩显示器和固态照明的关键技术。然而，在利用单一QD发射材料的LEDs中实现宽的颜色可调性，仍然是一个重大挑战。

该文中，研究人员展示了第一个利用了一种新型的单红色固态发射碳量子点（R-SSCQDs）的，明亮的多色电致发光LEDs的例子，其发射峰可调，跨度为535至640 nm。与传统的CQDs不同，R-SSCQDs在固态下通常表现出微弱或可忽略的发射，在固态下表现出亮红色发射，在稀释状态下表现出绿色发射。

实验研究和理论计算表明，R-SSCQDs独特的非平面空间结构和显著的空间位阻有效地抑制了π-π堆积，从而实现了高效的固态荧光发射。通过调整掺杂在主体材料中的R-SSCQDs的重量比，研究人员展示了明亮、高效和多色的基于CQD的LEDs，其发出绿光、黄光、橙光和红光，达到了创纪录的15834 cd m^-2的高亮度和10.3 cd A^-1的电流效率。

该项工作为创建高效的固态发射CQDs提供了一种简单而通用的策略，展示了颜色可调LED应用的巨大潜力。

附：英文原文

Title: Single Solid-State Emissive Carbon Quantum Dots for Multicolor, Bright and Efficient Electroluminescent Light-Emitting Diodes

Author: Chenhao Li, Jinyang Li, Qian Teng, Jinsui Li, Fanglong Yuan

Issue&Volume: 2024-12-09

Abstract: Color-tunable electroluminescent light-emitting diodes (LEDs) based on quantum dots (QDs) are rapidly emerging as a key technology for next-generation full-color displays and solid-state lighting. However, achieving broad color tunability in LEDs that utilize a single QD emissive material continues to pose significant challenges. Here, we present the first example of bright, multicolor electroluminescent LEDs with tunable emission peaks spanning from 535 to 640 nm, utilizing a new type of single red solid-state emissive carbon quantum dots (R-SSCQDs). Unlike conventional CQDs, which often exhibit weak or negligible emission in solid-state form, R-SSCQDs demonstrate bright red emission in solid state and green emission in diluted state. Experimental investigations and theoretical calculations reveal that the unique non-planar spatial structure and significant steric hindrance of R-SSCQDs effectively suppress π-π stacking, resulting in efficient solid-state fluorescence emission. By adjusting the weight ratios of R-SSCQDs doped in host materials, we showcase bright, efficient and multicolor CQD-based LEDs that emit green, yellow, orange, and red light, achieving a record-high luminance of 15,834 cd m-2 and current efficiency of 10.3 cd A-1. This work presents a straightforward and universal strategy for creating efficient solid-state emissive CQDs, showcasing significant potential for color-tunable LED applications.

DOI: 10.1002/anie.202419983

Source: https://onlinelibrary.wiley.com/doi/10.1002/anie.202419983