Li Chenhao, Li Jinyang, Teng Qian, Li Jinsui, Yuan Fanglong
Key Laboratory of Theoretical & Computational Photochemistry of Ministry of Education, College of Chemistry, Beijing Normal University, Beijing, 100875, China.
Angew Chem Int Ed Engl. 2025 Feb 10;64(7):e202419983. doi: 10.1002/anie.202419983. Epub 2024 Dec 18.
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 and current efficiency of 10.3 cd A. This work presents a straightforward and universal strategy for creating efficient solid-state emissive CQDs, showcasing significant potential for color-tunable LED applications.
基于量子点（QD）的颜色可调电致发光二极管（LED）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，在使用单一量子点发光材料的LED中实现广泛的颜色可调性仍然面临重大挑战。在此，我们展示了首个明亮的多色电致发光LED的实例，其发射峰可调范围为535至640纳米，采用了一种新型的单一红色固态发光碳量子点（R-SSCQD）。与传统的碳量子点不同，传统碳量子点在固态形式下通常表现出微弱或可忽略不计的发射，而R-SSCQD在固态下表现出明亮的红色发射，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-SSCQD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-SSCQD的重量比，我们展示了明亮、高效且多色的基于碳量子点的LED，其发出绿色、黄色、橙色和红色光，实现了创纪录的高亮度15,834 cd m和10.3 cd A的电流效率。这项工作提出了一种创建高效固态发光碳量子点的直接且通用的策略，展示了其在颜色可调LED应用中的巨大潜力。
