华南理工大学吴宏滨团队近日研究了超高亮度近红外有机发光二极管。2025年5月13日出版的《自然—光子学》杂志发表了这一最新研究成果。
近红外有机发光二极管具有广泛的应用前景，包括夜间监控和生物医学诊断和成像系统。然而，由于在高电流密度下效率滚降，获得许多应用所必需的高器件辐射率并保持高操作稳定性具有挑战性。 研究组开发了基于受体-供体-受体有机半导体的近红外有机发光二极管，其单重态-三重态湮灭率和三重态寿命大大降低，减轻了长寿命三重态对单重态的猝灭，从而在高电激发水平下实现了超高的单重态密度。
该设备显示J50值为59.2 A cm-2，即外部量子效率降低到其峰值1.34%的一半时的电流密度。在电流密度的六个数量级范围内，也保持了高的外部量子效率，其值高于5000 A cm-2。在连续电偏压、46700 W sr−1 m−2的脉冲电操作中，这些设备发出的最大辐射超过2000 W sr−1 m−2 。 半衰期为35 h表示初始辐射率为100 W sr−1 m−2。研究组还在1000 A cm-2实现了超过1016 cm−3的高电注入单线密度，这可以维持粒子数反转，表明有机激光器的潜力。这些结果为近红外有机发光二极管的进一步发展铺平了道路，并为电驱动有机激光二极管提供了一条潜在的途径。
附：英文原文
Title: Ultrahigh-radiance near-infrared organic light-emitting diodes
Author: Liu, Wansheng, Deng, Wanyuan, Wang, Weiping, Wu, Haimei, Gao, Chao, Xie, Yuan, Zhao, Jichen, Dong, Xiaobin, Zhao, Zujin, Zheng, Zhong, Chi, Yun, Duan, Lian, Zhan, Xiaowei, Zou, Yingping, Wu, Hongbin, Peng, Junbiao, Cao, Yong
Issue&Volume: 2025-05-13
Abstract: Near-infrared organic light-emitting diodes are attractive for a broad range of applications, including night-time surveillance and biomedical diagnostic and imaging systems. However, obtaining high device radiance, which is necessary for many applications, and maintaining high operational stability is challenging due to the rapid efficiency roll-off at a high current density. Here we develop near-infrared organic light-emitting diodes based on an acceptor–donor–acceptor organic semiconductor with greatly suppressed singlet–triplet annihilation rate and triplet lifetime, alleviating singlet quenching by long-lived triplets, thereby enabling an ultrahigh singlet density at high electrical excitation levels. Our devices exhibit J50 values of 59.2Acm2, that is, the current density at which the external quantum efficiency decreases to half its peak value of 1.34%. A high external quantum efficiency is also maintained over a six orders of magnitude range of current densities, at values above 5,000Acm2. The devices emit with the maximum radiance beyond 2,000Wsr1m2 under a continuous electrical bias and 46,700Wsr1m2 in the pulsed electrical operation. The half-lifetime is 35h for an initial radiance of 100Wsr1m2. We also achieve a high electrically injected singlet density of more than 1016cm3 at 1,000Acm2, which can sustain population inversion, indicating potential for organic lasers. These results pave the way for further developments of near-infrared organic light-emitting diodes as well as offer a potential route towards electrically driven organic laser diodes.
DOI: 10.1038/s41566-025-01674-5
Source: https://www.nature.com/articles/s41566-025-01674-5