Zhou Boyu, Zhou Mingming, Zhang Tong, Xie Shiyi, Jiang Yuhan, Chang Zongming, Wang Yanping, Tao Youtian, Zhang Dingke, Mi Xiaoyun, Liu Xiuling
School of Materials Science and Engineering, Changchun University of Science and Technology, Changchun 130022, People's Republic of China.
Engineering Research Center of Optoelectronic Functional Materials, Ministry of Education, Changchun 130022, People's Republic of China.
ACS Appl Mater Interfaces. 2025 Jun 18;17(24):35705-35713. doi: 10.1021/acsami.5c03725. Epub 2025 Jun 5.
Quantum-dot light-emitting diodes (QLEDs) are regarded as promising options for various optoelectronic applications. However, they struggle with an excessive injection of electrons relative to holes, constraining their performance. Here, we propose an efficient hole transport layer (HTL) sensitization method that can reuse leaked electrons and raise the hole transport capability to tackle this challenge. The HTL consists of poly(9-vinylcarbazole) (PVK) mixed with a light-blue thermally activated delayed fluorescence emitter, 2-(3,5-bis(trifluoromethyl)phenyl)-5-(2,3,4,5,6-penta(9-carbazol-9-yl)phenyl)-1,3,4-oxadiazole (dCF5CzOXD). The resulting red QLEDs at a mixing concentration of 25 wt % simultaneously yield a highest current efficiency/external quantum efficiency (EQE) of 42.3 cd A/35.8%, and an extended lifetime exceeding 81,408 h at 100 cd m, positioning them among the most efficient and stable QLEDs reported to date. Remarkably, a consistent EQE value exceeding 32.0% is maintained across a broad luminance range of 9000 to 200,000 cd m.
量子点发光二极管（QLED）被视为各种光电子应用的有前途的选择。然而，它们存在电子相对于空穴注入过多的问题，这限制了它们的性能。在这里，我们提出了一种有效的空穴传输层（HTL）敏化方法，该方法可以重新利用泄漏的电子并提高空穴传输能力来应对这一挑战。HTL由聚（9-乙烯基咔唑）（PVK）与浅蓝色热激活延迟荧光发射体2-（3,5-双（三氟甲基）苯基）-5-（2,3,4,5,6-五（9-咔唑-9-基）苯基）-1,3,4-恶二唑（dCF5CzOXD）混合而成。在混合浓度为25 wt%时，所得的红色QLED同时产生42.3 cd A/35.8%的最高电流效率/外量子效率（EQE），并且在100 cd m²的亮度下具有超过81,408小时的延长寿命，使其成为迄今为止报道的最有效和最稳定的QLED之一。值得注意的是，在9000至200,000 cd m²的宽亮度范围内，EQE值始终保持超过32.0%。
