Wang Shuaibing, Yang Wanying, Li Yu, Chen Jie, Bian Yangyang, Deng Jilin, Hu Binbin, Chen Fei, Shen Huaibin, Teng Feng, Yang Chunhe, Tang Aiwei
Key Laboratory of Luminescence and Optical Information, Ministry of Education, School of Physical Sciences and Engineering, Beijing Jiaotong University, Beijing 100044, China.
Key Laboratory for Special Functional Materials of Ministry of Education, National & Local Joint Engineering Research Center for High-efficiency Display and Lighting Technology, School of Materials, Henan University, Kaifeng 475004, China.
Nano Lett. 2024 Dec 11;24(49):15781-15787. doi: 10.1021/acs.nanolett.4c04580. Epub 2024 Nov 29.
Indium phosphide (InP) is a representative of environmentally friendly quantum dots (QDs), and quantum dot light-emitting diodes (QLEDs) based on InP QDs are prime candidates for next-generation display applications. However, there are numerous nonradiative sites on the surface of InP QDs, which compromise the operational stability of QLEDs. Herein, we employed cysteamine (CTA) molecules for post-treatment of QD films, effectively passivating surface defects and nonradiative sites, thereby enhancing stability. This treatment enabled a long lifetime of over 1,200 h at an initial luminance of 1,000 cd m. Additionally, CTA-treated QDs induced the formation of an interface dipole, elevating the energy levels of QDs and reducing the injection barrier for holes. Moreover, the dipole moment at the interface hindered electron injection, achieving a more balanced carrier injection in the device. Consequently, we achieved a peak external quantum efficiency (EQE) of 21.21%.
磷化铟（InP）是环境友好型量子点（QDs）的代表，基于InP量子点的量子点发光二极管（QLEDs）是下一代显示应用的主要候选者。然而，InP量子点表面存在大量非辐射位点，这会损害QLEDs的工作稳定性。在此，我们使用半胱胺（CTA）分子对量子点薄膜进行后处理，有效钝化表面缺陷和非辐射位点，从而提高稳定性。这种处理在初始亮度为1000 cd m时实现了超过1200小时的长寿命。此外，CTA处理的量子点诱导形成界面偶极子，提高了量子点的能级并降低了空穴的注入势垒。而且，界面处的偶极矩阻碍了电子注入，在器件中实现了更平衡的载流子注入。因此，我们实现了21.21%的峰值外量子效率（EQE）。
