Li Hongjin, Feng Yifeng, Zhu Meiyi, Gao Yun, Fan Chao, Cui Qiaopeng, Cai Qiuting, Yang Ke, He Haiping, Dai Xingliang, Huang Jingyun, Ye Zhizhen
School of Materials Science and Engineering, State Key Laboratory of Silicon and Advanced Semiconductor Materials, Zhejiang University, Hangzhou, People's Republic of China.
Wenzhou Key Laboratory of Novel Optoelectronic and Nano Materials and Engineering Research Centre of Zhejiang Province, Institute of Wenzhou, Zhejiang University, Wenzhou, People's Republic of China.
Nat Nanotechnol. 2024 May;19(5):638-645. doi: 10.1038/s41565-024-01652-y. Epub 2024 Apr 22.
Perovskite quantum dots (QDs) are promising for various photonic applications due to their high colour purity, tunable optoelectronic properties and excellent solution processability. Surface features impact their optoelectronic properties, and surface defects remain a major obstacle to progress. Here we develop a strategy utilizing diisooctylphosphinic acid-mediated synthesis combined with hydriodic acid-etching-driven nanosurface reconstruction to stabilize CsPbI QDs. Diisooctylphosphinic acid strongly adsorbs to the QDs and increases the formation energy of halide vacancies, enabling nanosurface reconstruction. The QD film with nanosurface reconstruction shows enhanced phase stability, improved photoluminescence endurance under thermal stress and electric field conditions, and a higher activation energy for ion migration. Consequently, we demonstrate perovskite light-emitting diodes (LEDs) that feature an electroluminescence peak at 644 nm. These LEDs achieve an external quantum efficiency of 28.5% and an operational half-lifetime surpassing 30 h at an initial luminance of 100 cd m, marking a tenfold improvement over previously published studies. The integration of these high-performance LEDs with specifically designed thin-film transistor circuits enables the demonstration of solution-processed active-matrix perovskite displays that show a peak external quantum efficiency of 23.6% at a display brightness of 300 cd m. This work showcases nanosurface reconstruction as a pivotal pathway towards high-performance QD-based optoelectronic devices.
钙钛矿量子点（QDs）因其高色纯度、可调节的光电特性和出色的溶液可加工性，在各种光子应用中具有广阔前景。表面特性会影响其光电特性，而表面缺陷仍是阻碍其发展的主要障碍。在此，我们开发了一种策略，利用二异辛基次膦酸介导的合成方法，并结合氢碘酸蚀刻驱动的纳米表面重构来稳定CsPbI量子点。二异辛基次膦酸强烈吸附在量子点上，提高了卤化物空位的形成能，从而实现纳米表面重构。具有纳米表面重构的量子点薄膜表现出增强的相稳定性、在热应力和电场条件下改善的光致发光耐久性，以及更高的离子迁移活化能。因此，我们展示了在644nm处具有电致发光峰的钙钛矿发光二极管（LED）。这些LED在初始亮度为100cd m时，实现了28.5%的外量子效率和超过30小时的工作半衰期，比先前发表的研究提高了十倍。将这些高性能LED与专门设计的薄膜晶体管电路集成，能够展示溶液加工的有源矩阵钙钛矿显示器，该显示器在300cd m的显示亮度下，峰值外量子效率为23.6%。这项工作表明纳米表面重构是通向高性能基于量子点的光电器件的关键途径。
