近日，浙江大学的金一政&叶志镇及其研究团队取得一项新进展。经过不懈努力，他们通过可切换的界面反应实现明亮稳定的深红色钙钛矿发光二极管。相关研究成果已于2024年1月9日在国际知名学术期刊《自然—光子学》上发表。
本文设计了一种可切换的钙钛矿和电子传递层之间的界面去质子化反应，以制造高质量的CsPbI3钙钛矿薄膜，从而制备出稳定明亮的深红色发光二极管。研究方法从含有氢碘胍和一层碱性氢氧化锌的前体溶液开始。在退火过程中，界面反应开启，形成高质量的CsPbI3。碱性氢氧化锌层同时原位转化为碱性氧化锌，有效避免了不良黄相CsPbI3钙钛矿的形成。
因此，基于CsPbI3的钙钛矿LED在100mAcm-2的驱动电流密度下表现出约33.6小时的长半衰期和约1980W sr-1 m-2的超高亮度。此外，通过用溴化物部分取代碘化物，获得了明亮的深红色钙钛矿LED，其发射波长为691nm，在100mAcm-2下工作半衰期为50.3小时。
据悉，高性能的深红色发光二极管（LED）在生物医学和农业应用中具有重要意义。然而，开发明亮且稳定的溶液处理深红色LED仍是一项具有挑战性的任务。
附：英文原文
Title: Switchable interfacial reaction enables bright and stable deep-red perovskite light-emitting diodes
Author: Zeng, Jiejun, Sun, Xiaoyue, Liu, Yang, Jin, Wangxiao, He, Siyu, Zhu, Xitong, Niu, Kai, Sun, Guolong, Li, Jinyi, He, Haiping, Sun, Tulai, Ye, Zhizhen, Jin, Yizheng
Issue&Volume: 2024-01-09
Abstract: High-performance deep-red light-emitting diodes (LEDs) are important for biomedical and agricultural applications. However, the development of bright and stable solution-processed deep-red LEDs remains challenging. Here we design a switchable interfacial deprotonation reaction between the perovskite and electron-transporting layer to fabricate high-quality CsPbI3 perovskite films, leading to stable and bright deep-red LEDs. Our approach starts with a precursor solution containing guanidine hydroiodide and a layer of alkaline zinc hydroxide. On annealing, the interfacial reaction is switched on, leading to the formation of high-quality CsPbI3. The alkaline zinc hydroxide layer is simultaneously converted in situ to alkalescent ZnO, which prevents the formation of the undesirable yellow-phase CsPbI3 perovskite. As a result, our perovskite LEDs based on CsPbI3 demonstrate a long half-lifetime of approximately 33.6h under a driving current density of 100mAcm–2 and an exceptionally high radiance of around 1,980W sr-1 m–2. Moreover, by partly substituting iodide with bromide, we achieve bright deep-red perovskite LEDs with an emission wavelength of 691nm and an operational half-lifetime of 50.3h at 100mAcm–2.
DOI: 10.1038/s41566-023-01369-9
Source: https://www.nature.com/articles/s41566-023-01369-9