Zhou Yingtong, Hua Yulu, Li Shuo, Zhang Jiaqi, Wang Haibo, Yin Wenxu, Zhang Xiaoyu, Zheng Weitao, Rogach Andrey L
Key Laboratory of Automobile Materials MOE, School of Materials Science & Engineering, and Jilin Provincial International Cooperation Key Laboratory of High-Efficiency Clean Energy Materials, Jilin University, Changchun, 130012, P. R. China.
Department of Materials Science and Engineering, and Centre for Functional Photonics (CFP), City University of Hong Kong, Hong Kong, SAR, 999077, P. R. China.
Adv Mater. 2025 Jul 1:e2506970. doi: 10.1002/adma.202506970.
Achieving efficient and stable blue-emitting quasi-two-dimensional (quasi-2D) perovskite light-emitting diodes (LEDs) remains a challenge due to the poor solubility of conventional chloride precursors and the difficulty to form thick, uniform films with a well-controlled phase distribution. A new strategy is proposed to address this challenge using CsPbCl quantum dots (QDs) capped with oleylamine (OLA) ligands as an alternative chlorine source. It is demonstrated how the use of these QDs enables formation of quasi-2D perovskite films with vertically aligned crystalline structure, thickness over 100 nm, and improved stability. OLA ligands regulate the crystal phase distribution and grain boundaries, suppressing the appearance of small-n 2D phases and reducing the number of crystal defects, while inorganic CsPbCl QD cores induce vertical crystallization of quasi-2D perovskite films, endowing them with enhanced structural stability. The use of this non-conventional chlorine source is proven instrumental in improving external quantum efficiency of quasi-2D perovskite sky-blue LEDs, reaching 26.2% at 485 nm, with significantly enhanced electroluminescence stability both in terms of peak position and brightness. This study demonstrates a novel methodology using CsPbCl QDs capped with conventional organic ligands to achieve thick quasi-2D perovskite layers for blue LEDs, addressing existing limitations in perovskite optoelectronics.
由于传统氯化物前驱体的溶解性差，以及难以形成具有良好控制的相分布的厚且均匀的薄膜，实现高效且稳定的蓝色发光准二维（准2D）钙钛矿发光二极管（LED）仍然是一项挑战。本文提出了一种新策略来应对这一挑战，即使用油酸胺（OLA）配体包覆的CsPbCl量子点（QD）作为替代氯源。结果表明，使用这些量子点能够形成具有垂直排列晶体结构、厚度超过100 nm且稳定性提高的准二维钙钛矿薄膜。OLA配体调节晶体相分布和晶界，抑制小n值二维相的出现并减少晶体缺陷数量，而无机CsPbCl量子点核心诱导准二维钙钛矿薄膜的垂直结晶，赋予它们增强的结构稳定性。事实证明，使用这种非常规氯源有助于提高准二维钙钛矿天蓝色LED的外量子效率，在485 nm处达到26.2%，在峰值位置和亮度方面的电致发光稳定性均显著增强。这项研究展示了一种使用传统有机配体包覆的CsPbCl量子点来实现用于蓝色LED的厚准二维钙钛矿层的新方法，解决了钙钛矿光电子学中的现有局限性。
