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Water-Driven Synthesis of Deep-Blue Perovskite Colloidal Quantum Wells for Electroluminescent Devices |
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| Authors: | Mengqi Zhang Dr. Chenghao Bi Yuexing Xia Dr. Xuejiao Sun Xingyu Wang Aqiang Liu Shuyu Tian Prof. Xinfeng Liu Prof. Nora H. de Leeuw Prof. Jianjun Tian |
| Affiliation: | 1. Institute for Advanced Materials and Technology, University of Science and Technology Beijing, Beijing, 100083 China Shunde Innovation School, University of Science and Technology Beijing, Foshan, Guangdong, 528399 China These authors contributed equally to this work.;2. CAS Key Laboratory of Standardization and Measurement for Nanotechnology, Beijing National Center for Nanoscience and Technology, Beijing, 100190 China University of Chinese Academy of Sciences, Beijing, 100049 China;3. Institute of Semiconductors Chinese Academy of Sciences, Beijing, 100083 China;4. School of Chemistry, University of Leeds, Leeds, LS2 9JT UK;5. Institute for Advanced Materials and Technology, University of Science and Technology Beijing, Beijing, 100083 China Shunde Innovation School, University of Science and Technology Beijing, Foshan, Guangdong, 528399 China;6. Institute for Advanced Materials and Technology, University of Science and Technology Beijing, Beijing, 100083 China |
| Abstract: | Perovskite colloidal quantum wells (QWs) are promising to realize narrow deep-blue emission, but the poor optical performance and stability suppress their practical application. Here, we creatively propose a water-driven synthesis strategy to obtain size-homogenized and strongly confined deep-blue CsPbBr3 QWs, corresponding to three monolayers, which emit at the deep-blue wavelength of 456 nm. The water controls the orientation and distribution of the ligands on the surface of the nanocrystals, thus inducing orientated growth through the Ostwald ripening process by phagocytizing unstable nanocrystals to form well-crystallized QWs. These QWs present remarkable stability and high photoluminescence quantum yield of 94 %. Furthermore, we have prepared light-emitting diodes based on the QWs via the all-solution fabrication strategy, achieving an external quantum efficiency of 1 % and luminance of 2946 cd m−2, demonstrating state-of-the-art brightness for perovskite QW-based LEDs. |
| Keywords: | Colloidal Quantum Wells Deep-Blue Light-Emitting Diodes Metal Halide Perovskite Water-Driven Synthesis |