A Demulsification–Crystallization Model for High‐Quality Perovskite Nanocrystals. Issue 2 (5th December 2022)

• Record Type: Journal Article
• Authors: Peng, Chencheng; Zhang, Rui; Chen, Hongting; Liu, Yang; Zhang, Shuai; Fang, Tao; Guo, Runda; Zhang, Jibin; Shan, Qingsong; Jin, Yizheng; Wang, Lei; Hou, Lintao; Zeng, Haibo
• Is Part Of: Advanced materials. Volume 35:Issue 2(2023)
• Page Start: n/a
• Page End: n/a
• Publication Date: 2022-12-05
• Subjects: accelerated crystallization -- accelerated demulsification -- acid ion assisted -- multiple‐stage nucleation -- room‐temperature synthesis; Materials -- Periodicals; Chemical vapor deposition -- Periodicals; 620.11
• DOI: 10.1002/adma.202206969
• Languages: English
• ISSNs: 0935-9648

Abstract

Abstract: A room‐temperature technique with all‐nonpolar‐solvent, which circumvents the sensitivity of ionic perovskite to polar solvent, has become attractive for the synthesis of metal halide perovskite nanocrystals (PNCs). However, the lack of understanding of the inner mechanism, especially for the state of the precursor and the crystallization process of the PNCs, hinders further development of this technique. Here, through systematic study of the Pb precursor and in situ characterization of the PNCs, it is revealed that the reverse micelle nature of the Pb precursor exactly creates a novel demulsification‐crystallization (D–C) model, namely, a two‐stage nucleation is divided by a demulsification process for the PNCs. On this basis, a top efficiency for green light‐emitting diodes based on PNCs is obtained with a maximum external quantum efficiency of 22.5% through tailoring the D–C model using a multiple‐acid‐anion synergistic assisted strategy to obtain high‐quality PNCs. Beyond the high efficiency, the work paves the way for diverse ideas in PNC synthesis. Abstract : A demulsification‐crystallization (D–C) model is constructed to describe the crystallization process of the perovskite nanocrystals (PNCs). Furtherly, a multiple‐acid‐anion synergistic assisted strategy is designed to optimize the D–C model for high‐quality PNCs. Finally, the green light‐emitting diodes based on the PNCs achieved EQE of 22.5%.