“Whole‐Body” Fluorination for Highly Efficient and Ultra‐Stable All‐Inorganic Halide Perovskite Quantum Dots

• Published in: Angewandte Chemie International Edition Vol. 63; no. 8; pp. e202315841 - n/a
• Main Authors: Wang, Zhaoyu, Wei, Youchao, Chen, Yameng, Zhang, Haoyu, Wang, Di, Ke, Jianxi, Liu, Yongsheng, Hong, Maochun
• Format: Journal Article
• Language: English
• Published: Germany Wiley Subscription Services, Inc 19.02.2024
• Edition: International ed. in English
• Subjects: Bonding strength; Crystal defects; Crystal lattices; Efficiency; Electronegativity; Fluorination; Halide Perovskite; Ionic interactions; Perovskites; Quantum Dots; Stability; Surface defects; Halide Perovskite; Stability; Quantum Dots; Fluorination; Efficiency
• ISSN: 1433-7851; 1521-3773
• DOI: 10.1002/anie.202315841

Inherent “soft” ionic lattice nature of halide perovskite quantum dots (QDs), triggered by the weak Pb−X (X=Cl, Br, I) bond, is recognized as the primary culprit for their serious instability. A promising way is to construct exceedingly strong ionic interaction inside the QDs and increase their crystal cohesive energy by substituting the interior X− with highly electronegative F−, however, which is challenging and hitherto remains unreported. Here, a “whole‐body” fluorination strategy is proposed for strengthening the interior bonding architecture of QDs, wherein the F− are uniformly distributed throughout the whole nanocrystal encompassing both the interior lattice and surface, successfully stabilizing their “soft” crystal lattice and passivating surface defects. This approach effectively mitigates their intrinsic instability issues including light‐induced phase segregation. As a result, light‐emitting devices based on these QDs exhibit exceptional efficiency and remarkable stability. To address the serious chemical instability induced by the inherent “soft” ionic lattice nature of halide perovskite quantum dots (QDs), a “whole‐body” fluorination strategy is proposed for strengthening their interior bonding architecture. The F− ions distributed throughout the whole nanocrystal impart exceedingly strong ionic interaction with the QDs, successfully stabilizing their “soft” crystal lattice and passivating surface defect.