Slowing Down for Growth Mechanism and Speeding Up for Performance Optimization Based on Single Ligand Passivated CsPbBr3 Nanoplatelets. Issue 18 (23rd June 2022)

• Record Type: Journal Article
• Authors: Yang, Huanxin; Yun, Rui; Sun, Changjiu; Chu, Yiyue; Su, Guodong; Yuan, Mingjian; Wu, Suli; Zhang, Libing; Li, Xiyan
• Is Part Of: Advanced optical materials. Volume 10:Issue 18(2022)
• Page Start: n/a
• Page End: n/a
• Publication Date: 2022-06-23
• Subjects: growth model -- nanoplatelets -- optimization -- pure blue emission -- single ligand passivation; Optical materials -- Periodicals; Photonics -- Periodicals; 620.11295
• DOI: 10.1002/adom.202200683
• Languages: English
• ISSNs: 2195-1071

Abstract

Abstract: Quasi 2D metal halide perovskite nanoplatelets (NPls), as a kind of important materials to achieve pure blue emission, attract significant attention in pursuit of high gamut trichromatic display. However, in‐depth study on the specific growth processes of NPls is still lacking due to the ultrafast reaction rate. Here, a single ligand passivation strategy to investigate the concrete growth mechanism of NPls is proposed, in which the PbBr x (OAm) y clusters play a pivotal template role in guiding the growth of crystals, and the final products with 3‐monolayer (3ML) are grown from the intermediate 2ML NPls instead of being synthesized directly. Based on the new discovery about growth mechanism of NPls, the reaction time has been shortened from hours to seconds by introducing hydrobromic acid and ethanol. The ethanol used here is considered as an accelerator for the transition from 2ML to 3ML NPls rather than an initiator for nucleation of products, which is different from the generally accepted viewpoints. With further passivation of hydrobromic acid, the synthesized 3ML NPls show 462 nm emission with quantum yield of 97.04% and great photostability. The novel growth model proposed in this work will provide a paradigm for future design and optimization of new synthesis schemes. Abstract : The PbBr x (OAm) y clusters have been discovered and corroborated to play a pivotal template role in guiding the growth of 2‐monolayer CsPbBr3 nanoplatelets, which are the intermediate products for growing to 3‐monolayer nanoplatelets. The ethanol introduced for quick preparation is proved as an accelerator for the transition from 2‐ to 3‐monolayer nanoplatelets rather than an initiator for nucleation of products.