Article pubs.acs.org/JPCC
Postsynthetic, Reversible Cation Exchange between Pb2+ and Mn2+ in Cesium Lead Chloride Perovskite Nanocrystals Di Gao,†,‡,§ Bo Qiao,†,‡,§ Zheng Xu,*,†,‡ Dandan Song,†,‡ Pengjie Song,†,‡ Zhiqin Liang,†,‡ Zhaohui Shen,†,‡ Jingyue Cao,†,‡ Junjie Zhang,†,‡ and Suling Zhao*,†,‡ †
Key Laboratory of Luminescence and Optical Information, Ministry of Education and ‡Institute of Optoelectronics Technology, Beijing Jiaotong University, Beijing 100044, China ABSTRACT: CsPbX3 (X = Cl, Br, I) perovskite nanocrystals (NCs) are promising materials due to their excellent optoelectronic properties. In this work, we show a successful partial and reversible cation exchange reaction between Pb and Mn in both CsPbCl3 NCs and CsMnCl3 NCs systems to yield luminescent CsPb1−xMnxCl3 NCs. By adjusting the reaction time, the photoluminescence from the exciton emission of CsPbCl3 and the electron transition of Mn2+ can be tuned gradually. This work highlights the feasibility of a postsynthetic interconversion of Pb2+ and Mn2+ in cesium lead chloride perovskite nanocrystals, which enables a new strategy to reduce the toxicity and adjust the emissions of CsPbCl3 NCs. In the end, we also discuss the plausible mechanisms for cation exchange in perovskite materials.
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to partially exchange Pb2+ ions in CsPbBr3 perovskites with several other divalent cations (Sn2+, Cd2+, and Zn2+).42 The partial Pb2+ for M2+ exchange leads to a blue shift in the optical spectra while maintaining the high photoluminescence quantum yields (>50%), sharp absorption features, and narrow emission of the parent CsPbBr3 NCs. This work opens up new possibilities to engineer the properties of halide perovskite NCs after synthesis. CsPbCl3 perovskite is another kind of potential material recently synthesized for blue emission. Wenyong Liu et al. reported Mn2+-doped CsPbCl3 perovskites with low concentrations and realized emissions from both the host CsPbCl3 and the Mn2+ ions at approximately 402 and 586 nm, respectively. In addition, the anion exchange between Cl− and Br− affords the opportunity to finely and reversibly tune the band gap of the perovskite NCs, which provides opportunity for application as dual-color emitters. The substitution ratio of Mn2+ is low (
