Spontaneous Self‐Assembly of Cesium Lead Halide Perovskite Nanoplatelets into Cuboid Crystals with High Intensity Blue Emission

Advanced Science

Sergey Gaponenko¹  Kaibo Zheng²  Tönu Pullerits²  Stephen V. Kershaw³  Andrey L. Rogach³  Shixun Wang⁴  Jianjun Tian⁴  Chenghao Bi⁴ 

[1] B. I. Stepanov Institute of Physics National Academy of Sciences of Belarus 68 Nezaležnasci Ave., 220072 Minsk Belarus;Department of Chemical Physics and NanoLund Lund University P. O. Box 124 22100 Lund Sweden;Department of Materials Science and Engineering and Centre for Functional Photonics (CFP) City University of Hong Kong Kowloon Hong Kong S.A.R.;Institute for Advanced Materials and Technology University of Science and Technology Beijing 100083 China;

关键词: blue emission;    cesium lead halide perovskite;    nanoplatelets;    quantum wells;    self‐assembly;   

DOI  :  10.1002/advs.201900462

来源: DOAJ

【 摘 要 】

Abstract Colloidal all‐inorganic perovskite nanocrystals have gained significant attention as a promising material for both fundamental and applied research due to their excellent emission properties. However, reported photoluminescence quantum yields (PL QYs) of blue‐emitting perovskite nanocrystals are rather low, mostly due to the fact that the high energy excitons for such wide bandgap materials are easily captured by interband traps, and then decay nonradiatively. In this work, it is demonstrated how to tackle this issue, performing self‐assembly of 2D perovskite nanoplatelets into larger size (≈50 nm × 50 nm × 20 nm) cuboid crystals. In these structures, 2D nanoplatelets being isolated from each other within the cuboidal scaffold by organic ligands constitute multiple quantum wells, where exciton localization on potential disorder sites helps them to bypass nonradiative channels present in other platelets. As a result, the cuboid crystals show an extremely high PL QY of 91% of the emission band centered at 480 nm. Moreover, using the same synthetic method, mixed‐anion CsPb(Br/Cl)3 cuboid crystals with blue emission peaks ranging from 452 to 470 nm, and still high PL QYs in the range of 72–83% are produced.

【 授权许可】

Unknown