Improving the integrity and stiffness of CsPbBr3 crystal to achieve narrow color saturation blue light emission

• Quantum-confined CsPbBr3 perovskites are promising blue-light emitters for ultra-high-definition displays, but their stability is limited by the soft lattice caused by their highly ionized nature.

  
  

  Here, Weijia Zheng of Victoria University, Xiaoyu Zhang of Jilin University, and Andrey L. Rogach of City University of Hong Kong, and others , utilize strongly binding N-dodecylbenzene sulfonic acid (DBSA) to endow CsPbBr3 nanosheets ( NPLs) atomic crystal-like structural rigidity. By optimizing the intermediate reaction stages, the transition from molecular cluster aggregation to single octahedron, and the interaction with DBSA leading to the formation of a CsxO monolayer shell covering the NPL surface, the stable and rigid crystal structure of these NPLs as well as the uniform, surface uniformity were achieved. Arrange in order.

  
  

  Therefore, the strong covalent bonding of DBSA enhances the structural and optical stability of CsPbBr3 NPLs, inhibiting the undesirable phase transition and decomposition of the perovskite phase that may be caused by ligand desorption. Furthermore, the smaller amount of DBSA ligands on the NPL surface results in shorter NPL spacing in their closely aligned films, which facilitates efficient charge injection and transport. The blue photoluminescence of the produced CsPbBr3 NPLs is bright (almost reaching the unit emission quantum yield), with a peak value of 457nm at 80K, and an extremely narrow bandwidth of only 3.7nm, while the bandwidth of the electroluminescence at room temperature (at 460nm peak) also reached a record 15nm. This value corresponds to CIE coordinates (0.141, 0.062) and complies with the Rec. 2020 standard for ultra-high definition displays.

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• Huang, Q., Yin, W., Gao, B. et al. Enhancing crystal integrity and structural rigidity of CsPbBr3 nanoplatelets to achieve a narrow color-saturated blue emission. Light Sci Appl 13, 111 (2024).

  
  

  https://doi.org/10.1038/s41377-024-01441-1