1. Tetrafluoroborate-Passivated CsPbBrxCl3–x Nanocrystals for Spectrally Stable Pure Blue Perovskite Light-Emitting Diodes.
- Author
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Chen, Tian, Ru, Xue-Chen, Ma, Zhen-Yu, Feng, Li-Zhe, Song, Kuang-Hui, Ge, Jing, Zhu, Bai-Sheng, Yang, Jun-Nan, and Yao, Hong-Bin
- Abstract
Mixed halide perovskite nanocrystals show great promise for high-performance light-emitting diodes (LEDs) due to their tunable band gaps, high photoluminescence efficiency, and excellent color purity. However, one major challenge in using mixed halide CsPbBr
x Cl3–x NCs for pure blue LEDs is the instability of their electroluminescence (EL) caused by halide segregation. Here, we report an effective pseudohalide tetrafluoroborate (BF4 – ) passivation approach to improve the EL stability of CsPbBrx Cl3–x NC-based LEDs. Our approach involves the solution-processed treatment of CsPbBrx Cl3–x NCs by the complex of tributylphosphine oxide and calcium tetrafluoroborate, which yields pseudohalide BF4 – -passivated CsPbBrx Cl3–x NCs. The BF4 – fills the surface halide ion vacancy, providing dual benefits of surface passivation and halide migration suppression. By using these BF4 – -passivated CsPbBrx Cl3–x NCs as the emitting layer, we have successfully fabricated spectrally stable and pure blue LEDs with an emission peak at 468 nm, a maximum luminance of 275 cd/m2 , and a maximum external quantum efficiency of 3.2%. Our proposed BF4 – -passivated NCs strategy will pave the way for the development of efficient, stable, and pure blue perovskite LEDs. [ABSTRACT FROM AUTHOR]- Published
- 2024
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