Perovskite light-emitting diodes (PeLEDs) are promising for next-generation high-definition displays. One of the keys to achieving high performance PeLEDs lies in how to fabricate crystalline and dense perovskite films. However, there exist challenges to directly grow well-crystallized CsPbBr₃ nanocrystal thin films on transport layers due to low solubility in solvents and fast precipitation of all-inorganic CsPbBr₃, and the corresponding bright, efficient, and stable green PeLEDs have rarely been reported. Herein, we report an efficient strategy to prepare well-crystallized and dense CsPbBr₃ nanocubes for ultrabright and efficient green PeLEDs. We introduce sulfobetaine zwitterion as crystallization control agent and strontium fluoride nanocrystals as nucleation seeds to grow high-quality CsPbBr₃ nanocube films. Eventually, the CsPbBr₃ films enable green PeLEDs with a maximum luminance of 162 767 cd m^–2 and a champion external quantum efficiency of 21.3% along with a narrow spectral line width of ∼14.7 nm, representing state-of-the-art performances in green PeLEDs.

中文翻译：

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由结晶良好的致密 CsPbBr3 纳米立方体实现的超亮和高效绿色钙钛矿发光二极管


钙钛矿发光二极管 （PeLED） 有望用于下一代高清显示器。实现高性能 PeLED 的关键之一在于如何制造晶体和致密钙钛矿薄膜。然而，由于在溶剂中的溶解度低且全无机 CsPbBr₃ 的快速沉淀，在传输层上直接生长结晶良好的 CsPbBr₃ 纳米晶薄膜存在挑战，相应的明亮、高效和稳定的绿色 PeLED 很少见报道。在此，我们报道了一种用于超亮和高效绿色 PeLED 制备结晶良好且致密的 CsPbBr₃ 纳米立方体的有效策略。我们引入磺基甜菜碱两性离子作为结晶控制剂，引入氟化锶纳米晶体作为成核种子，以生长高质量的 CsPbBr₃ 纳米立方体薄膜。最终，CsPbBr₃ 薄膜使绿光 PeLED 的最大亮度为 162 767 cd m^–2，冠军外部量子效率为 21.3%，光谱线宽为 ∼14.7 nm，代表了绿光 PeLED 的先进性能。