Preparing perovskite light emitting diodes (PeLEDs) by a solution process leads to inevitable imbalanced carrier injection and solvent erosion, which prevent us from obtaining high-performance PeLEDs. Here, we report a facile method to fabricate green-emitting PeLEDs with double hole transport layers (HTLs) that significantly promote the hole injection and charge balance. To address the problem of solvent erosion, 1,4-dioxane was adopted as the solvent for poly(9-vinylcarbazole) (PVK) and it was cast onto the surface of poly[(9,9-dioctylfluorenyl-2,7-diyl)-co-(4,40-(N-(p-butylphenyl))-diphenylamine)] (TFB). At the same time, an orthogonal solvent 1,4-dioxane was employed to improve the surface smoothness of the perovskite film on the double HTLs. The PeLEDs with TFB/PVK double HTLs showed a maximum current efficiency (CE) and an EQE of 53.5 cd A⁻¹ and 12.9%, respectively. The EQE of the device is about 1.7 and 3 times higher than that of the single HTL device with PVK and TFB, respectively. This remarkable improvement is mainly attributed to the cascade-like energy alignment of the double HTLs, which prevents charging in perovskite nanocrystals (NCs). This work offers a new insight into preparing high performance PeLEDs for displays and lighting devices.

中文翻译：

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基于双空穴传输层的高性能钙钛矿发光二极管

通过溶液法制备钙钛矿发光二极管（PeLED）导致不可避免的不平衡载流子注入和溶剂侵蚀，这使我们无法获得高性能的PeLED。在这里，我们报告了一种简便的方法来制造具有双空穴传输层（HTL）的绿色发光PeLED，该LED可显着促进空穴注入和电荷平衡。为了解决溶剂侵蚀的问题，采用1,4-二恶烷作为聚（9-乙烯基咔唑）（PVK）的溶剂，并将其浇铸到聚[（9,9-二辛基芴基-2,7-二基] ）-co-（4,40-（N-（p-丁基苯基））-二苯胺）]（TFB）。同时，使用正交溶剂1，4-二恶烷来改善双HTL上钙钛矿薄膜的表面光滑度。具有TFB / PVK双HTL的PeLED的最大电流效率（CE）和EQE分别为53.5 cd A ^-1和12.9％。该设备的EQE分别比具有PVK和TFB的单个HTL设备的EQE高1.7和3倍。这种显着的改善主要归因于双HTL的级联状能量排列，这防止了钙钛矿纳米晶体（NC）的带电。这项工作为准备用于显示器和照明设备的高性能PeLED提供了新的见解。