Wu Chen1, Yatao Zou1, Tian Wu1, Muyang Ban1, Vincenzo Pecunia1, Yujie Han1, Qipeng Liu1, Tao Song1, Steffen Duhm1, Baoquan Sun1
1Jiangsu Key Laboratory for Carbon‐Based Functional Materials & Devices Institute of Functional Nano & Soft Materials (FUNSOM) and Collaborative Innovation Center of Suzhou Nano Science and Technology Soochow University 199 Ren'ai Road Suzhou 215123 P. R. China
Tóm tắt
All‐inorganic perovskite light‐emitting diodes (LEDs) reveal efficient luminescence with high color purity, but their modest brightness and poor stability are still critical drawbacks. Here, the luminescent efficiency and the stability of perovskite LEDs (PeLEDs) are boosted by antisolvent vapor treatment of CsPbBr3 embedded in a dielectric polymer matrix of polyethylene oxide (PEO). A unique method is developed to obtain high quality CsPbBr3 emitting layers with low defects by controlling their grain sizes. CsPbBr3 in PEO matrix is post‐treated with antisolvent of chloroform (CF), leading to microcrystals with a size of ≈5 µm along the in‐plane direction with active emitting composite of 90%. A device based on CF post‐treatment (CsPbBr3‐PEO‐CF) film displays a brightness of up to 51890 cd m−2 with an external quantum efficiency of 4.76%. CsPbBr3‐PEO‐CF PeLED still maintains 82% of its initial efficiency after 80 h continuous operation in ambient air, which indicates relatively good device stability. This work highlights that film quality is not only key to promoting fluorescence in CsPbBr3, but also to achieving higher performance PeLEDs.
