Bright and Effectual Perovskite Light-Emitting Electrochemical Cells Leveraging Ionic Additives
Bright and Effectual Perovskite Light-Emitting Electrochemical Cells Leveraging Ionic Additives
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DOI：
10.1021/acsenergylett.9b01925
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发表时间：
2019-12-01
影响因子：
22
通讯作者：
Zakhidov, Anvar A.
中科院分区：
文献类型：
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作者：
Alahbakhshi, Masoud;Mishra, Aditya;Zakhidov, Anvar A.
钙钛矿发光二极管因其良好的光电性能而受到广泛关注。钙钛矿发光电化学电池（Pe-LECs）是一种利用移动离子的器件，最近有报道，但尚未达到最好的pe - leds的性能。我们在CsPbBr3薄膜中利用聚（环氧乙烷）电解质和锂盐来生产亮度和效率更高的PeLECs。特别是，我们发现含有0.5 wt % LiPF6的CsPbBr3:PEO:LiPF6的单层PeLEC产生明亮的（类似于5000 cd/m(2)）电致发光，效率提高（3.0 Lm/W）。为了了解这种性能的提高，我们用光致发光（PL）光谱、扫描电子显微镜（SEM）、原子力显微镜（AFM）、x射线光电子能谱（XPS）和x射线衍射（XRD）对这些钙钛矿薄膜进行了表征。这些研究表明，这种最佳LiPF6浓度可以改善双电层的形成，减少空隙、电荷陷阱和针孔的出现，并增加晶粒尺寸和堆积密度。
Perovskite light-emitting diodes (PeLEDs) have drawn considerable attention for their favorable optoelectronic properties. Perovskite light-emitting electrochemical cells (Pe-LECs)-devices that utilize mobile ions-have recently been reported but have yet to reach the performance of the best PeLEDs. We leveraged a poly(ethylene oxide) electrolyte and a lithium salt in CsPbBr3 thin films to produce PeLECs of improved brightness and efficiency. In particular, we found that a single-layer PeLEC from CsPbBr3:PEO:LiPF6 with 0.5 wt % LiPF6 produced bright (similar to 5000 cd/m(2)) electroluminescence of improved efficiency (3.0 Lm/W). To understand this improved performance among PeLECs, we characterized these perovskite thin films with photoluminescence (PL) spectroscopy, scanning electron microscopy (SEM), atomic force microscopy (AFM), X-ray photoelectron spectroscopy (XPS), and X-ray diffraction (XRD). These studies revealed that this optimal LiPF6 concentration improves electrical double-layer formation, reduces the occurrence of voids, charge traps, and pinholes, and increases grain size and packing density.