Pure Blue Electroluminescence by Differentiated Ion Motion in a Single Layer Perovskite Device
Pure Blue Electroluminescence by Differentiated Ion Motion in a Single Layer Perovskite Device
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单层钙钛矿型器件中差动离子运动产生的纯蓝色电致发光
DOI：
10.1002/adfm.202102006
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发表时间：
2021-06-04
影响因子：
19
通讯作者：
Slinker, Jason D.
中科院分区：
文献类型：
--
作者：
Mishra, Aditya;Alahbakhshi, Masoud;Slinker, Jason D.
蓝色电致发光对于用于显示应用和一般光电子学的新兴发光器件是高度期望的。然而，实现饱和、有效和稳定的蓝色发射一直是具有挑战性的，特别是在混合卤化物钙钛矿中，其中固有的离子运动和卤化物分离损害光谱纯度。在这里，利用CsPbBr 3-xClx钙钛矿、聚电解质和盐添加剂来展示来自单层发光电化学电池（LEC）的纯蓝色发射。电解质从盐添加剂中传输离子，增强电荷注入并稳定固有的钙钛矿发射晶格，以实现高纯和持续的蓝色发射。将Cl取代到CsPbBr 3中将钙钛矿发光从绿色调谐到蓝色。天蓝色和饱和蓝色设备分别产生国际照明委员会坐标（0.105，0.129）和（0.136，0.068），后者符合美国国家电视委员会的蓝色基色标准。同样，最大亮度为2900和1000 cd m（-2），外量子效率（EQE）的4.3%和3.9%，亮度半衰期为5.7和4.9小时，分别获得天蓝色和饱和蓝色设备。聚合物和LiPF 6夹杂物增加了光致发光效率，抑制卤化物偏析，诱导薄膜的平滑性和均匀性，并降低微晶尺寸。总的来说，这些器件在蓝色钙钛矿发光二极管（PeLED）和普通LEC中显示出上级性能。
Blue electroluminescence is highly desired for emerging light-emitting devices for display applications and optoelectronics in general. However, saturated, efficient, and stable blue emission has been challenging to achieve, particularly in mixed-halide perovskites, where intrinsic ion motion and halide segregation compromises spectral purity. Here, CsPbBr3-xClx perovskites, polyelectrolytes, and a salt additive are leveraged to demonstrate pure blue emission from single-layer light-emitting electrochemical cells (LECs). The electrolytes transport the ions from salt additives, enhancing charge injection and stabilizing the inherent perovskite emissive lattice for highly pure and sustained blue emission. Substituting Cl into CsPbBr3 tunes the perovskite luminescence from green through blue. Sky blue and saturated blue devices produce International Commission on Illumination coordinates of (0.105, 0.129) and (0.136, 0.068), respectively, with the latter meeting the US National Television Committee standard for the blue primary. Likewise, maximum luminances of 2900 and 1000 cd m(-2), external quantum efficiencies (EQEs) of 4.3% and 3.9%, and luminance half-lives of 5.7 and 4.9 h are obtained for sky blue and saturated blue devices, respectively. Polymer and LiPF6 inclusion increases photoluminescence efficiency, suppresses halide segregation, induces thin-film smoothness and uniformity, and reduces crystallite size. Overall, these devices show superior performance among blue perovskite light-emitting diodes (PeLEDs) and general LECs.