Vacuum-Assisted Preparation of High-Quality Quasi-2D Perovskite Thin Films for Large-Area Light-Emitting Diodes
Vacuum-Assisted Preparation of High-Quality Quasi-2D Perovskite Thin Films for Large-Area Light-Emitting Diodes
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DOI：
10.1002/adfm.202107644
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发表时间：
2021-10-07
影响因子：
19
通讯作者：
Guo, Fei
中科院分区：
文献类型：
--
作者：
Chen, Chaoran;Zeng, Linxiang;Guo, Fei
近年来，钙钛矿基发光二极管（PeLED）的电致发光效率取得了显著进展。然而，大多数高效器件的特点是只有几平方毫米的钙钛矿发光层通过不可扩展的方法沉积，这阻碍了它们在大面积照明和显示器中的有趣应用。在这里，设计了一种稳健的结晶方案，用于通过刮涂沉积高质量的钙钛矿发光层。该方法的核心是对新涂覆的前体膜进行真空处理，从而通过解耦前体沉积和随后的热退火来实现可控的结晶动力学。因此，获得了在均匀分布的2D和3D相之间具有有效能量分布的致密且均匀的钙钛矿薄膜。基于真空处理准二维三溴化铯铅层的PeLED器件在0.12和1 cm（2）的有源面积上分别实现了8.24%和6.12%的高外量子效率。通过制造具有明亮和均匀发射特性的3.5 x 3.5 cm（2）器件，进一步证明了该技术的可扩展性。这项工作提供了一个可行的方法，通过可扩展的方法进一步提高大面积PeLED的性能。
Recent years have witnessed marked progress in the electroluminescence efficiency of perovskite-based light emitting diodes (PeLEDs). Nevertheless, the majority of highly efficient devices feature only several square millimeters with the perovskite emitting layers deposited by nonscalable methods, which hinders their intriguing application in large-area lightings and displays. Here, a robust crystallization protocol is devised for the deposition of high-quality perovskite emitting layers by blade coating. Central to this method is the deployment of a vacuum process to the freshly coated precursor film, thereby achieving controllable crystallization kinetics by decoupling precursor deposition and the subsequent thermal annealing. Accordingly, dense and uniform perovskite thin films with efficient energy funneling among the evenly distributed 2D and 3D phases are obtained. PeLED devices based on the vacuum-processed quasi-2D cesium lead tribromide layers achieve high external quantum efficiencies of 8.24% and 6.12% on active areas of 0.12 and 1 cm(2), respectively. The scalability of the technology is further demonstrated by fabricating a 3.5 x 3.5 cm(2) device with bright and uniform emitting characteristic. This work offers a viable approach for further advancing the performance of large-area PeLEDs by scalable methods.