Yang Xianqi, Gu Huaimin, Li Shuti, Li Jihang, Shi Hengzhi, Zhang Jinyuan, Liu Nana, Liao Zebing, Xu Wenzhu, Tan Yuan
Institute of Semiconductor Science and Technology, South China Normal University Guangzhou Guangdong China
RSC Adv. 2019 Oct 25;9(59):34506-34511. doi: 10.1039/c9ra05053a. eCollection 2019 Oct 23.
The exceptional optical and electronic properties of all-inorganic cesium lead bromide (CsPbBr) perovskite make it an ideal new optoelectronic material, but low surface coverage limits its performance. The morphological characteristics of thin films have a great influence on the performance of perovskite light emitting diodes, especially at low coverage, and an inhomogeneous surface will lead to current leakage. To tackle this problem, the widespread adoption of composite layers including polymers poly(ethylene oxide) (PEO) and organic insulating poly(vinylpyrrolidone) (PVP) and all-inorganic perovskites is an effective way to increase the surface coverage and uniformity of perovskite films and improve the performance of perovskite light emitting devices. In our work, the perovskite thin films are investigated by using PEO and PVP dual additives, and the optimized CsPbBr-PEO-PVP LED with maximum luminance, current efficiency, and external quantum efficiency of 2353 cd m (at 7.2 V), 2.14 cd A (at 6.5 V) and 0.85% (at 6.5 V) was obtained. This work indicates that the method of using additives is not only the key to enhancing the quality of perovskite thin film, but also the key to achieving a higher performance perovskite LED.
全无机溴化铯铅（CsPbBr）钙钛矿优异的光学和电学性质使其成为一种理想的新型光电子材料，但低表面覆盖率限制了其性能。薄膜的形态特征对钙钛矿发光二极管的性能有很大影响，尤其是在低覆盖率时，表面不均匀会导致电流泄漏。为了解决这个问题，广泛采用包括聚环氧乙烷（PEO）和有机绝缘材料聚乙烯吡咯烷酮（PVP）以及全无机钙钛矿的复合层是提高钙钛矿薄膜表面覆盖率和均匀性以及改善钙钛矿发光器件性能的有效方法。在我们的工作中，通过使用PEO和PVP双添加剂对钙钛矿薄膜进行了研究，获得了优化后的CsPbBr-PEO-PVP发光二极管，其最大亮度、电流效率和外量子效率分别为2353 cd m（在7.2 V时）、2.14 cd A（在6.5 V时）和0.85%（在6.5 V时）。这项工作表明，使用添加剂的方法不仅是提高钙钛矿薄膜质量的关键，也是实现更高性能钙钛矿发光二极管的关键。
