Ou Jianfeng, Guo Xiaoyang, Lv Ying, Fan Yi, Li Yantao, Zou Deyue, Bao Zhiqiang, Song Li, Liu Xingyuan
State Key Laboratory of Luminescence and Applications, Changchun Institute of Optics, Fine Mechanics and Physics, Chinese Academy of Sciences, Changchun 130033, China.
University of Chinese Academy of Sciences, Beijing 100049, China.
ACS Appl Mater Interfaces. 2021 Dec 22;13(50):60571-60580. doi: 10.1021/acsami.1c15477. Epub 2021 Dec 10.
Accumulating evidence shows that metal halide perovskite light-emitting diodes (PeLEDs) are well-described to show broad application prospects in lighting and display due to the wide color gamut and high color purity. However, it is still a great challenge to prepare high-quality all-inorganic PeLEDs by a solution method. For example, it is difficult to obtain all-inorganic perovskite films with good crystallinity and high grain orientation because of too fast and uncontrollable crystallization of all-inorganic perovskite films. Here, we demonstrated a multifunctional interface of formamide (FA)-doped PEDOT:PSS, which improved the crystallinity of all-inorganic perovskite films by inducing grain arrangement. As a result, a highly crystalline, ordered, and defect-passivated CsPbBr film was obtained by the multiple roles of FA, and the CsPbBr-based PeLED treated with FA achieved both high brightness and high efficiency: the peak external quantum efficiency (EQE) reaches 9.61%, and the maximum brightness is 185,000 cd/m. In addition, Tween 80, used as a passivator of perovskite films, reduced the defect states and suppressed ion migration. Under the synergistic effect of FA interface treatment and Tween 80 passivation treatment, efficient CsPbBr-based PeLEDs were obtained with an EQE of 15.02% and an operation lifetime of 182.5 min at an initial brightness of 1000 cd/m, which is among the best reported lifetimes under high brightness. Our study provides a simple and effective strategy for the realization of all-inorganic PeLEDs with high efficiency, high brightness, and ultralong operation lifetime.
越来越多的证据表明，金属卤化物钙钛矿发光二极管（PeLEDs）因其色域广、色纯度高，在照明和显示领域具有广阔的应用前景。然而，通过溶液法制备高质量的全无机PeLEDs仍然是一个巨大的挑战。例如，由于全无机钙钛矿薄膜的结晶速度过快且无法控制，很难获得具有良好结晶度和高晶粒取向的全无机钙钛矿薄膜。在此，我们展示了一种甲酰胺（FA）掺杂的PEDOT:PSS多功能界面，它通过诱导晶粒排列提高了全无机钙钛矿薄膜的结晶度。结果，通过FA的多重作用获得了高度结晶、有序且缺陷钝化的CsPbBr薄膜，用FA处理的基于CsPbBr的PeLED实现了高亮度和高效率：峰值外量子效率（EQE）达到9.61%，最大亮度为185,000 cd/m²。此外，吐温80用作钙钛矿薄膜的钝化剂，减少了缺陷态并抑制了离子迁移。在FA界面处理和吐温80钝化处理的协同作用下，获得了高效的基于CsPbBr的PeLEDs，在初始亮度为1000 cd/m²时，EQE为15.02%，工作寿命为182.5分钟，这是在高亮度下报道的最佳寿命之一。我们的研究为实现具有高效率、高亮度和超长工作寿命的全无机PeLEDs提供了一种简单有效的策略。
