Kong Lingmei, Sun Changjiu, You Mengqing, Jiang Yuanzhi, Wang Guangzhao, Wang Lin, Zhang Chengxi, Chen Shi, Wang Sheng, Yang Shengyuan A, Wang Shenghao, Yang Yingguo, Zhang Xiaoyu, Yuan Mingjian, Yang Xuyong
Key Laboratory of Advanced Display and System Applications of Ministry of Education, Shanghai University, Shanghai200072, P. R. China.
Key Laboratory of Advanced Energy Materials Chemistry of Ministry of Education, Renewable Energy Conversion and Storage Center (RECAST), College of Chemistry, Nankai University, Tianjin300071, P. R. China.
Nano Lett. 2023 Feb 8;23(3):985-992. doi: 10.1021/acs.nanolett.2c04459. Epub 2023 Jan 30.
Despite the rapid progress in perovskite light-emitting diodes (PeLEDs), the electroluminescence performance of large-area perovskite devices lags far behind that of laboratory-size ones. Here, we report a 3.5 cm × 3.5 cm large-area PeLED with a record-high external quantum efficiency of 12.1% by creating an amphipathic molecular interface modifier of betaine citrate (BC) between the perovskite layer and the underlying hole transport layer (HTL). It is found that the surface wettability for various HTLs can be efficiently improved as a result of the coexistence of methyl and carboxyl groups in the BC molecules that makes favorable groups to selectively contact with the HTL surface and increases the surface free energy, which greatly facilitates the scalable process of solution-processed perovskite films. Moreover, the luminous performance of perovskite emitters is simultaneously enhanced through the coordination between C═O in the carboxyl groups and Pb dangling bonds.
尽管钙钛矿发光二极管（PeLEDs）取得了快速进展，但大面积钙钛矿器件的电致发光性能仍远远落后于实验室规模的器件。在此，我们报告了一种3.5厘米×3.5厘米的大面积PeLED，通过在钙钛矿层和底层空穴传输层（HTL）之间创建一种两性离子分子界面改性剂柠檬酸甜菜碱（BC），其外量子效率达到了创纪录的12.1%。研究发现，由于BC分子中甲基和羧基的共存，使得有利基团能够选择性地与HTL表面接触并增加表面自由能，从而有效地提高了各种HTL的表面润湿性，这极大地促进了溶液法制备钙钛矿薄膜的可扩展工艺。此外，通过羧基中的C═O与Pb悬键之间的配位作用，同时增强了钙钛矿发光体的发光性能。
