Multi-site anchoring lead-halide octahedral by benzylphosphonic acid to regulate phase distribution for efficient PeLEDs  

作　　者：Jiahao Tang Yifei Wang Hengyang Xiang Run Wang Kun Zhang Xinyi Lv Xinrui Chen Ziqing Xu Zhesheng Chen Lei Wang Aidi Zhang An Xie Haibo Zeng 

机构地区：[1]MIIT Key Laboratory of Advanced Display Materials and Devices, Institute of Optoelectronics and Nanomaterials, College of Materials Science and Engineering, Nanjing University of Science and Technology, Nanjing, 210094, China [2]Wuhan National Laboratory for Optoelectronics, Huazhong University of Science and Technology, Wuhan, 430074, China [3]Engineering Research Center of Functional Polymer Membrane Materials of Jiangsu Province, Nanjing Bready Advanced Materials Technology Co., Ltd., Nanjing, 211103, China [4]School of Materials Science and Engineering, Xiamen University of Technology, Xiamen, 361024, China

出　　处：《Nano Research》2024年第11期10034-10041,共8页纳米研究（英文版）

基　　金：financially supported by the National Key Research and Development Program of China(No.2022YFB3606502);the National Natural Science Foundation of China(Nos.52131304 and 62004101).

摘　　要：Quasi-two-dimensional perovskite light-emitting diodes (quasi-2D PeLEDs) are emerging as high-potential candidates for new generation of wide-color gamut displays due to their simple, low-cost solution process, and high color purity. However, the luminescence performance of quasi-2D perovskite films is severely limited by dispersed phase distribution and excessive defect density, which are caused by excessive diffusion of nucleation sites during the perovskite growth stage. Here, the benzylphosphonic acid (BPA) molecule, owing to its strong P-O-Pb bond energy sites and strong electronegativity to PEA+, can aggregate lead-halide octahedron to grow high-dimensional phases, avoiding scattered low-dimensional phases (n = 1). The continuous gradient phase distribution will be beneficial to smooth carrier injection and effectively suppress the leakage current in PeLEDs. Meanwhile, the introduction of phosphonic acid groups will fill the vacancies of Pb ions and reduce non-radiative recombination. As a result, the maximum external quantum efficiency (EQE) of PeLEDs can be increased from 8% to 20.6% with a 514 nm light emission and a 21 nm full-width half maximum, and the device lifetime (T 50) is nearly 6-fold of the pristine sample. In addition, this strategy is also suitable for other wavelength. For example, in blue light, performance improvement is also realized that the maximum EQE of 8% and the luminance increased from 1045 to 5264 cd/m2. These results provide a feasible strategy to regulate the phase distribution and passivate the defects of quasi-2D perovskites.

关 键 词：quasi-2D perovskites light-emitting diodes benzylphosphonic acid phase distribution defect passivation 

分 类 号：TN312.8[电子电信—物理电子学]