Molecular Bridging Strategy Enables High Performance and Stable Quasi-2D Perovskite Light-Emitting Devices
Xinyu Bao, Yanbo Gao, Yue Liu, Zehua Xu, Fujun Zhang, Min Lu, Zhennan Wu, Yanjie Wu, Quan Wang, Yù Zhang, Yinghui Wang, Zhifeng Shi, Junhua Hu, Xue Bai
Abstract
Quasi-two-dimensional (quasi-2D) Ruddlesden–Popper (RP) perovskites have attracted extraordinary attention due to their favorable energy funnel structures and outstanding optical performance. However, quasi-2D perovskites commonly contain the disordered mixture of phases, which results in low energy transfer between phases and subsequently limits the performance of the device. In this work, 4′-(Aminomethyl)-biphenyl-3-carboxylic acid (4-ABCA) was introduced into PEA 2 (FAPbBr 3 ) 2 PbBr 4 (PEA = phenethylammonium) film. The experimental and theoretical investigations demonstrate that 4-ABCA can coordinate Pb 2+ and Br – with its carboxyl and amion groups, respectively, which reconstructs the phase distribution of PEA 2 (FAPbBr 3 ) 2 PbBr 4 film, and simultaneously reduces the van der Waals gap, resulting in the efficient energy transfer of carriers. Finally, the external quantum efficiency (EQE) of 23.15% and the maximal brightness of 133560 cd/m 2 were achieved in the green perovskite light-emitting diodes (PeLEDs) based on quasi-2D film by adding 4-ABCA. Notably, it is the highest brightness for the pure green quasi-2D PeLEDs reported in the literature.