Spatial Cross-Linking Strategy for Realizing Stable and Efficient Perovskite Light-Emitting Diodes toward Microscale Displays
Junming Ma, Lvpeng Yang, Yazhuo Xue, Yerun Gao, Haoyu Chen, Di Zhang, Zhenye Wang, Yunhui Kuang, Yu Yu, Ming Shao
Abstract
Low efficiency, poor stability, and lack of high-resolution patterning hinder the future commercialization of perovskite light-emitting diodes (PeLEDs). Herein, we developed a spatial cross-linking and photolithography strategy to fabricate quasi-2D perovskite films using pentaerythritol tetra(3-mercaptopropionate) (PETMP) and pentaerythritol allyl ether (PAE) as cross-linkers. These cross-linkers containing multiple cross-linking sites facially form hydrophobic and defect-passivating spatial networks at grain boundaries and the surface of perovskite, improving moisture resistance and device efficiency. The cross-linking networks also enhance the lattice rigidity and suppress the ion-migration in perovskite, reducing nonradiative recombination and improving device stability. Consequently, the optimized PeLEDs achieved a high external quantum efficiency (EQE) of 21.36%, and an unencapsulated device exhibits T 50 of 47 min at an initial brightness of 1000 cd m –2 . Besides, we used photolithography to pattern a perovskite pixel array with a size of ∼80 μm. Our work provides an effective methodology for efficient and stable PeLEDs for high-definition display applications.