Constructing multifunctional polymer-terminated surfaces to achieve high-performance flexible perovskite LEDs

• Flexible perovskite light-emitting diodes (f-PeLEDs) have attracted increasing attention for achieving true-color, low-cost, and lightweight wearable optoelectronics and flexible display applications. However, their external quantum efficiency (EQE) and mechanical stability lag far behind due to the intrinsic surface and brittleness issues of polycrystalline perovskite films.

  
  

  In this work, Wenbin Guo from Jilin University and Wallace CH Choy from the University of Hong Kong et al. constructed a multifunctional perovskite film polymer-terminated surface to achieve efficient and mechanically stable f-PeLEDs. Its role is not only to reduce defects and improve emission performance through coordination groups, but also to optimize film morphology, eliminate pinholes, and solve the long-standing leakage current problem. At the same time, the polymer-terminated surface with anchor points on the perovskite and the polymer soft chain show stronger synergistic effects than pure functional group or pure polymer strategies in reducing Young's modulus and improving mechanical flexibility.

  
  

  Finally, a record-breaking EQE of 22.1% and significantly enhanced mechanical stability were achieved in pure green f-PeLEDs, maintaining 82% of the initial performance after 2000 bending cycles at a radius of 5 mm. This work paves the way for the development of high-performance flexible optoelectronic devices.

• 
• 
• 
• 

• C. Liu, D. Zhang, J. Sun, D. Li, Q. Xiong, B. Lyu, W. Guo, W. C. H. Choy, Constructing Multi-Functional Polymeric-Termination Surface Enables High-Performance Flexible Perovskite LEDs. Adv. Funct. Mater. 2024, 2404791.

  
  

  https://doi.org/10.1002/adfm.202404791