Multifunctional Interfacial Molecular Bridge for Highly Efficient and Mechanically Robust Flexible Blue Perovskite Light‐Emitting Diodes

ABSTRACT Metal halide perovskites have emerged as promising candidates for flexible optoelectronics, yet the development of efficient blue‐emitting devices remains hindered by low charge utilization and poor mechanical durability. Herein, we propose a multifunctional molecular bridging strategy using trifluoroacetate (TFA − )‐based molecule to construct efficient and mechanically robust flexible blue perovskite light‐emitting diodes (PeLEDs). The TFA − bridge enhances interfacial adhesion and creates a stress‐redistributing network at the interface, effectively dissipating bending‐induced strain. Concurrently, this molecular bridge effectively modulates the crystallization of low‐dimensional perovskites through competitive coordination and hydrogen bond‐guided phase reorganization, facilitating efficient exciton confinement and energy transfer. The resulting flexible blue PeLEDs achieve an external quantum efficiency of 20.05% and outstanding bending durability, maintaining over 90% of their initial performance after 2000 cycles at a 5 mm radius. This work demonstrates the dual role of biomimetic molecular bridges in simultaneously stabilizing the bulk perovskite phase and the device interface, providing a generalizable route toward high‐performance and mechanically robust flexible optoelectronics.