Stretchable and Self-Healing Thermally Activated Delayed Fluorescence Polymer via Dynamic Hydrogen Bond Engineering for Durable Flexible OLEDs

The development of intrinsically stretchable and self-healing electroluminescent materials has remained a critical challenge for next-generation skin-like displays and biointegrated optoelectronics. Here, we report the first dynamic bond-engineered thermally activated delayed fluorescence (TADF) polyurethane (PUCN-x) that combines practical stretchability, high efficiency, and a robust self-healing capability. By integrating a TADF emitter into a segmented polyurethane backbone synthesized with isophorone diisocyanate (IPDI) and tunable polyalcohol soft segments, we achieve simultaneous control over the chain mobility and chromophore stacking. The resulting material exhibits exceptional functional recovery─after being subjected to stretching, bending, or scratch damage─and the polymer consistently maintains high electroluminescent performance. It demonstrates efficient self-healing under mild conditions (50 °C) without compromising luminescence, achieving a peak external quantum efficiency (EQE) of 13.3%. Optimized PUCN-1 retains over 85% of its original EQE after multiple damage-healing cycles, highlighting outstanding operational resilience. This work establishes a versatile molecular design strategy for durable, high-performance TADF elastomers, paving the way toward reliable, flexible displays and lighting technologies.