Intrinsically Stretchable Fully π‐Conjugated Polymer Films Enabled by Supramolecular Plasticized Micro‐Crosslinking‐Network for Flexible Polymer Light‐Emitting Diodes

Stretchable fully π‐conjugated polymers (FπCPs) films with a fantastic optoelectronic property and outstanding deformation tolerance capacity, is a promising candidate for the fabrication of flexible optoelectronics devices. However, previous reported stretchable FπCPs films undergo irreversible chain slippage and alignment upon strain release, leading to plastic deformation, and consequently severe performance degradation during cyclic‐deformation operation. Herein, we proposed a supramolecular soft‐micro‐crosslinked strategy to achieve the stretchable p ‐ n FπCPs (P X ‐OXI 1‐X ‐HDI) films with a recoverable‐deformation ability for the flexible electronics. Three‐dimensional (3D) supramolecular micro‐crosslinked network formed by oxime‐urethane and hydrogen bonds allow for the excellent elastic deformation to dissipate transient stress while fundamentally suppressing permanent chain slippage. Micro‐crosslinked p ‐ n FπCPs free‐standing films achieved an elongation at break of > 40%. Flexible PLED based on P X ‐OXI 1‐X ‐HDI showed a stable green emission with brightness of ∼3300 cd cm −2 . Meanwhile, the performance of transferred PLED based on stretchable micro‐crosslinked films are independent on the tensile ratio (>20%) with a maximum brightness of ∼2000 cd m −2 , revealed the excellent cycle‐deformation‐stability than device based on crosslinked films. Therefore, these supramolecular micro‐crosslinked networks can enhance instantaneous toughness and confer a critical resistance to long‐term stress relaxation and plastic deformation, further ensure the device excellent deformation stability.