Submicron Structure Confined Polymers for High-Performance Intrinsically Stretchable Light-Emitting Diodes

Stretchable polymer light-emitting diodes (PLEDs) hold promises for skin-like wearable displays, yet simultaneously achieving high stretchability, efficient luminescence performance, and facile integration remains challenging. Here, a novel strategy introducing microcrystalline elastomer into light-emitting polymer matrices to fabricate intrinsically stretchable PLEDs that meet all these characteristics is presented. This approach enables the formation of submicron optical self-gain structures in light-emitting polymers and the structures confine polymers to form a nanofiber morphology through spatial nanoconfinement effects, which improves polymer crystallinity, facilitates carrier transport, and enhances light outcoupling efficiency through increased reflection and scattering. Leveraging these characteristics, the intrinsically stretchable PLEDs achieved a current efficiency (CE) of 13.70 cd A^-1, an external quantum efficiency (EQE) of 4.70%, a low turn-on voltage of 3.70 V and a luminance of 32 013 cd m^{- 2} at 9 V. Additionally, 12 × 12 intrinsically stretchable PLED arrays are fabricated by electrohydrodynamic printing, which exhibit excellent photoelectric stability under tensile and bending strain. This approach holds significant potential for high-performance stretchable and wearable displays.