A multinational team led by Seoul National University and Drexel University reports a flexible, stretchable OLED that preserves luminescence when stretched up to 1.6 times its original size, using an ExciPh layer and MXene-based transparent electrodes.

The device combines a flexible exciplex-assisted phosphorescent (ExciPh) layer with MXene-based electrodes to address luminescence durability under repeated bending and stretching.

The advancement centers on integrating ExciPh with transparent MXene stretchable electrodes to overcome deformation-related durability limits in flexible OLEDs.

Readers can access the full Nature paper via the linked article in the report.

Performance assessments include electroluminescence characteristics, transient responses, and recombination dynamics as the device undergoes strain.

Extended data figures explore the photophysics, morphology, and energy transfer of stretchable ExciPh-containing layers under mechanical strain, including high tensile strains.

The study analyzes exciplex-forming co-hosts versus exciplex-free systems to understand how deformation affects electroluminescent efficiency.

The work is supported by NSF and the National Research Foundation of Korea, with authors from Drexel, Seoul National University, Kyushu University, University of Tennessee, Yonsei University, and other institutions.

The ExciPh layer is an exciplex-assisted phosphorescent material that converts a large majority of excitons into light, surpassing 57% efficiency compared with 12–22% for conventional polymer layers.

The ExciPh layer boosts exciton usage to over 57% of generated excitons, significantly increasing light output relative to traditional OLEDs.

In short, ExciPh enhances both exciton formation and emission, achieving over 57% exciton-to-photon conversion.

The ExciPh layer is embedded in a thermoplastic polyurethane elastomer to improve mechanical flexibility and longevity.