Stretchable light-emitting materials are the key components for realizing skin-like displays and optical biostimulation. All the stretchable emitters reported to date, to the best of our knowledge, have been based on electroluminescent polymers that only harness singlet excitons, limiting their theoretical quantum yield to 25%. Here we present a design concept for imparting stretchability onto electroluminescent polymers that can harness all the excitons through thermally activated delayed fluorescence, thereby reaching a near-unity theoretical quantum yield. We show that our design strategy of inserting flexible, linear units into a polymer backbone can substantially increase the mechanical stretchability without affecting the underlying electroluminescent processes. As a result, our synthesized polymer achieves a stretchability of 125%, with an external quantum efficiency of 10%. Furthermore, we demonstrate a fully stretchable organic light-emitting diode, confirming that the proposed stretchable thermally activated delayed fluorescence polymers provide a path towards simultaneously achieving desirable electroluminescent and mechanical characteristics, including high efficiency, brightness, switching speed and stretchability as well as low driving voltage.

可拉伸发光材料是实现类皮肤显示和光学生物刺激的关键组件。据我们所知，迄今为止报道的所有可拉伸发射器都是基于仅利用单线态激子的电致发光聚合物，将其理论量子产率限制在 25%。在这里，我们提出了一种赋予电致发光聚合物可拉伸性的设计概念，该聚合物可以通过热激活延迟荧光利用所有激子，从而达到接近一致的理论量子产率。我们表明，我们将柔性线性单元插入聚合物主链的设计策略可以显着提高机械拉伸性，而不影响底层的电致发光过程。结果，我们合成的聚合物达到了 125% 的拉伸率，外量子效率为 10%。此外，我们展示了一种完全可拉伸的有机发光二极管，证实所提出的可拉伸热激活延迟荧光聚合物提供了一条同时实现理想的电致发光和机械特性的途径，包括高效率、亮度、开关速度和可拉伸性以及低驱动电压。