Highly flexible ultrathin organic light emitting diodes (OLEDs) hold vast potential as light sources particularly for wearable and imperceptible electronics. Most of the work demonstrated to date for highly flexible OLEDs, however, has relied on non-conventional transparent conductors such as conjugated polymers and has had no proper encapsulation or, if any, simple polymer-based encapsulation. We here demonstrate OLEDs that can be bent at a sub-mm radius even with conventional transparent conductive oxides (TCOs) and full encapsulation based on a multilayer gas barrier containing aluminum oxides, both of which are prone to strain-induced fracture. We realize such a small bending radis not only by adopting ultrathin substrates but also by exploiting the beneficial neutral plane shift toward the top of substrates identified in a system consisting of a ultrathin substrate and a multilayer device structure on its top. The proposed OLEDs exhibit stable performance after 1,000 bending iterations even at a bending radius far smaller than 1 mm and show similar reliability to that of glass-based reference devices even after two weeks in the acceleration test chamber.

高度灵活的超薄有机发光二极管（OLED）具有巨大的潜力，尤其是作为可穿戴和不可感知电子设备的光源。迄今为止，已证明的有关高柔性OLED的大多数工作都依赖于非常规的透明导体（例如共轭聚合物），并且没有适当的封装，或者如果有的话，也没有基于聚合物的简单封装。我们在这里展示了即使使用常规的透明导电氧化物（TCO）以及基于包含氧化铝的多层阻气层的完全封装也可以弯曲到亚毫米半径的OLED，这两种方法都容易引起应变破裂。我们不仅可以通过采用超薄基板来实现如此小的弯曲半径，还可以通过利用朝着由薄基板及其顶部的多层器件结构组成的系统中确定的基板顶部的有益中性面偏移来实现如此小的弯曲半径。所提出的OLED即使在弯曲半径远小于1 mm的情况下，在经过1000次弯曲迭代后仍表现出稳定的性能，并且即使在加速测试室中放置两周后，其显示的可靠性也与基于玻璃的参考设备相似。