Brittle materials-based fully stretchable organic light-emitting diodes

Stretchable small-molecule organic light-emitting diodes (OLEDs) are hampered by random cracking and efficiency degradation of inherently brittle small-molecule organic semiconductors (SMOS) under mechanical deformation, severely limiting their practical application. Herein, we propose an interfacial stress regulation strategy based on a hierarchical architecture. Departing from the conventional crack-suppression paradigm in stretchable optoelectronics, our strategy employs active crack engineering to guide controlled nanocrack formation, enabling the fabrication of nanocracked, fully stretchable OLEDs compatible with inherently brittle SMOS while achieving both high efficiency and excellent stretchability. The devices achieve a maximum brightness of 16,050 cd/m2, current efficiency of 85.7 cd/A, external quantum efficiency of 24.7%, and 250% tensile strain. Stable operation is maintained under complex deformations, while the strategy demonstrates broad universality for multicolor emission. This work offers a general strategy for integrating brittle high-performance SMOS into stretchable displays, advancing the development of wearable and conformal electronics. Stretchable devices are limited by random cracking and efficiency degradation under strain. Here, the authors present an active crack engineering strategy for brittle small-molecule organic semiconductors, enabling stretchable OLEDs with a maximum current efficiency of 85.7 cd A-1 and a tensile strain of 250%.