Research on stretchable OLEDs with high fill factor using a 3D rigid-Island platform

Abstract

Stretchable optoelectronic devices have conventionally been developed by combining rigid elements and stretchable connectors to ensure device functionality when subjected to stretching deformations. However, this approach, often involving two-dimensional rigid-island configurations, unavoidably compromises the density of active components to improve interconnector stretchability and maximum strain. In this context, we introduce a novel 3D buckled pop-up architecture for stretchable OLEDs, substantially reducing the lateral space occupied by the connectors. This reduction allows for a higher fill factor of active components and a significant enhancement in stretchability and maximum strain. These innovations are underpinned by a selective bonding approach employing a dimpled pop-up assisting adhesion blocking layer. This layer facilitates reliable out-of-plane buckling by reducing adhesion energy. Consequently, we achieve a simultaneous high initial fill factor (density) of 85% in the emission region and a remarkable increase in the lateral dimensions of the connecting region by 510%. With this proposed method, we present stretchable OLEDs that maintain consistent performance even after enduring 2,000 biaxial cycles at 40% system strain. Additionally, we confirm the mechanical robustness of the proposed system when subjected to convex deformation.