Releasing the Trapped Light for Efficient Silver Nanowires-Based White Flexible Organic Light-Emitting Diodes

Flexible organic light-emitting diodes (OLEDs) are attracting tremendous attention due to their promise as a key element in bendable display and curved lighting applications. However, their performance in terms of efficiency and bendability is limited, since flexible transparent electrodes with superior electrical, optical, and mechanical properties are rare. Here, a multifunctional electrode architecture that is based on flexible plastic, and consists of electrically conductive silver nanowires, a nanopatterned ZnO outcoupling layer, and a hole-injection polymer layer, is proposed for the actualization of high-performance flexible OLEDs. The trapped light in the waveguide and substrate modes is effectively released by integrating aperiodic nanostructures into high-refractive-index ZnO layers on both sides of the plastic substrate. A maximum external quantum efficiency of 61.7% and a power efficiency of 126.6 lm W⁻¹ are achieved for the white-emission flexible OLEDs with broadband and angle-independent outcoupling enhancement. In addition, the proposed approach allows for high-level mechanical flexibility, retaining over 80% of the initial efficiency after 3000 cycles of repeated bending.