Ultra-thin and smooth transparent electrode for flexible and leakage-free organic light-emitting diodes

• DOI: 10.1038/srep09464
• Publication Date: 2015-03-31T09:05:25Z
• Authors: Ki-Hun Ok; Jiwan Kim; So-Ra Park; Youngmin Kim; Chan-Jae Lee; Sung-Jei Hong; Min-Gi Kwak; Namsu Kim; Chul Jong Han; Jong-Woong Kim
• Keywords: Leakage (economics)

Abstract A smooth, ultra-flexible and transparent electrode was developed from silver nanowires (AgNWs) embedded in a colorless polyimide (cPI) by utilizing an inverted film-processing method. The resulting AgNW-cPI composite had transparency of >80%, low sheet resistance 8 Ω/□ ultra-smooth surfaces comparable to glass. Leveraging the robust mechanical properties flexibility cPI, thickness film reduced less than 10 μm, which is conducive extreme flexibility. This exhibited durability, for both outward inward bending tests, up radius 30 while maintaining its electrical performance under cyclic (bending radius: 500 μm) 100,000 iterations. Phosphorescent, blue organic light-emitting diodes (OLEDs) were fabricated using these composites as bottom electrodes (anodes). Hole-injection poor, because AgNWs largely buried beneath composite's surface. Thus, we used simple plasma treatment remove thin cPI layer overlaying without introducing other conductive materials. As result, able finely control flexible OLEDs' electroluminescent enlarged pathways. devices showed only slight reductions <3% even after repeated foldings with μm radius.