title: Ultra-thin and smooth transparent electrode for flexible and leakage-free organic light-emitting diodes.
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 electrode had a transparency of >80%, a low sheet resistance of 8 Ω/□, and ultra-smooth surfaces comparable to glass. Leveraging the robust mechanical properties and flexibility of cPI, the thickness of the composite film was reduced to less than 10 μm, which is conducive to extreme flexibility. This film exhibited mechanical durability, for both outward and inward bending tests, up to a bending radius of 30 μm, while maintaining its electrical performance under cyclic bending (bending radius: 500 μm) for 100,000 iterations. Phosphorescent, blue organic light-emitting diodes (OLEDs) were fabricated using these composites as bottom electrodes (anodes). Hole-injection was poor, because AgNWs were largely buried beneath the composite's surface. Thus, we used a simple plasma treatment to remove the thin cPI layer overlaying the nanowires without introducing other conductive materials. As a result, we were able to finely control the flexible OLEDs' electroluminescent properties using the enlarged conductive pathways. The fabricated flexible devices showed only slight performance reductions of <3% even after repeated foldings with a 30 μm bending radius.
authors.affiliation: Display Components &Materials Research Center, Korea Electronics Technology Institute, Seongnam 463-816, Korea.
authors.forename: Ki-Hun
authors.initials: KH
authors.lastname: Ok
authors.affiliation: Display Convergence Research Center, Korea Electronics Technology Institute, Seongnam 463-816, Korea.
authors.forename: Jiwan
authors.initials: J
authors.lastname: Kim
authors.affiliation: Display Convergence Research Center, Korea Electronics Technology Institute, Seongnam 463-816, Korea.
authors.forename: So-Ra
authors.initials: SR
authors.lastname: Park
authors.affiliation: Display Components &Materials Research Center, Korea Electronics Technology Institute, Seongnam 463-816, Korea.
authors.forename: Youngmin
authors.initials: Y
authors.lastname: Kim
authors.affiliation: Display Components &Materials Research Center, Korea Electronics Technology Institute, Seongnam 463-816, Korea.
authors.forename: Chan-Jae
authors.initials: CJ
authors.lastname: Lee
authors.affiliation: Display Components &Materials Research Center, Korea Electronics Technology Institute, Seongnam 463-816, Korea.
authors.forename: Sung-Jei
authors.initials: SJ
authors.lastname: Hong
authors.affiliation: Display Components &Materials Research Center, Korea Electronics Technology Institute, Seongnam 463-816, Korea.
authors.forename: Min-Gi
authors.initials: MG
authors.lastname: Kwak
authors.affiliation: Department of Mechanical Design and Production Engineering, School of Engineering, Konkuk University, Seoul 143-701, Korea.
authors.forename: Namsu
authors.initials: N
authors.lastname: Kim
authors.affiliation: Display Convergence Research Center, Korea Electronics Technology Institute, Seongnam 463-816, Korea.
authors.forename: Chul Jong
authors.initials: CJ
authors.lastname: Han
authors.affiliation: Display Components &Materials Research Center, Korea Electronics Technology Institute, Seongnam 463-816, Korea.
authors.forename: Jong-Woong
authors.initials: JW
authors.lastname: Kim
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