title: Flexible top-emitting organic light-emitting diodes using semi-transparent multi-metal layers.
abstract: In this paper, the improved device performance of top-emitting organic light-emitting diodes (TEOLEDs) with a thin multi-metal layer stack of nickel/silver/nickel (Ni/Ag/Ni) and aluminum/silver/aluminum (Al/Ag/Al) that were used as the anode and cathode on a flexible substrate is discussed. In particular, Indium-Tin-Oxide (ITO) as an anode electrode has been used recently even though it has some problems for flexible devices. Therefore we suggested that a thin multi-metal layer electrode as a new anode is fabricated instead of ITO anode. It was verified that the ITO-free TEOLEDs showed an enhanced probability of the recombination of the electrons and holes through an improved electron/hole charge balance. We also analyzed the optical and electrical characteristics using the current density, luminance, luminance efficiency, external quantum efficiency (EQE), CIE x, y coordinates, and EL spectra of flexible TEOLED devices were characterized. ITO-free, flexible, green-emitting OLEDs with a low cost and a simple process were demonstrated.
authors.affiliation: Department of Materials Science and Engineering, Hongik University, Seoul 121-791, Korea.
authors.forename: Gun Woo
authors.initials: GW
authors.lastname: Hyung
authors.forename: Jaehoon
authors.initials: J
authors.lastname: Park
authors.forename: Ja-Ryong
authors.initials: JR
authors.lastname: Koo
authors.forename: Seok Jae
authors.initials: SJ
authors.lastname: Lee
authors.forename: Ho Won
authors.initials: HW
authors.lastname: Lee
authors.forename: You Hyun
authors.initials: YH
authors.lastname: Kim
authors.forename: Woo Young
authors.initials: WY
authors.lastname: Kim
authors.forename: Young Kwan
authors.initials: YK
authors.lastname: Kim
mesh_terms: D004867:Equipment Design; D019544:Equipment Failure Analysis; D008029:Lighting / Q000295:instrumentation*; D053768:Metal Nanoparticles / Q000737:chemistry* / Q000648:ultrastructure*; D009930:Organic Chemicals / Q000737:chemistry*; D012031:Refractometry; D012666:Semiconductors
chemical_list: D009930:Organic Chemicals