title: Polarizer-free, high-contrast inverted top-emitting organic light emitting diodes: effect of the electrode structure.
abstract: Circular polarizer (CP)-free, high-contrast inverted top-emitting organic light-emitting diodes (ITOLEDs) are demonstrated by using a semitransparent Ag electrode capped with a single dielectric layer as a top anode and Cs(2)CO(3) (1.5 nm)/Al (1.5 nm)/Cr (100nm) as a partially absorbing bottom cathode. Low luminous reflectance is achieved by combining the broadband absorption of Cr, the weak but inherent cavity structure, and the optimal thickness of the capping layer yielding a high transmittance of a top electrode. With the optimized organic capping layer, contrast-enhanced ITOLEDs exhibit a luminous reflectance as low as 3.6% with a large thickness margin. Their luminous efficiency is shown to be comparable to or even higher than that of CP-based conventional OLEDs.
authors.affiliation: Department of Electrical Engineering, Korea Advanced Institute of Science and Technology (KAIST), Guseong-dong, Daejeon, South Korea.
authors.forename: Hyunsu
authors.initials: H
authors.lastname: Cho
authors.forename: Seunghyup
authors.initials: S
authors.lastname: Yoo
mesh_terms: D004566:Electrodes; D004867:Equipment Design; D008029:Lighting / Q000295:instrumentation*; D008962:Models, Theoretical; D055096:Optical Devices; D009942:Organometallic Compounds / Q000737:chemistry; D013440:Sulfides / Q000737:chemistry; D017967:Zinc Compounds / Q000737:chemistry
chemical_list: D009942:Organometallic Compounds; D013440:Sulfides; D017967:Zinc Compounds; C547306:tris-(8-hydroxyquinoline)aluminum; C031238:zinc sulfide