Science · 1995 · 282 citations · 24 references
EngineeringOrganic ElectronicsDevice LifetimeChemical EngineeringLight-emitting DiodesElectronic PackagingPolymer ChemistryMaterials ScienceElectrical EngineeringOrganic SemiconductorNew Lighting TechnologyElectron TransportFunctional MaterialsElectron-transporting Organic MaterialsOrganic MaterialsOrganic Charge-transfer CompoundWhite OledSemiconducting PolymerPolymer ScienceOptoelectronicsOperating Lifetime
Operating lifetime is the main problem that complicates the use of polymeric light-emitting diodes (LEDs). A class of electron transport (ET) polymers [poly(aryl acrylate) and poly(aryl ether)s] is reported in which moieties with high electron affinities are covalently attached to stable polymer backbones. Devices based on poly(p-phenylenevinylene) (PPV) prepared with these materials exhibited a 30-fold improvement in stability and, in one case, dramatically lower (10 volts versus about 30 volts) operating voltage relative to those having conventional ET layers. The current-carrying capacity of indium tin oxide-PPV-polymeric ET layer-aluminum LEDs was also increased by a factor of 30. These improvements lead to an enhancement in power efficiency of nearly an order of magnitude. Choosing polymers with high glass transition temperatures increases device lifetime.
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Organic electroluminescent diodes
Chak Wah Tang, S. A. VanSlyke · Applied Physics Letters · 1987 · 14.1K citations
Light-emitting diodes based on conjugated polymers
J. H. Burroughes, Donal D. C. Bradley, Adam R. Brown et al. · Nature · 1990 · 11.3K citations