Organic Electronics (OE) Advanced Technology Program at GE Global ResearchMaterial Options for Transparent Hermetic BarrierDefect-Driven Moisture PermeationUltra-high Barrier: Single Layer ApproachUltra-high Barrier: Multilayered ApproachUltra-high Barrier: Graded ApproachGraded Ultra-high Barrier Plastic FilmUltra-high Barrier PlasticMSE5420 Flexible ElectronicsMartin Yan, GE Global ResearchOutline•Introduction to plastic substrate and need for barrier•Barrier technologies •WVTR measurement technologies•Summary2/September 30th, 20083/September 30th, 2008Source: Displaybank’s presentation on 2007 Flexible Display & Microelectronics ConferenceEvolution of Display Technology4/September 30th, 2008OLED TechnologyCathoden-layerp-layerAnodeLightSony XEL-1 11” OLED TVDZ7086 OLED watch by DieseliRiver SPINN A/V PlayerNokia Prism Mobile PhoneKodak EasyShare LS633 Camera5/September 30th, 2008Flexible OLED DisplaySource: UDC presentation on 2007 Flexible Display & Microelectronics Conference6/September 30th, 2008Replace Glass with Plastic SubstrateNOWGlass SubstratePlastic Advantages• Rugged.• Thinner.•Lighter.• Enable flexible display.• Enable R2R processing. FUTURE“Roll-Up Displays”Plastic Film SubstrateEnergy Consumption for Lighting: Year 200122% of the total electricity generated in the U.S. was used for lighting!Total U.S. Primary Energy Consumption for Lighting by SectorLighting Energy Consumption by Sector & SourceSource: U.S. Lighting Market Characterization Volume I:7/September 30th, 2008Need to replace incandescent with more efficient light technology!8/September 30th, 2008Organic Electronics (OE) Advanced Technology Program at GE Global ResearchTechnologies:Flexible substrateTransparent contactMetal contactVOrganic Active Layers“Newspaper-Like”Roll-to-Roll FabricationV• OLED Devices• Low Cost Manufacturing• High Barrier SubstrateHigh barrier substrate enables R2R OLED manufacturing.9/September 30th, 2008OLED Offers Novel FeaturesMechanical Flexibility Thin and Light Transparent Color Tunability10 /September 30th, 2008Source: Polymer Vision’s presentation on 5thFlexible Display and Microelectronics ConferenceSource: UDC’s presentation on 5thFlexible Display and Microelectronics ConferenceUDC’s Flexible Display ConceptPolymer Vision’s Flexible Display ConceptGE’s Flexible Lighting ConceptFlexible OLED Product ConceptsSource: Best Life Magazine – February 200611 /September 30th, 2008Opportunity for Plastic Substrate•Flex.Display-OLED-LCD•Digital Paper-E-paper- Postage•Lighting- General lighting- Back lighting•Solar Cell (PV)- Thin Film PVBarrier Plastic FilmMajor PlayersChallenges for Flexible OLED SubstrateThe ProblemOLEDPolymeric substrateTransparent electrodeH2OO2Commercial available polymeric substrate12 /September 30th, 2008Transparent ConductorMoisture/Oxygen PermeabilityHole InjectorLight Emitting PolymerMetal CathodeUltra High BarrierUltra High BarrierTransparent AnodeMoisture OxygenLow Temp.PlasticHigh Temp.PolycarbonateLow Conductivity,Low Transmission AnodeHigh Conductivity,High TransmissionAnodeThermo-mechanical stability Optical TransmissionCTE Reduction / Stress BalanceCTE Reduction / Stress BalanceHigh CTE PlasticH2Olow 10-6g/m2/dayO2< 10-3cc/m2/day13 /September 30th, 2008< 40 Ohm/ sq> 90 %TShrinkage< 20 ppm/hr @150°CBendingdiameter <=1”Adhesion≥ 4BLight Emitting PolymerMetal CathodeUltra High BarrierUltra High BarrierTransparent AnodeHole InjectorSubstrate Requirement- Key Properties > 80 %TBarrier Substrate Development at GE Global ResearchPlastic Substrate FilmUltra-high Barrier CoatingChemical Resistant CoatingTransparent Conductor CoatingTechnology Development at GEEnableIntegrated Plastic OLED Substrate14 /September 30th, 2008Chem resist layerHigh heat polycarbonateGraded ultra high barrierChem resist layerTransparent electrodeOutline•Introduction to plastic substrate and need for barrier•Barrier technologies •WVTR measurement technologies•Summary15 /September 30th, 200816 /September 30th, 2008Material Options for Transparent Hermetic BarrierMoisture PermeabilityTime to Reach 50% of Outside RHRef. TraegerLog Thickness (meters)OTR through Perfect SiO2 Barrier:10nm ⇒ 10-24cc/m2/day10 nm continuous glass-like coatings would exceed the needs17 /September 30th, 2008Defect-Driven Moisture Permeation1 10 100 10000.010.11101001000Uncoated OTR @ 250 @ 100% O2SiNx Thickness (nm)Detection limitNon-Fickian Diffusion~ 100 defects/mm220x~1mmDefect Imaging w/ AcetoneBarrier performance of single layer inorganic coating is defect limited18 /September 30th, 2008Ultra-high Barrier: Single Layer Approach–Uni. Of Colorado: Atomic Layer Deposition of AlOx–Dow Corning: Plasma Enhanced Chemical Vapor Deposition of SiOxCy–Symmorphix: Sputtering of AlSixOySource: Symmorphix’s presentation on 4thFlexible Display and Microelectronics Conference19 /September 30th, 2008Ultra-high Barrier: Multilayered ApproachConcept for Multilayer UHBTens of µmHundreds of nmOrganic coatingInorganic coatingDefectsSource: VITEX’s presentation on 5thFlexible Display and Microelectronics ConferencePermeation Simulation: Multilayered Barrier20 /September 30th, 2008Assumptions: - 2 perfect barriers- each barrier has 1 defect- defects are offset/decoupledLowHighFick’s Law:Continuity:DiffusionEquation:0.1 1 100.11ConductionLimitedRegime Flux RatioDistance/OffsetOffsetDistanceFlux Ratio =Flux2 Layer SystemFlux 1Barrier SystemWork in this regime toachieve Ultra-High Barrier21 /September 30th, 2008Ultra-high Barrier: Graded ApproachXPS Spectrum of Graded UHBGE’s Graded Ultra High BarrierInorganic OrganiczoneContinuous composition transitionCross-sectional TEM of Graded UHB22 /September 30th, 2008Graded Ultra-high Barrier Plastic FilmParallel plate PECVDHigh T Lexan® filmLow temperature PECVD process is compatible with plastic substratesBase Film Surface Quality is Critical23 /September 30th, 2008Flexible OLED substrateThe ProblemOLEDPolymeric substrateTransparent electrodeH2OO2Commercial available polymeric substrate3,530 hrs at 23°C 40%RHThe Solution24 /September 30th, 2008OLEDChem resist layerHigh heat polycarbonateGraded ultra high barrierChem resist layerTransparent electrodeGE Barrier SubstrateH2OO212 mmProved that high barrier substrate is possibleKey USDC Specifications* GEGR Performance• Moisture Barrier 10-6g/m2/day low 10-5~mid 10-6(at 23°C 50 % RH)• Chemical Resistance acid, solvent, alkali Pass•