有机光电半导体材料及其未来之应用(精)

有機光電半導體材料及其未來之應用InstituteofElectro-OpticalScienceandEngineering,NationalChengKungUniversity,Tainan,Taiwan701成功大學光電科學與工程研究所01/16/2007郭宗枋助理教授T.-F.GuoNCKUInstititeofElectro-OpticalScience&Engineering2Outlines•Semiconductors•Organicsemiconductors(energyanddelocalizationofchargecarriers)•OLEDsandPLEDs基礎原理和應用•Organnicphotovoltaicandsolarcells•ConclusionsT.-F.GuoNCKUInstititeofElectro-OpticalScience&Engineering3FundamentalscienceofinorganicsemiconductorsT.-F.GuoNCKUInstititeofElectro-OpticalScience&Engineering4TypicalSemiconductingMaterialsT.-F.GuoNCKUInstititeofElectro-OpticalScience&Engineering5EnergyBandDiagramofaconductor,semiconductor,andinsulator(a)aconductor(b)asemiconductor(c)aninsulatorT.-F.GuoNCKUInstititeofElectro-OpticalScience&Engineering6Beginningoforgnaicsemiconductor(πbonding)Side-by-SideBondingT.-F.GuoNCKUInstititeofElectro-OpticalScience&Engineering7Conjugated(共軛):alternativelydouble-singlebondsCHCHCHCHCHCHCHHCCHHCCHHCCHHCCHHCCHHCCHHCC雙鍵單鍵T.-F.GuoNCKUInstititeofElectro-OpticalScience&Engineering8BangGapofPolyacetylene………..……BandGapT.-F.GuoNCKUInstititeofElectro-OpticalScience&Engineering9ConjugatedpolymerSigmabondDelocalizedelectroncloud=2.4eVPPVOR1nOEg=2.1eVR2R1nEg=2.4eVR2nEg=3.0eVPPPnEg=1.4eVPAThroughthestructureengineering,polymerswithdifferentemittingcolorsweresynthesized.T.-F.GuoNCKUInstititeofElectro-OpticalScience&Engineering11DelocalizationofChargeCarriersinPolyacetyleneLocalized!Chargecannotgoanywhere!!!Delocalized!Chargecarrierscanmovearound!!!T.-F.GuoNCKUInstititeofElectro-OpticalScience&Engineering12DelocalizationandTransportofChargeCarriersT.-F.GuoNCKUInstititeofElectro-OpticalScience&Engineering13ConjugatedPolymers:BasicMaterialsandChemistry•Conductionpolymers:Polyacetylene,Polyaniline,PEDOT/PSS…etc.•Semiconductingpolymers:Polythiophenes,Oligothiophenes…etc.•Light-emitting/PhotovoltaicPolymers:Poly-(para-phenylene-vinylene),Poly(para-phenylene),Polyfluorene…etc.T.-F.GuoNCKUInstititeofElectro-OpticalScience&Engineering14ScientificInterestinOrganicMaterials•1950’s–steadyworkoncrystallineorganicsstarts•1970’s–organicphotoconductors(Xerography)•1980’s–organicnon-linearopticalmaterials•1987–Kodakfirstpublishedtheefficientorganiclight-emittingdevices(OLED)•1990–Cambridgegroupspublishthefirstpolymerlight-emittingdiodes(PLED)•Sincethen,thefieldhasdramaticallyexpandedbothcommerciallyandscientifically,includingOLED,PLED,transistors,potovoltaic,solarcells………T.-F.GuoNCKUInstititeofElectro-OpticalScience&Engineering15WhataretheOLEDs?•InventedbyDr.ChingWTang（鄧青雲博士）(kodak)1987年•OLED全名叫做有機發光二極體(OrganicLight-EmittingDiode)•部分國外又稱OEL為有機電激光顯示(OrganicElectroluminescenceDisplay)T.-F.GuoNCKUInstititeofElectro-OpticalScience&Engineering16OLEDBasicDeviceConfigurationDoublelayersstructure•電洞傳輸層-HoleTransport(injection)Layer(HTL)•電子傳輸層–ElectronTransportLayer(ETL)•發光層-EmittingLayer(EML)T.-F.GuoNCKUInstititeofElectro-OpticalScience&Engineering17FirstOLEDInventedbyDr.ChingWTang(kodak)1987T.-F.GuoNCKUInstititeofElectro-OpticalScience&Engineering18Absorption,Fluorescence&PhosphorescenceProcessT.-F.GuoNCKUInstititeofElectro-OpticalScience&Engineering19SingletexcitonsTripletexcitonshν1hν2fluorescencenon-radiationheate-/h+dissociationrecombinationIntersystemcrossingT-TannihilationphosphorescencedissociationcarrierseparationcarrierinjectionPhotophysicsprocessgroundstateT.-F.GuoNCKUInstititeofElectro-OpticalScience&Engineering20OperationofOLEDsGlassorPETsubstrateITOETLHTL+_+_++++++_______+CathodeAnodeT.-F.GuoNCKUInstititeofElectro-OpticalScience&Engineering21ElectroluminescenceofO/PLEDSinglelayerdeviceDoublelayerdevicePLEDDoublelayerdeviceOLEDT.-F.GuoNCKUInstititeofElectro-OpticalScience&Engineering22221/+-3symmetricstatesTriplets1antisymmetricstateSinglet1/++orsinglettriplethole(+)electron(-)exciton(*)MechanismofElectroluminescenceT.-F.GuoNCKUInstititeofElectro-OpticalScience&Engineering23Intersystemcrossing(ISC)S0S1T1GroundstateFluorescencePhosphorescenceFluorescenceandPhosphorescenceDecayfromsingletallowedbysymmetry:fastandoftenefficient.Decayfromtripletdisallowedbysymmetry:slowandusuallyinefficient.25%75%SingletexcitonTripletexcitonT.-F.GuoNCKUInstititeofElectro-OpticalScience&Engineering24DevicepreparationITO/GlasssubstrateOrganicmaterialsVacuum10-5torrLecturenoteofProf.Chou,NTUPhys.T.-F.GuoNCKUInstititeofElectro-OpticalScience&Engineering25WhatarePLEDs?•InventedbyRichard.H.Friend(UniversityofCambridge,CavendishLaboratory)1990年•PLED全名叫做高分子發光二極體(PolymerLight-EmittingDiode)•UsuallyforsinglelayerdeviceconfigurationT.-F.GuoNCKUInstititeofElectro-OpticalScience&Engineering26FirstPLEDInventedbyRichard.H.Friend(CambridgeUniversity,CavendishLaboratory)1990TheyusedAlasthecathodematerialatthattime.T.-F.GuoNCKUInstititeofElectro-OpticalScience&Engineering27SyntheticRoutetoPPVJ.H.Burroughes,D.D.C.Bradley,A.R.Brown,R.N.Marks,K.Mackay,R.H.Friend,P.L.Burns,andA.B.Holmes,Nature