LED的發(fā)展與應用

LED江蘇恩洋光電科技股份有限公司LightEmittingDiode2017/1/26Contents

HistoryApplicationEpitaxyFabricationPackagingOLEDFutureThehistoryoflightingandLEDInancienttimes,therewerenolamps,sopeoplecouldonlyusefireforlighting.candlekerosenelampPeoplesteppedintotheworldoflight.ThefirstgenerationoflightingincandescentlampsIncandescentlampswerewidelyusedbecauseoftheextensiveapplicationofelectricity.ThesecondgenerationoflightingNow,fluorescentlampsarethemostwidelyused.ThethirdgenerationoflightingFluorescentlampscompactfluorescentlampLEDisthefourthgenerationoflighting.ThedevelopinghistoryofLEDs

TheapplicationofLEDLEDsignallightsStreetLightsA—LEDStreetLightsB—MetalHalideStreetLightsC—SodiumStreetLampsSolarStreetLampsAirportrunwaylightingandLEDtunnellampsAutomotiveApplicationwithLEDsLEDinteriorlightingBarLandscapeLightingMobileApplicationWithLEDsLEDScreenDisplayThepaintedscrollismadeupof44,000LEDs.TheOlympicringsaremadeupof2,000blueand44,794whiteLEDs.EpitaxyThefirstgenerationmaterials:Si,Ge;Thesecondgenerationmaterials:GaAs,InP,GaP,InAs,AlAs;Thethirdgenerationmaterials:SiC,ZnAs,GaN,diamand.Epitaxialgrowthtechnology(GaN-basedmaterials)MOCVD(metalorganicchemicalvapordeposition)MBE(molecularbeamepitaxy)HVPE(hydridevaporphaseepitaxy)ThechoiceofsubstratematerialsSapphirecommonused,fabricationmaturity,lowprice;largelatticedismatch,poorelectricconductivity,poorthermalconductivity.SiCsmalllatticedismatch,goodelectricconductivity;highprice.Silowprice,bigarea,highquality,goodelectricconductivity;largelatticedismatch.TheepitaxialstructureofGaN-basedLEDSubstrate(siliconorsapphire)AlNsufferlayern-typeSi-dopingGaNMulti-quantumwellp-typeMg-dopingGaNverticalstructureofepitaxialwafersiliconepitaxialwafersapphireepitaxialwaferFabricationHundredsofthousandsofLEDchipsareproducedononeepitaxialwafer.LEDchips1mm2Multi-quantumwells(MQW)verticalstructureofepitaxialwaferBluelightcomesfromMQW,whereisalsocalledactiveregion.CanwemakeLEDelectrodeswithverticalstructure?1.Theanswerdependsonthesubstrate.2.Theverticalstructurewillcausehighresistance.3.Itisnotgoodforfabricationwhenthetwoelectrodesare

atdifferentsides.PhotoetchingandICPetchingP-electrodeandn-electrode

aremadeatthesameside.ICP:InductivelyCoupledPlasmaTransparentelectrodeevaporationSincep-GaNlayerisinhighresistance,weneedtoevaporatetransparentelectrodetoimprovecurrentspreading.Theelectrodeisasthinasabout12nm,soitistransparent.LEDchiplateralstructureLEDchipVSverticalstructureLEDchipDifferentp-electrodestructuresToimprovecurrentspreadingandluminousefficiencyLEDchipsinourlabThemechanismofLEDbalancedstateThemechanismofLEDForwardvoltageisapplied.ThemechanismofLEDElectronsandholesrecombinetoemitlight.ThedevelopmentofLEDpackagingLEDPackagingTogettheinputsignalToprotecttheLEDchipsTogettheoutputofvisiblelightPurposeforpackaging1.PintypepackagingTwomainmethodsofLEDpackaging2.PlanarpackagingHowtomakewhiteLED?LEDissinglecolor,suchasred,yellow,green,blueandsoon.However,whiteismixedcolor.SoweneedtomixcolorstomakewhiteLED.TwomainmethodsofmakingwhiteLED1.blueLED+yellowphosphor=whiteLED2.red+green+blue=whiteOLED=OrganicLightEmittingDiodeItslight-emittingmechanismissimilartoLED.OLEDThestructureofOLEDAccordingtolight-emittingmaterials:SmallmolecularOLED:Alq3(八羥基喹啉鋁鋁)PolymerOLED(PLED)：PPV,MEH-PPVAccordingtodisplaymodels:PassiveMatrix(PM-OLED):AcitiveMatrix(AM-OLED):TFTFOLED:FlexibleOLEDClassificationThicknesscanbelessthan1mm.Lowcost;Simpleprocess;(30~40%).Self-luminous;Highlyefficientandkindtoenvironment.Lowdrivevoltageandlowpowerconsumption.Microsecondresponsetime(1000times)andwideperspective(>170°°).Highbrightness(100~14000cd/m2),widetemperaturerange(-30~80℃)AdvantagesLifeisusuallyonly5,000hours,lessthanthatofLCDatleast1millionhours.Colorpurityisnotenoughtoshowbrightandrichcolor.Large-sizeOLEDpanelproductionhasverylowyield(<30%),comparedwithLCD’s(>99%).Highpatentfees.DisadvantagesComparedwithIPhoneViewfromside(LG‘sfirstOLEDtelevision)FirstOLEDwirelessdigitalphotoframeofKODAKFirstOLEDnotebookintheworld(SUMSUNG)ApplicationBracketlightMilitarydisplayE-book;

E-magazine;E-newspaperTVanddisplayhead-mounteddisplayApplicationI’MCUTE!MynameisLED.Firstly,Iamsmaller.Secondly，Ineedlesspower.Thirdly，Ienjoylongerlife.Atthesametime，youcancallmeenergysavinglamp.It’slastbutnottheleast,I’’mafashiongirl.ThefutureofLEDWhenitcomestomyweakn