LED照明技术概述-中英文

('OverviewofLEDlightingtechnologyLEDSummaryLED(LightEmittingDiode),light-emittingdiode,isasolidstatesemiconductordevices,whichcanbedirectlyconvertedintoelectricitytolight.LEDistheheartofasemiconductorchip,thechipisattachedtooneendofastent,isthenegativeside,theotherendofthepowerofthecathode,theentirechippackagetobeepoxyresin.Semiconductorchipiscomposedoftwoparts,partoftheP-typesemiconductor,itinsidethehole-dominated,theothersideistheN-typesemiconductor,hereismainlyelectronic.Butlinkingthetwosemiconductors,amongthemtheformationofa"PNjunction."Whenthecurrentthroughthewiresroleinthischip,willbepushinge-P,Pzoneintheholewithelectroniccomposite,andthentobeissuedintheformofphotonenergy,andthisistheprincipleofLEDluminescence.Thewavelengthoflightthatisthecoloroflight,isformedbythePNjunctionofthedecisionsofthematerial.WiththeappearanceoftheWhiteLight-EmittingDiodes,theLEDalsodevelopedtobeusedforlighting.Itisanewtypeoflightsourceinthe21stcenturywithadvantagesofhighefficiency,long-lifespanandinvulnerabilitywhichcannotbecomparedwiththetraditionallightsources.Whenbeingpressuredwithpositivevoltage,theLEDcanemitsingle-color,discontinuouslight,whichbelongstoakindofOrganicElectroluminescentEffect.Varyingthechemiccomponentofthesemiconductormaterialbeingused,wecanmaketheLEDemitacertainlightwhichisveryclosedtoultravioletradiation,visiblelightandinfraredray.LEDhistory50yearsago,peoplehavetounderstandsemiconductormaterialscanproducelightofthebasicknowledge,thefirstcommercialdiodesin1960.EnglishistheLEDlightemittingdiode(LED)acronym,anditsbasicstructureisanelectroluminescentsemiconductormaterials,placedinawirerack,thensealedwithepoxyresinaround,thatis,solidpackage,Therefore,theprotectionoftheinternalbatteriescanplaytheroleofline,sotheseismicperformanceLEDgood.LEDisthecoreoftheP-typesemiconductorandcomponentsoftheN-typesemiconductorchips,theP-typesemiconductorandN-typesemiconductorbetweenatransitionlayer,calledthePNjunction.InsomesemiconductormaterialsinthePNjunction,theinjectionofasmallnumberofcarrier-carrierandthemajorityoftheextratimewillbeintheformoflightenergytorelease,thusthepowertodirectconversionofsolarenergy.PNjunctiononreversevoltage,afewhard-carrierinjection,itisnotluminous.Thisuseofinjectionelectroluminescentdiodesisproducedbytheprincipleoflight-emittingdiodes,commonlyknownasLED.Whenitinapositivestateofthework(thatis,atbothendswithforwardvoltage),thecurrentflowsfromtheLEDanode,cathode,semiconductorcrystalsontheissuefromtheultraviolettoinfraredlightofdifferentcolors,lightandthestrengthofthecurrents.InstrumentsusedforthefirstLEDlightsourceinstructions,butallkindsoflightcoloredLEDlightsintrafficandlargescreenhasbeenwidelyapplied,haveaverygoodeconomicandsocialbenefits.The12-inchredtrafficlightsasanexample,isusedintheUnitedStateshavelonglife,low-efficiency140wattincandescentlampasalightsource,itproduced2,000lumensofwhitelight.Theredfilter,theloss-90percent,only200lumensofredlightInthelightofthenewdesign,Lumiledscompanieshave18redLEDlightsource,includingthelossofcircuit,atotalpowerconsumptionof14wattstogeneratethesameopticaleffect.AutomotiveLEDlightsisalsothesourceofimportantareas.Forgenerallighting,peopleneedmorewhitelightsources.The1998whiteLEDsuccessfuldevelopment.ThisistheGaNLEDchipandYttriumAluminumGarnet(YAG)packagetogethercause.GaNchipoftheBlu-ray(λp=465nm,Wd=30nm),madeofhigh-temperaturesinteringoftheCe3+YAGphosphorsexcitedbythisBlu-rayafterirradiatingayellow,thepeak550nm.Blue-chipinstalledintheLED-basedWanxingreflectioninthecavity,coveredwitharesinmixedwithYAGthinlayer,about200-500nm.LED-basedtabletsissuedbytheBlu-rayabsorptionpartofthephosphor,thephosphoranotherpartoftheBlu-rayandayellowlightmixed,canbeawhite.Now,theInGaN/YAGwhiteLED,YAGphosphorbychangingthechemicalcompositionofthephosphorlayerandadjustthethicknessofthe3500-10000Kcolortemperaturecanbecoloredwhite.ThisblueLEDthroughthemethodbywhite,constructedsimple,low-cost,hightechnologyismature,sousethemost.Inthe1960s,theuseofscienceandtechnologyworkerssemiconductorPNjunctionofTheprincipleofdevelopingaLEDlight-emittingdiodes.Atthattime,thedevelopmentofLED,thematerialsusedareGaASP,itsluminouscolorisred.Afternearly30yearsofdevelopment,andnowweareveryfamiliarwiththeLED,hasbeensenttored,orange,yellow,green,blue,andothershade.HoweverlightingnecessaryforwhiteLEDlightonlyinrecentyearstodevelop,readersheretotellusaboutlightingwithwhiteLEDConductorlight-emittingdiode(LED)asathird-generationsemiconductorlightingsource.Thisfantasticproducthasalotofadvantages:(1)efficientlight:spectraofalmostallconcentratedinthevisiblelightfrequency,theefficiencycanreach80%-90%.Theluminousefficiencyofincandescentvisiblelightefficiencyofalmost10%-20%only(2)highqualityoflight:notasaresultofspectrumUVandinfrared,thereisnoheat,noradiation,istypicallyagreenlightillumination.(3)energyconsumptionofthesmall:singlepowergenerally0.05-1w,throughtheclustercanbetailoredtomeetdifferentneeds,andwasteverylittle.Asalightsource,underthebrightnessinthesamepowerconsumptionofonlyordinaryincandescent1/8-10.(4)longlife:fluxattenuationto70%ofthestandardlifeexpectancyis100,000hours.Asemiconductorlightcanbeusedundernormalcircumstances50years,evenifthelonglifeofthepeople,lifewillbeuseduptotwolights.(5)durableandreliable:Notungstenwire,glassandothereasilydamagedcomponents,non-normalretirementrateisverysmall,verylowmaintenancecosts.(6)theapplicationofflexibility:smallsize,canflatpack,easytodevelopintoashortthinproducts,makepoint,line,facevariousformsofspecificapplications.(7)Security:workingvoltage1.5-5vorlessinbetweenthecurrent20-70mAinbetween.(8)green:recyclablewaste,nopollution,unlikefluorescentlampscontainingmercuryasingredients.(9)responsetimeisshort:toadapttofrequentandhigh-frequencyswitchingoperationofoccasions.Greenlighting,Energyconservation,notonlyrespondsthegovernmentbuilding"resource-savingandenvironment-friendlysociety"requirement,butalsoradicallyreducestheenvironmentalpressureofeconomicgrowth.TheadventofLEDproducts,willeffectivelypromotetherealizationofscientificconceptofdevelopment,realizethesustainabledevelopmentofsociety,andachievewin-wineconomicandsocialbenefits-whichareatanewstartingpoint,tothehistoricalmissionandcommitmentofpeople-orientedlightingtechnology.Changingtraditionalmethodsoflighting,LEDisthesolid-statesemiconductorwhichtransferselectricitydirectlyintothevisiblelight,LEDhasbecometheinnovationoflightworld,LEDistheessentialgreentechnologyrevolutiontohuman.LEDlightingproductswithDCdrives,ultra-lowpowerconsumption,andelectro-opticalconversionclose100%,Comparedwithtraditionallight,itsavesmorethan80%lightenergybasedonthesamelightingeffect.Undertheappropriatecurrentandvoltagedriver,theworkinglifecanreach60,000to100,000hours,whichis10timesmorethanthetraditionalilluminant.Meanwhile,withoutStarterandBallast,LEDlighthasfaststart-up,withoutstrobe,softlight,purespectrum,highCRI,behelpfulforvisualprotectionandphysicalhealth,createaharmoniousandcomfortablelivingenvironment.OnbehalfofHighPointtechnologyrepresentativeofSemiconductoroptoelectronicdevices,LEDproductswillconstantlybreakscientificrecord;achievehigherluminousefficiency,morepowerful,smaller,morepurespectrum,andintelligentcontrol.WiththematuringofLEDtechnology,decliningtrendofmanufacturingcosts,Inthenearfuture,LEDlightingwillreplacethefullrangeoftraditionallighting,bringrevolutionarychangeforeveryone’sworkandlife.LED照明技术概述LED概述LED（LightEmittingDiode），发光二极管，是一种固态的半导体器件，它可以直接把电转化为光。LED的心脏是一个半导体的晶片，晶片的一端附在一个支架上，一端是负极，另一端连接电源的正极，使整个晶片被环氧树脂封装起来。半导体晶片由两部分组成，一部分是P型半导体，在它里面空穴占主导地位，另一端是N型半导体，在这边主要是电子。但这两种半导体连接起来的时候，它们之间就形成一个“P-N结”。当电流通过导线作用于这个晶片的时候，电子就会被推向P区，在P区里电子跟空穴复合，然后就会以光子的形式发出能量，这就是LED发光的原理。而光的波长也就是光的颜色，是由形成P-N结的材料决定的。LED历史50年前人们已经了解半导体材料可产生光线的基本知识，第一个商用二极管产生于1960年。LED是英文lightemittingdiode（发光二极管）的缩写，它的基本结构是一块电致发光的半导体材料，置于一个有引线的架子上，然后四周用环氧树脂密封，即固体封装，所以能起到保护内部芯线的作用，所以LED的抗震性能好。发光二极管的核心部分是由P型半导体和N型半导体组成的晶片，在P型半导体和N型半导体之间有一个过渡层，称为P-N结。在某些半导体材料的PN结中，注入的少数载流子与多数载流子复合时会把多余的能量以光的形式释放出来，从而把电能直接转换为光能。PN结施加反向电压时，少数载流子难以注入，故不发光。这种利用注入式电致发光原理制作的二极管叫发光二极管，通称LED。当它处于正向工作状态时（即两端加上正向电压），电流从LED阳极流向阴极时，半导体晶体就发出从紫外到红外不同颜色的光线，光的强弱与电流有关。最初LED用作仪器仪表的指示光源，后来各种光色的LED在交通信号灯和大面积显示屏中得到了广泛应用，产生了很好的经济效益和社会效益。以12英寸的红色交通信号灯为例，在美国本来是采用长寿命、低光效的140瓦白炽灯作为光源，它产生2000流明的白光。经红色滤光片后，光损失90%，只剩下200流明的红光。而在新设计的灯中，Lumileds公司采用了18个红色LED光源，包括电路损失在内，共耗电14瓦，即可产生同样的光效。汽车信号灯也是LED光源应用的重要领域。对于一般照明而言，人们更需要白色的光源。1998年白光的LED开发成功。这种LED是将GaN芯片和钇铝石榴石（YAG）封装在一起做成。GaN芯片发蓝光（λp=465nm，Wd=30nm），高温烧结制成的含Ce3+的YAG荧光粉受此蓝光激发后发出黄色光射，峰值550nm。蓝光LED基片安装在碗形反射腔中，覆盖以混有YAG的树脂薄层，约200-500nm。LED基片发出的蓝光部分被荧光粉吸收，另一部分蓝光与荧光粉发出的黄光混合，可以得到得白光。现在，对于InGaN/YAG白色LED，通过改变YAG荧光粉的化学组成和调节荧光粉层的厚度，可以获得色温3500-10000K的各色白光。这种通过蓝光LED得到白光的方法，构造简单、成本低廉、技术成熟度高，因此运用最多。上个世纪60年代，科技工作者利用半导体PN结发光的原理，研制成了LED发光二极管。当时研制的LED，所用的材料是GaASP，其发光颜色为红色。经过近30年的发展，现在大家十分熟悉的LED，已能发出红、橙、黄、绿、蓝等多种色光。然而照明需用的白色光LED仅在近年才发展起来，这里向读者介绍有关照明用白光LED。导体发光二极管(LED)作为第三代半导体照明光源。这种产品具有很多梦幻般优点：(1)光效率高：光谱几乎全部集中于可见光频率，效率可以达到80%-90%。而光效差不多的白炽灯可见光效率仅为10%-20%。(2)光线质量高：由于光谱中没有紫外线和红外线，故没有热量，没有辐射，属于典型的绿色照明光源。(3)能耗小：单体功率一般在0.05-1w，通过集群方式可以量体裁衣地满足不同的需要，浪费很少。以其作为光源，在同样亮度下耗电量仅为普通白炽灯的1/8-10。(4)寿命长：光通量衰减到70%的标准寿命是10万小时。一个半导体灯正常情况下可以使用50年，即使长命百岁的人，一生最多也就用2只灯。(5)可靠耐用：没有钨丝、玻壳等容易损坏的部件，非正常报废率很小，维护费用极为低廉。(6)应用灵活：体积小，可以平面封装，易开发成轻薄短小的产品，做成点、线、面各种形式的具体应用产品。(7)安全：单位工作电压大致在1.5-5v之间，工作电流在20-70mA之间。(8)绿色环保：废弃物可回收，没有污染，不像荧光灯一样含有汞成分。(9)响应时间短：适应频繁开关以及高频运作的场合。绿色照明、节能减排，既响应了政府建设“资源节约型和环境友好型社会”的要求，而且从根本上减轻了经济增长对环境的压力。LED产品的问世，将有效促进科学发展观的落实，实现社会的可持续发展，实现经济效益与社会效益的双赢——这是站在新的起点上，照明科技以人为本的历史使命和承诺。LED改变传统发光方式，将电能直接转化为可见光的固态半导体，已成为光世界的创新，对人类来说是必不可少的绿色技术光革命。目前世界各国越来越重视照明节能及环保问题，作为一种新型的节能、环保的绿色光源产品，LED技术代表了未来照明产业发展的趋势。LED照明产品具有直流驱动，超低功耗等特点，电光功率转换接近100%，相同照明效果比传统光源节能80%以上。且在合适的电流和电压驱动下，使用寿命可达6万到10万小时，比传统光源寿命长10倍以上。同时，因无需起辉器和镇流器，LED灯具启动快，无频闪，光线柔和，光谱纯，显色指数高，有利于视力保护及身体健康，创造了和谐舒适的生活环境。作为半导体光电器件“高新尖”技术的代表，LED产品将不断突破科学纪录，达到光效更高，功率更大，体积更小，光谱更纯，以及控制更智能化的行业目标。随着LED技术的日渐成熟，制造成本呈逐年下降的趋势。在不久的将来，LED照明将全方位取代传统照明，给每一个人的工作和生活带来革命性的改变。LED护栏管:LEDHurdleLampLED点光源:LEDPointSourceLED大功率洗墙灯:LEDHighPowerwashwallLED大功率投光灯:LEDHighPowerLED光纤LEDopticalfiberLED柔性灯带LEDSoftRopeLightLED柔性霓虹灯LEDSoftNoLED灯饰LEDlightingaccessorizeLED显示屏LEDpanelLED喷绘屏LEDPictureModuleLED背景屏LEDBackdropscreen',)