【MOOC】光电子学-南京邮电大学 中国大学慕课MOOC答案

【MOOC】光电子学-南京邮电大学中国大学慕课MOOC答案光的认识1-随堂测验1、【判断题】托勒密发现的入射角和折射角成比例是否正确？本题答案：【错误】2、【判断题】望远镜是伽利略发明的？本题答案：【错误】3、【判断题】威特洛将星星的闪烁解释为空气的运动，是否正确？本题答案：【正确】4、【填空题】用透明度极好的石头点火，其中石头形状类似于凸透镜还是凹透镜？本题答案：【凸透镜】光的认识2-随堂测验1、【判断题】折射定律是斯涅耳最早发现的。本题答案：【正确】2、【判断题】笛卡尔用理论推导出折射定律。本题答案：【正确】3、【判断题】微粒说可以解释光的反射、折射现象。本题答案：【正确】4、【判断题】菲涅耳将惠更斯原理与杨氏干涉原理相结合，不仅解释直线传播，还可解释衍射现象。本题答案：【正确】光的认识3-随堂测验1、【判断题】麦克斯韦根据麦克斯韦方程预言了电磁波的存在。本题答案：【正确】2、【判断题】光电效应、热辐射、光压体现了光的波动性。本题答案：【错误】3、【判断题】光具有波动性和粒子性两重特性，称为波粒二象性。本题答案：【正确】麦克斯韦方程微分形式-随堂测验1、【判断题】麦克斯韦方程只有一个方程。本题答案：【错误】2、【判断题】麦克斯韦方程的微分形式在真空中和介质中形式有所不同。本题答案：【正确】3、【判断题】由麦克斯韦方程，结合具体的边界条件及初始条件，可定量研究光的各种传输特性。本题答案：【正确】矢量运算-随堂测验1、【判断题】矢量有大小、没有方向。本题答案：【错误】2、【判断题】矢量具有结合律。本题答案：【正确】3、【判断题】梯度的散度是存在的。本题答案：【正确】4、【判断题】梯度的旋度是存在的。本题答案：【正确】物质方程-随堂测验1、【判断题】光波在各种介质中的传播过程是光与介质相互作用的过程。本题答案：【正确】2、【判断题】物质方程是描述介质特性对电磁场影响的方程。本题答案：【正确】3、【判断题】物质方程给出了媒质的电学和磁学性质，它们是光与物质相互作用时媒质中大量分子平均作用的结果。本题答案：【正确】4、【判断题】在光学各向异性介质中，磁导率和介电常数是张量。本题答案：【正确】麦克斯韦方程积分形式-随堂测验1、【判断题】麦克斯韦方程的微分形式和积分形式是等价的。本题答案：【正确】2、【判断题】麦克斯韦方程的微分形式和积分形式是可以相互推导出来的。本题答案：【正确】3、【判断题】麦克斯韦方程的积分形式也是4个方程。本题答案：【正确】麦克斯韦方程物理意义-随堂测验1、【判断题】麦克斯韦方程1式代表电场的高斯定律：电场可以是有源场；电力线必须从正电荷出发终止于负电荷。本题答案：【正确】2、【判断题】麦克斯韦方程2式代表磁通连续定律（磁场高斯定理）：磁场是无源场；通过闭合面的磁通量等于零，磁力线是闭合的。本题答案：【正确】3、【判断题】麦克斯韦方程3式代表了法拉第电磁感应定律：变化磁场产生感应电场（涡旋场），其电力线是闭合的。本题答案：【正确】4、【判断题】麦克斯韦方程3式代表了安培全电流定律：传导电流和位移电流都对磁场的产生有贡献。本题答案：【正确】波动方程-随堂测验1、【判断题】波动方程可以由麦克斯韦方程推导出来。本题答案：【正确】2、【判断题】波动方程描述了电磁场在空间中传播的规律。本题答案：【正确】3、【判断题】根据波动方程可以推算电磁波速度。本题答案：【正确】光的偏振-随堂测验1、【判断题】线偏振、圆偏振都属于是特殊的椭圆偏振。本题答案：【正确】2、【判断题】光的偏振状态可以由一个椭圆方程来描述。本题答案：【正确】3、【判断题】圆偏振光分为左旋和右旋两种状态。本题答案：【正确】光的反射和折射-随堂测验1、【判断题】光的入射角等于反射角。本题答案：【正确】2、【判断题】光的折射角一定等于光的入射角。本题答案：【错误】3、【判断题】光的折射定律描述了光的入射角和折射角之间的定量关系。本题答案：【正确】光的干涉和衍射-随堂测验1、【判断题】用惠更斯-菲涅耳原理，可以解释光的干涉和衍射现象。本题答案：【正确】2、【判断题】光的衍射现象可以看作是多个光的干涉。本题答案：【正确】3、【判断题】光的衍射和干涉体现了光的波动性。本题答案：【正确】第一单元作业单元测验1、【判断题】托勒密发现的入射角和折射角成比例是否正确？本题答案：【错误】2、【判断题】威特洛将星星的闪烁解释为空气的运动，是否正确？本题答案：【正确】3、【判断题】折射定律是斯涅耳最早发现的。本题答案：【正确】4、【判断题】笛卡尔用理论推导出折射定律。本题答案：【正确】5、【判断题】菲涅耳将惠更斯原理与杨氏干涉原理相结合，不仅解释直线传播，还可解释衍射现象。本题答案：【正确】6、【判断题】光电效应、热辐射、光压体现了光的波动性。本题答案：【错误】7、【判断题】麦克斯韦方程只有一个方程。本题答案：【错误】8、【判断题】麦克斯韦方程的微分形式在真空中和介质中形式有所不同。本题答案：【正确】9、【判断题】光波在各种介质中的传播过程是光与介质相互作用的过程。本题答案：【正确】10、【判断题】物质方程给出了媒质的电学和磁学性质，它们是光与物质相互作用时媒质中大量分子平均作用的结果。本题答案：【正确】11、【判断题】在光学各向异性介质中，磁导率和介电常数是张量。本题答案：【正确】12、【判断题】麦克斯韦方程的微分形式和积分形式是可以相互推导出来的。本题答案：【正确】13、【判断题】波动方程可以由麦克斯韦方程推导出来。本题答案：【正确】14、【判断题】波动方程描述了电磁场在空间中传播的规律。本题答案：【正确】15、【判断题】根据波动方程可以推算电磁波速度。本题答案：【正确】16、【判断题】线偏振、圆偏振都属于是特殊的椭圆偏振。本题答案：【正确】17、【判断题】光的偏振状态可以由一个椭圆方程来描述。本题答案：【正确】18、【判断题】圆偏振光分为左旋和右旋两种状态。本题答案：【正确】19、【判断题】光的入射角等于反射角。本题答案：【正确】20、【判断题】光的折射角一定等于光的入射角。本题答案：【错误】21、【判断题】光的折射定律描述了光的入射角和折射角之间的定量关系。本题答案：【正确】22、【判断题】用惠更斯-菲涅耳原理，可以解释光的干涉和衍射现象。本题答案：【正确】23、【判断题】光的衍射现象可以看作是多个光的干涉。本题答案：【正确】24、【判断题】光的衍射和干涉体现了光的波动性。本题答案：【正确】测验1、【判断题】EnergylevelsinaLiatomarediscrete.本题答案：【正确】2、【判断题】Above0K,duetothermalexcitation,someoftheelectronsarenotatenergiesaboveEF.本题答案：【错误】3、【判断题】TheprobabilityofoccupancyofastateatanenergyEisf(E):Fermi-Diracfunction.本题答案：【正确】4、【判断题】Theproductg(E)f(E)isnotthenumberofelectronsperunitenergyperunitvolumeorelectronconcentrationperunitenergy.本题答案：【错误】5、【判断题】TheinteractionsbetweentheSiatomsandtheirvalenceelectronsresultintheelectronenergyinthecrystalfallingintotwodistinctenergybandscalledthevalenceband(VB)andconductionsband(CB).本题答案：【正确】6、【判断题】Thevalencebandrepresentselectronwavefunctionsinthecrystalthatcorrespondtobondsbetweentheatoms.本题答案：【正确】7、【判断题】ThewidthoftheCBiscalledtheelectronaffinityχ.本题答案：【正确】8、【判断题】Eg=Ev-Ec本题答案：【错误】9、【判断题】TheCBrepresentselectronwavefunctionsinthecrystalthathavehigherenergiesthanthoseintheVBandarenormallyemptyatzeroKelvin.本题答案：【正确】10、【判断题】AllelectronsplacedintheCBisfreetomovearoundthecrystalandalsotorespondtoelectricfieldbecausethereareplentyofneighboringemptyenergylevels.本题答案：【正确】11、【判断题】GenerallywecantreatanelectronintheCBasifitwerefreewithinthecrystalbysimplyassigninganeffectivemassme*toit.本题答案：【正确】12、【判断题】Thiseffectivemassisaquantummechanicalquantity,whichtakesintoaccountthattheelectronintheCBinteractswithperiodicpotentialenergyasitmovesthroughthecrystal.本题答案：【正确】13、【判断题】WhenaphotonbreaksaSi-Sibond,afreeelectronandaholeintheSi-Sibondiscreated.Theresultisthephotogenerationofanelectronandaholepair(EHP)本题答案：【正确】14、【判断题】Insomesemiconductors,suchasSiandGe,thephotonabsorptionprocessalsoinvolveslatticevibrations(vibrationsoftheSiatoms)本题答案：【正确】15、【判断题】Thefreeelectron,whichisintheCB,canwanderaroundthecrystalandcontributetotheelectricalconductionwhenanelectricfieldisapplied.本题答案：【正确】测验1、【判断题】ManyimportantpropertiesofsemiconductorsaredescribedbyconsideringthebehaviorofelectronsintheCBandholesintheVB.本题答案：【正确】2、【判断题】vde=Driftvelocityoftheelectrons本题答案：【正确】3、【判断题】me=Electrondriftmobility本题答案：【正确】4、【判断题】Ex=Appliedelectricfield本题答案：【正确】5、【判断题】mh=Holedriftmobility本题答案：【正确】6、【判断题】s=Conductivity本题答案：【正确】7、【判断题】n=ElectronconcentrationintheCB本题答案：【正确】8、【判断题】Thenpproductisa“constant”,ni2,thatdependsonthematerialpropertiesNc,Nv,Eg,andthetemperature.Ifsomehownisincreased(e.g.bydoping),pmustdecreasetokeepnpconstant.本题答案：【正确】9、【判断题】(3/2)kBTisalsotheaveragekineticenergyperatominamonatomicgas(kineticmoleculartheory)inwhichthegasatomsmovearoundfreelyandrandomlyinsideacontainer.本题答案：【正确】10、【判断题】TheelectronintheCBbehavesasifitwere“free”withameankineticenergythatis(3/2)kBTandaneffectivemassme*.本题答案：【正确】11、【判断题】Fermienergyisaconvenientwaytorepresentfreecarrierconcentrations(nintheCBandpintheVB)ontheenergybanddiagram.本题答案：【正确】12、【判断题】ThemostuselesspropertyofEFisintermsofachangeinEF.本题答案：【错误】13、【判断题】AnychangeofEFacrossamaterialsystemrepresentselectricalworkinputoroutputperelectron.本题答案：【正确】14、【判断题】Forasemiconductorsysteminequilibrium,inthedark,andwithnoappliedvoltageornoEMFgenerated,andEFmustbeuniformacrossthesystem.本题答案：【正确】15、【判断题】EFmustbeuniformacrossthesystem.Ifitisnotuniform,therewillbeexcessenergyandelectricworkwillbedonetomakeituniform.Actually,thebiasisthedifferenceofEFbetweendifferentpartsofthesystem.本题答案：【正确】测验1、【判断题】ThefourvalenceelectronsofAsallowittobondjustlikeSibutthefifthelectronisleftorbitingtheAssite.本题答案：【正确】2、【判断题】ThefifthvalenceelectroncanbereadilyfreedbythermalvibrationsoftheSilattice.本题答案：【正确】3、【判断题】TheAs+ionsremainimmobile.BecausetheAsatomdonatesanelectronintotheCB,itiscalledadonorimpurity.本题答案：【正确】4、【判断题】TherearedonorenergylevelsjustbelowEcaroundAs+sites.本题答案：【正确】5、【判断题】Ndni,thenatroomtemperature,theelectronconcentrationintheCBwillnearlybeequaltoNd,i.e.n≈Nd本题答案：【正确】6、【判断题】AsmallfractionofthelargenumberofelectronsintheCBrecombinewithholesintheVBsoastomaintainnp=ni2本题答案：【正确】7、【判断题】Theconductivityofasemiconductordependsonbothelectronsandholesasbothcontributetochargetransport.本题答案：【正确】8、【判断题】Bhasonlythreevalenceelectrons.WhenitsubstitutesforaSiatomoneofitsbondshasanelectronmissingandthereforeahole.本题答案：【正确】9、【判断题】AtroomtemperaturethethermalvibrationsofthelatticecanfreetheholeawayfromtheB-site.本题答案：【正确】10、【判断题】Fortheatomwithahole,anearbyelectroncantunnelintothisholeanddisplacetheholefurtherawayfromtheBatom.本题答案：【正确】11、【判断题】TheBatomintroducedintotheSicrystalthereforeactsasanelectronacceptorimpurity.本题答案：【正确】12、【判断题】Nani,thenatroomtemperature,theholeconcentrationintheVBwillnearlybeequaltoNa,i.e.p≈Na本题答案：【正确】13、【判断题】AsmallfractionofthelargenumberofholesintheVBrecombinewithelectronsintheCBsoastomaintainnp=ni2本题答案：【正确】14、【判断题】AlthoughtherearenostatesatEF,theworkfunctionnonethelessrepresentstheaverageenergyrequiredtoremoveanelectronfromasemiconductor本题答案：【正确】15、【判断题】Wecannotsimultaneouslyincreasetheelectronandholeconcentrationsbecausethatleadstoanincreaseintherecombinationratewhichreturnstheelectronandholeconcentrationstovaluesthatsatisfynp=ni2.本题答案：【正确】测验1、【判断题】Innondegeneratesemiconductors,thenumberofstatesintheCBfarexceedsthenumberofelectrons.ThePauliexclusionprinciplecanbeneglected.本题答案：【正确】2、【判断题】Whenthesemiconductorhasbeenexcessivelydopedwithdonors,nmaybesolarge,typically1019-1020cm-3,thePauliexclusionprinciplebecomesimportant.---Degeneratesemiconductors本题答案：【正确】3、【判断题】Byheavilydoping,thedonorsbecomeclosertoformaband.本题答案：【正确】4、【判断题】Bandtailing:therandomdistributionofalargenumberofdonorsinthecrystalalsointroducesarandomvariationinthepotentialenergy,whichcausesthebandtailing.本题答案：【正确】5、【判断题】Inadegeneratesemiconductor,onecannotassumethatn=Ndorp=Na,asthedopantconcentrationissolargethattheyinteractwitheachother.Notalldopantsareabletobecomeionized.Thesaturationistypicallyaround1020cm-3.本题答案：【正确】6、【判断题】Themassactionlawisnotvalidfordegeneratesemiconductors.本题答案：【正确】7、【判断题】Thewholeenergydiagramtiltsbecausetheelectronhasanelectrostaticpotentialenergy.本题答案：【正确】8、【判断题】TheE-kcurveconsistsofmanydiscretepointswitheachpointcorrespondingtoapossiblestate本题答案：【正确】9、【判断题】IntheenergyrangeEvtoEctherearenostates.本题答案：【正确】10、【判断题】InGaAstheminimumoftheCBisdirectlyabovethemaximumoftheVB.GaAsisthereforeadirectbandgapsemiconductor.本题答案：【正确】11、【判断题】InSi,theminimumoftheCBisdisplacedfromthemaximumoftheVBandSiisanindirectbandgapsemiconductor.本题答案：【正确】12、【判断题】RecombinationofanelectronandaholeinSiinvolvesarecombinationcenter(crystaldefectsorimpurities)本题答案：【正确】测验1、【判断题】Theelectricfieldacrossthepnjunctionisfoundbyintegratingthedensityofelectrons.本题答案：【正确】2、【判断题】Potentialenergyischarge*potential=qV本题答案：【正确】3、【判断题】Wo=Wn+Wpisthetotalwidthofthedepletionregionunderazeroappliedvoltage本题答案：【正确】4、【判断题】BoltzmannStatisticscanonlybeusedwithnondegeneratesemiconductors.本题答案：【正确】5、【判断题】ThenegativepolarityofthesupplywillreducethepotentialbarrierVobyVbecausetheappliedvoltagedropsmostlyacrossthedepletionwidthW.本题答案：【正确】6、【判断题】ThebulkregionsoutsidetheSCLhavehighconductivities,duetotheplentyofmajoritycarriersinthebulk,incomparisonwithdepletionregioninwhichtherearemainlyimmobileions(withlargerresistivity).本题答案：【正确】7、【判断题】Theprobabilitythataholeinthep-sidewillsurmountthepotentialbarrieranddiffusetothen-sidenowbecomesproportionaltoexp[-e(Vo-V)/kBT].Inotherwords,theappliedvoltageeffectivelyreducesthebuilt-inpotentialandhencethebuilt-infieldwhichactsagainstdiffusion.本题答案：【正确】8、【判断题】Manyholescandiffuseacrossthedepletionregionandenterthen-side.Thisresultsinthe“injectionofexcessminoritycarriers”,i.e.,holesintothen-region.本题答案：【正确】9、【判断题】Theholeconcentrationpn(0)justoutsidethedepletionregionatx’=0inthen-sideisverylargeduetotheinjectionofminoritycarriers.本题答案：【正确】10、【判断题】Whenholesareinjectedintotheneutraln-side,theydrawsomeelectronsfromthebulkofn-side(andhencefromthebattery)sothatthereisasmallincreaseintheelectronconcentration.Thissmallincreaseinthemajoritycarriersisnecessarytobalancetheholechargesandmaintainneutralityinthen-side.本题答案：【正确】11、【判断题】1/Lh=Meanprobabilityofrecombinationperunitdistance;ormeandistancediffused本题答案：【正确】12、【判断题】Disthediffusioncoefficientinnondegeneratesemiconductors,anditisrelatedtoandalsocanbecalculatedfromthedriftmobility本题答案：【正确】13、【判断题】Thetotalcurrentanywhereinthedeviceisconstant.Itisthesumofholeandelectroncontributions.Justoutsidethedepletionregionitisduetothediffusionofminoritycarriers.本题答案：【正确】14、【判断题】nidependsstronglyonthematerial(e.g.bandgap)andtemperature本题答案：【正确】15、【判断题】Joisaconstantandηisanidealityfactor,1:fordiffusion-controlledand2:forrecombination-controlledforwardcurrentcharacteristics本题答案：【正确】测验1、【判断题】Theelectricfieldbecomeslargerduetothereversebias.Toaccommodatethislargerfield,thewidthsofthedepletionregiononthepandnsidewidentoexposemoreionizeddopants.本题答案：【正确】2、【判断题】ThecurrentunderrevsersebiascomesfromdiffusioncurrentinneutralregionsandThermalgeneratedcurrentindepletionregion.本题答案：【正确】3、【判断题】InaGepnjunction,above238K,Ireviscontrolledbyni2andbelow238Kitiscontrolledbyni.本题答案：【正确】4、【判断题】DiffusioncurrentinneutralregionsiscalledShockleyreversecurrent.本题答案：【正确】测验1、【判断题】TheforwardvoltageacrossapnjunctionincreasesbydV,whichleadstofurtherminoritycarrierinjectionandalargerforwardcurrent,whichisincreasesbydI.AdditionalminoritycarrierchargedQisinjectedintothen-side.TheincreasedQinchargestoredinthen-sidewithdVappearsasifthereisacapacitanceacrossthediode.本题答案：【正确】2、【判断题】TheincreasedVresultsinanincreasedIinthediodecurrent.Thedynamicorincrementalresistanceisrd=dV/dI.本题答案：【正确】3、【判断题】Depletionregionhasnegative(-Q)chargesinWpandpositive(+Q)chargesinWn,whichareseparatedasinacapacitor.本题答案：【正确】测验1、【判断题】Assumingweakinjection,wecancalculatetherecombinationtimesteandthforelectronsandholesrecombiningintheneutralpandn-regionsrespectively.本题答案：【正确】2、【判断题】Theelectronsdiffusemuchfurtherinthep-side.本题答案：【正确】3、【判断题】RecombinationcomponentofthecurrentisquitedifficulttocalculatebecauseweneedtoknowthemeanelectronandholerecombinationtimesintheSCL.本题答案：【正确】4、【判断题】Therecombinationcurrentismorethananorderofmagnitudegreaterthanthediffusioncurrentunderlowerbias.本题答案：【正确】5、【判断题】TheEHPrecombinationthatoccursintheSCLandtheneutralregionsinthisGaAspnjunctioncasewouldresultinphotonemission,withaphotonenergythatisapproximatelyEg.ThisdirectrecombinationofinjectedminoritycarriersandtheresultingemissionofphotonsrepresenttheprincipleofoperationoftheLightEmittingDiode(LED).本题答案：【正确】测验1、【判断题】EFp-Evfarawayfromthejunctioninsidethep-typematerialshouldbethesameasintheisolatedp-typematerial.本题答案：【正确】2、【判断题】Theinstantthetwosemiconductorsarebroughttogethertoformthejunction,electronsdiffusefromthen-sidetothep-sideandastheydosotheydepletethen-sidenearthejunction.本题答案：【正确】3、【判断题】Anelectroninthen-sideatEcmustovercomeapotentialenergy(PE)barriertogoovertoEcinthep-side.ThisPEbarrieriseVowhereVoisthebuilt-inpotential,i.e.,themaximumextentEchasbeenbenttolineuptheFermilevels.本题答案：【正确】4、【判断题】Whenthepnjunctionisforwardbiased,themajorityoftheappliedvoltagedropsacrossthedepletionregionsothattheappliedvoltageisinoppositiontothebuilt-inpotential,Vo.本题答案：【正确】5、【判断题】TheShockleymodelpredictsasmallreversesaturationcurrentduetothediffusionofminoritycarriersinneutralregionstothedepletionregion.本题答案：【正确】测验1、【判断题】Aheterojunctionisajunctionbetweentwodifferentsemiconductorcrystalswithdifferentbandgaps.本题答案：【正确】2、【判断题】TheenergydiscontinuitiesindEcanddEvarecalledbandoffsetsandplayanimportantroleinheterojunctiondevices.本题答案：【正确】3、【判断题】ThedopinginthewiderbandgapsemiconductorisusuallydenotedwithacapitalletterNorP.andthatinthenarrowerbandgapsemiconductorwithlowercasenorp.本题答案：【正确】4、【判断题】Underopencircuitandequilibriumconditions,theFermilevelEFmustbeuniform,i.e.continuousthroughoutthedevice.本题答案：【正确】5、【判断题】FarawayfromthejunctionontheN-side,wehaveann-typewidebandgapAlGaAswithEFclosetoEc.本题答案：【正确】测验1、【判断题】TheappliedbiaspotentialVreducesVoandtherebyallowselectronstodiffuse,beinjected,intothep-side.本题答案：【正确】2、【判断题】Recombinationaroundthejunctionandwithinthediffusionlengthoftheelectronsinthep-sideleadstospontaneousphotonemission.本题答案：【正确】3、【判断题】misanumericalfactorthatistypicallybetween1.5and2.5,thoughformanyLEDs,m=3isagoodvalue.本题答案：【正确】4、【判断题】Aspreadintheoutputwavelengthsisrelatedtoaspreadintheemittedphotonenergies.本题答案：【正确】测验1、【判断题】AQWstructurehastheenergylevelsinthewells.本题答案：【正确】2、【判断题】InaQW,chargecarriersarebroughtinbythecurrentfallintothelowestenergylevelinthewellandthenrecombine,emittingaphoton.本题答案：【正确】3、【判断题】Theelectronsataparticularenergylevelalsohavekineticenergiesintheyzplane,whichisnotquantized.本题答案：【正确】4、【判断题】TheelectronsarethereforespreadinenergyaboveEn.本题答案：【正确】测验1、【判断题】FreespacewavelengthcoveragebydifferentLEDmaterialsfromthevisiblespectrumtotheinfraredincludingwavelengthsusedinopticalcommunications.本题答案：【正确】2、【判断题】LEDmaterialsincludedirectandindirectbandgapones.本题答案：【正确】3、【判断题】Someoftheinternallygeneratedlightsufferstotalinternalreflection(TIR)atthesemiconductor/airinterfaceandcannotbeemittedintotheoutside.本题答案：【正确】4、【判断题】AdistributedBraggreflector(DBR),thatisadielectricmirror,undertheconfininglayer(belowtheactiveregioningrey)actsasadielectricmirror,andincreasestheextractionratio.本题答案：【正确】5、【判断题】AnRCLEDisanLEDwithanopticalresonantcavity(RC)formedbytwoDBRshasanarroweremissionspectrum.本题答案：【正确】测验1、【判断题】Externalquantumefficiency(EQE)hEQEofanLEDrepresentstheefficiencyofconversionfromelectricalquanta,i.e.electrons,thatflowintheLEDtoopticalquanta,i.e.photons,thatareemittedintotheoutsideworld.本题答案：【正确】2、【判断题】Powerconversionefficiency(PCE)istheefficiencyofconversionfromtheinputofelectricalpowertotheoutputofopticalpower本题答案：【正确】3、【判断题】Luminousfluxisameasureofvisualbrightness,inlumens(lm).本题答案：【正确】4、【判断题】Theluminousefficiencyofthelight-adapted(photopic)eyeasafunctionofwavelength.本题答案：【正确】测验1、【判断题】Current-VoltagecharacteristicsofafewLEDSemittingatdifferentwavelengthsfromtheIRtobluelooklikethatofnormaldiodes.本题答案：【正确】2、【判断题】ThereisaLog-logrelationbetweentheemittedopticaloutputpowerandthedccurrent.本题答案：【正确】测验1、【判断题】LightcouldbecoupledfromasurfaceemittingLEDintoamultimodefiberusinganindexmatchingepoxy.本题答案：【正确】2、【判断题】AmicrolenscouldfocusdiverginglightfromasurfaceemittingLEDintoamultimodeopticalfiber.本题答案：【正确】3、【判断题】LightfromanedgeemittingLEDiscoupledintoafibertypicallybyusingalensoraGRINrodlens.本题答案：【正确】测验1、【判断题】Photoluminescenceistheemissionoflightbyamaterial,calledaphosphor.本题答案：【正确】2、【判断题】phosphor,thathasbeenfirstexcitedbylightofhigherfrequency.Higherenergyphotonsarefirstabsorbed,andthenlowerenergyphotonsareemitted.本题答案：【正确】3、【判断题】Typicallytheemissionoflightoccursfromcertaindopants,impuritiesorevendefects,calledluminescentorluminescencecenters,purposefullyintroducedintoahostmatrix,whichmaybeacrystalorglass.本题答案：【正确】4、【判断题】Manyphosphorsarebasedonactivatorsdopedintoahostmatrix.本题答案：【正确】5、【判断题】Theluminescentcenterisalsocalledanactivator.本题答案：【正确】第三单元作业第三单元测验1、【判断题】TheinteractionsbetweentheSiatomsandtheirvalenceelectronsresultintheelectronenergyinthecrystalfallingintotwodistinctenergybandscalledthevalenceband(VB)andconductionsband(CB).本题答案：【正确】2、【判断题】ThewidthoftheCBiscalledtheelectronaffinityχ.本题答案：【正确】3、【判断题】Eg=Ev-Ec本题答案：【错误】4、【判断题】vdh=Driftvelocityoftheholes本题答案：【正确】5、【判断题】TheareaunderpE(E)versusEisnottheholeconcentration.本题答案：【错误】6、【判断题】ThemostuselesspropertyofEFisintermsofachangeinEF.本题答案：【错误】7、【判断题】ThefifthvalenceelectroncanbereadilyfreedbythermalvibrationsoftheSilattice.本题答案：【正确】8、【判断题】Ndni,thenatroomtemperature,theelectronconcentrationintheCBwillnearlybeequaltoNd,i.e.n≈Nd本题答案：【错误】9、【判断题】Theconductivityofasemiconductordependsonbothelectronsandholesasbothcontributetochargetransport.本题答案：【正确】10、【判断题】ThereareacceptorenergylevelsjustaboveEvaroundB-sites.TheseacceptorlevelsacceptelectronsfromtheVBandthereforecreateholesintheVB.本题答案：【正确】11、【判断题】AtroomtemperaturethethermalvibrationsofthelatticecanfreetheholeawayfromtheB-site.本题答案：【正确】12、【判断题】Nani,thenatroomtemperature,theholeconcentrationintheVBwillnearlybeequaltoNa,i.e.p≈Na本题答案：【错误】13、【判断题】nadegeneratesemiconductor,onecannotassumethatn=Ndorp=Na,asthedopantconcentrationissolargethattheyinteractwitheachother.Notalldopantsareabletobecomeionized.Thesaturationistypicallyaround1020cm-3.本题答案：【正确】14、【判断题】Wo=Wn+Wpisthetotalwidthofthedepletionregionunderazeroappliedvoltage本题答案：【正确】15、【判断题】InaGepnjunction,above238K,Ireviscontrolledbyni2andbelow238Kitiscontrolledbyni.本题答案：【正确】16、【判断题】TheincreasedVresultsinanincreasedIinthediodecurrent.Thedynamicorincrementalresistanceisrd=dV/dI.本题答案：【正确】17、【判断题】TheEHPrecombinationthatoccursintheSCLandtheneutralregionsinthisGaAspnjunctioncasewouldresultinphotonemission,withaphotonenergythatisapproximatelyEg.ThisdirectrecombinationofinjectedminoritycarriersandtheresultingemissionofphotonsrepresenttheprincipleofoperationoftheLightEmittingDiode(LED).本题答案：【正确】18、【判断题】Aftertheformationofthepnjunction,thereisabuilt-involtageacrossthejunction.本题答案：【正确】19、【判断题】Anelectroninthen-sideatEcmustovercomeapotentialenergy(PE)barriertogoovertoEcinthep-side.ThisPEbarrieriseVowhereVoisthebuilt-inpotential,i.e.,themaximumextentEchasbeenbenttolineuptheFermilevels.本题答案：【正确】20、【判断题】IfEFisclosetotheconductionband(CB)edge,Ec,itresultsinann-type,andifitisclosetothevalenceband(VB)edge,Ev,itresultsinap-typesemiconductor.本题答案：【正确】21、【判断题】Recombinationaroundthejunctionandwithinthediffusionlengthoftheelectronsinthep-sideleadstospontaneousphotonemission.本题答案：【正确】22、【判断题】Theelectronsataparticularenergylevelalsohavekineticenergiesintheyzplane,whichisnotquantized.本题答案：【正确】23、【判断题】AnRCLEDisanLEDwithanopticalresonantcavity(RC)formedbytwoDBRshasanarroweremissionspectrum.本题答案：【正确】24、【判断题】LightcouldnotbecoupledfromasurfaceemittingLEDintoamultimodefiberusinganindexmatchingepoxy.本题答案：【错误】25、【判断题】Manyphosphorsarebasedonactivatorsdopedintoahostmatrix.本题答案：【正确】测验1、【判断题】Theions(Cr3+ions)inthegroundstatearepumpeduptotheenergylevelE3byphotonsfromanopticalexcitationsource.本题答案：【正确】2、【判断题】Photonsfromthestimulatedemissioncanthemselvesfurtherstimulateemissionsleadingtoanavalancheofstimulatedemissionsandcoherentphotonsbeingemitted.本题答案：【正确】3、【判断题】Atypicalconstructionforarubylaser,whichusesanellipticalreflector,andhastherubycrystalatonefocusandthepumplightattheotherfocus.本题答案：【正确】测验1、【判断题】Insemiconductorlaserdiode,banddiagramneedsasufficientlylargeforwardbiastocausepopulationinversionandhencestimulatedemission.本题答案：【正确】2、【判断题】RobertHallandhiscolleagues,whileworkingatGeneralElectric'sResearchandDevelopmentCenterinNewYork,wereamongthefirstgroupsofresearcherstoreportaworkingsemiconductorlaserdiodein1962.本题答案：【正确】测验1、【判断题】Adoubleheterostructuresemiconductorlaserdevicehasitsactiveregionburiedwithinthedeviceinsuchawaythatitissurroundedbylowrefractiveindexmaterialsrenderingtheactiveregionasawaveguide.本题答案：【正确】2、【判断题】Aburiedheterostructurelaserdiodefortelecomapplications:Theactivelayer(InGaAsP)issurroundedbythewiderbandgap,lowerrefractiveindexInPmaterial.LayersaregrownonanInPsubstrate.本题答案：【正确】测验1、【判断题】Thedensityofsatesg(E)isastep-likefunction,andisfiniteatE1andE1￠.本题答案：【正确】2、【判断题】Inmultiplequantumwell(MQW)heterostructurelaserdiode,electronsareinjectedbytheforwardcurrentintoquantumwells.本题答案：【正确】3、【判断题】InMQW,mostofthelightisintheactiveregion.本题答案：【正确】测验1、【判断题】Atsufficientlyhighdiodecurrentscorrespondingtohighopticalpower,theoperationbecomessinglemode.本题答案：【正确】2、【判断题】Extractionefficiency=(Lossfromtheexitcavityend)/(Totalloss)本题答案：【正确】3、【判断题】PowerConversionEfficiency=Opticaloutputpower/Electricinputpower本题答案：【正确】测验1、【判断题】Whenthelaserisinasteadystate,Rateofcoherentphotonlossinthecavity=Rateofstimulatedemissions本题答案：【正确】2、【判断题】Whenthelaserisinasteadystate,Rateofcoherentphotonlossinthecavity=Rateofstimulatedemissions本题答案：【正确】测验1、【判断题】PartiallyreflectedwavesatthecorrugationscanonlyconstituteareflectedwavewhenthewavelengthsatisfiestheBraggcondition.本题答案：【正确】2、【判断题】Themodefielddiameterisnormallylargerthantheactivelayerthicknessandtheradiationspreadsintotheguidinglayer.本题答案：【正确】测验1、【判断题】ThecavityinVerticalCavitySurfaceEmittingLasersisvertical.本题答案：【正确】2、【判断题】ThecrosssectionofVerticalCavitySurfaceEmittingLasersiscircular.本题答案：【正确】测验1、【判断题】Travelingwave(TW)semiconductoropticalamplifier:Theendsoftheopticalcavityhaveantireflection(AR)coatingssothattheopticalcavitydoesnotactasanefficientopticalresonator,aconditionforlaser-oscillations.本题答案：【正确】2、【判断题】Lightfromanopticalfiberiscoupledintotheactiveregionofthelaserstructure.Astheradiationpropagatesthroughtheactivelayer,opticallyguidedbythislayer,itbecomesamplifiedbytheinducedstimulatedemissions,andleavestheopticalcavitywithahigherintensity.本题答案：【正确】第四单元作业第四单元测验1、【判断题】IonsatE3rapidlydecaytothelong-livedstateattheenergylevelE2byemittinglatticevibrations(phonons).本题答案：【正确】2、【判断题】AsthestatesatE2arelong-lived,theyquicklybecomepopulatedandthereisapopulationinversionbetweenE2andE1.本题答案：【正确】3、【判断题】Arandomphoton(fromspontaneousdecay)ofenergyhu21=E2-E1cannotinitiatestimulatedemission.本题答案：【错误】4、【判断题】Insemiconductorlaserdiode,banddiagramdoesnotneedasufficientlylargeforwardbiastocausepopul