Lesson 04 Diode电子技术专业英语教程

Lesson4DiodeUnit2Semiconductordevice《电子技术专业英语教程》冯新宇主编电子工业出版社《电子技术专业英语教程》2Lesson4Diode•Backgrounds•Texttour•Languageinuse–VocabularyStructure–Reading/writingtechniques2020/1/30《电子技术专业英语教程》3•Terminology–thresholdvoltage–Depletionregion•Historyofdiode•SomediodesymbolsBackgrounds2020/1/30《电子技术专业英语教程》4Terminology2020/1/30《电子技术专业英语教程》5•forward-biase正向偏置•voltagedrop压降•depletionregion耗尽层•boltzmann’sconstant玻耳兹曼常数•emissioncoefficient发射系数•thermalvoltage热电压•roomtemperature室温2020/1/30《电子技术专业英语教程》6•leakagecurrent漏电流•peakinversevoltage峰值反向电压•Schottkydiode肖特基二极管•minoritycarrier少数载流子•heterojunctiondiode异质结二极管•homojunctiondiode同质结二极管•thresholdvoltage阈值电压2020/1/30《电子技术专业英语教程》7Thresholdvoltage•ThethresholdvoltageofaMOSFETisusuallydefinedasthegatevoltagewhereaninversionlayerformsattheinterfacebetweentheinsulatinglayer(oxide)andthesubstrate(body)ofthetransistor.2020/1/30《电子技术专业英语教程》8Depletionregion•Insemiconductorphysics,thedepletionregion,alsocalleddepletionlayer,depletionzone,junctionregionorthespacechargeregion,isaninsulatingregionwithinaconductive,dopedsemiconductormaterialwherethechargecarriershavediffusedaway,orhavebeenforcedawaybyanelectricfield.•Thedepletionregionissonamedbecauseitisformedfromaconductingregionbyremovalofallfreechargecarriers,leavingnonetocarryacurrent.Understandingthedepletionregioniskeytoexplainingmodernsemiconductorelectronics:diodes,bipolarjunctiontransistors,field-effecttransistors,andvariablecapacitancediodesallrelyondepletionregionphenomena.2020/1/30《电子技术专业英语教程》9HistoryofdiodeAlthoughthecrystal(solidstate)diodewaspopularizedbeforethethermionicdiode,thermionicandsolidstatediodesweredevelopedinparallel.ThebasicprincipleofoperationofthermionicdiodeswasdiscoveredbyFrederickGuthriein1873.Guthriediscoveredthatapositively-chargedelectroscopecouldbedischargedbybringingagroundedpieceofwhite-hotmetalclosetoit(butnotactuallytouchingit).Thesamedidnotapplytoanegativelychargedelectroscope,indicatingthatthecurrentflowwasonlypossibleinonedirection.TheprinciplewasindependentlyrediscoveredbyThomasEdisononFebruary13,1880.AtthetimeEdisonwascarryingoutresearchintowhythefilamentsofhiscarbon-filamentlightbulbsnearlyalwaysburnedoutatStructureofavacuumtubediode2020/1/30《电子技术专业英语教程》10Historyofdiodethepositive-connectedend.Hehadaspecialbulbmadewithametalplatesealedintotheglassenvelope,andhewasabletoconfirmthataninvisiblecurrentcouldbedrawnfromtheglowingfilamentthroughthevacuumtothemetalplate,butonlywhentheplatewasconnectedtothepositivesupply.EdisondevisedacircuitwherehismodifiedlightbulbmoreorlessreplacedtheresistorinaDCvoltmeterandonthisbasiswasawardedapatentforitin1883(U.S.Patent307,031).Therewasnoapparentpracticaluseforsuchdeviceatthetime,andthepatentapplicationwasmostlikelysimplyaprecautionincasesomeoneelsedidfindausefortheso-calledEdisonEffect.About20yearslater,JohnAmbroseFleming(scientificadvisertotheMarconiCompanyandformerEdisonemployee)realizedthattheEdisoneffectcouldbeusedasaprecisionradiodetector.FlemingpatentedthefirsttruethermionicdiodeinBritainonNovember16,1904(followedbyU.S.Patent803,684inNovember1905).2020/1/30《电子技术专业英语教程》11HistoryofdiodeTheprincipleofoperationofcrystaldiodeswasdiscoveredin1874bytheGermanscientist,KarlFerdinandBraun.Braunpatentedthecrystalrectifierin1899.Braun'sdiscoverywasfurtherdevelopedbyJagdishChandraBoseintoausefuldeviceforradiodetection.ThefirstactualradioreceiverusingacrystaldiodewasbuiltbyGreenleafWhittierPickard.PickardreceivedapatentforasiliconcrystaldetectoronNovember20,1906(U.S.Patent836,531).Otherexperimenterstriedavarietyofmineralsandothersubstances,althoughbyfarthemostpopularwastheLeadSulfidemineralGalena.Althoughothersubstancesofferedslightlybetterperformance,galenahadtheadvantageofbeingcheapandeasytoobtain,andwasusedalmostexclusvelyinhome-builtcrystalsets,untiltheadventofinexpensivefixedgermaniumdiodesinthe1950s.Atthetimeoftheirinvention,suchdeviceswereknownasrectifiers.In1919,WilliamHenryEcclescoinedthetermdiodefromGreekroots;diameansthrough,andodemeanspath.2020/1/30《电子技术专业英语教程》12Somediodesymbols2020/1/30《电子技术专业英语教程》13•Outline–Briefintroduction(para.1-2)–Someapplicationsofdiode(para.3)–Someterminologiesaboutdiode(para.4-12)Texttour2020/1/30《电子技术专业英语教程》14•diodeisanelectricaldevice•p-njunctiondiodeisaminoritycarrierdevice•p-nhomojunctiondiodeandp-nheterojunctiondiodeBriefintroduction2020/1/30《电子技术专业英语教程》15•Theinjectionofelectron-holepairstogeneratelightviarecombination•Theseparationofelectron-holepairsatthejunctiontoconstituteacurrentsource•ThetemperaturedependenceoftheI-Vcharacteristic•Thenon-linearnatureoftheI-Vcharacteristic(e.g.frequencymultipliersandmixers);•Thedeviceasaswitch(e.g.rectifiers,inverters,powersuppliesetc).Someapplicationsofdiode2020/1/30《电子技术专业英语教程》16•forward-biasedandreverse-biased•thewidthofdepletionregion•whatisthresholdvoltage?•thediodeequationSometerminologiesaboutdiode2020/1/30《电子技术专业英语教程》17•Vocabularycomponent，coil，amplifier•StructureLanguageinuse2020/1/30《电子技术专业英语教程》18Vocabulary2020/1/30《电子技术专业英语教程》19•toconsistofparticularpart