应用光伏学题库Word文档格式.docx

应用光伏学题库Word文档格式.docx

《应用光伏学题库Word文档格式.docx》由会员分享，可在线阅读，更多相关《应用光伏学题库Word文档格式.docx（58页珍藏版）》请在冰豆网上搜索。

6.★★Researchanddevelopmentofphotovoltaicsreceiveditsfirstmajorboostfromthespaceindustryinthe1960s.

1

1.★Aphotonischaracterizedbyeitherawavelength,denotedbyλ,orequivalentlyanenergy,denotedbyE.

2.★★Thereisaninverserelationshipbetweentheenergyofaphoton（E）andthewavelengthofthelight（λ）givenbytheequation:

，

.

3.★★Thephotonfluxisdefinedasthenumberofphotonspersecondperunitarea.

4.★★★Thetotalpowerdensityemittedfromalightsourcecanbecalculatedbyintegratingthespectralirradianceoverallwavelengthsorenergiesofinterest.

5.★★Intheanalysisofsolarcells,thephotonfluxisoftenneededaswellasthespectralirradiance.

6.★Theblackbodysourceswhichareofinteresttophotovoltaics,emitlightinthevisibleregion.

7.★★★ThespectralirradiancefromablackbodyisgivenbyPlank'

sradiationlaw.

8.★★Thepeakwavelengthofthespectralirradianceisdeterminedbydifferentiatingthespectralirradianceandsolvingthederivativewhenitequals0.TheresultisknownasWien‘sLaw:

9.★★★Solarradiationinspace:

.Hsun=5.961×

107W/m2.

10.★Thesolarradiationoutsidetheearth'

satmospherehavebeendefinedasastandardvaluecalledairmasszero（AM0）andtakesavalueof1.353kW/m2.

11.★Thespectralirradiancefromablackbodyat6000K（atthesameapparentdiameterasthesunwhenviewedfromearth）;

fromthesun’sphotosphereasobservedjustoutsideearth’satmosphere（AM0）;

andfromthesun’sphotosphereafterhavingpassedthrough1.5timesthethicknessofearth’satmosphere（AM1.5G）.

12.★★TheAirMassisdefinedas:

.whereθistheanglefromthevertical（zenithangle）.

13.★★Whenthesunisdirectlyoverhead,theAirMassis1.

14.★ThestandardspectrumattheEarth'

ssurfaceiscalledAM1.5G（theGstandsforglobalandincludesbothdirectanddiffuseradiation）orAM1.5D（whichincludesdirectradiationonly）,thesecalculationsgiveapproximately970W/m2forAM1.5G。

15.★ThestandardAM1.5Gspectrumhasbeennormalizedtogive1kW/m2duetotheconvenienceoftheroundnumberandthefactthatthereareinherentlyvariationsinincidentsolarradiation.

16.★ThestandardspectrumoutsidetheEarth'

satmosphereiscalledAM0,becauseatnostagedoesthelightpassthroughtheatmosphere.

17.★ThestandardAM0spectrumistypicallyusedtopredicttheexpectedperformanceofcellsinspace.

18.★★★Wavelengthsbelow0.3μmarestronglyabsorbedbyozone.Theabsorptionbandsaround1μmareproducedbywatervaporabsorption,complementedbyCO2absorptionatlongerwavelengths.

19.★★★TheairmassrepresentstheproportionofatmospherethatthelightmustpassthroughbeforestrikingtheEarthrelativetoitsoverheadpathlength.

20.★★Diffuseradiationispredominantlyattheblueendofthespectrumbecauseofmoreeffectivescatteringatsmallwavelengths.Hence,theskyappearsblue.

21.★★AM1radiation（radiationwhenthesunisdirectlyoverhead）,hasadiffusecomponentofabout10%whenskiesareclear.

22.★★★Carbondioxideabsorbsstronglyinthe13-19μmwavelengthbandandwatervapour,anotheratmosphericgas,absorbsstronglyinthe4-7μmwavelengthband.Mostoutgoingradiation（70%）escapesinthe“window”between7-13μm.

23.★★Thetwocommonmethodswhichcharacterizesolarradiationarethesolarradiance（orradiation）andsolarinsolation.

24.★★Whilesolarirradianceismostcommonlymeasured,amorecommonformofradiationdatausedinsystemdesignisthesolarinsolation.

25.★ThesolarradianceisaninstantaneouspowerdensityinunitsofkW/m2.

26.★★Thesolarinsolationisthetotalamountofsolarenergyreceivedataparticularlocationduringaspecifiedtimeperiod,ofteninunitsofkWh/（m2day）,alsoinunitsofMJ/m2peryear.

27.★★TheaveragedailysolarinsolationinunitsofkWh/m2perdayissometimesreferredtoas“peaksunhours”.Forexample,alocationthatreceives8kWh/m2perdaycanbesaidtohavereceived8hoursofsunperdayat1kW/m2.

28.★Thedeclinationofthesunistheanglebetweentheequatorandalinedrawnfromthecentreoftheearthtothecentreofthesun.

29.★★★Thedeclinationofthesuniszeroattheequinoxes（March22andSeptember22）,positiveduringthenorthernhemispheresummerandnegativeduringthenorthernhemispherewinter.

30.★★★Theelevationoraltitudeangleistheangularheightofthesunintheskymeasuredfromthehorizontal.Theelevationis0°

atsunriseand90°

whenthesunisdirectlyoverhead.

31.★★Thezenithangleissimilartotheelevationanglebutitismeasuredfromtheverticalratherthanfromthehorizontal.

32.★★★TheazimuthangleisthecompassdirectionfromwhichthesunlightiscomingwithNorth=0°

South=180°

90°

atsunriseand270°

atsunset.

33.★★Forafixedtiltangle,themaximumpoweroverthecourseofayearisobtainedwhenthetiltangleisequaltothelatitudeofthelocation.

34.★Themoduleisorientatedtotheequatorsoitfacesnorthinthesouthernhemisphereandsouthinthenorthernhemisphere.

35.★★Thesunisatanaltitudeof30°

tothehorizontal,thecorrespondingairmassis2.

36.★★Thelengthoftheshadowcastbyaverticalpostwithaheightof1munderAM1.5illuminationis.

2

1.★★Themostimportantparametersofasemiconductormaterialforsolarcelloperationare:

（1）thebandgap;

（2）thenumberoffreecarriersavailableforconduction;

（3）thegenerationandrecombinationoffreecarriersinresponsetolightshiningonthematerial.

2.★Theelectricalpropertiesofsemiconductorscanbeexplainedusingtwomodels,thebondandthebandmodels.

3.★★Thebandmodeldescribessemiconductorbehaviorintermsoftheenergylevelbetweenvalenceandconductionbands.

4.★★Thelowerenergylevelofasemiconductoriscalledthe"

valenceband"

（EV）andtheenergylevelatwhichanelectroncanbeconsideredfreeiscalledthe"

conductionband"

（EC）.Thebandgap（EG）isthedistancebetweentheconductionbandandvalenceband.

5.★Thebandgapcorrespondstotheminimumenergyneededtoreleaseanelectronfromavalencebondtotheconductionbandwhereitcanconductacurrent.

6.★★★Boththeelectronandholecanparticipateinconductionandarecalled"

carriers"

7.★★Itispossibletoshiftthebalanceofelectronsandholesinasiliconcrystallatticeby"

doping"

itwithotheratoms.

8.★★Atomswithonemorevalenceelectronthansiliconareusedtoproduce"

n-type"

semiconductormaterial,whichaddselectronstotheconductionbandandhenceincreasesthenumberofelectrons.

9.★★★Inp-typematerial,thenumberofelectronstrappedinbondsishigher,thuseffectivelyincreasingthenumberofholes.

10.★★Indopedmaterial,thereisalwaysmoreofonetypeofcarrierthantheotherandthetypeofcarrierwiththehigherconcentrationiscalleda"

majoritycarrier"

whilethelowerconcentrationcarrieriscalleda"

minoritycarrier"

11.★★★Thenumberofcarriersintheconductionandvalencebandwithnoexternallyappliedbiasiscalledtheintrinsiccarrierconcentration.

12.★★★Formajoritycarriers,theequilibriumcarrierconcentrationisequaltotheintrinsiccarrierconcentrationplusthenumberoffreecarriersaddedbydopingthesemiconductor.

13.★★Siliconorothersemiconductormaterialsusedforsolarcellscanbesinglecrystalline,multicrystalline,polycrystallineoramorphous.

14.★★Terminologyforvarioustypesofcrystallinesilicon（c-Si）

Descriptor

Symbol

GrainSize

CommonGrowthTechniques

Singlecrystal

sc-Si

>

10cm

Czochralski（CZ）floatzone（FZ）

Multicrystalline

mc-Si

1mm-10cm

Cast,sheet,ribbon

Polycrystalline

pc-Si

1μm-1mm

Chemical-vapordeposition

Microcrystalline

c-Si

<

1μm

Plasmadeposition

15.★★★Ithasbeenfoundthattheincorporationofatomichydrogeninamorphoussilicon,toalevelof5–10%,saturatesthedanglingbondsandimprovesthequalityofthematerial.

16.★★Theminoritycarrierdiffusionlengthsinthesilicon-hydrogenalloys（a-Si:

H）aremuchlessthan1μm.

17.★★Photonsincidentonthesurfaceofasemiconductorwillbeeitherreflectedfromthetopsurface,willbeabsorbedinthematerialor,failingeitheroftheabovetwoprocesses,willbetransmittedthroughthematerial.

18.★Forphotovoltaicdevices,reflectionandtransmissionaretypicallyconsideredlossmechanismsasphotonswhicharenotabsorbeddonotgeneratepower.

19.★★★Ifthephotonisabsorbeditwillraiseanelectronfromthevalencebandtotheconductionband.

20.★Theabsorptiondepthisausefulparameterwhichgivesthedistanceintothematerialatwhichthelightdropstoabout36%ofitsoriginalintensity,oralternatelyhasdroppedbyafactorof1/e.

21.★★Neglectingreflection,theamountoflightwhichisabsorbedbyamaterialdependsontheabsorptioncoefficientandthethicknessoftheabsorbingmaterial.

22.★★★Assumingthatthelossinlightintensity（i.e.,theabsorptionofphotons）directlycausesthegenerationofa