DSSC染料敏化太陽能電池英文教學課件

DyeSensitized

NanocrystallinePhotovoltaicCellGroup1–Luke,Matt,andJeffTheorynSchematicof

GraetzelCellTheory?

Theadsorbeddyemoleculeabsorbsaphotonforminganexcitedstate.

[dye*]?

Theexcitedstateofthedyecanbethoughtofasanelectron-holepair(exciton).?

Theexciteddyetransfersanelectrontothe

semiconductingTiO

(electron2injection).

Thisseparatestheelectron-holepairleavingtheholeonthedye.[dye*?

Theholeis

filledbyanelectronfromaniodideion.[2dye*

+3I

2dye+I

]+]+--3Theory:ChargeSeparationChargemustberapidlyseparatedtopreventbackreaction.Dyesensitizedsolarcell,theexciteddyetransfersanelectrontotheTiO2andaholetotheelectrolyte.InthePNjunctionin

Sisolarcellhasabuilt-inelectricfieldthattearsaparttheelectron-holepairformedwhenaphotonisabsorbedinthejunction.ObjectivennLearnaboutthephotovoltaiceffect.Understandthe

Scherrer

formula.Procedure:TiO2Suspension1.

Beginwith6gcolloidal

DegussaP25TiO22.

Incrementalyadd1mLnitricoraceticacidsolution(pH3-4)ninetimes,whilegrindinginmortarandpestle3.

Addthe1mLadditionofdiluteacidsolutiononlyafterpreviousmixingcreatesauniform,lump-freepaste4.

Processtakesabout30minandshouldbedoneinventilatedhood5.

Letequilibrateatroomtemperaturefor15minutesProcedure:DepositionofTiO2FilmAligntwoconductiveglassplates,placingoneupsidedownwhiletheonetobecoatedisrightsideupTape1mmwidestripalongedgesofbothplatesTape4-5mmstripalongtopofplatetobecoatedUniformlyapplyTiO

suspensiontoedgeofplate25microliterspersquarecentimeterDistributeTiO

overplatesurfacewithstirringrod2Drycoveredplatefor1minuteincovered

petridishProcedure:DepositionofTiO2Film?

AnnealTiO

filmonconductiveglass2?

Tubefurnaceat450

Co?

30minutes?

Allowconductiveglasstocooltoroomtemperature;willtakeovernight?

StoreplateforlateruseProcedure:PreparingAnthrocyaninDye?

Naturaldyeobtainedfromgreenchlorophyll?

Redanthocyanindye?

Crush5-6blackberries,raspberries,etc.in2

mLdeionizedH

Oandfilter(canusepapertoweland2squeezefilter)Procedure:StainingTiO

Film2?

SoakTiO

platefor10minutesin

anthocyanindye2?

InsurenowhiteTiO

canbeseenoneithersideof2glass,ifitis,soakindyeforfivemoremin?

WashfilminH

Othenethanolor

isopropanol2?

Wipeawayanyresiduewitha

kimwipeProcedure:CarbonCoatingtheCounterElectrode?

ApplylightcarbonfilmtosecondSnO

coated2glassplateonconductiveside?

Softpencillead,graphiterod,orexposuretocandleflameProcedure:AssemblingtheSolarCell?

Placetwobinderclipsonlongeredgestoholdplatestogether(DONOTcliptootight)?

Place2-3dropsofiodideelectrolytesolutionatoneedgeofplates?

AlternatelyopenandcloseeachsideofsolarcelltodrawelectrolytesolutioninandwetTiO

film2?

Ensureallofstainedareaiscontactedbyelectrolyte?

Removeexcesselectrolytefromexposedareas?

FastenalligatorclipstoexposedsidesofsolarcellProcedure:MeasuringtheElectricalOutput?

Attachtheblack(-)wiretotheTiO

coatedglass2?

Attachthered(+)wiretothecounterelectrode?

Measureopencircuitvoltageandshortcircuitcurrentwiththe

multimeter.?

Forindoormeasurements,canusehalogenlamp?

MakesurelightentersfromtheTiO

side2?

Measurecurrent-voltageusinga1

kohmpotentiometer?

Thecentertapandoneleadofthepotentiometerarebothconnectedtothepositivesideofthecurrent?

Connectonemultimeteracrossthesolarcell,andoneleadofanothermetertothenegativesideandtheotherleadtotheloadResultsnOpencircuitvoltage:0.388VAnalysis:PowernnMaximumPower:21

mWMax.powerperunitarea:30

mW/in2Active

Area:

0.7

in

2QuestionsnnApproximateTiO

particlesize:assume~25nmdiameter2NumberofTiO

unitspernanoparticle:2Volumeofone

nanoparticle

=8.18*10^-18cm

Massofonenanoparticle

=3.27*10^-17g=79.87g/mol

molesofTiO

inonenanoparticle

=4.10*10^-19moles3nnnDensity

of

TiO

~

4

g/cm32MolarmassofTiO22n4.10*10^-19moles*6.022*10^23molecules/mole=2.48*10^5TiOunitspernanoparticle2nNanoparticle

surfaceareapergram:nNumberof

nanoparticles

pergram=1/(3.27*10^-17)=3.06*10^16nanoparticlesSurfaceareaofone

nanoparticle

=1.96*10^-15mSurfaceareapergram=3.06*10^16

nanoparticles/gram*1.96*10^-15m2/nanoparticle

=60.0m

/gram2nn2QuestionsnFractionofatomsthatresideonthesurface:Surfaceareaofoneparticle=1.96*10^-11cm2nApproximateatomsperu