一种有机聚合物光伏电池的发展简史

SolarEnergyMaterials&SolarCells83(2004)125–146AbriefhistoryofthedevelopmentoforganicandpolymericphotovoltaicsHolgerSpanggaard*,FrederikC.KrebsTheDanishPolymerCentre,RisøNationalLaboratory,P.O.Box49,Frederiksborgvej399,Roskilde,DK-4000DenmarkAbstractInthispaperanoverviewofthedevelopmentoforganicphotovoltaicsisgiven,withemphasisonpolymer-basedsolarcells.Theobservationofphotoconductivityinsolidanthraceneinthebeginningofthe19thcenturymarkedthestartofthisfield.Thefirstrealinvestigationsofphotovoltaic(PV)devicescameinthe1950s,whereanumberoforganicdyes,particularlychlorophyllandrelatedcompounds,werestudied.Inthe1980sthefirstpolymers(includingpoly(sulphurnitride)andpolyacetylene)wereinvestigatedinPVcells.However,simplePVdevicesbasedondyesorpolymersyieldlimitedpowerconversionefficiencies(PCE),typicallywellbelow0.1%.Amajorbreakthroughcamein1986whenTangdiscoveredthatbringingadonorandanacceptortogetherinonecellcoulddramaticallyincreasethePCEto1%.Thisconceptofheterojunctionhassincebeenwidelyexploitedinanumberofdonor–acceptorcells,includingdye/dye,polymer/dye,polymer/polymerandpolymer/fullereneblends.Duetothehighelectronaffinityoffullerene,polymer/fullereneblendshavebeensubjecttoparticularinvestigationduringthepastdecade.EarlierproblemsinobtainingefficientchargecarrierseparationhavebeenovercomeandPCEofmorethan3%havebeenreported.Differentstrategieshavebeenusedtogainbettercontroloverthemorphologyandfurtherimproveefficiency.Amongthese,covalentattachmentoffullerenestothepolymerbackbone,creatingso-calleddouble-cablepolymers,isthelatest.TheimprovedPCEofplasticsolarcellscombinedwithincreased(shelfandoperating)lifetime,superiormaterialpropertiesandavailablemanufacturingtechniquesmaypushplasticPVstothemarketplacewithinafewyears.r2004ElsevierB.V.Allrightsreserved.Keywords:Organicphotovoltaics;Plasticsolarcells;Heterojunction;LED;PhotocurrentARTICLEINPRESS*Correspondingauthor.Tel.:[phone];fax:[phone].E-mailaddress:[e-mail](H.Spanggaard).0927-0248/$-seefrontmatterr2004ElsevierB.V.Allrightsreserved.doi:10.1016/j.solmat.2004.02.0211.IntroductionThediscoveryofthephotovoltaic(PV)effectiscommonlyascribedtoBecquerel(seeFig.A),whodiscoveredaphotocurrentwhenplatinumelectrodes,coveredwithsilverbromideorsilverchloride,wasilluminatedinaqueoussolution(strictlyspeakingthisisaphotoelectrochemicaleffect)[1].SmithandAdamsmadethefirstreportsonphotoconductivity,in1873and1876,respectively,workingonselenium[2].AnthracenewasthefirstorganiccompoundinwhichphotoconductivitywasobservedbyPochettinoin1906[3]andVolmerin1913[4].Inthelate1950sand1960sthepotentialuseoforganicmaterialsasphotoreceptorsinimagingsystemswasrecognized[5].Thescientificinterestaswellasthecommercialpotentialledtoincreasedresearchintophotoconductivityandrelatedsubjects.Intheearly1960sitwasdiscoveredthatmanycommondyes,suchasmethyleneblue,hadsemiconductingproperties[6].Later,thesedyeswhereamongthefirstorganicmaterialstoexhibitthePVeffect[7].Also,thePVeffectwasobservedinmanyimportantbiologicalmoleculessuchascarotenes,chlorophyllsandotherporphyrins,aswellasthestructuralrelatedphthalocyanines(PC).DespitemanyimprovementsovertheyearsorganicPVshasnotyetreachedthemarketplaceunlikeinorganicsolarcells.ThefirstinorganicsolarcellwasdevelopedatBellLaboratoriesin1954[8].ItwasbasedonSiandhadanefficiencyof6%.Overtheyearstheefficiencyhasreached24%forcrystallineSisolarcellsinthelaboratory[9].TodaySi-basedsolarcellsarebyfarthemostdominatingtypeofPVsusedandaccountfor99%ofallPVs[10].ARTICLEINPRESSSomeimportantmilestonesinthedevelopmentoforganicsolarcells2001-Ramosuseddouble-cablepolymersinPVcells.2001-Schmidt-Mendemadeaself-organisedliquidcrystallinesolarcellofhexabenzocoroneneandperylene.2000-Peters/vanHalusedoligomer-C60dyads/triadsastheactivematerialinPVcells.1995-Yu/Hallmadethefirstbulkpolymer/polymerheterojunctionPV.1994-Yumadethefirstbulkpolymer/C60heterojunctionPV.1993-Sariciftcimadethefirstpolymer/C60heterojunctiondevice.1991-Hiramotomadethefirstdye/dyebulkheterojunctionPVbyco-sublimation.1986-TangpublishedthefirstheterojunctionPVdevice.1964-Delacoteobservedarectifyingeffectwhenmagnesiumphthalocyanines(CuPh)wasplacedbetweentwodifferentmetalelectrodes.1958-KearnsandCalvinworkedwithmagnesiumphthalocyanines(MgPh),measuringaphotovoltageof200mV.1906-Pochettinostudiedthephotoconductivityofanthracene.1839-Becquerelobservedthephotoelectrochemicalprocess.Fig.AH.Spanggaard,F.C.Krebs/SolarEnergyMaterials&SolarCells83(2004)125–146126WithincreasingefficiencyandreducedproductioncoststheworldPV-markethasincreased.Inthepast20years,thedemandforsolarenergyhasgrownconsistentlywithgrowthratesof20–25%peryear,reaching427MWin2002.FiftyyearsofresearchandinnovationhasdramaticallyreducedthepriceofSiPVstothelevelpossibleusingexistenttechnology.However,despitemucheffortoffurtherreducingthepriceofSibasedPVs,thistechnologyisconfinedtoniches.Thus,semiconductorPVsstillaccountforlessthan0.1%ofthetotalworldenergyproduction.Organicsemiconductorsarealessexpensivealternativetoinorganicsemiconduc-torslikeSi.Also,organicmolecul