iset_2004_status_report_6

《iset_2004_status_report_6》由会员上传分享，免费在线阅读，更多相关内容在行业资料-天天文库。

1、‘LabtoLargeScale’TransitionforNon-VacuumThinFilmCIGSSolarCellsStatusReportNo.6November1,2003–January31,2004NRELContract#XCQ-230630-30InternationalSolarElectricTechnologyInc.(ISET)ThegoalofthiscontractistoidentifythechallengesfacedbyISETinscalingupitsnon-vacuumprocessfromalaboratorytolargescalema

2、nufacturingandtodevelopworkablesolutionsforthesechallengessuchthattheycanbereadilyimplementedinlargescaleprocessingofCIGSsolarcellsandmodules.InphaseII(2ndyear)ofthis3-yearcontract,ISETisfocusingoni)furtherimprovementincellefficiency,ii)evaluationofalternatedepositiontechniquesforcoatingISET’sin

3、ksuniformlyonlargeareasubstrates,iii)developingmonolithicintegrationschemesformakingCIGSmodulesonglasssubstratesandiv)increasingmaterial’susageandminimizingwaste.I.ImprovingSolarCellEfficiencyPreviously,wereportedconsiderablecellvoltageimprovementsbysurfacemodificationwithanovelgalliumsurfacetre

4、atment,whichincludedspraydeposition,filmconversion,post-annealingandetchingsteps.OursearchforaselectivedissolutionprocedureforremovalofunincorporatedphasesaftermodificationshowedustheeffectsofvariousetchantsonGa-modifiedsamples.WeobservedstatisticallysignificantgainsinVocaftermodificationbutthes

5、eresultsweretypicallycoupledwithlossesincurrentcollection.OurinitialstrategytomodifysurfacewithgalliumastheonlygroupIIIcationwasastepintherightdirection,howeverthisroutetogalliumrichadlayersposedfundamentalchallengesinstabilizingdevicecurrentsduetopossibleformationofdefectivebinaryandternaryphas

6、esatthesurface.Wegotaroundthisproblemofdeepcurrentlossesbytreatingthesurfacewithaslighttwistonthenormalscheme.Ourgallium-onlysurfacetreatmentreliesonextendedhightemperatureselenizationtimestofusesurfaceadlayerswiththebulkchalcopyritesemiconductor.Afewproblemsarisewiththismethod:(i)galliumcationi

7、nasemi-infiniteoverlayerisasourceofdefectivematerialatthesurface(ii)hightemperatureprocessingcausesaneventualdegradationoftheMobackcontactinaselenizationambientbecauseoftheformationofMoSeand(iii)thesurfacemodificationprocess