Influence oftheexcitonblockinglayeronthestabilityoflayeredorganic solar cells

摘要

The life-timeofmulti-layerorganicsolarcellsbasedonthecoupledonoracceptorcopperphthalocyanine/fullereneisstudiedasafunctionofthenatureoftheexcitonblockinglayer(EBL).Itisshownthatorganic EBL aremoreefficientthanaretheinorganicIn2S3 EBLs. MoreoveramongtheorganicEBL,Alq3 is themost efficientEBLprotectinglayer.Anorganicsolarcell’slifetimedependsonoxygen-andwater-contaminationoftheorganicmaterials.Thesolarcell’sdegradationmaycorrespondtobulkorinterface phenomena.Usingequivalentelectricalschemesofsolarcelldiodes,weshowthatthestructure degradationismainlyrelatedtobulkmodification.Itisproposedthatoxygen-andwater-diffusioninto the C_(60) inducealargeincreaseinitsresistivityand,thereforeanincreaseintheseriesresistance,which decreasesthesolarcellefficiency.InthecaseofIn_2S_3 EBLs, thedegradationlawpredictsthatwithtime two differentphenomenawillbepresent.Theclassicaloxygen-andwater-diffusionintotheorganic material,duringthefirsthourofairexposure,leadstoamodificationintheIn_2S_3 EBL/organicinterface properties.