银纳米线在太阳能电池中的应用

Solution-Processed Highly Conductive PEDOT:PSS/AgNW/GOTransparent Film for E? cient Organic-Si Hybrid Solar CellsQiaojing Xu, Tao Song,* Wei Cui, YuqiangLiu, WeidongXu, Shuit-TongLee,and BaoquanSun*JiangsuKey Laboratoryfor Carbon-BasedFunctionalMaterials silvergrid electrode;andpristine AgNW TCE with aconcentrationof 3.5 mg/mL. The short-circuitcurrent density(Jsc), the open-circuitvoltage(Voc), the ?ll factor (FF), andthePCE of solarcellswith di?erenttop anodesaresummarizedinTable 1 and Table S2 in the Supporting Information. Thedevicesbasedon PEDOT:PSS/AgNW/GO TCEs showhigherPCE than those based on either conventionalAg grids orPEDOT:PSS/AgNW TCEs without GO. With the GO layer,the PCEof the hybrid devicesis enhancedfrom ～ 11 to ～ 12%on average.In particular,the FF is signi?cantly improved byintegrationof GO becauseof reducedseriesresistanceof thedevices(Table 1 andTableS2in the SupportingInformation).Seriesresistancewasextractedfrom slopeof J- V curvesat J =0.40 Seriesresistanceof the deviceswith PEDOT:PSS/AgNW/GO TCEs is much lower than that of the devicewithout GOand the Ag grids device. Seriesresistanceof solar cells isin?uencedby the lateralRs aswell asthe contactresistance.41Lateral resistanceof PEDOT:PSS ?lms was reducedby thepercolatedAgNW networks.Meanwhile,contact resistanceofthe “ sandwich” structure of PEDOT:PSS/AgNW/GO is lowbecauseof the strong electrostaticadhesionbetween hydro-philic PEDOT:PSSand GO.By analyzingthe device performance,we found that GOtendedto takea more prominentrole in the sparsedistributedAgNW network than the denselypackedone.Speci?cally,forthe GO-covereddevicefabricatedfrom 1.5 mg/mL AgNWs,the FF and the PCE were improved by 12.2 and 11.8%,respectively.While for the GO-covereddevice with a higherAgNW concentrationof 5 mg/mL, the correspondingFF andthe PCE wereslightly increasedby 5.4 and 3.4%,respectively.This phenomenoncanbeexplainedasfollows:dueto the loosemorphology of the AgNW mesh, the sparseAgNW networkcannot provide enough conducting paths to deliver chargecarriersgeneratedby light; it could be readilycompensatedbyincreasingthe amount of contactingjunctionsand decreasingthe junction resistancein AgNW network by the GO sheetscoating.For the denseAgNW network, the Rs is alreadyverylow and the space for further improvementsby the GOcoverageis ratherlimited. Asa resultof abalancebetweenlightabsorptionand chargecarriercollection,a remarkablePCE of13.3%(with a Jsc of 28.4mA/cm2, a Voc of 0.601V, anda FF of78.4%)wasachievedemployingthe PEDOT:PSS/AgNW/GOcompositeTCEs with a AgNW suspensionconcentrationof 3.5mg/mL. It is worth noting that thisresultis alsoconsistentwiththe maximum Φ TC value of the PEDOT:PSS/AgNW/GOcomposite TCEs fabricated from 3.5 mg/mL AgNWconcentration. The reference device based on the PE-DOT:PSS/AgNW TCE with the sameAgNW concentrationexhibiteda lower PCE of 11.6%(with a Jsc of 28.3 mA/cm2, aVoc of 0.579 V and a FF of 70.9%),which may be partiallycausedby the largeroughnessof thepristine AgNW mesh.Theperformanceof the referencedeviceswas consistentwith thepreviousresultswhere nanostructuredsilicon substrateswereemployed as photoactive layers and PEDOT:PSS/AgNWsacted as TCEs.8 We believethat the higher e? ciency of thehybrid solarcell basedon PEDOT:PSS/AgNW/GO compositeTCE can be attributed to the more e? cient chargecarriercollection and transfer, wherein the AgNW networks weree?ectivelyweldedby GO nanosheets.Though electrical conductivity has been improved usingcompositeelectrodewith and without GO coverage,similarJscwasobtainedfor those two typesof devices.Accordingto theEQE spectraof hybrid solar cells as shown in Figure 3c, thecalculatedJsc was27.8and 27.7mA/cm2 for the deviceswithPEDOT:PSS/AgNWelectrodesandPEDOT:PSS/AgNW/GOcompositeelectrodes,respectively.The integratedJsc valuesarein good accordance with those extracted from the J- Vcharacteristics.EQE spectraare closely correlatedwith bothoptical and electricalcharacteristicsof the solar cells,suchaslight trapping and electrode conductivity, as well as chargeseparationandtransferin the devices.As shownin FigureS2din the SupportingInformation,re?ectanceis almostthe samefor the PEDOT:PSS/AgNW ?lms with or without GO,indicating that light re?ection is not the main reasonfor PVperformancedi?erence.On the other hand,we comparedlighttransmittance of the PEDOT:PSS/AgNW ?lms and thePEDOT:PSS/AgNW/GO ones, as shown in Figure S2c inthe SupportingInformation.This analysiscon?rmsthat for thedeviceswith PEDOT:PSS/AgNW/GO composite TCEs, theslightdecreaseof EQE at the wavelengthsshorterthan600nmis causedby the light absorptionof GO. 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