红外反射谱-AZO-Ag-AZO

  • 格式:pdf
  • 大小:1.88 MB
  • 文档页数:7

CERAMICSINTERNATIONAL

Availableonlineatwww.sciencedirect.com

CeramicsInternational40(2014)12847–12853InfraredreflectivepropertiesofAZO/Ag/AZOtrilayerspreparedbyRFmagnetronsputtering

DagangMiao,ShouxiangJiangn,SongminShang,ZhuomingChenInstituteofTextilesandClothing,TheHongKongPolytechnicUniversity,HungHom,Kowloon,HongKong,ChinaReceived26March2014;receivedinrevisedform14April2014;accepted27April2014Availableonline2May2014

AbstractAZO/Ag/AZOtrilayerfilmswerepreparedonglasssubstratesbyradiofrequency(RF)magnetronsputteringtechnology.Crystalstructure,surfacemorphology,visibletransmittance,andcolorscaleoftheAZO/Ag/AZOcoatedtrilayersasfunctionsofAgandAZOlayersthicknesswereinvestigatedbyX-rayDiffraction(XRD),ScanningElectronMicroscope(SEM),AtomicForceMicroscopy(AFM),opticaltransmittancespectraandCIELABsystem.Inaddition,theelectricalandinfraredreflectionpropertiesofthecoatedtrilayerswereexaminedbyfour-pointprobesystemandFourierTransformInfraredSpectroscopy.TheresultsindicatedthattheAginnerlayerstartedformingacontinuousfilmatthethicknessof10nmwhichwassupportedbyXRDresultofthedistinct200and220Agpeaks.Besides,thehighestaveragevisibletransmittanceof80.5%wasobtainedbytheAZO(30nm)/Ag(10nm)/AZO(30nm)structure.Furthermore,thelowestsheetresistivityof4.36Ω/sqandthehighestinfraredreflectionrateof96%inFIRregioncanbeobtainedbytheAZO(30nm)/Ag(13nm)/AZO(30nm)structure.ThehighinfraredreflectionpropertyoftheAZO/Ag/AZOtrilayersmakesitapromisingcandidateforenergyconservationcoatings.&2014ElsevierLtdandTechnaGroupS.r.l.Allrightsreserved.

Keywords:AZO;Ag;Multilayerthinfilms;Infraredreflection;RFmagnetronsputtering1.IntroductionThegrowingdemandforenergyconservationinrecentyearshasbeenaccompaniedbyincreasingscholarlyinterestinhighlyvisibletransparentandnear-infrared(NIR)reflectivethinfilms[1].Transparentconductiveoxides(TCOs)areoneofthepotentialcandidatesforenergyconservationfilmsduetotheirhighvisibletransparentandhighconcentrationoffreeelectrons[2–4].Al-dopedZnO(AZO)isanemergingTCOmaterialandhasbeenextensivelyinvestigatedtosubstitutethewidelyusedexpensiveIndiumTinOxide(ITO),becauseofitsrichstorage,non-toxic,reductionstabilitytohydrogenplasmasaswellastheeasywayforitssynthesisandprocessing[5];andAZOfilmhasbeenreportedtohavehighvisibletransmittance(about80–85%)andhighNIRreflectance(about50%at2000nm)[6].Nevertheless,thebestNIRreflectanceofAZOfilmscanonlybeobtainedwhenheatingtreatments

areemployedduringorafterthedepositionprocess,whichincreasestheoverallcostofsolarmaterialsfabrication.Inordertoacquirethedesiredinfraredreflectionrateandmaintainhightransmittance,TCO/metal/TCOmultilayerfilmhasrecentlyreceivedarenewedinterestasahighlypromisingrouteinsolarmaterials[7,8].Inthiscase,Agistheoptimalmetalbecauseofitslowresistivity(approximately1.6Â10À6Ωcm),

andithasbeenwellpreparedbymagnetronsputtering[9,10].Currently,manyresearchersarededicatedtoinvestigatethevisibletransmittanceandelectricalresistivityofAZO/Ag/AZOfilm,andmanyusefulresultshavebeenreported.Sahu[11–13]haspreparedAZO/Ag/AZOtrilayersbyelectronbeamevaporation.Hefoundthatthetrilayersshowedsatisfactorypropertiesoflowresistanceandhightransmittanceforapplicationastransparentconductiveelectrodes.Park[14]andSutthana[15]haveinnovativelypreparedtheAZO/Ag/AZOfilmbyDCmagnetronsputteringforsolarcellapplica-tions.Crupi[16]hasinvestigatedtheoptimizationofAZO/Ag/AZOstructurespreparedbyRFmagnetronsputtering.Inaddition,Wu[17]studiedtheinfluenceofAgthicknessin

www.elsevier.com/locate/ceraminthttp://dx.doi.org/10.1016/j.ceramint.2014.04.1390272-8842/&2014ElsevierLtdandTechnaGroupS.r.l.Allrightsreserved.

nCorrespondingauthor.Tel.:þ85227666430;fax:þ85227731432.

E-mailaddress:kinor.j@polyu.edu.hk(S.Jiang).AZO/Ag/AZOthinfilms,theyalsofoundtheimportantresults.Miao[18]hasinvestigatedtheinfraredpropertiesofAZO/Ag/AZOtrilayersdepositedonpolyesterfilmforflexiblesolarcontrolfilm.However,onlylittleattentionhasbeendevotedtotheinfraredreflectionpropertiesofAZO/Ag/AZOfilm,especiallytheinfraredreflectionunder20μmwhichisthemainregionofsolarenergyandthermalinfraredradiationfromothersub-stancesabsorbedsolarenergy[19].Therefore,itisanimportantstudytofurtherinvestigatetheIRreflectionpropertyofAZO/Ag/AZOtrilayersforenergyconservationcoatingapplications.Magnetronsputteringisaneffectivetechnologytoproducestablequalitythinfilmsatahighdepositionrate.Inordertoobtaingoodqualityofenergyconservationcoatings,theAZO/Ag/AZOmultilayerfilmwaspreparedbyRFmagnetronsputteringonunheatedglasssubstrates.Inthisstudy,surfacemorphology,crystalstructure,electrical,opticalandinfraredpropertiesoftheAZO/Ag/AZOcoatedmultilayerfilmsweresystematicallyinvestigated.