ZnO和ZnO基稀磁半导体薄膜的PLD法制备及其特性研究

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1、河北工业大学博士学位论文ZnO和ZnO基稀磁半导体薄膜的PLD法制备及其特性研究姓名：滕晓云申请学位级别：博士专业：材料物理与化学指导教师：刘彩池;于威20070501ZnO和ZnO基稀磁半导体薄膜的PLD法制备及其特性研究PHYSICALCHARACTERISTICSOFZnOANDZnO-BASEDDILUTEDMAGNETICSEMICONDUCTORSFABRICATEDBYPLDABSTRACTThecrystallineZnOfilmshavebeendepositedbythepulsedlaserdeposition(PLD).Therelationbetweendif

2、ferentdepositionparametersandthestructurepropertiesofZnOfilmsisanalyzedandtheoptimizedconditionisobtained.Basedonthoseresults,thefilmswithAl,Ni,MndopinginZnOfilmshavealsobeenpreparedandtheinfluenceofdopingcontentsonpropertiesofthefilmsisstudied.Furthermore,usingaNd:YAGlaserasfundamentalbeam,thes

3、econd-harmonicefficiencyofthefilmsismeasured.Themainresultsareasfollows:ZnOthinfilmswithhighlyc-axisorientationhavebeenfabricatedbyPLDmethod.Theinfluenceofsubstratetemperatureandoxygenpressureonthepropertiesofthefilmsisstudied.ThereasonwhythegrowthmodelofZnOfilmschangedwiththedepositioncondition

4、isexplained.Theroom-temperaturePLspectraoftheZnOfilmsgrownatdifferentoxygenpressureshavebeeninvestigated.Allfilmsshowatypicalluminescencebehaviorwithanarrowultraviolet(UV)andabroadgreen-yellowband.ItisproposedthattheintensityofUVemissiondependsoncrystalstructureandthedeeplevelemissioncorrelatest

5、otheelectrontransitionsfromthebottomoftheconductionbandtotheantisiteoxygenOZn.HighqualityAldopingZnOtransparentconductivefilmshavebeenfabricatedbymixingAlintoZnOtarget.Theeffectofdopingconcentrationontheirstructure,electricalandopticalpropertiesisstudied.Theresultsshowthatthelowelectricalresisti

6、vitycanbeobtainedunderappropriatedopingcontentandtheopticaldirectbandgapoffilmsisdependentonthecarrierconcentration.High-qualityNi-,Mn-dopedZnOthinfilmshavebeendepositedandobviouslyii河北工业大学博士学位论文room-temperatureferromagneticbehaviorisobtained.Theeffectofdopingconcentrationontheferromagnetismmech

7、anismofZn1-xNixOfilmsisanalyzed.TheferromagnetismofZn1-xMnxOfilmsisstronglyrelatedtothedefectsinZnOfilms,butthecorrectdopingconcentrationiscrucialforobtainingroom-temperatureferromagnetism.UsingaNd:YAGlaserof1064nmasafundame