学科分类
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412 个结果
  • 简介:Pureandneodymium-dopedgadoliniumcalciumoxoboratecrystalsofhighqualityweregrownbytheCzochralskimethod.Theorientationofcrystalwaspreciselydetermined,andthesamplesformeasurementswereprepared.Throughsynchrotronx-raytopographyandhigh-resolutionx-raydiffractometry,thetwinstructurewasdiscovered.Somepropertiessuchasthefigureofmeritvalue,anddielectric,piezoelectric,andelasticconstantsweremeausuredalongwithadiscussionoftheanisotropyofthelaserproperties.

  • 标签: GdCa4O(BO3)3晶体 钕掺杂 硼酸盐晶体 Nd:GdCa4O(BO3)3晶体 晶体生长 形貌学
  • 简介:我们在一Y3Ga5O12(YGG)主人系统调查Bi3+和RE3+(RE=Tb或Eu)的光性质。Bi3+的另外的做能在这位主人提高Tb3+或Eu3+的光。到Tb3+和Eu3+的从Bi3+的精力转移被观察,精力转移的机制被调查。自从Bi3+排放乐队或Eu3+刺激乐队,转移能作为电的多极相互作用被解释的精力的机制重叠,当Tb3+或Eu3+的紧张随Tb3+或Eu3+集中的增加增加时,Bi3+排放紧张减少。因此,Bi3+离子是到在Y3Ga5O12主人的Tb3+和Eu3+使活跃之物的一种有效sensitizer。

  • 标签: 发光光谱 发光特征 能量传递
  • 简介:Ca3Y2(BO3)(4):Eu3+黄磷被高温度solid-statereaction方法综合,并且光特征被调查。排放光谱在相应于电的dipoleD-5(0)的613和621nm展出二强壮的红排出物在365nm刺激下面的Eu3+的-F-7(2)转变,原因是Eu3+代替forY3+在Ca3Y2(BO3)(4)的水晶结构占据非中心对称的位置。为613nm的Theexcitation光谱显示黄磷能是有效地激动的由紫外(紫外)(254nm,365nm和400nm)并且蓝色(470nm)光。Ca3Y2(BO3)(4)的排放紧张上的Eu3+集中的效果:Eu3+黄磷被测量,排放紧张与增加Eu3+集中增加的结果表演,然后减少。Ca3Y2(BO3)(4)的CIE颜色坐标:Eu3+黄磷是(0.639,0.357)在15mol%Eu3+。

  • 标签: 发光特征 高温 固体 光谱
  • 简介:Asanimportantmulti-functionalmaterialappliedinsurfaceacousticwavedevices,opticalcommunications,laserandoptoelectronicsduetoitsgoodphotoelectricandpiezoelectricproperties,lithiumtantalate(LiTaO3)hasdrawnextensiveinterests[1].NumerousphysicalpropertiesofLiTaO3,suchasacoustical,electronicstructures,opticalpropertiesandeffectivemass,thermodynamicproperties,havebeenreportedinseveralpapers.Pointdefectswillaffecttheelectronicstructurewhichshouldberesponsibleformanyphysicalproperties,especiallyopticalproperties.

  • 标签: FIRST-PRINCIPLE INVESTIGATION LITAO3
  • 简介:MP3风靡我们的时候,我们就开始患上MP3疯魔症——眼睛睁开的第一秒,便搜索最爱的MP3,低头走路,孤立进食,默默无语……自始至终,活在一人的世界里,你说,这不是疯了是怎么了?

  • 标签: MP3 设计 整机 电池
  • 简介:研究了钙钛矿太阳能电池材料CH3NH3PbI3(CH3NH3=MA,MAPbI3)的输运特性,理论分析了有机分子MA对晶格结构的影响。发现:MA沿[110]方向排布且近邻MA分子相互垂直的构型最稳定,将此构型作为MAPbI3的标准结构,使用第一性原理方法,通过分析晶格的振动散射或声子散射,计算了MAPbI3材料中形变势散射主导的载流子迁移率,分析了材料的输运特性,讨论了载流子迁移率理论计算值和实验值之间的差异。

  • 标签: CH3NH3PbI3 几何结构 形变势散射 迁移率
  • 简介:YbxY1-xAl3(BO3)4(x=0.1,0.07and0)crystalshavebeengrownbythefluxmethod.ThegrowthdefectsofYbxY1-xAl3(BO3)4crystalsweredetectedbyX-raytopography.ItisfoundthattheperfcetionofYbYABcrystalwithlowYbdopantisbetterthanthatwithhighYbdopant.InYb0.1Y0.9Al3(BO3)4crystal,growhtbands,growthboundaries,grown-indislocationsandinclusionswereobserved.Howver,thedensitiesofgrowthdefectsforYb0.07Y0.93Al3(BO3)4andYAl3(BO3)4arelowandnoobviousinclusionsareobservedinthesecrytals.Inaddition,growthtwinswrerdetectedinYbxY1-xAl3(BO3)4crystalbyusingthechemicaletchingmethod.ItisfoundthatthegrowthtwinsoccurfrequentlyinYb0.01Y0.9Al3(BO3)4crystalwhereasnogrowthtwinappearsinYAl3(BO3)4crystal.Basedontheexperimentalobservations,theformationmechanismofgrowthtwinsisdiscussed.Inthemeantime,theeffectivemeasuresforreducingthegrowthtwinsanddefectsareproposed.2001ElsevierScienceB.V.Allrightsreserved.

  • 标签: YbxY1-xAl3(BO3)4晶体 晶体生长 结构缺陷 硼酸盐晶体 形貌学 X射线
  • 简介:Inthispaper,wereportedamultiwavelengthpassivelyQ-switchedYb3+:GdAl3(BO3)4solid-statelaserwithtopologicalinsulatorBi2Te3asasaturableabsorber(SA)forthefirsttime,tothebestofourknowledge.Bi2Te3nanosheetswerepreparedbythefacilesolvothermalmethod.TheinfluenceofthreeBi2Te3densitiesonthelaseroperationwascompared.Themaximumaverageoutputpowerwasupto57mWwithapulseenergyof511.7nJ.Theshortestpulsewidthwasmeasuredtobe370nswith110kHzpulserepetitionrateand40mWaveragepower.Thelaseroperatedatthreewavelengthssimultaneouslyat1043.7,1045.3,and1046.2nm,ofwhichthefrequencydifferenceswerewithintheterahertzwaveband.OurworksuggeststhatsolvothermalsynthesizedBi2Te3isapromisingSAforsimultaneouslymultiwavelengthlaseroperation.

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  • 简介:Multilayerblackphosphorus(BP)nanoplateletsofdifferentthicknesseswerepreparedbytheliquidphaseexfoliationmethodanddepositedontoyttriumaluminumgarnetsubstratestoformsaturableabsorbers(SAs).Thesewerecharacterizedwithrespecttotheirthickness-dependentsaturableabsorptionpropertiesat3μm.TheBP-SAswereemployedinapassivelyQ-switchedEr:Lu2O3laserat2.84μm.ByusingBPexfoliatedindifferentsolvents,stablepulsesasshortas359nsweregeneratedatanaverageoutputpowerofupto755mW.Therepetitionrateintheexperimentwas107kHz,correspondingtoapulseenergyof7.1μJ.TheseresultsprovethatBP-SAshaveagreatpotentialforopticalmodulationinthemid-infraredrange.

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  • 简介:WepresentthetemperaturedependentelectricaltransportmeasurementsofAg/Si(111)-(√3×√3)R30°bytheinsitumicro-four-pointprobemethodintegratedwithscanningtunnelingmicroscopy.Thesurfacestructurecharacterizationsshowhexagonalpatternsatroomtemperature,whichsupportstheinequivalenttriangle(IET)model.Ametal-insulatortransitionoccursat-115K.Thelowtemperaturetransportmeasurementsclearlyrevealthestronglocalizationcharacteristicsoftheinsulatingphase.

  • 标签: surface CONDUCTIVITY METAL-INSULATOR transition LOCALIZATION SCANNING
  • 简介:LargeGdCa4O(BO3)3crystalhasbeengrownbytheCzochralskimethod.ThequalityofGdCa4(BO3)3crystalwasassessedbywhite-beamsynchrotronradiationtopography.Ithasbeenfoundthatthereisasub-grainboundaryintheGdCa4O(BO3)3crystal.TheboundarydividesthelargeGdCa4O(BO3)3crystalintotwoindividuals.Duetothemisorientationbetweenthetwoindividuals,theimageshiftscanbeobservedinthesynchrotrontopopraphs.BasedonthemisorientationdeterminedbyhighresolutionX-raydiffractometer,theimageshiftswerecalculatedforseveralreflections.ThecalculationsareinagreementwiththemeasurementsfromthetopogrphsveryWell.Inaddition,theformationmechanismofsub-grainboundaryisdiscussed.2001ElsevierscienceB.V.Allrightsreserved.

  • 标签: GdCa4O(BO3)3晶体 硼酸盐晶体 晶体结构 X射线衍射分析 晶体生长 同步辐射形貌术