学科分类
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38 个结果
  • 简介:ThesinglecrystalgrowthofstoichiometrichostluminescentcrystalNa5Eu(WO4)4hasbeeninvestigated.UsingNa2WO4asaflux,theoptimumconditionstogrowapuresinglecrystalbyflux-slow-coolingmethodhavebeendetermined.Ahighopticalqualitysinglecrystalofdimention4.5mmhasbeengrown,whichisthelargestoneasweknowsofar.Themicro-hardnessofNa5Eu(WO4)4singlecrystalis3.46×103MPa.Itsrefractiveindexis1.81inwhitelightwavelengthregionandthespecificgravityis5.65g/cm3.Thefluorescentandexcitationspectrahavebeendeterminedandthereasonofthefluorescentquenchof5D2and5D1to7FjofEu3+canbeexplainedasmulti-phononnon-radiationtransition.

  • 标签: Na5Eu(WO4)4 single crystal Host LUMINESCENCE Eu3+luminescence
  • 简介:Luminescentcoordinationcompoundswithnitrogen-containingligandshaveattractedmuchattentionduetotheirgoodperformanceinsensorandelectroluminescentdevicetechniques[1-17].Todevelopnewluminescentmaterials,alargenumberofd10metalcomplexes,especiallyzinccomplexes,withthenitrogen-containingligandshavebeensynthesizedandtheirluminescencebehaviourhavebeenstudied[1-11].Ithasbeenfoundthatforagivencomplex,thesizeoftheπ-conjugatedsystemoftheligandandtheelectroniceffectofsubstituentsattheligandareimportantfactorsformodulatingitsluminescentproperties[5,8,9].

  • 标签: 合成 X射线晶体结构 2 6-二(亚氨基)吡啶配合体 锌配合物 发光性质
  • 简介:Unlikeorganic–inorganichybridperovskites,all-inorganiccesiumleadhalideperovskitesholdgreatpromisefordevelopinghigh-performanceoptoelectronicdevices,owingtotheirimprovedstability.Herein,weinvestigatetheperovskite-relatedCsPb2Br5nanoplatelets(NPLs)withtunableemissionwavelengthsviachangingthereactiontemperaturesto100°C,120°C,and140°C.ReactiontemperatureplaysakeyroleindeterminingtheshapesandthicknessesoftheresultingCsPb2Br5NPLs.AhighertemperatureisinfavoroftheformationofsmallerandthickerNPLs.Todeveloptheirpotentialapplicationsinoptoelectronicdevices,greenlightemittingdiodes(LEDs)andphotodetectorsbasedonCsPb2Br5NPLsarefabricated.ThegreenLEDsbasedonCsPb2Br5NPLssynthesizedat140°Cexhibitanexcellentpuregreenemission(fullwidthathalf-maximumof<20nm)anddisplayaluminousefficiencyof34.49lm∕Wunderanoperationcurrentof10mA.Moreover,thephotodetectorbasedonCsPb2Br5NPLssynthesizedat100°Chasbetterperformancewitharisetimeof0.426s,adecaytimeof0.422s,andaratioofthecurrent(withandwithoutirradiation)of364%.

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  • 简介:AnovelTb(III)ternarycomplexTb(p-BBA)_3MAAwassynthesizedwith4-benzoylbenzoicacid(p-BBA)andmethacrylicacid(MAA)asligands.ThecomplexwascharacterizedbyIR,UV-visible,thermogravimetricanalysisandfluorescencespectroscopy.Monitoredat544nm,thecomplexdisplayedwideandstrongexcitationbandat300–400nm,whichmatchedwellwiththe365nm-emittingUVchip.Thecomplexexhibitedexcellentgreenemissionat544nm(~5D_4→~7F_5transitionofTb~(3+))underanexcitationat365nm.Besides,thecomplexshowedhighthermalstability.Itsintramolecularenergytransferprocesswasfurtherdiscussed.Furthermore,thecomplexalsohadhigherfluorescencelifetime(1.38ms)andhigherquantumyield(0.372).Finally,electroluminescentpropertiesindicatedthatwhenusedtofabricateLEDwith365nmUVchip(powerefficiencyis18.6lm/W),thecomplexremaineditsfavorableopticalperformance.TheseresultsimpliedthatTb(p-BBA)_3MAAcouldbeusedasagreenphosphorforNUV-basedwhiteLED.

  • 标签: LUMINESCENT excitation FABRICATE visible LIFETIME phosphor
  • 简介:在这研究,新有点磁性、光的Fe3O4/CdTenanocomposites的准备被表明。SuperparamagneticFe3O4nanoparticles被铁、铁的离子的热水的一起沉淀首先综合,与丁氨二酸酸与tetramethylammonium氢氧化物(TMAOH)和化学激活由他们的表面的修正列在后面。修改表面的Fe3O4nanoparticles当时与CdTe量点(QD)是covalently涂的,它与mercaptoacetic酸(MPA)被修改,到通过Fe3O4和carboxyl的表面上的氨基的组的协作的Fe3O4/CdTe磁性、光的nanocomposites在CdTeQD上组织的形式。同样综合的nanocomposites的结构和性质被描绘。nanocomposites与40-50nm,黄绿色的排放特征和房间温度强磁性的一条平均直径拥有了结构,这被显示。荧光和nanocomposites的紫外力的吸收系列显示出CdTeQD与那些作比较的蓝移动。蓝移动的机制被介绍。nanocomposites与8.9emu/g的浸透磁化保留了铁磁性的性质。

  • 标签: 纳米复合材料 超顺磁性 水热合成 FE3O4纳米粒子 天冬氨酸 发光
  • 简介:Inthispaper,wepresenttheluminescentpropertiesofTm3+∕Ho3+co-dopednewglass.Aseriesofsilicategermanateglasswaspreparedbytheconventionalmelt-quenchingmethod.IntheTm3+∕Ho3+co-dopedsilicategermanateglass,astrongemissionof2μmoriginatingfromtheHo3+:5I7→5I8transitioncanbeobservedunderconventional808nmpumping.Thecharacteristictemperatures,structure,andabsorptionspectrahavebeenmeasured.TheradiativepropertiesofHo3+inthepreparedglasswerecalculated.TheemissioncrosssectionofHo3+ionstransitioncanreach4.78×10-21cm2around2μm,andtheFWHMisashighas153nm.TheenergytransferefficiencybetweenHo3+andTm3+hasalargevalue(52%),whichindicatestheTm3+∕Ho3+co-dopedsilicategermanateglassisasuitablecandidateforthe2μmlaser.Moreover,theenergytransfermechanismbetweenTm3+andHo3+ionswasinvestigated.

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  • 简介:Sr1.995–1.5xGdxSiO4:0.005Eu2+phosphorserieswithx=0–0.08molfornear-ultravioletwhitelight-emittingdiodes(NUVw-LEDs)weresynthesizedviasolid-statereactionmethod.XRDprofilepatternandrefinementresultsdemonstratedthatdopingGd3+ionsresultedinthephasetransformation(β-Sr2SiO4→α’-Sr2SiO4).Thephotoluminescencespectrumofthesamplewithx=0moldisplayedtwoemissionpeakscenteredat470and525nm.Thetwo-peakspectrabecameone-peakspectrawiththeGd3+concentrationincreasing.Actually,thefittingresultsdemonstratedthattheone-peakspectrawerestillcomposedoftwosingleemissionspectra.ThephotoluminescenceintensitywasimprovedandtheCIEchromaticitycoordinateswereadjustedviadopingGd3+.

  • 标签: 过掺杂 荧光粉 Gd 发光性能 晶体结构 紫外发光二极管
  • 简介:Organicsubstancesuchassolventandresin'seffectonluminescentcapabilityofSrAl2O4:Eu2+,Dy3+phosphorwasstudied.Someorganicsolventsandresinswereselectedforexperimentation.TheresultsindicatethatthoseorganicsolventswillnothavenegativeeffectontheappliedcapabilityofSrAl2O4:Eu2+,Dy3+phosphor.Adoptingtheorganicresinsandcoveringmethod,theafterglowluminanceofSrAl2O4:Eu2+,Dy3+phosphorwasincreasedby85.01%and82.51%.

  • 标签: ORGANIC solvent ORGANIC RESIN effect LUMINESCENT
  • 简介:PolycrystallineGd2(MoO4)3:Dy3+phosphorshavebeensynthesizedbyhightemperaturesolid-statereactionmethod.ThephosphorswerecharacterizedwithX-raydiffractometer,thermogravimetricanalysisanddifferentscanningcalorimeter,scanningelectronmicroscopy,andphotoluminescencespectrofluorimeter.Severalpeaksat351,389,425,452,and472nmappearedinphotoluminescenceexcitationspectrum,whichmatchedwellwiththeemissionoftheultraviolet(UV)andblue-lightemittingdiode(LED)chips.Uponexcitationat389nmUVlight,intenseemissionscenteredat484,575and668nmwereattributedtothetransitionsof4F9/2→6H15/2,4F9/2→6H13/2and4F9/2→6H11/2ofDy3+,respectively.ThechromaticitycoordinatesandcorrelativecolortemperatureshavebeencalculatedandpresentedintheCommissionInternationaldeI'Eclairage(CIE)diagrams.TheresultsindicatedthatGd1.9(MoO4)3:Dy0.13+withCIEcoordinatesof(x=0.38,y=0.41)andthecorrelativecolortemperatureof4134KisapotentialcandidateforwhiteLEDs.

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  • 简介:Three-dimensional(3D)flowerlikehierarchicalZn2GeO4andMn2+-dopedZn2GeO4microstructureshavebeenpreparedbyafacilehydrothermalapproach.X-Raydiffraction(XRD),fieldemissionscanningelectronmicro-scopy(FESEM),transmissionelectronmicroscopy(TEM)andphotoluminescence(PL)spectrometrywereemployedtocharacterizethesamples.SuchflowerlikehierarchicalZn2GeO4microstructureswithanaveragediameterof3―4μmwerefoundtobeconstructedbyabundantsinglecrystallinenanorodsofabout90nmindiameter.TheluminescentpropertiesofZn2GeO4:xMnphosphorswithdifferentcontentsofMn2+asanactivatorwereinvestigated.TheMn2+-dopedsamplesshowedgreenluminescencecorrespondingtothed-dtransitionofMn2+undertheirradiationofUVlight.Theredshift(from531nmto538nm)inλemwithincreasingMn2+contentwasobservedintheluminescentspectra,whichshouldbeattributedtoaweakcrystalfieldbecauseofthesubstitutionofZn2+byMn2+atadistortedtetrahedrallatticesite.

  • 标签: 锰掺杂 体系结构 场发射扫描电子显微镜 水热法 透射电子显微镜 X-射线衍射
  • 简介:Luminescentpolystyrenemicrosphereswereeasilyfabricatedfrompoly(styrene-co-methacrylicacid)andaqueousRE(III)chloridesolution(RE=Eu,Tb)inthepresenceof2,20-bipyridineassecondligand.Thenegativechargesofcarboxylgroupsonthesurfaceofmicrospherescoordinatedwithrareearthionsatfirst,suchascomplexescovalentlylinkedto2,20-bipyridine,resultinginstrongphotoluminescence.Variousmethods,includingtransmissionelectronmicroscope(TEM),scanningelectronmicroscope(SEM),energydispersivespectroscopy(EDS),Fouriertransforminfraredspectroscopy(FT-IR),andfluorescencespectrophotometer,wereusedtocharacterizetheresultantpolystyrenecompositemicrospheres.Thisworkhighlightstheideathatitisfaciletosynthesisluminescentmicrospheresbysurface-modifiedmethoddirectly.

  • 标签: LUMINESCENT Polystyrene TERBIUM EUROPIUM 2 2’-bipy
  • 简介:Aseriesofnovelbluelong-lastingphosphorescencephosphorsSr6Al18Si2O37:Eu2+,RE3+(RE3+=Ho3+,Gd3+,Dy3+andPr3+)werepreparedbytheconventionalhigh-temperaturesolid-statereactioninareductiveatmosphere.TheirpropertiesweresystematicallyinvestigatedutilizingX-raydiffraction(XRD),photoluminescence,phosphorescenceandthermoluminescence(TL)spectra.ThephosphorsemittedbluelightthatwasrelatedtotheemissionofEu2+dueto5d-4ftransition.Brightbluelong-lastingphosphorescence(LLP)couldbeobservedaftertheexcitationsourcewasswitchedoff.Fortheoptimizedsample,thebluelong-lastingphosphorescencecouldlastfornearly4hinthelightperceptionofthedark-adaptedhumaneye(0.32mcd/m2).TheeffectsofRE3+ionsonphosphorescencepropertiesofthephosphorswerestudied,andtheresultsshowedthattheco-dopingofRE3+ionsgreatlyenhancedtheintensityofthepeakaround315Kwhichwasrelatedtothelonglastingphosphorescenceofthephosphorsatroomtemperatureandconsequentlyimprovedtheperformanceofthebluephosphorescencesuchasintensityandpersistenttime.

  • 标签: 荧光粉 长余辉 磷光 蓝色 发光特性 高温固相反应
  • 简介:Eu(TTA)4CsHsNC16H33(TTA:1-(2-Thenoy)-3,3,3-Trifluoracetate)isencapsulatedinSi-MCM41modifiedwithN-(3-Trimethoxysilethyl)ethylenediamine.Theemissionspectrumoftheassemblyshowsonlya5D0→7F2transition.Ascomparedwiththerareearthcomplexitself,thelifetimeoftheassemblybecomeslongeranditsstabilityundertheUVradiationismuchbetter.

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