简介:Eu2+andDy3+codoped(Ca,Sr)7(SiO3)6Cl2yellowphosphorsweresuccessfullysynthesizedbyself-fluxmethod.Thestructure,morphologyandphotoluminescencepropertieswereinvestigatedbyX-raydiffraction(XRD),scanningelectronmicroscopy(SEM)andphotoluminescencespectra.Theas-preparedphosphorshowedabroademissionspectrumcenteredat550nmforEu2+single-dopedphosphor,whilelocatedat548–544nmfortheEu2+,Dy3+codopedsamplesunderexcitationat380nmlight.TheemissionintensitywasgreatlyimprovedwhenDy3+wasdopedintothe(Ca,Sr)7(SiO3)6Cl2:Eu2+system.Thecomposition-optimizedsamplewith3mol.%ofDy3+andconstant10mol.%ofEu2+exhibiteda220%PLenhancementcomparedtothephosphorwith10mol.%Eu2+single-doped.Meanwhile,itwasfoundthatthequantumefficiencyofphosphornamely(Ca,Sr)7(SiO3)6Cl2:3mol.%Dy3+,10mol.%Eu2+couldgetupto24.6%.Thesynthesizedyellow-emitting(Ca,Sr)7(SiO3)6Cl2:Dy3+,Eu2+isapromisingcandidateashigh-efficiencyyellowphosphorforNUV-excitedwhiteLEDs.
简介:二进制铕建筑群EuL3(L=4-tert-butylbenzoate)和第三的铕建筑群EuL3TTA0.1(TTA=2-thenoyltrifluoroacetone),EuL3DBM0.5(DBM=dibenzoylmethane)和EuL3phen0.5(phen=1,10-phenanthroline)被综合。poly(甲基methacrylate)(PMMA)或有composites与铕建筑群做了的丙烯酸的酸(AA)的甲基methacrylate(MMA)的共聚物被基在原处准备聚合。铕建筑群,ligands,N,N-dimethylformamide(DMF)和做的聚合物的光性质上的单体的影响被调查。结果证明二进制、第三的建筑群的荧光刺激乐队根据他们的紫外吸收乐队。所有建筑群和做的聚合物composites展出了Eu3+离子的敏化ligand的红典型排放。聚合物composites的荧光紧张在EuL3/PMMA的顺序增加了
简介:缩放Nano的氧化钇粒子基于含水的钇硝酸盐和乙二醇经由非水的sol-gelprocess被综合。到雏晶上的钇离子和锻烧温度的乙二醇的臼齿的比率的效果产品缩放我们再学习。为铵perehlorate(AP)的同样准备的氧化钇的催化表演分解被微分扫描调查热量测定(DSC)。结果显示有在平均雏晶尺寸的不到20nm的缩放nano的立方的氧化钇粒子能在70degC在2h倒流以后被获得,在90degC弄干,形成xerogel,并且由为2hxerogel退火列在后面,并且到AP的缩放nano的氧化钇的增加在温度合并AP的二座小发热的山峰,这310~变化350degC并且400-470degC进AP和增加的一座强壮的发热的山峰从515的明显的分解热到超过1110Jcentre点g~(-1)。发热的山峰减少和明显的分解AP加热的AP分解的温度随数量的增加增加缩放ofnano的氧化钇,也是清楚的。到AP的5%缩放nano的氧化钇的增加减少的事实到由114.6degC的减小的337.7degC的AP发热的山峰的温度,并且从515~1240J中心点g~增加明显的分解热(-1),揭示那缩放nano的氧化钇hows为AP的强壮的催化性质热分解。
简介:ThesurfaceofacommercialY3Al5O12:Ce3+phosphorwasmodifiedby99%NH4F+CH3COOHsolutioninasupersonicbathwithwatertemperatureof80oCfor4h.Thescanningelectronmicroscopy(SEM)resultsshowedthattheedgeangleswerenotassharpastheunmodifiedparticlesandtheflatsurfacesturnedroughwithmanymicro-structurescovered.Positronlifetimemeasurementsquantitativelyshowedthatsurfacedefectswereremovedawaybymorethan50%.Asaresult,thephotoluminescencedeterminationsshowedthatthebackscatterlosswasreducedby4.2%andtheemissionpowerwasenhancedby5.6%afterthesurfacemodification.Theconversionefficiencywasgreatlyimprovedfrom47.3%to51.1%,aspresentedbythefluorescenceimages.Therefore,itwouldbegreatlyhelpfulfortheimprovementofefficiency,transparencyandstabilityofpc-LED.Moreover,thismethodwassignificantlysuitableformassproductionduetoitseasyoperationandlowcost.
简介:AdetailedstudyofthefluorescenceemissionpropertiesandenergytransfermechanisminEr3+/Tm3+co-dopedleadsilicateglasseswasreported.Enhancednearinfrared1.8μmandvisibleup-conversionemissionswereinvestigatedunder808and980nmexcitations,respectively.TheenergytransfermechanismbetweenEr3+andTm3+wasanalyzedaccordingtotheabsorptionspectra,theemissionspectraandthelevelstructuresofEr3+andTm3+.TheenergytransferefficiencybetweenEr3+andTm3+reached68.1%intheEr3+/Tm3+co-dopedleadsilicateglasseswhenpumpedby808nmlaserdiode.Basedontheabsorptionspectra,theJudd-Ofeltparameters,spontaneousemissionprobability,absorptionandemissioncrosssections,gaincoefficientswerecalculatedandanalyzed.Itwasfoundthatthecalculatedemissioncrosssectionandthemaximumgaincoefficientaround1.8μmwere4.9×10–21cm2and1.12cm–1,respectively.TheseresultsindicatedthattheEr3+/Tm3+co-dopedlead-silicateglasseshadpotentialapplicationinnearinfraredlasers.
简介:探讨了在大生产条件下4Cr5MoSiV1钢的脱碳层测定原则。结果表明,金相法测定结果较准确且操作简便
简介:Thesinglecrystalofthecomplex[Sc(NO3)3(H2O)2]·(15C5)hasbeenpreparedinacetonitrile.Thenewcomplexhasbeencharacterizedbyelementalanalysis,IRspectra,solubilityandmolarconductancemeasurements.ThestructureofthecomplexisdeterminedbysinglecrystalX-raydiffractionanalysis.
简介:(Ba0.66Sr0.33)Mg0.8Al11.47O19:Tm0.013+(BSMA:Tm3+)phosphorwassynthesizedbysolid-statereactions.ThesamplewascharacterizedbyX-raydiffraction(XRD),scanningelectronicmicroscope(SEM),vacuumultraviolet(VUV)spectra,ultraviolet(UV)spectraandFT-IRspectrum.XRDpatternrevealsthatBSMA:Tm3+hasthesamestructureasBaAl12O19phase.SEMimageillustratesthatthephosphorhasthehexagonalshapeanddeepslicestructure.VUVandUVemissionspectraat20,50and100Kshowthatthelowtemperatureluminescenceintensitiesbecomeweakgraduallywiththeincreasingofthetemperatureunder147and254nmexcitation.Thestrongbroadbandpeaksataround357and397nmandthepeakat516nmunder147nmexcitationallcorrespondtothecharacteristictransitionsofTm3+ions.However,underUV(254nm)excitation,themainpeakbecomes530nmwhichhasveryhighlineintensity,andthepeaksatabout362and403nmareveryweak.Theexcitationspectrumat20Kshowsthattherearethreeabsorptionpeaksataround153,186and193nmwhen516nmemissionismonitored.Theabsorptionpeaksof[AlO4],[AlO6]andAl-OcanbeobservedinFT-IRspectrum.