简介:(Y,Gd)BxV1-xO4-x:Eu3+phosphorswerepreparedbysolidstatereaction.Theredemissioncolorpurityof(Y,Gd)BxV1-xO4-x:Eu3+phosphorismuchbetterthanthatoftherecentwidely-usedcommercialredemittingphosphor(Y,Gd)BO3:Eu3+anditsrelativeemissionintensityis84%ofthecommercialphosphor(Y,Gd)BO3:Eu3+.Itisexpectedthat(Y,Gd)BxV1-xO4:Eu3+phosphorwillbeapromisingcandidateforPDP(plasmadisplaypanels)application.
简介:ThereactionofNdCl3withlithiummethylnaphthalenein1:2moleratioinTHFgeneratesblackpowder.Thepowderreactswithcyclooctatetraene(COT)inTHFtoformthetitlecomplex.[Li(THF)4Nd(C8H8)2]·2THFcrystallizesinthemonoclinicspacegroupP2/cwithunit-celldimensionsa=1.7858(7)nm,h=1.3243(4)nm,c=1.8086(6)nm.β=106.52(4)°,V=4.10nm3andDc=1.268g/cm3forZ=4.F(000)=1660,R=0.0774,Rn=0.0733.Thecomplexconsistsofdiscreteion-pairandtwoTHFmoleculesadduct.Intheanion,theneodymiumatomiscoordinatedbytwoCOTrings.ThestructureofthecationshowsthatthelithiumatomisattachedwithTHFmoleculesonly.
简介:Tobreakthroughthebottle-neckofquantumyieldinupconversion(UC)core-shellsystem,weelucidatedthattheenergytransferefficiencyincore-shellsystemhadanevidentcontributionfromthechargetransferofinterfacewithrelatedtotwofactors:(1)bandoffsetsand(2)bindingenergyareadensity.Thesetwovariablesweredeterminedbymaterialintrinsicpropertiesandcore-shellthicknessratio.Wefurtherunraveledthemechanismofnon-radiativeenergytransferbychargetransferinduceddipoleattheinterface,basedonaquasi-classicalderivationfromF?rstertyperesonantenergytransfer(FRET)model.Withstablebondingacrosstheinterface,thecontributionsonenergytransferinbothradiativeandnon-radiativeenergytransfershouldalsobeaccountedtogetherinAuzel'senergytransfer(ETU)modelincore-shellsystem.Basedonthediscussionaboutinterfacebonding,bandoffsets,andformationenergies,wefiguredoutthesignificanceofinterfacebondinginducedgapstates(IBIGS)thatplayedasignificantroleforinfluencingthechargetransferandradiativetypeenergytransfer.Theinterfacebandoffsetswereakeyfactorindominatingthenon-radiativeenergytransfer,whichwasalsocorrelatedtocore-shellthicknessratio.Wefoundthattheenergyareadensitywithrelatedtocore/shellthicknessratiofollowedthetrendofBoltzmansigmoidalgrowthfunction.Bythephysicaltrend,thisworkcontributedareferencehowthemulti-layeredcore-shellstructurewasformedstartingfromtheverybeginningwithinminimumsize.Aroutewaspavedtowardsasystematicstudyoftheinterfacetounveiltheenergytransfermechanismincore-shellsystems.
简介:Thesynthesis,compositionoptimization,VUVPhotoluminescence(PL)spectra,andopticalproperties,of(Y,Gd)(V,P)O4∶Eu3+phosphorswereinvestigatedbysynchrotronradiation.TheVUVPLEspectraandthecorrelationamongVUVPLintensity,λem,andEu3+,Gd3+,andP-contentwereestablished.ThePLEspectralstudiesshowedthat(Y,Gd)(V,P)O4∶Eu3+exhibitedsignificantabsorptionintheVUVrange.TheVUVPLintensitywasfoundtoenhancewithPO43-andGd3+-doping.Furthermore,thechromaticitycharacteristicsof(Y,Gd)(V,P)O4∶Eu3+werealsofoundtobe(0.6614,0.3286)andcomparedagainst(Y,Gd)BO3∶Eu3+asareference.Basedonthecharacterizationresults,wearecurrentlyimprovingandevaluatingthepotentialapplicationof(Y,Gd)(V,P)O4∶Eu3+asanewred-emittingPDPphosphor.
简介:Whitelight-emittingYVO_4:1mol.%Dy~(3+),xmol.%Eu~(3+)phosphorpowderswithordermorphologyandwellcrystallizationwerehydrothermallysynthesizedat180°C.Themicrostructure,white-lightemission,andlight-emittingmechanismofthepowderswerecarefullystudiedusingX-raydiffractometry,scanningelectronmicroscopyandphotoluminescencespectra.TheexcitationandemissionspectraofthephosphorpowdersindicatedthecoexistenceofefficientenergytransferfromEu~(3+)toDy~(3+)andinefficientenergytransferfromDy~(3+)toEu~(3+)besidestheenergytransferfromVO_4~(3–)toEu~(3+).IncreasingtheEu~(~(3+))concentrationinitiallyenhancedandthenweakenedtheluminescentintensityofDy~(3+).Thewhite-lightemissionsofYVO_4:1mol.%Dy~(3+),xmol.%Eu~(3+)phosphorpowderswerebothrelatedtotheenergytransferbetweenVO_4~(3–)andDy~(3+)/Eu~(3+),aswellasbetweenEu~(3+)andDy~(3+).TheinefficientenergytransferfromDy~(3+)toEu~(3+)wasfirstfound.
简介:Reactionof(MeC5H4)3LnwithHOCH2CH2NMe2intetrahydrofuran(THF)givesthenewcomplexes[(MeC5H4)2Ln(μ-OCH2CH2NMe2)]2(Ln=Sm,Y,Nd)withnitrogenfunctionalizedμ-alkoxideligand.ThecomplexeswerecharacterizedbyelementalanalysisandIR,and[(MeC5H4)2Sm(μ-OCH2CH2NMe2)]2wasstructurallycharacterizedbytheX-raydiffractiontobeadimerformedbytwounsymmetricoxygenbridges.ThecomplexhasatricyclicskeletonwiththeadditionaltwoSm-NbondsviaintramolecularcoordinationofOCH2CH2NMe2.ThecoordinationnumberofthecentralmetalSmisnine.Thetitlecomplexesshowgoodcatalyticactivityforring-openingpolymerizationofε-caprolactone.