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.
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简介:InordertosensitizetheluminescenceofEu3+ionsinheavymetalglass,zincleadborateglasssamplescontainingvariousconcentrationsofEu3+andTb3+ionswerepreparedtostudytheTb3+toEu3+non-radiativeenergytransferphenomena.EnergylevelstructuresofTb3+andEu3+ionswereplottedtoshowtheexcitationandenergytransferroutes.EfficientenergytransferfromTb3+toEu3+wasobservedandstudiedqualitativelyintermsofdopingconcentrations.Thesensitizationturnedouttobelesseffectivethanexpected.FurtherstudiestocharacterizetheoxidationofTb3+intotetravalentstateandtoexaminethemechanismofenergytransferareproposed.
简介:LanthanidedopedNaYF4microcrystalsweresynthesizedviaafacilehydrothermalmethod.MulticolorupconversionluminescencewasobservedinNaYF4microcrystalsdopedwithYb3+/Er3+,Yb3+/Tm3+,andYb3+/Er3+/Tm3+undertheexcitationof980nminfraredlight.Importantly,theexcitationpowerdensitydependenceofupconversionemissionintensityindicatedclearlytheenergytransferfromTm3+toEr3+ionsundertheexcitationoflowpowerdensity(5×102–9×102W/cm2).Meanwhile,theinverseenergytransferfromEr3+toTm3+ionsundertheexcitationofrelativelyhigherpowerdensity(4.1×104–4.9×104W/cm2)wasalsorevealed.ThiswasadirectevidenceforreversibleenergytransferbetweenEr3+andTm3+ions.Undertheexcitationofhighpowerdensity(4.1×104–4.9×104W/cm2),darksensitizerswerealsomotivatedsothatthebottleneckeffectofhighconcentrationYb3+iondopingwasbroken.ThiswasthemainreasonforrealizinghighupconversionefficiencyofthesampleswithheavydopingofYb3+ion.
简介:FluorescencespectraofSm2+andEu2+→Sm2+energytransferwerestudiedinSrB4O7.Thereappearsonlyfluorescencefrom5D0transitionofSm2+at77K.Thevibroniclinesassociatedwith5D0→7F0transitionwereobserved.Thethermalpopulationtoupperstatesof5D1and4f5dlevelsfrom5D0givesriseto5D1→7FJand5d→4fradiativetransitionsofSin2+athighertemperature.
简介:Cr的Nanopowder:Cr的GGG和nanopowder,Nd:有从0.1at.%到1.5at.%的Cr3+的不同集中的GGG被大音阶的第五音胶化方法用醋酸和乙烯乙二醇综合。热gravimetric分析和微分扫描热量测定(TGA-DSC),X光检查衍射(XRD)和光致发光光谱学被用来描绘粉末。当在1000点对待时,雏晶尺寸是大约58nm?????????????????猯灵?匠?猼'T资???猼灵?????????猯'T??猼灵???? ̄?????猯'T????猯灵??猼'T?????吗????????????????‵渠????????浮??