球形釔鋁石榴石（Y-,3-Al-,5-O-,12-：Ce）熒光粉的制備及熒光性能研究.pdf

1、江蘇大學(xué)碩士學(xué)位論文球形釔鋁石榴石（YAlO：Ce）熒光粉的制備及熒光性能研究姓名：楊叢林申請(qǐng)學(xué)位級(jí)別：碩士專業(yè)：材料學(xué)指導(dǎo)教師：沈湘黔20060401江蘇大學(xué)碩士學(xué)位論文ABSTRACTWhitelight—emittingdiode(WLED)，謝t11lotsofexcellentproperties，suchasenergysaving，longlastinglife，non—pollution，lowappliedvoltag

2、eandfaststartup，istobethefourtheralightinglamphousesourceThewhiteLEDconsistingofablueLEDandyellowemittingY3A15012：Ce(YAG：Ce)isthemainroute，butithasalowluminescentefficiencyPhosphorswithhighefficiency(non—aggregation，fine

3、particlesandregularmorphology(sphericity))CallimprovetheluminescentefficiencyofWLEDeffectivelyYAG：Cephosphorcanbepreparedbysolidreaction，sol—gelprocessing，combustionsynthesis，sprypyrolysisandprecipitationmethodButtheseme

4、thodscallnotsatisfyallrequirementsofphosphorsThesphericalprecursorsofY3A15012：CepowderswerepreparedbythecontinuousreactionprecipitationprocessusingNH4HC03，NH4AI(S04)2‘12HEO，Y203andCe203asthestartingreagentsTheprecursoran

5、ditsproductswerecharacterisedbyFTIRSEM，EDS，XRDandTG—DSCItwasfoundthatpHvalues，concentrationsandvelocitiesoffloweffectedsurfaceshapesofsamplesprofoundlyTheresultsshowthatthesphericalprecursorsofY3A15012：Cewerepreparedunde

6、rtheoptimizedprocessingconditions(pH=75，c[AJ3q=040mol／LandV([A13y3])=o35ml／min)Non—aggregationandsphericalY3A15012：Cepowderswereobtainedfromsintenngtheprecursorsat900“Cfor2hoursinreducingatmosphere，andtheformationtempera

7、tureforY3A15012：Cewasapproximately600℃lowerthantraditionalhightemperaturesolid—reactionmethodInadditiontheformationmechanismsofthesphericalprecursorsandYAGphasewerediscussedaswellExcitationandemissionspectrumsofYAG：Cewer

8、echaracterisedbyFluorescenceSpectrophotometerCeconcentrationandhealtemperatureeffettheemissionspectrumsofYAG：CegreatlyHealtreeingat500“Cforalongtimeinairatmosphere，oracidoralkalitreatingcouldleadthedecreaseofluminescence