ZnSe基核壳量子点中光致发光特性中温度依赖性的研究

[43]这一事实来解释。这些数据可以通过以下表达式得到较好的拟合：（3）其中，A是一个常数，I₀是0开尔文时的发射强度，kB是玻尔兹曼常数，Eb是激子结合能。对于5.2纳米的ZnSe核，Eb=37毫电子伏特；对于ZnSe(5.2)/ZnS核壳量子点，Eb=47毫电子伏特，这样得到的最佳拟合曲线与实验数据吻合良好。这表明包覆壳层能够增加量子点的激子结合能，从而减弱与温度相关的非辐射弛豫过程，进而提高发光效率和热稳定性。激子结合能的增加可归因于壳层使量子点的量子限域效应增强在本论文中，仅简要讨论了一种壳层厚度的情况。我推测，壳层厚度对量子点与温度相关的光致发光强度也有显著影响，此外，在未来的研究工作中，我将探究更为复杂和详细的与温度相关的非辐射弛豫过程。图65.2纳米ZnSe核及ZnSe核直径为5.2纳米的ZnSe/ZnS核壳量子点，在80K至300K温度范围内的积分光致发光发射强度与温度的函数关系。图中线条为文中所讨论的最佳拟合曲线。结论综上所述，本文主要研究合成不同尺寸（直径：3.5-8.8纳米）的ZnSe核量子点，其发射波长覆盖410-444纳米，还合成了在435纳米处具有11.5纳米窄发射线宽的高质量ZnSe/ZnS核壳量子点。随后，研究了三种尺寸（4.1、5.2和8.3纳米）的ZnSe核量子点以及ZnSe/ZnS核壳量子点的温度相关光致发光特性。研究发现，对于裸ZnSe核量子点，尺寸增加会导致激子-声子耦合减弱。这种现象表现为均匀展宽对量子点发射线宽的贡献减小。此外，通过比较ZnSe核量子点和ZnSe/ZnS核壳量子点可知，壳层不仅减弱了激子-声子耦合，增加了激子结合能。我认为，在较大尺寸的ZnSe核量子点中观察到的激子-声子耦合减弱，以及在ZnSe/ZnS核壳量子点中激子结合能的增加，可归因于光生激子与无机-有机界面的空间分离。这种分离可能是由于核量子点尺寸增大或添加外延壳层所促成，它们有效地使激子远离与界面相关的干扰，对基于ZnSe的核壳量子点温度相关光致发光特性的研究，对其未来在有机-无机混合光子学和光电器件中的应用具有重要意义。参考文献TrianaMA,RestrepoAA,LanzafameRJ,etal.Quantumdotlight-emittingdiodesaslightsourcesinphotomedicine:photodynamictherapyandphotobiomodulation[J].JournalofPhysics:Materials,2020,3(3):032002.YangZ,GaoM,WuW,etal.Recentadvancesinquantumdot-basedlight-emittingdevices:Challengesandpossiblesolutions[J].MaterialsToday,2019,24:69-93.YuanQ,WangT,YuP,etal.Areviewontheelectroluminescencepropertiesofquantum-dotlight-emittingdiodes[J].OrganicElectronics,2021,90:106086.JangE,JangH.Review:QuantumDotLight-EmittingDiodes[J].ChemicalReviews,2023.ReshmaVG,MohananPV.Quantumdots:Applicationsandsafetyconsequences[J].JournalofLuminescence,2019,205:287-298.MoonH,LeeC,LeeW,etal.StabilityofQuantumDots,QuantumDotFilms,andQuantumDotLightEmittingDiodesforDisplayApplications[J].AdvancedMaterials,2019,31(34):1804294.QiH,WangS,JiangX,etal.Researchprogressandchallengesofbluelight-emittingdiodesbasedonII–VIsemiconductorquantumdots[J].JournalofMaterialsChemistryC,2020,8(30):10160-10173.ReissP,ProtiereM,LiL.Core/Shellsemiconductornanocrystals[J].Small,2009,5(2):154-168.MokariT,BaninU.SynthesisandPropertiesofCdSe/ZnSCore/ShellNanorods[J].ChemistryofMaterials,2003,15(20):3955-3960.CirilloM,AubertT,GomesR,etal.“Flash”SynthesisofCdSe/CdSCore–ShellQuantumDots[J].ChemistryofMaterials,2014,26(2):1154-1160.KimS,FisherB,EislerH-J,etal.Type-IIQuantumDots: CdTe/CdSe(Core/Shell)andCdSe/ZnTe(Core/Shell)Heterostructures[J].JournaloftheAmericanChemicalSociety,2003,125(38):11466-11467.BangJ,ParkJ,LeeJH,etal.ZnTe/ZnSe(Core/Shell)Type-IIQuantumDots:TheirOpticalandPhotovoltaicProperties[J].ChemistryofMaterials,2010,22(1):233-240.KimS,FisherBR,EislerH-J,etal.Type-IIquantumdots:CdTe/CdSe(core/shell)andCdSe/ZnTe(core/shell)heterostructures[J].JournaloftheAmericanChemicalSociety,2003,125(38):11466-11467.ReissP,BleuseJ,PronA.HighlyLuminescentCdSe/ZnSeCore/ShellNanocrystalsofLowSizeDispersion[J].NanoLetters,2002,2(7):781-784.ZhangW,LouQ,JiW,etal.Color-TunableHighlyBrightPhotoluminescenceofCadmium-FreeCu-DopedZn–In–SNanocrystalsandElectroluminescence[J].ChemistryofMaterials,2014,26(2):1204-1212.ShenR,ZengR,YinY,etal.FacileSynthesisofMn-DopedZnSNanocrystalsandDeterminationofCriticalTemperatureforLatticeDiffusionProcess[J].JournalofNanoscienceandNanotechnology,2012,12(11):8356-8363.SantraPK,KamatPV.Mn-DopedQuantumDotSensitizedSolarCells:AStrategytoBoostEfficiencyover5%[J].JournaloftheAmericanChemicalSociety,2012,134(5):2508-2511.LeeS-H,HanC-Y,SongS-W,etal.ZnSeTeQuantumDotsasanAlternativetoInPandTheirHigh-EfficiencyElectroluminescence[J].ChemistryofMaterials,2020,32(13):5768-5775.ChanWCW,NieS.QuantumDotBioconjugatesforUltrasensitiveNonisotopicDetection[J].Science,1998,281(5385):2016-2018.DonegáCDM.Synthesisandpropertiesofcolloidalheteronanocrystals[J].ChemicalSocietyReviews,2011,40(3):1512-1546.LimJ,BaeWK,LeeD,etal.InP@ZnSeS,Core@CompositionGradientShellQuantumDotswithEnhancedStability[J].ChemistryofMaterials,2011,23(20):4459-4463.BattagliaD,PengX.FormationofhighqualityInPandInAsnanocrystalsinanoncoordinatingsolvent[J].NanoLetters,2002,2(9):1027-1030.MurrayC,NorrisDJ,BawendiMG.SynthesisandcharacterizationofnearlymonodisperseCdE(E=sulfur,selenium,tellurium)semiconductornanocrystallites[J].JournaloftheAmericanChemicalSociety,1993,115(19):8706-8715.PengX,WickhamJ,AlivisatosA.KineticsofII-VIandIII-Vcolloidalsemiconductornanocrystalgrowth:“focusing”ofsizedistributions[J].JournaloftheAmericanChemicalSociety,1998,120(21):5343-5344.SugimotoT.Preparationofmonodispersedcolloidalparticles[J].AdvancesinColloidandInterfaceScience,1987,28:65-108.ReissP,ProtiereM,LiL.Core/shellsemiconductornanocrystals[J].Small,2009,5(2):154-168.E.JangandH.Jang,ChemicalReviews.,2023,123,4663-4692.J.Kim,J.Roh,M.ParkandC.Lee,AdvancedMaterials.,2024,36,2212220.K.D.WegnerandN.Hildebrandt,TrACTrendsinAnalyticalChemistry.,2024,117922.L.Wang,J.Bai,X.Huang,X.He,Z.Yang,T.Zhang,Q.Li,X.Jin,Y.WangandX.Zhang,OpticsExpress.,2024,32,25000-25011.G.Almeida,R.F.Ubbink,M.Stam,I.duFosséandA.J.Houtepen,NatureReviewsMaterials.,2023,8,742-758.L.Qinghua,B.Jinke,B.Cuiying,C.Zimei,H.Jiyan,N.Xuerong,J.XiaoandX.Bing,OpticsExpress.,2023,31,36691-36701.M.Gao,H.Yan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