硫脲修饰ZnSe:Cu量子点的水相合成及荧光特性  

Preparation and Fluorescence Properties of Aqueous Soluble Thiourea Modified ZnSe:Cu Quantum Dots

作　　者：汤子龙[1] 李冬梅[1] 程经纬[1] 蒋洁如[1] 

机构地区：[1]上海大学材料科学与工程学院,上海200072

出　　处：《物理化学学报》2013年第3期653-659,共7页Acta Physico-Chimica Sinica

摘　　要：以3-巯基丙酸为稳定剂在水相中合成了Cu掺杂的ZnSe量子点(QDs),并利用硫脲(CH4N2S)对其进行表面修饰,制备出核壳结构的ZnSe:Cu/ZnS量子点.制得的量子点呈闪锌矿结构,尺寸约为5nm,有较好的分散性。其荧光发射峰在460nm左右.经CH4N2S修饰后,量子点表面形成了宽禁带的ZnS包覆层,将电子和空穴限域在了ZnSe:Cu核内,减少了表面发生非辐射复合的载流子,显著提高了量子点的荧光强度.与Na2S、硫代乙酰胺(TAA)等常用硫源相比,以CH4N2S为硫源制得的ZnSe:Cu/ZnS量子点壳层厚度可控,表面钝化效果更好,显示出更佳的荧光效率和稳定性.ZnSe:Cu/ZnS量子点经过紫外线照射后消除了表面的悬空键,进一步提高了其量子产率,最终获到了具有较好荧光性质的ZnSe:Cu/ZnS量子点.Aqueous phase Cu doped ZnSe （ZnSe：Cu） quantum dots （QDs） stabilized with mercaptopropionic acid were prepared,and thiourea was used as a surface modifier to obtain core-shell ZnSe：Cu/ZnS QDs.QDs had a sphalerite structure,were uniformly dispersed,had an average particle size of approximately 5nm and an emission peak at around 460nm.After thiourea modification,a wide band-gap ZnS shell was coated on the QDs to passivate the surface,reduce surface states,and significantly improve fluorescence intensity.Thiourea modified ZnSe：Cu/ZnS QDs exhibit better surface passivation,fluorescence efficiency,and stability than those of other surface modifiers like Na2S and thioacetamide.Quantum yields were further improved after UV irradiation eliminated surface dangling bonds.

关 键 词：量子点 ZNSE Cu ZNS 水相合成 硫脲修饰 低毒性 紫外光照 

分 类 号：O611.4[理学—无机化学]