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.
出处
《物理化学学报》
SCIE
CAS
CSCD
北大核心
2013年第3期653-659,共7页
Acta Physico-Chimica Sinica
