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利用水溶性前驱体材料在水性介质中制备了ZnS:Mn和ZnS:Mn/ZnS核/壳结构量子点(QDs,quantumdots),并用X射线衍射(XRD)、光致发光(PL)对ZnS:Mn和ZnS:Mn/ZnS核/壳结构QDs的结构和发光性能进行研究。ZnS:Mn和ZnS:Mn/ZnS QDs XRD谱与标准谱吻合,根据Debye-Scherrer公式,ZnS:Mn/ZnS QDs的粒径大于ZnS:Mn QDs的粒径,说明随着ZnS壳层增加,QDs不断生长。在波长325 nm紫外光激发下,ZnS:Mn和ZnS:Mn/ZnS QDs在波长586 nm处均有发射峰,ZnS:Mn/ZnS核/壳结构QDs在波长586 nm处的光发射大幅度增强,且发射峰并未发生红移或蓝移,主要由于包覆ZnS壳层后Mn离子被束缚到ZnS:Mn/ZnS核/壳结构QDs的核内,表面缺陷得到修饰,减少了表面态缺陷能级,阻断了某些无辐射跃迁的通道,增强了ZnS:Mn/ZnS核/壳结构QDs的荧光发射,并构建了发光模型。同时,利用巯基乙酸(TAG)修饰ZnS:Mn和ZnS:Mn/ZnS QDs,改善了其稳定性和水溶性,但是被TAG修饰后ZnS:Mn QDs发光强度大幅下降,ZnS:Mn/ZnSQDs发光强度下降较小。
The ZnS: Mn and ZnS: Mn / ZnS quantum dots (QDs, quantum dots) were prepared in aqueous media using water-soluble precursors. The XRD and PL spectra of ZnS: The structures and luminescent properties of Mn and ZnS: Mn / ZnS core / shell QDs were investigated. The XRD patterns of ZnS: Mn and ZnS: Mn / ZnS QDs agree well with the standard spectra. According to the Debye-Scherrer formula, the particle size of ZnS: Mn / ZnS QDs is larger than that of ZnS: Mn QDs. Growing constantly. The ZnS: Mn and ZnS: Mn / ZnS QDs all have emission peaks at 586 nm under the excitation of 325 nm UV light. The emission of ZnS: Mn / ZnS core / shell QDs at 586 nm is greatly enhanced , And there is no redshift or blue shift of the emission peak, mainly due to the Mn ions being bound to the core of the ZnS: Mn / ZnS core / shell QDs after the ZnS shell is coated, the surface defects are modified, and the surface state defects are reduced Level, blocked some non-radiative transition channels, enhanced the fluorescence emission of ZnS: Mn / ZnS core / shell QDs, and constructed the luminescence model. At the same time, the stability and water solubility of ZnS: Mn and ZnS: Mn / ZnS QDs modified by thioglycolic acid (TAG) were improved. However, the luminescence intensity of ZnS: Mn QDs was significantly decreased after TAG modification. The emission intensity of ZnS: Mn / ZnSQDs Small decrease.