Microstructures and luminescence behaviors of Mn²⁺ doped ZnS nanoparticle clusters with different core/shell assembled orders

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• 作者：Chunyan Song ; Bing Chen ; Yunchao Chen ; Yimin Wu ; Zhengjie Zhuang ; Xuhui Lu ; Xvsheng Qiao ; Xianping Fan
• 关键词：ZnS ; Mn2+ ; Core/shell ; Nanoparticle clusters ; Energy migration ; Luminescence
• 刊名：Journal of Alloys and Compounds
• 出版年：25 March, 2014
• 年：2014
• 卷：590
• 期：Complete
• 页码：546-552
• 全文大小：2523 K

文摘

Mn²⁺ doped ZnS nanoparticle (NP) clusters composed of densely packed ZnS:Mn²⁺ NPs, ZnS/ZnS:Mn²⁺ core/shell NPs, or ZnS:Mn²⁺/ZnS core/shell NPs were prepared by a chemical co-precipitation method. Estimation of the lattice parameters and the band gap of the ZnS NP clusters through X-ray diffraction and optical diffuse reflectance spectra showed no noticeable divergence due to Mn²⁺ dopants. Transmission electron microscopy revealed that ZnS:Mn²⁺/ZnS NP clusters contained much larger NP crystallites associated with the high growth rate of undoped ZnS shell layers. In contrast, Mn²⁺ dopants limited the deposition of ZnS:Mn²⁺ shell layers, leading to smaller particle sizes of ZnS:Mn²⁺ and ZnS/ZnS:Mn²⁺ NPs in the clusters. Among all the samples, ZnS/ZnS:Mn²⁺ NP clusters exhibited the most intense orange emission of Mn²⁺, which was further confirmed by the estimated energy transfer (from ZnS to Mn²⁺) efficiency values, i.e., ZnS/ZnS:Mn²⁺ (42.1%) > ZnS:Mn²⁺/ZnS (15.9%) > ZnS:Mn²⁺ (1%). An energy migration mechanism was proposed for interpreting the high energy transfer efficiency of the ZnS/ZnS:Mn²⁺ structure.