论文标题
微波辅助的合成和未掺杂和锰掺杂的硫化锌纳米颗粒的表征
Microwave-assisted synthesis and characterization of undoped and manganese doped zinc sulfide nanoparticles
论文作者
论文摘要
通过微波辅助溶剂热方法产生未蛋白和MN掺杂的ZnS纳米晶体，并通过X射线衍射，光致发光光谱和扫描电子显微镜具有能量分散性X射线光谱的特征。所有样品均具有立方锌混合物结构，其晶格参数在$ a $ =5.406-5.411Å的范围内，水晶的平均尺寸在6-9 nm的范围内。这些纳米颗粒聚集并形成大型晶粒，平均大小高达180 nm。未掺杂的ZnS样品的光致发光显示位于530 nm的宽发射带归因于纳米颗粒表面的缺陷。在所有MN掺杂样品中，都观察到598 nm处的排放峰分配给了激发（$^4 $ t $ _1 $）和地面（$^6 $ a $ _1 $）之间的特征性禁止过渡。基于进化算法的Zn和Mn K-Edges的同步辐射X射线吸收光谱以及Mn K-Edges与反向蒙特卡洛（RMC）模拟结合使用，证实了锰离子替代锌离子。但是，离子大小的差异（$ r $（Mn $^{2+} $（iv））=0.66Å和$ r $（Zn $^{2+} $（iv））=0.60Å）对较大的原子间距离MN-S（2.40（2.40（2.40（2）Å），与Zn-S（2.40（2）Å）负责。 ZnS：Mn纳米颗粒中的静态结构弛豫是由RMC模拟获得的Zn，S和MN原子的均方根位移因子的较大值。
Undoped and Mn-doped ZnS nanocrystals were produced by the microwave-assisted solvothermal method and characterized by X-ray diffraction, photoluminescence spectroscopy and scanning electron microscopy with energy-dispersive X-ray spectroscopy. All samples have the cubic zinc blende structure with the lattice parameter in the range of $a$ = 5.406-5.411 Å, and the average size of crystallites is in the range of 6-9 nm. These nanoparticles agglomerate and form large grains with an average size of up to 180 nm. The photoluminescence of the undoped ZnS sample shows a broad emission band located at 530 nm, attributed to the defects at the surface of nanoparticles. In all Mn-doped samples, the emission peak at 598 nm was observed assigned to the characteristic forbidden transition between excited ($^4$T$_1$) and ground ($^6$A$_1$) levels of Mn$^{2+}$. Synchrotron radiation X-ray absorption spectroscopy at the Zn and Mn K-edges combined with reverse Monte Carlo (RMC) simulations based on the evolutionary algorithm confirms that manganese ions substitute zinc ions. However, the difference in the ion sizes ($R$(Mn$^{2+}$(IV)) = 0.66 Å and $R$(Zn$^{2+}$(IV)) = 0.60 Å) is responsible for the larger interatomic distances Mn-S (2.40(2) Å) compared to Zn-S (2.33(2) Å). The static structural relaxations in ZnS:Mn nanoparticles are responsible for the large values of the mean-square displacements factors for Zn, S and Mn atoms obtained by RMC simulations.
