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应用反胶束法制备了稀磁半导体 Cd1 - x Mnx S量子点 .量子点的大小可通过改变ωo 值 ( wo=[水 ]/ [表面活性剂 ])来控制 .高分辨透射电镜的分析结果表明 ,量子点呈单分散性 ,是几乎没有缺陷的单晶体 .量子点的大小约为 4.8～ 6nm,随 wo 值增大而增大 .电子能谱 ( EDS)测定结果表明 ,Mn2 +离子在量子点中的摩尔分数为 1 .5 % .由电子自旋共振 ( ESR)分析确定一部分 Mn2 + 离子取代 Cd2 + 离子位置而位于晶格 ,另一部分 Mn2 +离子位于 Cd1 - x Mnx S的表面或间隙位置 .吸收光谱显示 ,随着量子点变小 ,吸收带边发生蓝移 ,显示明显的量子尺寸效应 .光致荧光光谱分析表明 ,发光峰属于 Mn2 + 的 4 T1 -6 A1 跃迁 ,而且随着ωo 和粒径的增大 ,发光峰从 2 .2 6,2 .1 0 ,2 .0 5 e V红移到 1 .88e V;其发光峰偏离 2 .1 2 e V,主要是由于 Mn2 + 离子位于扭曲的四面体晶体场所致 .
The Cd1 - x MnxS quantum dots of dilute magnetic semiconductors were prepared by reverse micellar method.The size of the quantum dots can be controlled by changing the value of ωo (wo = [water] / [surfactant]) Analysis results of high resolution transmission electron microscopy Indicating that the quantum dots are monodispersed and almost single crystal defect.The quantum dot size of about 4.8 ~ 6nm, with increasing wo value increases.Electron spectrum (EDS) measurement results show that the Mn2 + ions in the quantum The molar fraction in the dot was 1.5% .Analysis by ESR showed that some Mn2 + ions were located in the lattice instead of Cd2 + and the other part was located on the surface or gap of Cd1 - x MnxS The absorption spectra show that with the decrease of the quantum dot, the blue shift of the absorption band edge shows obvious quantum size effect.The photoluminescence spectroscopy analysis shows that the luminescence peak belongs to 4 T1 -6 A1 transition of Mn2 + ωo and particle size increased, the luminescence peak red-shifted from 2.26, 2.01.0, 2.05 eV to 1.88eV, and its emission peak deviated from 2.12 eV, mainly due to the decrease of Mn2 + Ions are located in the distorted tetrahedral crystal field.