【作者】 刘红娟；

【导师】 孙挺； 陈延明；

【作者基本信息】 东北大学 ， 应用化学， 2008， 硕士

【摘要】 近年来,纳米半导体微粒已经吸引了科学家们的广泛关注。作为ⅡB-ⅥA族中重要的半导体纳米材料,CdS、ZnS具有不同于其体相材料的物理和化学性质,在许多领域有潜在的应用。因此,对这些半导体纳米微粒的合成方法的研究在国内外已经成为一个非常活跃的领域。在本文中,我们用简单经济的化学方法成功地在液相中合成,得到了CdS、ZnS半导体纳米微粒和复合结构ZnXCd1-XS纳米微粒。其合成路线为,以溶剂无水乙醇为反应介质,浓度为0.002 mol·L-1的乙酸镉和乙酸锌、0.004 mol·L-1的硫脲为反应前驱体,不同浓度的聚乙烯吡咯烷酮(PVP)为大分子表面活性剂,整个体系在持续的强磁力搅拌下保持在乙醇回流温度下反应,分别制备得到了CdS和ZnS半导体纳米微粒。改变反应前躯体乙酸锌与乙酸镉的化学计量比,制备得到复合结构的ZnXCd1-XS纳米微粒。在N,N-二甲基甲酰胺为介质的体系中,反应恒温在100℃进行,同样得到了CdS、ZnS纳米半导体及复合结构ZnXCd1-XS纳米微粒。利用紫外-可见吸收光谱、荧光光谱、透射电子显微镜、X-射线衍射等测试手段对合成的CdS、ZnS半导体纳米微粒及复合结构ZnXCd1-XS纳米微粒样品进行光学性质及结构方面的表征。通过分析其在室温下的紫外-可见吸收光谱图,发现吸收峰值波长明显地朝短波长方向移动,这是由量子尺寸效应引起的“蓝移现象”。用透射电子显微镜观察,结果发现制备得到的纳米微粒的尺寸都在20～60nm的范围内。这些样品在无水.乙醇及N,N-二甲基甲酰胺中有良好的分散性和稳定性。荧光光谱测试结果表明合成的CdS及ZnS半导体纳米微粒可以产生较为明显的表面缺陷态发光。通过改变复合结构ZnXCd1-XS中的化学计量比,可以获得不同颜色的发光光谱。XRD的结果给出了典型的纳米半导体CdS晶体的衍射谱图。更多还原

【Abstract】 Nanosemiconductor particles have attracted broad attention from scientists in recent years. As importantⅡB-ⅥA semiconductor nanometerials, CdS and ZnS exhibit unique physical and chemical properties that can not be obtained in their bulk corresponding counterpas. They have potential application in many areas. So the investigation for the synthesis ways to nanosemiconductor particles becomes a very active topic home and overseas.In this paper, CdS, ZnS nanosemiconductors and composite ZnXCd1-XS nanoparticles were obtained successfully through a facile and inexpensive chemical synthesis scheme in solutions respectively. The organic regent ethanol was used as reaction medium, acetic cadmium (0.002mol·L-1), acetic zinc (0.002mol·L-1) and thiourea (0.004mol·L-1) were the reaction precursors, different concentration of Polyvinylpyrrolidone was the macromolecular surfactant. The whole reaction system keep the temperature of ethanol circumfluence under strongly continuous magnetic stirring, a few minutes latter, CdS and ZnS semiconductor particles were obtained respectively. The composite ZnXCd1-XS nanoparticles were also prepared via changing the molar ratios of acetic cadmium and acetic zinc in this mixed ternary. Keep the consistent conditions with the front all the same, foregoing three kinds nanoparticles were gained in the reaction system of N,N-Dimethylformamide(DMF) at 100℃.UV-Vis absorption spectrum, Transmission electron mirror images, Fluorescence spectra and X-ray diffraction patterns were used to characterize optical properties and crystalloid structures of samples. The UV-Vis absorption spectrum of samples was analyzed. Their spectrums shift evidently to short wavelength. This is so called the phenomenon of blue-shift due to quantum size effect. The transmission electron mirror images showed that the size of particles was the range of 25～60nm. The dispersibility and stability of them were good in ethanol and DMF. Besides, their photoluminescence spectrum was measured. The results indicated CdS and ZnS semiconductor nanoparticals brought obvious surface trap irradiance. Lots of color-tunable emission of the composite ZnXCd1-XS nanoparticles could be watched by changing the composition of particles. X-ray diffraction patterns of nanosemiconductor CdS was obtained and indicated that it was cubic crystalloid.更多还原