【作者】 秦竹丽；

【导师】 江元汝；

【作者基本信息】 西安建筑科技大学 ， 应用化学， 2007， 硕士

【摘要】 纳米硫化锌是一种过渡金属硫化物半导体材料，其独特的结构性能在电子、光催化、光电转化材料等领域有广泛的应用。由于ZnS材料自身存在一些局限和缺陷，阻碍了它的进一步应用。本课题在微乳液体系中首次利用转化法制备了核壳型ZnS／CdS纳米复合半导体，并进行了系统研究。确定了较佳的制备工艺条件，实现了ZnS／CdS纳米复合半导体的简单制备。为今后合成此类材料提供了理论参考和实践经验。通过UV、PL表征了ZnS／CdS纳米复合材料的光学性能，探讨了影响ZnS／CdS纳米复合半导体光学性能的实验因素和影响规律。经过大量的实验探索得出：ZnS单晶的最佳生长温度为35℃，实现ZnS／CdS核壳结构的转化反应的较佳温度为60℃，转化时间为120min，n(Cd／Zn)的最佳比值为1.0。将在同等条件下制备的单体ZnS、CdS纳米颗粒、ZnCdS混晶样品和ZnS／CdS纳米复合颗粒进行UV、PL比较，发现所得的ZnS／CdS纳米复合颗粒吸收光谱发生了很大程度的红移，发光性能得到了较大改善与提高，初次证实了ZnS／CdS核壳结构的实现。利用原子力显微镜(AFM)、透射电子显微镜(TEM)等方法对所制样品进行了进一步表征，结果表明，所制备的样品ZnS／CdS纳米复合颗粒确实具有核壳两层包覆结构。颗粒平均直径80nm左右，粒径尺寸分布窄。颗粒呈球形、表面光滑且无团聚现象。实验结果表明，在微乳液体系中采用转化法可成功制备核壳型ZnS／CdS纳米复合半导体。与传统上制备此类材料的方法相比，该制备方法合理、工艺简单且容易控制，为制备此类材料提出了一条新的途径。并且所得产品的光学性能得到了极大的完善，扩展了其在电子、发光材料、光催化等领域的应用范围。更多还原

【Abstract】 Nanometer ZnS is extensively applied in the fields of electronic, photocatalytic and photoelectric materials because of its unique structure and property. But some limitation and defection on ZnS itself hinder its application.Core/shell structure ZnS/CdS composite semiconductor nanoparticles were synthesized by using an ion exchange reaction in microemulsion for the first time in this paper. The better experimental conditions were obtained. And the simple synthesization of core/shell structure ZnS/CdS composite semiconductor nanoparticles was achieved. The optical properties were characterized by UV absorption spectra and PL spectra in order to probe into the experimental elements and affect law of ZnS/CdS composite semiconductor nanoparticles. It can provide the important theoretical reference and practical experience to synthesize this type material in future. After many probing trials, the final experimental results were set: the best suitable growing temperature of ZnS crystal is 35°C, the exchanging temperature of the ion exchange reaction synthesized ZnS/CdS is 60°C, the exchanging time is 120min, and Cd/Zn ratio is 1.0.The result indicated ZnS/CdS composite semiconductor nanoparticles’ absorption wavelength occured the red shift, their luminant properties were also increased greatly by comparing with the optical properties of pure ZnS, CdS nanoparticles and ZnCdS mixture with UV absorption spectra and PL spectra. And the achievement of core/shell structure was proved firstly. The samples were presented further by AFM and TEM. The results indicated that ZnS/CdS composite nanoparticles had core/shell structure , and their surface was smooth, globular. The average diameter of ZnS/CdS composite nanoparticles was about 80nm.The method of synthesizing core/shell structure ZnS/CdS composite nanoparticles in this paper was reasonable, simple and controlled easily. In the field of synthesization of these nanometer particles, it had its own unique advantages, and opened up a new way to prepare similar material. If the experimental condition is controlled very well, the core/shell structure ZnS/CdS will be realized certainly, and its absorption spectra will occur the red shift so that the scope used in the fields of electronic, photocatalytic and photoelectric materials is extended.更多还原