【作者】 徐洪图；

【导师】 徐长山；

【作者基本信息】 东北师范大学 ， 凝聚态物理， 2008， 硕士

【摘要】 氧化锌是一种II-VI族宽带隙半导体(Eg=3.37 eV),激子束缚能高达60 meV。在紫外发射LED和LD、紫外探测、传感器、光催化等诸多方面具有广阔的应用前景。氧化锌纳米材料的光电特性在很大程度上受到其尺寸和形貌的影响,因此人们便利用各种方法来制备不同尺寸的氧化锌纳米材料,并控制其形貌。到目前为止合成氧化锌纳米材料的方法主要有两类:一类是通过物理方法,主要包括:气相沉积、热分解、热蒸发等。另外一类是通过化学法,如溶剂热方法、溶胶-凝胶法、电化学沉积等。由于化学方法制备氧化锌具有经济、高效、方法简单、可用于大量工业生产等优点,在本文中我们采用了常用的溶剂热合成方法制备小尺寸的氧化锌纳米结构。针对目前用溶剂热法制备的氧化锌纳米结构尺寸往往比较大的缺点,我们通过选择不同的溶剂和辅助试剂,优化反应温度、反应物浓度等反应条件,制备出了小尺寸氧化锌纳米结构,进而对其结构和光学特性进行了研究。本篇论文采用溶剂热法制备了两种小尺寸的氧化锌纳米结构:一是在1-6己二胺辅助的条件下,甲醇作为溶剂,制备出了小粒径的氧化锌纳米球;通过高放大倍数的场发射扫描电镜观察,氧化锌纳米球由许多小球组成,其粒径20-30 nm。实验结果表明1-6己二胺对纳米球的形成起到了非常关键的作用。通过对样品的XRD谱图分析表明所得样品均为氧化锌纤锌矿结构,随着反应时间延长、反应温度的提高样品结晶质量逐渐变好。二是与制备氧化锌纳米球的反应条件类似,但将反应溶剂由甲醇变为乙醇,合成出氧化锌纳米棒,直径为5 nm。实验中采用X射线衍射谱、透射电镜、扫描电镜、光致发光谱、紫外可见吸收光谱等测量手段对样品的结构、形貌和光学特性进行了表征。更多还原

【Abstract】 ZnO, as a direct wide-band-gap semiconductor with a large exciton binding energy (60 meV) which makes it an attractive candidate for room-temperature ultra-violate emission material, has been extensively investigated for applications to UV-LED and–LD, solar cell window and electrode, piezoelectric transducers, surface acoustic coatings, varistors, photo-catalysts and so on. For those applications that make use of the unique optical, chemical and electrical properties of ZnO powders, which strongly depend on its morphology, size and size distribution, the development of easy and cheap routes to synthesize mono-dispersed ZnO nano-particles is of great importance. So far, there are mainly two ways to prepare zinc oxide: one is physical approach, the other is chemical approach. The later approach is highly effective, very simple, and fit for mass production requirements. Therefore we use the chemical process to prepare small-sized zinc oxide nanostructures, and investigate its structural and optical characteristics. Although there have been many reports on solvothermal synthesis of zinc oxide, the size of the obtained zinc oxide nanostructures is usually quite large. In this work we have successfully reduced the size of the nanosturctures through controlling the reaction condition, and the optical and structural properties of the nanostructures were investigated.We expatiate two approaches to prepare ZnO nanostructures via solvothermal: First, using 1,6-Hexylenediamime as an auxiliary agent, methanol as reaction solution, we successfully synthesized smaller zinc oxide nanospheres; We observe that the big sphere have complex structure. The nanospheres are consisted of smaller spheres (20nm-30nm) which can be seen in high resolution FESEM. Experimental results indicate that 1,6-Hexylenediamime play the key role in the procedure of nanospheres formation. Through the obtained sample’s XRD spectrum analysis, the as-prepared samples are all wurtzite zinc oxide. Second, the reaction condition is similar with that applied in the preparation of zinc oxide nanospheres, but the reaction solution was changed from methanol to ethanol, ZnO nanorods of diameter 5 nm were obtained. Scanning electron microscope, Photoluminescence spectroscopy, UV–vis absorption spectroscopy were employed to study the structure and optical properties.更多还原