一維氧化鋅的合成與結構對於光電特性及生醫應用的研究

Abstract

氧化鋅被視為明星的奈米材料之一，由於其寬廣的能隙(3.37 eV)，並且具有卓越的化學和熱穩定性，使得在眾多產業上有著很好地應用。隨著一維奈米材料的發展，如何合成一維氣化鋅奈米結構，就變成了一項重要的研究。在過去幾年，發展出利用低溫溶液法成長氧化鋅奈米結構，並且，可以控制成長好幾種的形態。然而，氧化鋅本身的複雜地缺陷結構，卻大大地影響了其應用。因此，如何改善和操控缺陷，就變成了一項非常值得深入的研究主題，另外，一個聰明的氧化鋅元件，在生物醫學方面的研究，也是令人期待。所以，本論文研究會深入地探討，一維氧化鋅的合成即其光學特性、氧化鋁-氧化鋅殼核結構的光學性質，最後會利用染料摸擬藥物釋放，來研究藥物載體(氧化鋅)在電場下的釋放行為。 在第一章，我們會一般地介紹氧化鋅材料。在第二章，將會討論氧化鋅的基本特性、缺陷、製程、應用和生醫藥物。第三章將會介紹實驗製程，包含氧化鋅和氧化鋁-氧化鋅殼核結構的製程，並且，量測方法和設備皆會在這章做介紹。 第四章主要會說明氧化鋅奈米柱如何經由水溶液法成長在，鍍有氧化鋅薄膜的矽基版上，而其成長的形態跟薄膜上的晶粒大小有絕對的關係。第五章將會討論在兩種基版上氧化鋅奈米柱的成長行為。 第六章將會展示陣列式氧化鋁-氧化鋅殼核奈米結構，經由溶凝膠法在室溫所製成，並且經由光譜分析得知，此結構在400oC、600oC的氧氣、氮氣熱處理後，能發出在450 nm強烈藍光。第七章將會先介紹如何經由化學溶液法，合成氧化鋅奈米管，更進一步展示氧化鋁-氧化鋅奈米管的成長。在經過不同溫度和氣氛熱處理下，此奈米管將會發出各種不同顏色的光，經由高斯分析可知，這些光有藍、藍-綠，綠和黃光，這些光和奈米管的缺陷有強烈的相關性。 最後，在第八章將會展示如何用高頻電場控制FITC-ZnO奈米管的釋放行為。另外，也可以證明此氧化鋅結構，具有低能量損耗、良好的生物相容性、生物標示和低成本的特性。

ZnO has been recognized as one of the promising nanomaterials in a broad range of high-technology applications because ZnO has a large direct band gap (3.37 eV), excellent chemical and thermal stability, and the electrical properties of a large exciton binding energy (60 meV). Furthermore, with one-dimensional materials developing, the synthesis of one-dimensional ZnO nanostructure becomes an important research. In the past several years, a low-temperature solution-based method to prepare complex ZnO nanostrucutes has been developed. In addition, ZnO morphology can be controlled via simple solution route. However, a fatal problem for ZnO material is complex defects. Therefore, it is worth to be studied on how to improve and manipulate defects. In addition, ZnO nanostructures are believed to be nontoxic and possibly biocompatible. A smart ZnO device for bio-medical is expected to develop. Therefore, this thesis outlines the process and optical of one-dimensional ZnO nanstructures and the study of photoluminescent properties and light-emitting characteristics of ZnO/alumina core/shell nanostructure. Finally, Drug release behavior from dye-ZnO nanostructure by applying high frequency electric field is also given in this thesis. In chapter 1, we will present an introductory overview to ZnO materials. Chapter 2 will discuss fundamental, defects, synthesis process, application and bio-medical. Chapter 3 will introduce the experimental process, including ZnO and alumina-coated ZnO nanostructure. The measurement setup for optoelectronic characteristics is also shown in this chapter. Chapter 4 will demonstrate that highly arrayed ZnO nanorods were fabricated on the Si substrate buffered with patterned ZnO film (ZnOf/Si) via wet-chemical process. It was found that the growth morphology of ZnO nanorods is strongly dominated by the grain size of the ZnO film on the Si substrate. Chapter 5 will discussed growth behavior of the ZnO nanorods. Two substrates, Si and ZnO film-coated Si (ZnOf/Si), were used to investigate growth behavior and microstructure evolution of single-crystal ZnO nanorods (ZNs) in aqueous solutions at low temperatures. Chapter 6 will show that hetrostructured AlOx-ZnO core-shell nanocables arrays have been successfully synthesized by soaking the ZnO nanorods in the sol-gel solution of Al(NO3)3 and NH4OH at room temperature. Photoluminescence measurement indicates that a strong blue emission peak at ~450 nm appears at 400oC and 600oC in O2 and N2 atmospheres, respectively. Chapter 7 will induce to synthesize the ZnO nanotubes by chemical solution method. Moreover, a simple chemical solution process for alumina/ZnO nanotubes will be studied. After thermal treatment at different temperatures under various atmospheres, photoluminescence (PL) measurements showed that the alumina nanoparticles coated on ZnO nanotubes (ANZTs) emitted a variety of colors, including blue, green and white light. Gaussian curve fitting of the PL spectra revealed that the competition between the blue, blue-green, green and yellow band emissions and their relative emission intensities were strongly associated with various defects. Finally, Chapter 8 will demonstrate the controlled release behavior of the FITC-ZnO nanotubes by high frequency electric-field. This ZnO-based nanostructure possesses low power consumption, biocompatible, bio-imaging and low-cost characteristic.