Growth and Characterization of ZnO andMgZnO Nanostructures

• Main Authors: Si-Fong Chiu, 邱士峰
• Other Authors: Wei-Kuan Hung
• Format: Others
• Language: zh-TW
• Published: 2008
• Online Access: http://ndltd.ncl.edu.tw/handle/rbj289

碩士 === 國立臺北科技大學 === 光電工程系研究所 === 96 === Aligned nanorods or nanotubes with similar diameter are ideal candidate material for fabricating nanodevices. In addition, the formation of heterostrucure in nanorods is essential for their potential applications in nanoelectronic and photonic devices. Here we demonstrate that well-aligned ZnO nanorods, ZnO/MgZnO core-shell nanorods, and Mg(Zn)O nanotubes can be successfully synthesized via catalyst-free vapor phase transport combined with pulse laser deposition (PLD) method. The thesis consists of three parts. Fist, vertically aligned ZnO nanorods were grown on a PLD-predeposited ZnO thin film via a simple thermal evaporation and vapor transport process. These ZnO nanorods were quite uniform with a diameter of ~20 nm and length of ~1μm. Room-temperature photoluminescence spectra of the samples showed only a strong band-edge emission, indicating the high crystalline quality. The vertically aligned ZnO nanorods were used as templated for the synthesis of nanorods heterostructures. In the second part, ZnO/MgZnO heterstructure nanorods were fabricated using a thermal evaporation procedure, in which the Mg powder was used as the source material and the aforementioned ZnO nanorods slice was used as the substrate. We found that different nanotructures can obtained by varying the amount of Mg source. Smaller amount of Mg resulted in ZnO/MgO core-shell nanorods. However, as the source material was increased, an MgxZn1-xO (with~0.4) interlayer formed between the ZnO core and the MgO shell. Further increasing the Mg amount finally led to the formation of MgO nanotubes. In the third part, aligned ZnO/Mgo core-shell nanorods were synthesized by PLD of MgO onto the ZnO nanorod template. Compared with the similar nanostructure produced by thermal evaporation process (as described in the second part), the PLD produced ZnO/MgO nanorods had rougher surfaces, while exhibited better quality in alignment, crystallinity, and luminescence efficiency.