Interest in nanomaterials is motivated partly by their potential for sensor arrays to detect different gases. Nanowires in particular are of interest because their high surface-to-volume ratio promises the possibility of high sensitivity. However, because of their discrete quasi-one-dimensional geometry, electrical integration of nanowires into photolithographically defined devices and circuits is challenging and remains one of the obstacles to their widespread use. In this thesis, a novel method for fabricating electrically integrated zinc oxide nanobridge devices using carbonized photoresist is investigated. The conductivity of carbonized photoresist is known and nanowire growth on carbonized photoresist has recently been reported, suggesting the possibility of simultaneous use as a nucleation layer and electrode. However, these reports did not characterize the contact between the ZnO nanowires and carbonized photoresist. In this work, ZnO nanobridges are fabricated between opposing carbonized photoresist electrodes and characterized both electrically and with electron microscopy. Operation of nanobridge devices as bottom gate transistors, UV sensors, and gas sensors is demonstrated. / Graduation date: 2010

Thesis (Ph. D.)--West Virginia University, 2008. / Title from document title page. Document formatted into pages; contains ix, 161 p. : ill. (some col.). Vita. Includes abstract. Includes bibliographical references (p. 152-158).

Thesis (Ph. D.)--University of Canterbury, 2008. / Typescript (photocopy). Includes bibliographical references (p. 153-159). Also available via the World Wide Web.

Thesis (M.E.)--University of Canterbury, 2009. / Typescript (photocopy). "November 2009." Includes bibliographical references (leaves 73-78). Also available via the World Wide Web.

Yau Man Yan Eric = 鎂和氧化鋅反應製備氧化鎂納米棒 / 游文仁. / Thesis (M.Phil.)--Chinese University of Hong Kong, 2004. / Includes bibliographical references. / Text in English; abstracts in English and Chinese. / Yau Man Yan Eric = Mei he yang hua xin fan ying zhi bei yang hua mei na mi bang / You Wenren. / Acknowledgement --- p.i / Abstract --- p.ii / 摘要 --- p.iii / Table of contents --- p.iv / List of tables --- p.viii / List of figures --- p.ix / Chapter Chapter 1 --- Introduction / Chapter 1.1 --- Nanostructured materials --- p.1-1 / Chapter 1.2 --- Application of nano-materials --- p.1-1 / Chapter 1.3 --- Current development of nano-materials --- p.1-2 / Chapter 1.4 --- Synthesis of nano-materials --- p.1-2 / Chapter 1.4.1 --- Physical methods --- p.1-3 / Chapter 1.4.1.1 --- Physical vapor deposition --- p.1-3 / Chapter 1.4.1.2 --- Arc-discharge process --- p.1-3 / Chapter 1.4.1.3 --- Laser ablation --- p.1-4 / Chapter 1.4.2 --- Chemical methods --- p.1-4 / Chapter 1.4.2.1 --- Chemical vapor deposition --- p.1-4 / Chapter 1.4.2.2 --- Metal-organic chemical vapor deposition (MOCVD) --- p.1-4 / Chapter 1.4.2.3 --- Solgel method --- p.1-5 / Chapter 1.5 --- Study on growth mechanism of nano-materials --- p.1-5 / Chapter 1.5.1 --- Vapor-liquid-solid (VLS) mechanism --- p.1-5 / Chapter 1.5.2 --- Vapor-solid (VS) mechanism --- p.1-6 / Chapter 1.6 --- Applications of Magnesium Oxide (MgO) materials --- p.1-7 / Chapter 1.7 --- Previous works on MgO nanostructures --- p.1-8 / Chapter 1.7.1 --- Network like MgO nanobelts --- p.1-8 / Chapter 1.7.2 --- Decorated MgO crystalline fibers --- p.1-9 / Chapter 1.7.3 --- Mg2Zn11 - MgO belt-like nanocables --- p.1-9 / Chapter 1.7.4 --- MgO nanowires with uniform diameter distribution --- p.1-10 / Chapter 1.7.5 --- Aligned MgO nanorods on MgO (100) substrates --- p.1-11 / Chapter 1.8 --- Objectives and approaches of this project --- p.1-12 / Chapter 1.8.1 --- Addition of sodium chloride (NaCl) --- p.1-13 / Chapter 1.9 --- Thesis Layout --- p.1-13 / Chapter 1.10 --- References --- p.1-15 / Chapter Chapter 2 --- Methodology and Instrumentation / Chapter 2.1 --- Introduction --- p.2-1 / Chapter 2.2 --- Powder Metallurgy --- p.2-1 / Chapter 2.3 --- Sample fabrication --- p.2-1 / Chapter 2.3.1 --- Starting materials --- p.2-1 / Chapter 2.3.2 --- Cold pressing --- p.2-2 / Chapter 2.3.2.1 --- Single pellet method --- p.2-2 / Chapter 2.3.2.2 --- Double pellet method --- p.2-3 / Chapter 2.3.3 --- Argon tube furnace sintering --- p.2-3 / Chapter 2.4 --- Study of fabrication parameters --- p.2-4 / Chapter 2.4.1 --- Heat treatment temperature --- p.2-4 / Chapter 2.4.2 --- NaCl content in sample --- p.2-4 / Chapter 2.4.3 --- Duration of heat treatment --- p.2-5 / Chapter 2.5 --- Control Experiments --- p.2-5 / Chapter 2.5.1 --- Effect of addition of NaCl --- p.2-5 / Chapter 2.5.2 --- Effect of residual oxygen --- p.2-5 / Chapter 2.5.3 --- Geometrical effect of experimental setup --- p.2-6 / Chapter 2.5.3.1 --- Compressed double pellet method --- p.2-6 / Chapter 2.5.3.2 --- Powder on Magnesium pellet method --- p.2-6 / Chapter 2.5.3.3 --- Single pellet method --- p.2-7 / Chapter 2.6 --- Characterization Methods --- p.2-7 / Chapter 2.6.1 --- Thermal analysis - Differential thermal analyzer (DTA) --- p.2-7 / Chapter 2.6.2 --- Structural analysis --- p.2-7 / Chapter 2.6.2.1 --- Scanning electron microscopy (SEM) --- p.2-7 / Chapter 2.6.2.2 --- Transmission electron microscopy (TEM) --- p.2-8 / Chapter 2.6.3 --- Phases determination - X-ray powder diffractometry (XRD) --- p.2-8 / Chapter 2.7 --- References --- p.2-9 / Chapter Chapter 3 --- Results of Mg-ZnO-NaCl System / Chapter 3.1 --- Introduction --- p.3-1 / Chapter 3.2 --- Results of thermal analysis --- p.3-1 / Chapter 3.2.1 --- Chemical reactions --- p.3-1 / Chapter 3.2.2 --- DTA results --- p.3-2 / Chapter 3.3 --- Variation of heat treatment temperature --- p.3-3 / Chapter 3.3.1 --- XRD pattern --- p.3-3 / Chapter 3.3.2 --- SEM images --- p.3-4 / Chapter 3.4 --- Variation of NaCl content --- p.3-5 / Chapter 3.4.1 --- TEM analysis --- p.3-5 / Chapter 3.5 --- Variation of duration of heat treatment --- p.3-6 / Chapter 3.6 --- Additional findings --- p.3-7 / Chapter 3.7 --- Discussions --- p.3-7 / Chapter 3.8 --- References --- p.3-10 / Chapter Chapter 4 --- Results of Control Experiments / Chapter 4.1 --- Introduction --- p.4-1 / Chapter 4.2 --- The study of Mg-ZnO system --- p.4-1 / Chapter 4.3 --- The study of residual oxygen effect --- p.4-2 / Chapter 4.4 --- The study of geometrical effect of experiment setup --- p.4-2 / Chapter 4.5 --- Discussions --- p.4-3 / Chapter 4.5.1 --- Effect of addition of NaCl --- p.4-3 / Chapter 4.5.2 --- Effect of residual oxygen --- p.4-3 / Chapter 4.5.3 --- Role of ZnO --- p.4-4 / Chapter 4.5.4 --- Growth model --- p.4-4 / Chapter 4.6 --- References --- p.4-7 / Chapter Chapter 5 --- Conclusions and Further Studies / Chapter 5.1 --- Conclusion --- p.5-1 / Chapter 5.2 --- Further studies --- p.5-2 / Chapter 5.3 --- References --- p.5-3

Thesis (Ph. D.)--University of Hong Kong, 2007. / Title proper from title frame. Also available in printed format.

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In this research, we used the zinc oxide (ZnO) which is die pressed and sintered for studying. We want to know the variations of microstructure and luminescence property when we doped 0.2 mol.% Al2O3 or Li2O to ZnO, or sintered under different atmospheres (high purity oxygen, high purity nitrogen, high purity argon). Using X-ray diffractometry (XRD), scanning electron microscope (SEM), and catholuminescence (CL) spectrometry equipped with a SEM to analyze the different samples. The all six samples¡¦ crystal structure didn¡¦t change via XRD. We investigated for the in-gap-level modification using the CL spectrometry. CL analysis results indicated that ZnO emitted UV light, visible light (blue, green, yellow light), and Near-infrared light emissions. The UV light emission was attributed to the two electronic transitions from the donor level of free exciton and Zn interstitial to valence band. The blue light (2.53 eV) emission was attributed to the donor level of oxygen vacancy-related defect. The green light emission was attributed to the electronic transition from the acceptor level of zinc vacancy-related defect.And the yellow light emission was attributed to the O interstitial and Li-related defects. The Near-infrared light may be attributed to the deep levels recombination.

Thesis (Ph. D.)--University of Canterbury, 2009. / Typescript (photocopy). Includes bibliographical references (p. 241-266). Also available via the World Wide Web.

　Zinc oxide (ZnO) is a wide band gap (3.4eV at 300K) II-VI semiconductor with an exciton binding energy up to 60meV and is promising in the realization of excitonic or polaritonic lasing effect. Photoluminescence is widely used in studying the band gap and defect levels of ZnO. However, understanding in defects of ZnO is still far from satisfaction and remains controversial. Different authors suggest different explanations and mechanisms. 　In the present study we investigate in the photoluminescence spectra of four kinds of ZnO single crystal, namely as-grown (not implanted) Zn-face polished, Zn-implanted, O-implanted and He-implanted. The samples are annealed both in air and argon gas at a temperature of 350, 650, 750, 900 and 1200oC. The results show that O-implanted sample is weaker in excitonic emission and has an annealing effect tendency not consistent with that of Zn-implanted and He-implanted. Ion implantation would introduce defects in favor of yellow luminescence and the defects would anneal out gradually as the annealing temperature is rising. / published_or_final_version / Physics / Master / Master of Philosophy