Download or read book The Synthesis Characterization and Device Fabrication of ZnO NiO and Their Composite Nanostructures written by and published by . This book was released on 2014 with total page 55 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Synthesis and Characterization of ZnO Graphene Nanostructures for Electronics and Photocatalysis written by Seyed Ebrahim Chalangar and published by Linköping University Electronic Press. This book was released on 2021-04-08 with total page 132 pages. Available in PDF, EPUB and Kindle. Book excerpt: Recent rapid development of electronics and electro-optical devices demands affordable and reliable materials with enhanced performance. Forming nanocomposites of already well-known materials is one possible route towards novel functional materials with desirable synergistic enhanced properties. Incompatible chemical properties, mismatched crystal structures and weak bonding interactions between the substances, however, often limit the number of possible nanocomposites. Moreover, using an inexpensive, facile, large-area and flexible fabrication technique is crucial to employ the new composites in industrially viable applications. This thesis focuses on the synthesis and characterization of different zinc oxide/graphene (ZnO/GR) nanocomposites, well suited for optoelectronics and photocatalysis applications. Two different approaches of i) substrate-free random synthesis, and ii) template-assisted selective area synthesis were studied in detail. In the first approach, ZnO nanoparticles/rods were grown on GR. The obtained nanocomposites were investigated for better GR dispersity, electrical conductivity and optical properties. Besides, by adding silver iodide to the nanocomposite, an enhanced plasmonic solar-driven photocatalyst was synthesized and analyzed. In the second approach, arrays of single, vertically aligned ZnO nanorods were synthesized using a colloidal lithography-patterned sol-gel ZnO seed layer. Our demonstrated nanofabrication technique with simple, substrate independent, and large wafer-scale area compatibility improved the alignment and surface density of ZnO nanorods over large selective growth areas. Eventually, we found a novel method to further enhance the vertical alignment of the ZnO nanorods by introducing a GR buffer layer between the Si substrate and the ZnO seed layer, together with the mentioned patterning technique. The synthesized nanocomposites were analyzed using a large variety of experimental techniques including electron microscopy, photoelectron spectroscopy, x-ray diffraction, photoluminescence and cathodoluminescence spectroscopy for in-depth studies of their morphology, chemical and optical properties. Our findings show that the designed ZnO/GR nanocomposites with vertically aligned ZnO nanorods of high crystalline quality, synthesized with the developed low-cost nanofabrication technique, can lead to novel devices offering higher performance at a significantly lower fabrication cost.

Download or read book Metal Oxide Nanostructures written by Daniela Nunes and published by Elsevier. This book was released on 2018-11-01 with total page 328 pages. Available in PDF, EPUB and Kindle. Book excerpt: Metal Oxide Nanostructures: Synthesis, Properties and Applications covers the theoretical and experimental aspects related to design, synthesis, fabrication, processing, structural, morphological, optical and electronic properties on the topic. In addition, it reviews surface functionalization and hybrid materials, focusing on the advantages of these oxide nanostructures. The book concludes with the current and future prospective applications of these materials. Users will find a complete overview of all the important topics related to oxide nanostructures, from the physics of the materials, to its application. Delves into hybrid structured metal oxides and their promising use in the next generation of electronic devices Includes fundamental chapters on synthesis design and the properties of metal oxide nanostructures Provides an in-depth overview of novel applications, including chromogenics, electronics and energy

Download or read book Fabrication and Characterization of Metal Oxide Nanostructures written by Dan Li and published by Open Dissertation Press. This book was released on 2017-01-27 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: This dissertation, "Fabrication and Characterization of Metal Oxide Nanostructures" by Dan, Li, 李丹, was obtained from The University of Hong Kong (Pokfulam, Hong Kong) and is being sold pursuant to Creative Commons: Attribution 3.0 Hong Kong License. The content of this dissertation has not been altered in any way. We have altered the formatting in order to facilitate the ease of printing and reading of the dissertation. All rights not granted by the above license are retained by the author. Abstract: Abstract of thesis entitled FABRICATION AND CHARACTERIZATION OF METAL OXIDE NANOSTRUCTURES Submitted by Li Dan for the degree of Doctor of Philosophy at The University of Hong Kong in July 2007 Among various nanostructured materials, metal oxides are very promising for a variety of practical applications. Among different possible synthesis methods for metal oxide nanostructures, hydrothermal synthesis is of great interest because it is safe and environmentally friendly, and is typically performed at temperatures of less than 200 C. In this dissertation, several metal oxide nanostructures, including zinc oxide (ZnO), copper oxide (CuO) and nickel oxide (NiO) nanostructures, were fabricated by hydrothermal synthesis from aqueous solutions of zinc/copper/nickel nitrate hydrate and hexamethylenetetramine. The morphological, structural, optical and electrochemical properties of resultant nanostructures were studied by scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray diffractometry (XRD), energy dispersive X-ray spectroscopy (EDX), photoluminescence (PL), and electron paramagnetic resonance spectroscopy (EPR). The obtained ZnO nanorods are straight and perpendicular to the substrate. The substrate conditions have considerable effects on the size and the orientation of the nanorods. The pH value of solutions also has significant influence on the morphology of resultant ZnO nanostructures. The PL spectra of the ZnO nanorods exhibit one UV peak and one yellow peak ( 578 nm). The ZnO nanorods also show very strong EPR signal at g 1.96. For different synthesis conditions, spherical assemblies of CuO platelets and CuO nanostructured films were obtained respectively. The solution concentration, pH value, synthesis temperature, and presence of seeds significantly affect obtained morphology as well as adhesion to the substrate. For different synthesis conditions, NiO nanowalls and NiO nanostructured films were obtained respectively. The influence of pH value is different on different NiO nanostructures. Finally, transition metal (Mn, Cr, and Co) doped ZnO nanostructures were synthesized by a hydrothermal method from aqueous solutions of zinc nitrate hydrate, TM (TM = Mn, Cr, Co) nitrate hydrate, and hexamethylenetetramine. The addition of TM nitrate hydrate resulted in the change of the shape and preferential orientation of ZnO nanorods. Also, the addition of the dopant affects the optical properties, including the ratio of UV to defect emission and the position of the UV emission peak. DOI: 10.5353/th_b3877735 Subjects: Nanostructures Metallic oxides

Download or read book Zinc Oxide Nanostructures Synthesis and Characterization written by Sotirios Baskoutas and published by MDPI. This book was released on 2018-12-04 with total page 303 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book is a printed edition of the Special Issue "Zinc Oxide Nanostructures: Synthesis and Characterization" that was published in Materials

Download or read book Synthesis and Characterization of Zinc Oxide Based Nanostructures and Composites for Energy Related Applications written by Ahmed Salah Mahdi Al-Asadi and published by . This book was released on 2016 with total page 214 pages. Available in PDF, EPUB and Kindle. Book excerpt: The main objective of this communication is to report the synthesis and characterization of zinc oxide (ZnO) based nanostructures and composites for energy related applications using a simple and cost-effective chemical bath deposition (CBD) technique. Highly crystalline zinc oxide (ZnO) nanowires (NWs) were synthesized through CBD method using a simple seeding technique. This seeding process includes dispersion of commercially available ZnO nanoparticles through spraying on a desired substrate prior to the CBD growth. A typical growth period of 16 h produced ZnO NW assemblies with an average diameter of ~45 nm and lengths of 1–1.3 μm, with an optical band gap of ~3.61 eV. The NWs growth was successfully achieved on various substrates (e.g silicon dioxide, plastic sheets, copper grid, and carbon nanotube buckypaper). The as-prepared ZnO NWs were found to be photoactive under ultra violet (UV) illumination. UV photosensor devices fabricated using these NW assemblies demonstrated a high photodetection abilities at room temperature under moderate UV illumination power of ~ 250 μW/cm2. These findings indicate the possibility of using ZnO NWs, grown using the same seeding method, for various opto-electronic applications. The same seeding technique was also used to grow ZnO NWs onto aligned multi-wall carbon nanotubes (MWCNTs), which were synthesized by using air assisted chemical vapor deposition (CVD) onto a SiO2/Si substrate. This ZnO NW/MWCNT hybrid structure was characterized by scanning electron microscopy (SEM), energy dispersive spectroscopy (EDS) and Raman spectroscopy. The fabricated structure was used as an electrode for supercapacitor (SC) measurements. Good electrochemical performance was accomplished with a specific capacitance of ~192 F/g along with a maximum energy density of ~3.8Wh/kg and a high power density of ~ 28 kW/kg. The fabricated device showed high stability and it retained over 99% of its initial specific capacitance value after 2000 cycles. In addition, we report on the synthesis & electrochemical characterization of two-dimensional Zinc-Aluminum (ZnAl) layered double hydroxides (LDHs) directly grown on Al substrate by using CBD method. After details structural characterization by SEM, Raman spectroscopy, EDS elemental mapping, and X-ray powder diffraction (XRD), the electrochemical performances of an electrode fabricated based on this material were evaluated via cyclic voltammetry and galvanostatic charge-discharge using various electrolytes. The ionic electrolyte device showed a maximum specific capacitance of 120 F/g along with a maximum energy density of 5.17 Wh/Kg and a high power density of 8.4 kW/h. Additionally, we found that a high specific capacitance value of 358 F/g was achieved using an aqueous electrolyte.

Download or read book Chemically Deposited Nanocrystalline Metal Oxide Thin Films written by Fabian I. Ezema and published by Springer Nature. This book was released on 2021-06-26 with total page 926 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book guides beginners in the areas of thin film preparation, characterization, and device making, while providing insight into these areas for experts. As chemically deposited metal oxides are currently gaining attention in development of devices such as solar cells, supercapacitors, batteries, sensors, etc., the book illustrates how the chemical deposition route is emerging as a relatively inexpensive, simple, and convenient solution for large area deposition. The advancement in the nanostructured materials for the development of devices is fully discussed.

Download or read book Synthesis of ZnO CuO and Their Composite Nanostructures for Optoelectronics Sensing and Catalytic Applications written by Saima Zaman and published by . This book was released on 2012 with total page 59 pages. Available in PDF, EPUB and Kindle. Book excerpt: Research on nanomaterials has become increasingly popular because of their unique physical, chemical, optical and catalytic properties compared to their bulk counterparts. Therefore, many efforts have been made to synthesize multidimensional nanostructures for new and efficient nanodevices. Among those materials, zinc oxide (ZnO), has gained substantial attention owing to many outstanding properties. ZnO besides its wide bandgap of 3.34 eV exhibits a relatively large exciton binding energy (60 meV) at room temperature which is attractive for optoelectronic applications. Likewise, cupric oxide (CuO), having a narrow band gap of 1.2 eV and a variety of chemo-physical properties that are attractive in many fields. Moreover, composite nanostructures of these two oxides (CuO/ZnO) may pave the way for various new applications.??This thesis can be divided into three parts concerning the synthesis, characterization and applications of ZnO, CuO and their composite nanostructures.??In the first part the synthesis, characterization and the fabrication of ZnO nanorods based hybrid light emitting diodes (LEDs) are discussed. The low temperature chemical growth method was used to synthesize ZnO nanorods on different substrates, specifically on flexible non-crystalline substrates. Hybrid LEDs based on ZnO nanorods combined with p-type polymers were fabricated at low temperature to examine the advantage of both materials. A single and blended light emissive polymers layer was studied for controlling the quality of the emitted white light.??The second part deals with the synthesis of CuO nanostructures (NSs) which were then used to fabricate pH sensors and exploit these NSs as a catalyst for degradation of organic dyes. The fabricated pH sensor exhibited a linear response and good potential stability. Furthermore, the catalytic properties of petals and flowers like CuO NSs in the degradation of organic dyes were studied. The results showed that the catalytic reactivity of the CuO is strongly depending on its shape.??In the third part, an attempt to combine the advantages of both ZnO and CuO NSs was performed by developing a two-step chemical growth method to synthesize the composite NSs. The synthesized CuO/ZnO composite NSs revealed an extended light absorption and enhanced defect related visible emission.

Download or read book Solution Methods for Metal Oxide Nanostructures written by Rajaram S. Mane and published by Elsevier. This book was released on 2023-06-27 with total page 448 pages. Available in PDF, EPUB and Kindle. Book excerpt: Solution Methods for Metal Oxide Nanostructures reviews solution processes that are used for synthesizing 1D, 2D and 3D metal oxide nanostructures in either thin film or in powder form for various applications. Wet-chemical synthesis methods deal with chemical reactions in the solution phase using precursors at proper experimental conditions. Wet-chemical synthesis routes offer a high degree of controllability and reproducibility for 2D nanomaterial fabrication. Solvothermal synthesis, template synthesis, self-assembly, oriented attachment, hot-injection, and interface-mediated synthesis are the main wet-chemical synthesis routes for 2D nanomaterials. Solution Methods for Metal Oxide Nanostructures also addresses the thin film deposition metal oxides nanostructures, which plays a very important role in many areas of chemistry, physics and materials science.Each chapter includes information on a key solution method and their application in the design of metal oxide nanostructured materials with optimized properties for important applications. The pros and cons of the solution method and their significance and future scope is also discussed in each chapter. Readers are provided with the fundamental understanding of the key concepts of solution synthesis methods for fabricating materials and the information needed to help them select the appropriate method for the desired application. Reviews the most relevant wet chemical solution methods for metal oxide nanostructures, including sol-gel, solvothermal, hydrothermal, co-precipitation methods, and more Addresses thin film deposition techniques for metal oxide nanostructures, such as spray-pyrolysis, electrodeposition, spin coating and self-assembly Discusses the pros and cons of each solution method and its significance and future opportunities

Download or read book Nanostructured Zinc Oxide written by Kamlendra Awasthi and published by Elsevier. This book was released on 2021-08-10 with total page 781 pages. Available in PDF, EPUB and Kindle. Book excerpt: Nanostructured Zinc Oxide covers the various routes for the synthesis of different types of nanostructured zinc oxide including; 1D (nanorods, nanowires etc.), 2D and 3D (nanosheets, nanoparticles, nanospheres etc.). This comprehensive overview provides readers with a clear understanding of the various parameters controlling morphologies. The book also reviews key properties of ZnO including optical, electronic, thermal, piezoelectric and surface properties and techniques in order to tailor key properties. There is a large emphasis in the book on ZnO nanostructures and their role in optoelectronics. ZnO is very interesting and widely investigated material for a number of applications. This book presents up-to-date information about the ZnO nanostructures-based applications such as gas sensing, pH sensing, photocatalysis, antibacterial activity, drug delivery, and electrodes for optoelectronics. Reviews methods to synthesize, tailor, and characterize 1D, 2D, and 3D zinc oxide nanostructured materials Discusses key properties of zinc oxide nanostructured materials including optical, electronic, thermal, piezoelectric, and surface properties Addresses most relevant zinc oxide applications in optoelectronics such as light-emitting diodes, solar cells, and sensors

Download or read book Fabrication and Characterization of Zinc Oxide Zno Nanostructures written by Yu-Hang Leung and published by Open Dissertation Press. This book was released on 2017-01-27 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: This dissertation, "Fabrication and Characterization of Zinc Oxide (ZnO) Nanostructures" by Yu-hang, Leung, 梁宇恆, was obtained from The University of Hong Kong (Pokfulam, Hong Kong) and is being sold pursuant to Creative Commons: Attribution 3.0 Hong Kong License. The content of this dissertation has not been altered in any way. We have altered the formatting in order to facilitate the ease of printing and reading of the dissertation. All rights not granted by the above license are retained by the author. Abstract: Abstract of thesis entitled FABRICATION AND CHARACTERIZATION OF ZINC OXIDE (ZnO) NANOSTRUCTURES Submitted by Leung Yu Hang For the degree of Master of Philosophy at The University of Hong Kong in January 2006 Since the discovery of carbon nanotubes by Iijima in 1991, increasing research effort has been devoted to the synthesis and characterization of nanostructured materials. Materials at this scale exhibit novel properties which cannot be found in their bulk form. In silicon nanowires, for example, the bandgap of Si nanowires increases from 1.1 eV to 3.7 eV when the nanowire diameter decreases from 7 nm to 1.3 nm. In recent years, nanostructures of various semiconductors like Si, gallium arsenide, gallium nitride, and zinc oxide have been demonstrated. Among them, ZnO has been recognized as a promising material for a variety of applications in the field of photonics, optoelectronics, gas sensing, field emission, and piezoelectrics. To realize the incorporation of ZnO nanostructures into real life applications, lots of work need to be done, including synthesis of the nanostructures, and understanding of their properties. In this study, a number of ZnO nanostructures (tetrapods, nanorods, nanoribbons/combs, multipods) were fabricated by thermal evaporation and hydrothermal synthesis methods. The morphologies and, structural and optical properties of the resultant nanostructures were then characterized by various techniques, such as scanning electron microscopy, transmission electron microscopy, selected area electron diffraction, energy dispersive X-ray spectroscopy, X-ray diffractometry, photoluminescence and electron paramagnetic resonance. It was observed that fabrication conditions could significantly affect the properties of the nanostructures. All nanostructures exhibited one UV peak and one broad peak in the visible spectrum. The major difference is that the nanostructures fabricated by thermal evaporation exhibited green PL emission while the nanorods synthesized by hydrothermal method gave yellow emission. Green emission was observed even without the presence of the EPR signal at g 1.96 in some samples. This result contradicts the commonly cited oxygen vacancy hypothesis of green emission of ZnO. Obviously, that hypothesis does not apply to all ZnO samples. The nanorod sample with yellow emission also exhibited strong EPR signal similar to the green emitting sample. A possible explanation for the obtained results is that there are two different deep levels responsible for the green and yellow emission respectively. Stimulated UV emission of three different nanostructures (tetrapods, nanoribbons/combs, and nanorods) was studied by time-resolved photoluminescence (TRPL). It was observed that different nanostructures exhibited different lasing thresholds, emission delay times and decay times. The difference in the lasing behaviors of the nanostructures is likely due to the difference in morphology, mode of cavity, or even native defects present in the material. DOI: 10.5353/th_b3617532 Subjects: Nanostructures Zinc oxide

Download or read book Metal Oxide Nanocomposite Thin Films for Optoelectronic Device Applications written by Rayees Ahmad Zargar and published by John Wiley & Sons. This book was released on 2023-09-18 with total page 436 pages. Available in PDF, EPUB and Kindle. Book excerpt: METAL OXIDE NANOCOMPOSITE THIN FILMS FOR OPTOELECTRONIC DEVICE APPLICATIONS The book provides insight into the fundamental aspects, latest research, synthesis route development, preparation, and future applications of metal oxide nanocomposite thin films. The fabrication of thin film-based materials is important to the future production of safe, efficient, and affordable energy as the devices convert sunlight into electricity. Thin film devices allow excellent interface engineering for high-performance printable solar cells as their structures are highly reliable and stand-alone systems can provide the required megawatts. They have been used as power sources in solar home systems, remote buildings, water pumping, megawatt-scale power plants, satellites, communications, and space vehicles. Metal Oxide Nanocomposite Thin Films for Optoelectronic Device Applications covers the basics of advanced nanometal oxide-based materials, their synthesis, characterization, and applications, and all the updated information on optoelectronics. Topics discussed include the implications of metal oxide thin films, which are critical for device fabrications. It provides updated information on the economic aspect and toxicity, with great focus paid to display applications, and covers some core areas of nanotechnology, which are particularly concerned with optoelectronics and the available technologies. The book concludes with insights into the role of nanotechnology and the physics behind photovoltaics. Audience The book will be an important volume for electronics and electrical engineers, nanotechnologists, materials scientists, inorganic chemists in academic research, and those in industries, exploring the applications of nanoparticles in semiconductors, power electronics, and more.

Download or read book Zinc Based Nanostructures for Environmental and Agricultural Applications written by Kamel A. Abd-Elsalam and published by Elsevier. This book was released on 2021-05-22 with total page 678 pages. Available in PDF, EPUB and Kindle. Book excerpt: Zinc-Based Nanostructures for Environmental and Agricultural Applications shows how zinc nanostructures are being used in agriculture, food and the environment. The book has been divided into two parts: Part I deals with the synthesis and characterization of zinc-based nanostructures such as biogenic, plant, microbial, and actinobacteria mediated synthesis of zinc nanoparticles, Part II is focused on agri-food applications such as antibacterial, antifungal, antimicrobial, plant disease management, controlling post-harvest diseases, pesticide sensing and degradations, plant promotions, ZnO nanostructure for food packaging application, safe animal food and feed supplement, elimination of mycotoxins, and veterinary applications. Part III reviews technological developments in environmental applications such as risks and benefits for aquatic organisms and the marine environment, antiseptic activity and toxicity mechanisms, wastewater treatment, and zinc oxide-based nanomaterials for photocatalytic degradation of environmental and agricultural pollutants. The book discusses various aspects, including the application of zinc-based nanostructures to enhance plant health and growth, the effect on soil microbial activity, antimicrobial mechanism, phytotoxicity and accumulation in plants, the possible impact of zinc-based nanostructures in the agricultural sector as nanofertilizer, enhancing crop productivity, and other possible antimicrobial mechanisms of ZnO nanomaterials. Explores the impact of a large variety of zinc-based nanostructures on agri-food and environment sectors Outlines how the properties of zinc-based nanostructures mean they are particularly efficient in environmental and agricultural application areas Assesses the major challenges of synthesizing and processing zinc-based nanostructured materials

Download or read book ZnO Nanostructures written by Yue Zhang and published by Royal Society of Chemistry. This book was released on 2017-06-21 with total page 307 pages. Available in PDF, EPUB and Kindle. Book excerpt: As wide band semiconductors with rich morphologies and interesting electric, optical, mechanical and piezoelectric properties, ZnO nanostructures have great potential in applications, such as strain sensors, UV detectors, blue LED, nano generators, and biosensors. ZnO Nanostructures: Fabrication and Applications covers the controllable synthesis and property optimization of ZnO nanostructures through to the preparation and performance of nanodevices for various applications. The book also includes recent progress in property modulation of ZnO nanomaterials and new types of devices as well as the latest research on self-powered devices and performance modulation of ZnO nanodevices by multi-field coupled effects. Authored by a leading researcher working within the field, this volume is applicable for those working in nanostructure fabrication and device application in industry and academia and is appropriate from advanced undergraduate level upwards.

Download or read book Controllable Fabrication of Zinc Oxide Functional Nano micro structure in Aqueous Solution written by Xiaodong Yan and published by . This book was released on 2010 with total page 312 pages. Available in PDF, EPUB and Kindle. Book excerpt: Nanostructures of ZnO show intriguing chemical, electrical, and physical properties and are promising for a broad range of applications in catalysis, electronics and photonics. Cost-effective techniques that can be used to prepare structures with controllable compositional, structural, and functional properties are fundamental to the utilization of ZnO in small scale devices with enhanced performance. Although many methods have been developed to fabricate ZnO nanostructures, systematic research on functional materials development based on ZnO is still needed as this fascinating material probably has the richest family of low-dimensional nanostructures. The research reported in this thesis aims to develop ZnO-based nanostructural materials using a facile and low-temperature aqueous solution growth approach, to analyze their compositional, mechanical, structural, and functional properties using advanced characterization techniques, to get a better understanding of the mechanisms behind nanostructure growth, and to explore their potentials in catalytic, optical, and electronic applications. In the first part of this thesis, low-dimensional ZnO nano-/micro-rods with tailored structural property (growth direction, aspect ratio, and surface distribution density) were grown on glass substrates in aqueous solutions containing zinc salt and hexamethylenetetramine at temperatures generally lower than 95oC. The substrates were pre-deposited with a thin layer of ZnO seeds using a magnetron sputter. The potential influences of growth conditions, typically including concentration, pH, type of zinc salt, solution temperature, reaction duration, and inorganic or organic additive, have been subjected to systematic investigation. This led to an improved understanding of the chemical reactions and nucleation/growth processes involved in the morphological evolution of ZnO-based hierarchical nanostructures. The second part of the thesis, ZnO nano-/micro-rod arrays with controllable distribution density have been successfully synthesized by adjusting the initial pH of the weak acidic growth solution. ZnO arrays with a large inter-rod space provide a good opportunity for characterizing the property of an individual rod. In this research, mechanical property tests have been successfully peformed directly on a single rod without the need of any complicated sample preparation. The electronic properties of these aligned ZnO nanorod arrays have also been explored by studying the I-V characteristics of both heterojuction and homojuction p-n devices. In next two chapters, complex ZnO structures, including nanotubes and three-dimensional ball-shaped clusters have been presented and disscussed, respectively. The morphology and microstructure of these structures were characterized by scanning electron microscopy, transmission electron microscopy, and in-situ cathodoluminescence. The corresponding growth mechanisms were proposed based on the analysis of the characterization results. Chapter 7 describes that aligned ZnO nano-rod arrays were further used as templates to prepare a novel composite nanostructure. By coating these ZnO nanorods with TiO2 nanowires using magnetron sputtering technique, a ZnO/TiO2 core-brush structure has been successfully achieved. Their morphology and microstructure have been investigated using scanning electron microscopy, transmission electron microscopy, powder X-ray diffractometer, energy-dispersive X-ray spectroscopy and X-ray Photoelectron Spectroscopy. This composite nanostructure shows a significantly enhanced photocatalytic activity in decomposition of a typical organic dye under UV and sunlight irradiation. This new structure has many other interesting properties and may have great potential in other optoelectronic applications. In the last part of this thesis, conclutions and future works are addressed according to the synthesis, characterization and application results.

Download or read book Understanding Solids written by Richard J. D. Tilley and published by John Wiley & Sons. This book was released on 2005-09-27 with total page 621 pages. Available in PDF, EPUB and Kindle. Book excerpt: A modern introduction to the subject taking a unique integrated approach designed to appeal to both science and engineering students. Covering a broad spectrum of topics, this book includes numerous up-to-date examples of real materials with relevant applications and a modern treatment of key concepts. The science bias allows this book to be equally accessible to engineers, chemists and physicists. * Carefully structured into self-contained bite-sized chapters to enhance student understanding * Questions have been designed to reinforce the concepts presented * Includes coverage of radioactivity * Relects a rapidly growing field from the science perspective

Download or read book Fabrication and Characterisation of Device Quality ZnO Nanostructures written by Augustine Che Mofor and published by Cuvillier Verlag. This book was released on 2007-07-11 with total page 138 pages. Available in PDF, EPUB and Kindle. Book excerpt: Since ZnO resurfaced as a very promising semiconductor material for applications in microelectronics, optoelectronics, sensor technology, biomedicine and spin electronics, producing high purity ZnO nanostructures for such applications has rather proven to be challenging. This book first revises the main properties of ZnO as a semiconductor and nanomaterial and also some fabrication techniques for nanostructures. It later concentrates on the development of a vapour transport system for the growth of high quality ZnO nanostructures (mainly nanorods). The book attempts to explain the influence of reactor pressure, growth temperature and growth time on the morphology and quality of ZnO nanorods. While intrinsic (undoped) ZnO nanorods were grown for extensive analysis, transition metal-doped ZnO nanorods were also fabricated and investigated for possible applications in magnetoelectronics/spintronics. Conventional material characterisation methods are also revisited and employed to analyse the crystalline quality, optical, electrical and magnetic properties of ZnO nanorods. Since the book is writtenin an application-oriented fashion, it extends to the fabrication of ZnO nanrorod-based device structures. Here, nano p-n junctions and nano ZnO/ZnMgO quantum well structures are also presented. At the end, the reader clearly sees how ZnO nanorods of extremely high crystalline quality can be grown using an unconventional technique.