Download or read book Three Dimensional Zinc Oxide Nanostructure Synthesis and Photonic Applications written by Jimmy Yao and published by . This book was released on 2015 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: The objective of this study was to investigate zinc oxide (ZnO)-based photonic nanostructure fabrications and their applications to solar energy. In the first section, a three-dimensional (3-D) ZnO nanoforest with large surface areas and good electron transport properties has been synthesized successfully by a two--step hydrothermal process and applied to the photoelectrode for a dye-sensitized solar cell (DSSC). The experimental results show that the solar conversion efficiency of the 3-D ZnO nanoforest is much higher than that of one-dimensional (1-D) ZnO nanorod arrays owing to its much larger surface areas. In the second section, zinc oxide/titanium dioxide (ZnO/TiO2) nanocomposite photoelectrodes for DSSC with density-controlled capability are presented. A high open-circuit voltage of up to 0.93 V was successfully achieved. To the best of the author's knowledge, this is the highest open--circuit voltage reported in the literature; this is beneficial for achieving a high-efficiency DSSC. The physical mechanism of high open-circuit voltage has been demonstrated and confirmed by electrochemical impedance spectroscopy; a reduced recombination loss was achieved with an improved charge carrier diffusion path. In addition, ZnO/TiO2 nanocomposite photoelectrodes have proven to further improve solar conversion efficiency as compared to conventional TiO2 nanoparticles photoelectrodes. In total, several future research topics that could benefit from the analysis in this dissertation have been examined.Although the development of ZnO nanostructures has been studied extensively by various synthesis methods in the past decade, this dissertation is focused on the practical aspect of synthesizing ZnO nanostructures on transparent conductive oxide substrates directly for the application of dye-sensitized solar cells in a low-cost manner. The dissertation is divided into six chapters and the contents of every chapter is briefly introduced as follows. Chapter 1 introduces the motivation of the dissertation. Chapter 2 presents the synthesis and characterization of ZnO nanostructures for one-dimensional (1-D) and three-dimensional (3-D) systems. 1-D ZnO nanostructures--ZnO nanowires--were delivered by a rapid growth microwave-assisted vapor--liquid--solid method. 3-D ZnO hierarchical nanostructures--ZnO nanoforest--were synthesized via a cost-effective hydrothermal method. The obtained ZnO nanoforest has the potential to break through the limitation of the surface areas of DSSC. Chapter 3 presents the synthesis and characterization of ZnO/TiO2 composite nanostructures. The discussions were focused on the density-controlled capability of ZnO nanorod arrays and the conformal shell coating of ZnO--TiO2 core--shell nanostructures which have the feasibility to provide a direct electron transport pathway for conventional TiO2 nanoparticles DSSC. Chapter 4 investigates the DSSC performances from ZnO nanoforest photoelectrodes and ZnO/TiO2 nanocomposite photoelectrodes. Moreover, a high open-circuit voltage is reported and the physical mechanism is discussed and verified with electrochemical impedance spectroscopy. Furthermore, the overall solar conversion efficiency can be improved by this nanocomposite photoelectrode.In addition, radiation detection has been investigated during my Ph.D. studies. Chapter 5 demonstrates the standoff alpha radiation detection technique based on the physical mechanism of excited state absorption of air molecules. Both theoretical analysis and experimental verifications were conducted. The experimental results confirmed that the radiation could be detected at a 10 m standoff distance.Chapter 6 summarizes the dissertation with two developed photoelectrodes with the improvement of surface areas and electron transport property for a high solar conversion efficiency of DSSC and proposes potential future works regarding to further enhanced the efficiency.

Download or read book Zinc Oxide Based Nano Materials and Devices written by , Prof. Dr. Ahmed Nahhas and published by BoD – Books on Demand. This book was released on 2019-10-09 with total page 148 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book presents a review of recent advances in ZnO-based nanomaterials and devices. ZnO as a nanomaterial has gained substantial interest in the research area of wide bandgap semiconductors and is considered to be one of the major candidates for electronic and photonic applications. ZnO has distinguished and interesting electrical and optical properties and is considered to be a potential material in optoelectronic applications such as solar cells, surface acoustic wave devices, and UV emitters. ZnO's unique properties have attracted several researchers to study its electrical and optical properties. As a nanostructured material, ZnO exhibits many advantages for nanodevices. Moreover, it has the ability to absorb the UV radiation.

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 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 Toward the Optimization of Low temperature Solution based Synthesis of ZnO Nanostructures for Device Applications written by Hatim Alnoor and published by Linköping University Electronic Press. This book was released on 2017-10-06 with total page 96 pages. Available in PDF, EPUB and Kindle. Book excerpt: One-dimensional (1D) nanostructures (NSs) of Zinc Oxide (ZnO) such as nanorods (NRs) have recently attracted considerable research attention due to their potential for the development of optoelectronic devices such as ultraviolet (UV) photodetectors and light-emitting diodes (LEDs). The potential of ZnO NRs in all these applications, however, would require synthesis of high crystal quality ZnO NRs with precise control over the optical and electronic properties. It is known that the optical and electronic properties of ZnO NRs are mostly influenced by the presence of native (intrinsic) and impurities (extrinsic) defects. Therefore, understanding the nature of these intrinsic and extrinsic defects and their spatial distribution is critical for optimizing the optical and electronic properties of ZnO NRs. However, identifying the origin of such defects is a complicated matter, especially for NSs, where the information on anisotropy is usually lost due to the lack of coherent orientation. Thus, the aim of this thesis is towards the optimization of the lowtemperature solution-based synthesis of ZnO NRs for device applications. In this connection, we first started with investigating the effect of the precursor solution stirring durations on the deep level defects concentration and their spatial distribution along the ZnO NRs. Then, by choosing the optimal stirring time, we studied the influence of ZnO seeding layer precursor’s types, and its molar ratios on the density of interface defects. The findings of these investigations were used to demonstrate ZnO NRs-based heterojunction LEDs. The ability to tune the point defects along the NRs enabled us further to incorporate cobalt (Co) ions into the ZnO NRs crystal lattice, where these ions could occupy the vacancies or interstitial defects through substitutional or interstitial doping. Following this, high crystal quality vertically welloriented ZnO NRs have been demonstrated by incorporating a small amount of Co into the ZnO crystal lattice. Finally, the influence of Co ions incorporation on the reduction of core-defects (CDs) in ZnO NRs was systematically examined using electron paramagnetic resonance (EPR).

Download or read book Multifunctional Oxide Based Materials From Synthesis to Application written by Teofil Jesionowski and published by MDPI. This book was released on 2019-09-03 with total page 204 pages. Available in PDF, EPUB and Kindle. Book excerpt: The book deals with novel aspects and perspectives in metal oxide and hybrid material fabrication. The contributions are mainly focused on the search for a new group of advanced materials with designed physicochemical properties, especially an expanded porous structure and defined surface activity. The proposed technological procedures result in an enhanced activity of the synthesized hybrid materials, which is of great importance when considering their potential fields of application. The use of such materials in different technological disciplines, including aspects associated with environmental protection, allows for the verification of the proposed synthesis method. Thus, it can be stated that those aspects are of interdisciplinary character and may be located at the interface of three scientific disciplines—chemistry, materials science, and engineering—as well as environmental protection. Furthermore, the presented scientific scope is in some way an answer to the continuous demand for such types of materials and opens new perspectives for their practical use

Download or read book Zinc Oxide Nanostructures written by Magnus Willander and published by CRC Press. This book was released on 2014-07-22 with total page 234 pages. Available in PDF, EPUB and Kindle. Book excerpt: Zinc oxide (ZnO) in its nanostructured form is emerging as a promising material with great potential for the development of many smart electronic devices. This book presents up-to-date information about various synthesis methods to obtain device-quality ZnO nanostructures. It describes both high-temperature (over 100° C) and low-temperature (under 100° C) approaches to synthesizing ZnO nanostructures; device applications for technical and medical devices, light-emitting diodes, electrochemical sensors, nanogenerators, and photodynamic therapy; and the concept of self-powered devices and systems using ZnO nanostructures. The book emphasizes the utilization of non-conventional substrates such as plastic, paper, and textile as new platforms for developing electronics.

Download or read book Synthesis of One Dimensional Zinc Oxide Nanostructure and Their Applications written by Pang Lin and published by . This book was released on 2012 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Mesoscopic Electronics in Solid State Nanostructures written by Thomas Heinzel and published by John Wiley & Sons. This book was released on 2008-07-11 with total page 412 pages. Available in PDF, EPUB and Kindle. Book excerpt: This text treats electronic transport in the regime where conventional textbook models are no longer applicable, including the effect of electronic phase coherence, energy quantization and single-electron charging. This second edition is completely updated and expanded, and now comprises new chapters on spin electronics and quantum information processing, transport in inhomogeneous magnetic fields, organic/molecular electronics, and applications of field effect transistors. The book also provides an overview of semiconductor processing technologies and experimental techniques. With a number of examples and problems with solutions, this is an ideal introduction for students and beginning researchers in the field. "This book is a useful tool, too, for the experienced researcher to get a summary of recent developments in solid state nanostructures. I applaud the author for a marvellous contribution to the scientific community of mesoscopic electronics." Prof. K. Ensslin, Solid State Physics Laboratory, ETH Zurich

Download or read book Chemical Sensors and Biosensors written by Brian R. Eggins and published by John Wiley & Sons. This book was released on 2008-04-30 with total page 298 pages. Available in PDF, EPUB and Kindle. Book excerpt: Covering the huge developments in sensor technology and electronic sensing devices that have occurred in the last 10 years, this book uses an open learning format to encourage reader understanding of the subject. An invaluable distance learning book Applications orientated providing invaluable aid for anyone wishing to use chemical and biosensors Key features and subjects covered include the following: Sensors based on both electrochemical and photometric transducers Mass-sensitive sensors Thermal-sensitive sensors Performance factors for sensors Examples of applications Detailed case studies of five selected sensors 30 discussion questions with worked examples and 80 self-assessment questions 140 explanatory diagrams An extensive bibliography

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 331 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 1 Dimensional Metal Oxide Nanostructures written by Zainovia Lockman and published by CRC Press. This book was released on 2018-12-07 with total page 331 pages. Available in PDF, EPUB and Kindle. Book excerpt: 1-D metal oxide nanostructures, especially those with semiconducting properties, have attracted much attention in recent years due to their potential and emerging applications, specifically in environment purification and energy devices. For these applications, there have been many efforts to grow 1-D nanostructures in the form of nanotubes, nanorods, and nanowires using processes that conserve energy, are cost effective, and can be scaled up for large-scale production. 1-Dimensional Metal Oxide Nanostructures gathers under one title the most recent development of oxide nanomaterials, especially those fabricated via oxidation process in the nanoscale field. Thermal and anodic oxidation processes are reviewed with an aim to offer an in-depth understanding of mechanisms of 1-D nanostructure formation, their characteristics, and limitations. Other more common methods are also discussed, including sol-gel, hydrothermal, and other templated methods. Important applications of 1-D nanostructures are then presented, focusing on oxides like zinc oxide, titanium oxide, zirconium oxide, copper oxide, and iron oxide. A chapter on carbon nanotubes hybrid with these oxides is also included as well as one on silicon oxide nanowires formation by local anodic oxidation process. Aimed at researchers, academics, and engineers working across the fields of nanotechnology, materials science, chemistry, physics, semiconductors, and environmental and biomedical engineering, this essential reference enables readers to grasp the main concepts of nanomaterials in 1-D: formation technique, characteristics, and uses. It also encourages practical innovations in nanotechnology, especially in curbing pressing global issues related to energy, environment, and security.

Download or read book Synthesis of Zinc Oxide by Sol Gel Method for Photoelectrochemical Cells written by Siti Salwa Alias and published by Springer Science & Business Media. This book was released on 2013-11-20 with total page 59 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book focuses on the study of synthesized ZnO powder using Zn(CH3COO)2∙2H2O precursor, methanol (as solvent), and sodium hydroxide (NaOH) to vary the pH. The successfully synthesized ZnO powder from the sol-gel centrifugation and sol-gel storage methods were characterized and investigated by X-ray diffraction, field emission scanning electron microscopy, transmission electron microscopy, Fourier-transform infrared spectroscopy, UV–visible spectroscopy, and photoluminescence test to compare the properties of the nanoparticles. The best characteristic of the ZnO powder from both methods was observed when the powders were coated on an ITO glass to fabricate a PEC. The current density–voltage performances of both PECs were investigated under luminescent and dark conditions.

Download or read book Zinc Oxide Nanorods written by Kai-Hang Tam and published by . This book was released on 2017-01-27 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: This dissertation, "Zinc Oxide Nanorods: Hydrothermal Growth, Properties and Applications" by Kai-hang, Tam, 譚啟鏗, 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 ZINC OXIDE NANORODS: HYDROTHERMAL GROWTH, PROPERTIES AND APPLICATIONS Submitted by Tam Kai Hang for the degree of Master of Philosophy at The University of Hong Kong in December 2007 One-dimensional wide band-gap semiconductor nanostructures, such as nanorods, nanowires and nanobelts, have recently attracted much attention for their potential use as fundamental building blocks for new generation of electronic and photonic devices. Various semiconducting 1-D nanostructures have been synthesized, such as TiO, SnO, 2 2 GaN, GaAs, Si and ZnO. Among these nanostructures, zinc oxide (ZnO) has became particularly intersting in optoelectronic, field emission, gas sensing and biomedicine applications. ZnO is a wide band-gap (3.37 eV) semiconductor with high excitonic binding energy ( 60 meV), and it is non-toxic and environmentally friendly. Hydrothermal growth of ZnO provides an inexpensive method to fabricate large amounts of ZnO nanorods or nanowires on various substrates. However, the controversies still remain about the native defects in ZnO. In this work, ZnO nanorod arrays were fabricated by a hydrothermal method. The structural properties were characterized with scanning electron microscopy (SEM), transmission electron microscopy (TEM) and x-ray diffraction (XRD). Well-oriented nanorods, which exhibited strong defect-related photoluminescence (PL) were obtained. Stimulated UV emission was achieved in forming gas or oxygen annealed nanorods. Change in lasing threshold and defect emission, as well as spontaneous decay time, indicated that yellow defect emission was not caused by interstitial oxygen, which was commonly assumed to be dominant in the yellow emitted ZnO. The origins of defects emissions were investigated by x-ray photoelectron spectroscopy (XPS) and positron annihilation spectroscopy (PAS). The results showed that yellow emission of the as-grown nanorods originated from the presence of Zn(OH) on surface, while the green emission which appeared after annealing was due to the defect complex related to zinc vacancy. On the other hand, it was also observed that green emission originated from grain boundary in other ZnO nanostructures, such as nanoshells. The origin of the green emission has not yet been determined, but there was evidence that the emission was surface-related. Heterojunction of n-ZnO nanorod arrays / p-GaN film light-emitting-diodes (LEDs) were fabricated. Influence of annealing conditions on the performance of devices was examined. It was found that the position of recombination zone was shifted after annealing in some cases. Emission wavelength could be controlled through annealing processes. This study could help improve the performance of these heterojunction devices. In order to have more comprehensive studies on applications of these versatile ZnO nanorods, antibacterial properties of the nanorods were investigated. ZnO nanorods coating have exhibited great antibacterial activity. Other ZnO morphologies (nanoparticles and powder) were also studies for comparison. Mechanisms of ZnO against different bacteria were investigated. It was found that damaging of E. coli cell was partly due to the relaxation of hydrogen peroxide (H O ) from the structures. 2 2 DOI: 10.5353/th_b3955734 Subjects: Zinc oxide Nanostructures Nanotechnology

Download or read book Nanostructured Materials written by Mohindar Seehra and published by BoD – Books on Demand. This book was released on 2017-07-12 with total page 225 pages. Available in PDF, EPUB and Kindle. Book excerpt: There continues to be a worldwide interest in the size-dependent properties of nanostructured materials and their applications in many diverse fields such as catalysis, sensors, energy conversion processes, and biomedicine to name a few. The eleven chapters of this book written by different researchers include four chapters on the different methods of fabrication of specific materials followed by characterization of their properties, and the remaining seven chapters focusing on the fabrications and applications including three chapters on biomedical applications, two chapters on sensors, one chapter on solar cells, and one chapter on the use of nanoparticles in herbicides. These chapters provide up-to-date reviews useful for current and future researchers in these specific areas.

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 Synthesis and Characterization of Zinc Oxide Nanostructures for Piezoelectric Applications written by William L. Hughes and published by . This book was released on 2006 with total page 217 pages. Available in PDF, EPUB and Kindle. Book excerpt: Union between top-down and bottom-up assembly is inevitable when scaling down physical, chemical, and biological sensors and probes. Current sensor/probe-based technologies are firmly founded on top-down manufacturing, with limitations in cost of production, manufacturing methods, and material constraints. As an alternative to such limitations, contemporary synthesis techniques for one-dimensional nanostructures have been combined with established methods of micro-fabrication for the development of novel tools and techniques for nanotechnology. More specifically, this dissertation is a systematic study of the synthesis and characterization of ZnO nanostructures for piezoelectric applications. Within this study the following goals have been achieved: (1) rational design and control of a diversity of novel ZnO nanostructures, (2) improved understanding of polar-surface-dominated (PSD) phenomena among Wurtzite crystal structures, (3) confirmation of Tasker's Rule via the synthesis, characterization, and modeling of polar-surface-dominated nanostructures, (4) measurement of the surface-charge density for real polar surfaces of ZnO, (5) confirmation of the electrostatic polar-charge model used to describe polar-surface-dominated phenomena, (6) dispersion of ZnO nanobelts onto the selective layers of surface acoustic wave (SAW) devices for gas sensing applications, (7) manipulation of ZnO nanostructures using an atomic force microscope (AFM) for the development of piezoelectric devices, (8) fabrication of bulk acoustic resonator (BAR) and film bulk acoustic resonator (FBAR) devices based on the integrity of individual ZnO belts, (9) electrical characterization of a ZnO belt BAR device, (10) prediction and confirmation of the electrical response from a BAR device using a one-dimensional Krimholt-Leedom-Matthaei (KLM) model, and (11) development of a finite element model (FEM) to accurately predict the electrical response from ZnO belt BAR and FBAR devices in 3D.