Download or read book The Growth and Characterisation of Ordered Arrays of Zinc Oxide Nanostructures and Optical Studies of Defects in Zinc Oxide written by Daragh Byrne and published by . This book was released on 2012 with total page 188 pages. Available in PDF, EPUB and Kindle. Book excerpt:

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 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 Zinc Oxide Bulk Thin Films and Nanostructures written by Chennupati Jagadish and published by Elsevier. This book was released on 2011-10-10 with total page 600 pages. Available in PDF, EPUB and Kindle. Book excerpt: With an in-depth exploration of the following topics, this book covers the broad uses of zinc oxide within the fields of materials science and engineering:- Recent advances in bulk , thin film and nanowire growth of ZnO (including MBE, MOCVD and PLD), - The characterization of the resulting material (including the related ternary systems ZgMgO and ZnCdO), - Improvements in device processing modules (including ion implantation for doping and isolation ,Ohmic and Schottky contacts , wet and dry etching), - The role of impurities and defects on materials properties - Applications of ZnO in UV light emitters/detectors, gas, biological and chemical-sensing, transparent electronics, spintronics and thin film

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 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 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 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 Handbook of Zinc Oxide and Related Materials written by Zhe Chuan Feng and published by CRC Press. This book was released on 2012-09-26 with total page 565 pages. Available in PDF, EPUB and Kindle. Book excerpt: Through their application in energy-efficient and environmentally friendly devices, zinc oxide (ZnO) and related classes of wide gap semiconductors, including GaN and SiC, are revolutionizing numerous areas, from lighting, energy conversion, photovoltaics, and communications to biotechnology, imaging, and medicine. With an emphasis on engineering and materials science, Handbook of Zinc Oxide and Related Materials provides a comprehensive, up-to-date review of various technological aspects of ZnO. Volume Two focuses on devices and nanostructures created from ZnO and similar materials. The book covers various nanostructures, synthesis/creation strategies, device behavior, and state-of-the-art applications in electronics and optoelectronics. It also provides useful information on the device and nanoscale process and examines the fabrication of LEDs, LDs, photodetectors, and nanodevices. Covering key properties and important technologies of ZnO-based devices and nanoengineering, the handbook highlights the potential of this wide gap semiconductor. It also illustrates the remaining challenging issues in nanomaterial preparation and device fabrication for R&D in the twenty-first century.

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 ZnO and Their Hybrid Nano Structures written by Gaurav Sharma and published by Materials Research Forum LLC. This book was released on 2023-06-05 with total page 333 pages. Available in PDF, EPUB and Kindle. Book excerpt: ZnO and its hybrid nanostructures have unique optical, physical and chemical properties. The book covers recent trends in processing techniques and applications. Topics include solar cells, photo-voltaic devices, fuel cells, uv filters, lasers, light-emitting diodes, photo-detectors, spin-tronic devices, magnetic semiconductors, nano-generators, piezotronics, photo-catalytic applications against harmful organic pollutants like dyes, heavy metals, antibiotics, and sensors such as bio sensors, chemical sensors, gas sensors. Keywords: ZnO, Nano ZnO, Point Defects, Magnetic Semiconductors, Hybrid Nanostructures, Cell Applications, Nanoadsorbant for Heavy Metal Removals, Diagnostics, ZnO Nano-Carriers, ZnO Thin Films Fabrication.

Download or read book The Growth and Characterisation of Zinc Oxide Nanostructures written by and published by . This book was released on 2007 with total page 358 pages. Available in PDF, EPUB and Kindle. Book excerpt:

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 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 Zinc Oxide A Material for Micro and Optoelectronic Applications written by Norbert H. Nickel and published by Springer Science & Business Media. This book was released on 2005-12-28 with total page 245 pages. Available in PDF, EPUB and Kindle. Book excerpt: Recently, a significant effort has been devoted to the investigation of ZnO as a suitable semiconductor for UV light-emitting diodes, lasers, and detectors and hetero-substrates for GaN. Research is driven not only by the technological requirements of state-of-the-art applications but also by the lack of a fundamental understanding of growth processes, the role of intrinsic defects and dopants, and the properties of hydrogen. The NATO Advanced Research Workshop on “Zinc oxide as a material for micro- and optoelectronic applications”, held from June 23 to June 25 2004 in St. Petersburg, Russia, was organized accordingly and started with the growth of ZnO. A variety of growth methods for bulk and layer growth were discussed. These techniques comprised growth methods such as closed space vapor transport (CSVT), metal-organic chemical vapor deposition, reactive ion sputtering, and pulsed laser deposition. From a structural point of view using these growth techniques ZnO can be fabricated ranging from single crystalline bulk material to polycrystalline ZnO and nanowhiskers. A major aspect of the ZnO growth is doping. n-type doping is relatively easy to accomplish with elements such al Al or Ga. At room temperature single crystal ZnO exhibits a resistivity of about 0. 3 -cm, an electron mobility of 2 17 -3 225 cm /Vs, and a carrier concentration of 10 cm . In n-type ZnO two shallow donors are observable with activation energies of 30 – 40 meV and 60 – 70 meV.

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 ZnO Nanocrystals and Allied Materials written by M S Ramachandra Rao and published by Springer Science & Business Media. This book was released on 2013-09-12 with total page 377 pages. Available in PDF, EPUB and Kindle. Book excerpt: ZnO has been the central theme of research in the past decade due to its various applications in band gap engineering, and textile and biomedical industries. In nanostructured form, it offers ample opportunities to realize tunable optical and optoelectronic properties and it was also termed as a potential material to realize room temperature ferromagnetism. This book presents 17 high-quality contributory chapters on ZnO related systems written by experts in this field. These chapters will help researchers to understand and explore the varied physical properties to envisage device applications of ZnO in thin film, heterostructure and nanostructure forms.