Download or read book Influence of Zinc Oxide Particle Size and Surface Properties on the Electrical Optical and Cytotoxicity Characteristics of Zinc Oxide Discs written by Sendi Rabab Khalid M and published by . This book was released on 2015 with total page 572 pages. Available in PDF, EPUB and Kindle. Book excerpt:
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 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 Influence of Morphology and Surface Conditions on Defect Properties of Nanocrystalline Zinc Oxide written by Jorge Antonio Paramo and published by . This book was released on 2012 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Performance of nanoscale ZnO-based systems depends on the nanomorphology and surface conditions, in particular surface defect states. We investigated the impact of the surface/interface phenomena on the defect-related properties for ZnO-containing nanocrystalline systems. To probe these surface-related effects we employed photoluminescence (PL) spectroscopy. Among others, we studied ZnO-containing nanocrystalline specimens grown by wet precipitation with size and morphology controlled by the synthesis parameters. We observed a strong correlation between defect-related luminescence and morphological sample variations. For example, there was a consistent relationship between the surface/volume ratio and the relative intensity of the PL defect emission, indicating strong influence of the optically-active surface states. Commercially available ZnO nanopowders from several vendors were investigated by PL. Observation of the size effects was somewhat overshadowed by the sample-to-sample differences in quality, and thus defects' content and abundance. Temperature-dependent PL measurements in the bound-exciton (BEx) range were performed to elucidate surface-related corrections to the excitons thermodynamics. Specially, calculations for the excitonic activation energies indicated strong dependences of the nanocrystal size on the predominant BEx dissociation channels. Also, we observed nonlinear dependences of BEx peak broadening on temperature suggesting surface phonon contributions. We used remote plasma treatments to tailor surface defect properties of ZnO nanopowders. We report on the plasma-driven modifications of defect optical signatures such as BEx and visible luminescence. Besides, plasma treatments revealed size-dependent effects in the studied specimens. PL was used to study ZnO nanoparticles embedded into a polymethyl methacrylate (PMMA) matrix by bulk polymerization. We found that the polymer encapsulation enhances room-temperature excitonic luminescence by several orders of magnitude, similar to the effects of low temperatures on the as-received nanoparticles. At the same time, relative intensities of the visible defect luminescence did not change noticeably after the PMMA embedding. Intensity-dependent PL experiments showed no indication of a random lasing threshold, thus we attributed the observed phenomena to the influence of the PMMA/ZnO interfaces.
Download or read book The Effect of Grain Size and Forming of Gas Reduction on the Electrical Properties of Zinc Oxide written by Rofeideh Mansourian and published by . This book was released on 2013 with total page 83 pages. Available in PDF, EPUB and Kindle. Book excerpt: Zinc oxide is an n-type transparent conducting oxide (TCO), which is used in solar cells and optoelectronics devices. ZnO has the potential to become the future choice for a wide range of TCO commercial applications replacing the current, more expensive, and toxic indium-based materials. The isothermal grain growth of ZnO nano-powders with two different initial grain sizes and the effect of forming gas reduction on their electrical properties were studied at 900 °C. The particle size was determined using synchrotron x-ray diffraction data and scanning electron micrographs. The grain size, shape, trace impurities, and synthesis methods had an effect on the electrical performance of crystallites smaller than 300 nm. For grains larger than 300 nm, similar conductivity values were achieved regardless of the initial grain size and impurities. While grain growth modestly increased the electrical performance of ZnO, the exposure to reduction gases dramatically improved the conductivity by five orders of magnitude. Synchrotron x-ray diffraction data collected in situ at 500 °C also showed that reducing gases enhanced the grain growth of nanoparticles.
Download or read book Physical and Sensing Properties of Zinc Oxide Thin Films written by Ali Mohammed and published by LAP Lambert Academic Publishing. This book was released on 2012-07 with total page 148 pages. Available in PDF, EPUB and Kindle. Book excerpt: Zinc oxide is one of the most candidate materials using in the detecting and sensing fields, physical properties such as structural, optical and electrical properties has been studied by so many researchers. This book provides an insight on the basic physical properties, [structural (as crystallite size, integral breadth, micro strain and dislocation density), optical (as transmittance absorption coefficient, extinction coefficient and energy gap), electrical (as dark and illuminated I-V characteristics)]. This book focuses on the principles of two main sensing methods, chemical and piezoelectrical. The mechanism and characterization for chemical vapors and gas sensing has been explained, also it contain the basic and simple demonstration of set-up for mechanical waves sensing depending on the some parameters as resonance frequency, band width, quality factor, damping coefficient and surface acoustic wave velocity (SAW). Finally the book shows those metal oxides especially ZnO can be used as a biomedical, mechanical or any other industrial or environmental sensors.
Download or read book Influence of the Adsorption of Gases and Vapors on the Characteristic Photoelectric Effect of ZnO and on the Photoelectric Effect of ZnO Sensitized by Chlorophyll and Similar Pigments written by Ye. K. Putseiko and published by . This book was released on 1953 with total page 4 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book The Physicochemical Properties and Cellular Toxicity of Variably Synthesized Zinc Oxide Nanoparticles written by Catherine Binns Anders and published by . This book was released on 2017 with total page 256 pages. Available in PDF, EPUB and Kindle. Book excerpt: "Nanotechnology has grown exponentially since its inception in the early 1970's. Since then, bionanotechnological devices and treatment options have significantly improved disease treatments and patient outcomes; however, this rapid growth in consumer related products has also prompted concern. Zinc oxide nanoparticles (nZnO), known for their inherent toxicity and prevalent global use in consumer products and medical applications, have received much of this attention. Significant research efforts have focused on both toxicity remediation through material property modification and the exploitation of these same factors to create potential cancer therapeutics. There is general agreement that the physicochemical properties of nZnO strongly contribute to NP-induced toxicity; however, inconsistencies in the material property characterization methods employed, and an understanding of how those properties influence cytotoxicity in mammalian cells has led to discrepancies in the literature. Additionally, more research is needed to connect the material properties of nZnO to downstream cellular responses. Here, a panel of variably synthesized nZnO was utilized to thoroughly investigate the material properties of the particles as they relate to cytotoxicity, oxidative stress, and transcriptome changes in different mammalian cell types. The goals of this study are three-fold: i) reduce NP agglomeration and sedimentation tendencies within complex media and achieve dispersion stability, ii) define which material property interactions have the greatest potential to affect cellular toxicity, and to iii) examine the preferential toxicity of nZnO towards Jurkat leukemic cells through genetic expression studies. Chapter 2 highlights the importance of dispersion stability and the effect of fetal bovine serum (FBS) proteins on the dispersion stability, dosimetry and NP-induced cytotoxicity of nZnO in suspension and adherent in vitro cell culture models. The presence of surface adsorbed proteins from the FBS on the nZnO decreased agglomeration and sedimentation potential. Furthermore, FBS-stabilized nZnO dispersions resulted in toxicity increases in suspension cells when compared to unstable dispersions; however, toxicity was decreased in adherent cell models with stable dispersions. These observations indicate that improved dispersion stability leads to increased NP bioavailability for suspension cells and reduced NP sedimentation onto adherent cell layers resulting in more accurate in vitro toxicity assessments. In Chapter 3, we utilized an expanded panel of nZnO synthesized through wet chemical and high temperature methods, followed by thorough characterization to examine the importance of material property changes in NP-induced toxicity. We found our diverse set of nZnO displayed significant differences in surface reactivity, dissolution potential and cytotoxicity towards cancerous and primary T cells. Additionally, principal component analysis (PCA) suggested that the synthesis procedure conferred unique material properties, and can be a determinant of cellular cytotoxicity. Furthermore, we showed that attributing NP-induced toxicity to one specific material property is shortsighted and that complex interactions between these properties needs to be considered. Finally, Chapter 4 introduces future work dedicated to investigating transcriptome changes in cancerous and primary T cells exposed to nZnO. Both cell types demonstrated significant up- and down-regulation of genes in a dose-dependent manner. Many significant differentially expressed genes (SDEGs) corresponded to proteins involved in the sequestration and transport of ionic zinc confirming the importance of nZnO in the cytotoxic response. Additional analysis will focus on the importance of specific SDEGs involved in the regulation of oxidative stress pathways, cellular metabolism, inflammation, T cell activation, and protein misfolding in the NP-induced toxicity mechanism."--Boise State University ScholarWorks.
Download or read book Electrical and Optical Properties of Amorphous Zinc Oxide Films written by Reid A. Mickelsen and published by . This book was released on 1963 with total page 174 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Influence of Processing Variables on the Structure and Properties of ZnO Films written by and published by . This book was released on 1995 with total page 18 pages. Available in PDF, EPUB and Kindle. Book excerpt: Zinc oxide films of high optical quality have been deposited onto both silica and silicon substrates using reactive sputtering, pulsed laser deposition, and an aqueous solution based technique. Films have been characterized with respect to crystalline phase and phase stability, surface morphology, and optical response by means of X-ray diffraction, Raman Spectroscopy, Atomic Force Microscopy, optical transmission and ellipsometry measurements. All films studied were of the wurtzite phase, fine-grained, and exhibited varying degrees of c-axis orientation with respect to the substrate normal depending upon deposition conditions. Films showed some degree of residual tensile stress which was inferred from the E2 Raman line shift relative to the single crystal frequency. The wurtzite phase was found to be stable to temperatures near 800°C, but at higher temperatures, reaction with silica led to evolution of Zn2SiO4 at the interface. Variations in Raman line intensities upon post deposition annealing has been correlated with oxidation of excess zinc in the lattice.
Download or read book An Investigation of the Electrical Properties of Zinc Oxide Thin Films Influenced by Oxygen Adsorption written by James Chi-Te Yen and published by . This book was released on 1973 with total page 258 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Zinc Oxide and Related Materials Volume 957 written by Jürgen H. Christen and published by . This book was released on 2007-04-05 with total page 470 pages. Available in PDF, EPUB and Kindle. Book excerpt: The MRS Symposium Proceeding series is an internationally recognised reference suitable for researchers and practitioners. The topics covered in this volume, first published in 2007, include devices, defects, spintronics and magnetism, growth, optical properties and nanostructures, and doping and processing TFTs.
Download or read book ZnO Thin Films written by Paolo Mele and published by . This book was released on 2019 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: Zinc oxide (ZnO) is an n-type semiconductor with versatile applications such as optical devices in ultraviolet region, piezoelectric transducers, transparent electrode for solar cells and gas sensors. This book "ZnO Thin Films: Properties, Performance and Applications" gives a deep insight in the intriguing science of zinc oxide thin films. It is devoted to cover the most recent advances and reviews the state of the art of ZnO thin films applications involving energy harvesting, microelectronics, magnetic devices, photocatalysis, photovoltaics, optics, thermoelectricity, piezoelectricity, electrochemistry, temperature sensing. It serves as a fundamental information source on the techniques and methodologies involved in zinc oxide thin films growth, characterization, post-deposition plasma treatments and device processing. This book will be invaluable to the experts to consolidate their knowledge and provide insight and inspiration to beginners wishing to learn about zinc oxide thin films.
Download or read book The Surface Properties of Zinc Oxide written by K. Atherton and published by . This book was released on 1974 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Polymeric and Self Assembled Hydrogels written by Xian Jun Loh and published by Royal Society of Chemistry. This book was released on 2013 with total page 275 pages. Available in PDF, EPUB and Kindle. Book excerpt: The only book to give a complete picture of current hydrogel research, covering all the major applications as well as the fundamental principles behind them.
Download or read book TiO2 Nanoparticles written by Aiguo Wu and published by John Wiley & Sons. This book was released on 2020-06-02 with total page 252 pages. Available in PDF, EPUB and Kindle. Book excerpt: A unique book that summarizes the properties, toxicology, and biomedical applications of TiO2-based nanoparticles Nanotechnology is becoming increasingly important for products used in our daily lives. Nanometer-sized titanium dioxide (TiO2) are widely used in industry for different purposes, such as painting, sunscreen, printing, cosmetics, biomedicine, and so on. This book summarizes the advances of TiO2 based nanobiotechnology and nanomedicine, covering materials properties, toxicological research, and biomedical application, such as antibacter, biosensing, and cancer theranostics. It uniquely integrates the TiO2 applications from physical properties, toxicology to various biomedical applications, and includes black TiO2 based cancer theranostics. Beginning with a comprehensive introduction to the properties and applications of nanoparticles, TiO2 Nanoparticles: Applications in Nanobiotechnology, Theranostics and Nanomedicine offers chapters on: Toxicity of TiO2 Nanoparticles; Antibacterial Applications of TiO2 Nanoparticles; Surface Enhanced Raman Spectrum of TiO2 Nanoparticle for Biosensing (TiO2 Nanoparticle Served as SERS Sensing Substrate); TiO2 as Inorganic Photosensitizer for Photodynamic Therapy; Cancer Theranostics of Black TiO2 Nanoparticles; and Neurodegenerative Disease Diagnostics and Therapy of TiO2-Based Nanoparticles. This title: -Blends the physical properties, toxicology of TiO2 nanoparticles to the many biomedical applications -Includes black TiO2 based cancer theranostics in its coverage -Appeals to a broad audience of researchers in academia and industry working on nanomaterials-based biosensing, drug delivery, nanomedicine TiO2 Nanoparticles: Applications in Nanobiotechnology, Theranostics and Nanomedicine is an ideal book for medicinal chemists, analytical chemists, biochemists, materials scientists, toxicologists, and those in the pharmaceutical industry.
Download or read book Electrical and Optical Properties of Zinc Oxide for Scintillator Applications written by Xiaocheng Yang and published by . This book was released on 2008 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
