Download or read book Novel Synthesis Routes to Colloidal Nanocrystals of Semiconductive Metal Pnictides and Metal Halides written by Georgian Nedelcu and published by . This book was released on 2019 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Colloidal Semiconductor Nanocrystals Synthesis Properties and Applications written by Vladimir Lesnyak and published by Frontiers Media SA. This book was released on 2020-01-06 with total page 110 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book The Colloidal Chemistry Synthesis and Electron Microscopy Characterization of Shape controlled Metal and Semiconductor Nanocrystals written by Adam Biacchi and published by . This book was released on 2014 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Solution methods of materials synthesis have found application in a variety of fields due to the diversity of products accessible, facility of process scalability, and the ease of tuning their properties through prudent selection of reaction conditions. Control of experimental variables during the formation of colloidally stable nanoscale solids within a liquid matrix allows for tailoring of the particles' characteristics, including shape, size, composition, and surface chemistry. In this dissertation, I will discuss how the manipulation of reaction chemistries can be used to synthesize shape-controlled metal and semiconductor colloidal nanocrystals. Further, I will elaborate on the mechanisms by which these particles form from molecular precursors and describe how their properties can differ from their bulk analogues through extensive characterization, especially using transmission electron microscopy. These studies contribute to the continued development of chemical routes to nanocrystals and their application as functional materials.First, I will review recent advances in the synthesis and characterization of shape-controlled nanocrystals, as well as highlight their promising applicability in a number of emerging technologies. These principles will then be leveraged to the specific case of catalytically-active rhodium nanocrystals, which can be synthesized with morphological and dimensional control using a polyol solution-mediated strategy. I describe an innovative shape-controlled synthesis to monodisperse colloidal rhodium icosahedra, cubes, triangular plates, and octahedra using this route. Additionally, new insights into the important role of the polyol reducing solvent on the synthesis of these nanocrystals are revealed, and how these might be exploited to engender superior reaction control and novel products.Next, I will describe how a crystallization mechanism was established for the synthesis of numerous morphologies of noble metal nanocrystals. I present a thorough analysis of the synthesis of shape-controlled rhodium nanocrystals, using extensive transmission electron microscopy characterization, and relate these findings to one of the primary synthetic levers available in the polyol synthesis: the anionic ligands present. Further, I show that the crystallization process proceeds by a nonclassical mechanism in which cluster particles serve as a stable intermediate between molecular precursors and the final product. I then apply these principles to the shape-controlled synthesis of other noble metal nanocrystals before expounding a generalized formation mechanism in the polyol synthesis of colloidal metal nanocrystals. Finally, I will highlight my efforts in the designed synthesis and characterization of colloidal tin(II) sulfide (SnS) semiconducting "quantum dot" nanocrystals. I describe a route for the solution synthesis of monodisperse colloidal SnS nanosheets, nanocubes, and nanospherical polyhedra in high yield. Further, detailed crystallographic characterization of these nanocrystals using transmission electron microscopy indicates that their atomic structure possesses a previously-unreported nanoscale deviation from the bulk phase. Additionally, I show that their electronic and photocatalytic properties of these quantum dots are both shape-dependent and distinct from bulk SnS.

Download or read book Synthesis of New Nanocrystal Materials written by Yasser Hassan Abd El-Fattah Hassan and published by . This book was released on 2016 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Abstract Colloidal semiconductor nanocrystals (NCs) have sparked great excitement in the scientific community in last two decades. NCs are useful for both fundamental research and technical applications in various fields owing to their size and shape-dependent properties and their potentially inexpensive and excellent chemical processability. These NCs are versatile fluorescence probes with unique optical properties, including tunable luminescence, high extinction coefficient, broad absorption with narrow photoluminescence, and photobleaching resistance. In the past few years, a lot of attention has been given to nanotechnology based on using these materials as building blocks to design light harvesting assemblies. For instant, the pioneering applications of NCs are light-emitting diodes, lasers, and photovoltaic devices. Synthesis of the colloidal stable semiconductor NCs using the wet method of the pyrolysis of organometallic and chalcogenide precursors, known as hot-injection approach, is the chart-topping preparation method in term of high quality and monodisperse sized NCs. The advancement in the synthesis of these artificial materials is the core step toward their applications in a broad range of technologies. This dissertation focuses on exploring various innovative and novel synthetic methods of different types of colloidal nanocrystals, both inorganic semiconductors NCs, also known as quantum dots (QDs), and organic-inorganic metal halide-perovskite materials, known as perovskites. The work presented in this thesis focuses on pursuing fundamental understanding of the synthesis, material properties, photophysics, and spectroscopy of these nanostructured semiconductor materials. This thesis contains 6 chapters and conclusions. Chapters 1ď 3 focus on introducing theories and background of the materials being synthesized in the thesis. Chapter 4 demonstrates our synthesis of colloidal linker-free TiO2/CdSe NRs heterostructures with CdSe QDs grown in the presence of TiO2 NRs using seededâ growth type colloidal injection approach. Chapter 5 explores a novel approach of directly synthesized CdSe NCs with electroactive ligands. The last Chapter focuses on a new class of perovskites. I describe my discovery of a (bottom-up) simple method to synthesize colloidally stable methyl ammonium lead halide perovskite nanocrystals seeded from high quality PbX2 NCs with a pre-targeted size. This chapter reports advances in preparation of both these materials (PbX2, and lead halide perovskite NCs).

Download or read book Novel Synthetic Routes to High quality II VI Colloidal Nanocrystals written by Nathan E. Stott and published by . This book was released on 2004 with total page 175 pages. Available in PDF, EPUB and Kindle. Book excerpt: Nanometer-sized colloidal quantum dots, or nanocrystals, are of current scientific interest based on their mesoscopic properties as an intermediate state between molecular and bulk materials. Particles sizes of semiconductor materials smaller than the Bohr exciton radius result in a quantum confinement effect that allows the optical properties to be tuned within the band energies of the bulk material such that smaller sizes lead to higher energy transitions at the band edge. The small sizes and tunable monochromatic emission properties make these nanocrystals desirable for a variety of applications, both realized and sought after. Research to further the exploitation of quantum dots includes such applications as biological fluorescence tracer tags and imaging agents, high resolution displays, light emitting diodes (LEDs), low bandwidth lasers, photovoltaic solar cells, and future "nanoelectronics." The thesis of this dissertation is that high-quality II-VI colloidal nanocrystals, CdSe and (CdSe)ZnS in particular, can be synthesized using mild precursors, exerting fine control though the proper selection of ligands. Chapters 2 and 3 show that extremely high-quality CdSe nanocrystals can be synthesized using mild precursors such as Cd(acac)2 and Cd(OH)2 while achieving higher quantum efficiencies, higher reaction yields, smaller size-distributions, and with finer control over the final size in comparison to previous methods. In addition to the batch synthesis, Chapter 3 shows the development of a microfluidic flow reactor using a mixed highboiling STP liquid solvent. It is found that the temperature, flow rate, and precursor ratios are parameters that can be used to control the size and size-distributions of the final products. The CdSe cores are overcoated with ZnS from Zn(acac)2 to form highly stable and highly luminescent (core)shell colloids in Chapter 4. Chapter 5 develops qualitative arguments based on the Drago-Wayland extension of Hard-Soft Acid-Base Theory to describe the actions of surfactant ligands in the growth solution. It is shown that crystal growth inhibitors can be used to finely control nanocrystal growth, and the precursor-to-inhibitor ratio is fundamental to the final size.

Download or read book Synthesis and Characterization of Semiconductor and Semiconductor metal Nanoparticles written by Elena Selishcheva and published by . This book was released on 2011 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: This work is a contribution to the development of colloidal synthesis of different nanomaterials, such as lead chalcogenide, indium oxide nanoparticles, and hybrid nanostructures, consisting of copper indium sulfide selenide and gold nanoparticles. In the first part, nearly monodispersePbE (E=S, Se, Te) semiconductor nanoparticles produced via a novel synthesis which includes the occurrence of in situ formed Pb0-particles are shown. Spherical PbSe nanoparticles are further investigated with respect to possible application in hybrid solar cells. The second part is about a novel non-injection synthesis route for the preparation of colloidal In2O3 nanocrystals. The shape of the nanocrystals can be influenced by the addition of copper ions. Finally, the selective growth of gold nanocrystals onto CuInSSe nanoparticles to form semiconductor/metal hybrid nanostructures is demonstrated. During the synthesis gold nanocrystals grow onto vertexes of CuInSSe pyramids. engl.

Download or read book Novel Routes to the Synthesis and Functionalization of Metallic and Semiconductor Thin Films and Nanoparticles written by Hanan Al Chaghouri and published by . This book was released on 2014 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Chemical Routes to Colloidal Chalcogenide Nanosheets written by and published by . This book was released on 2015 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: This project sought to develop new low-temperature synthetic pathways to intermetallic and chalcogenide nanostructures and powders, with an emphasis on systems that are relevant to advancing the synthesis, processing, and discovery of superconducting materials. The primary synthetic routes involved solution chemistry methods, and several fundamental synthetic challenges that underpinned the formation of these materials were identified and investigated. Methods for incorporating early transition metals and post transition metals into nanoscale and bulk crystals using low-temperature solution chemistry methods were developed and studied, leading to colloidal nanocrystals of elemental indium, manganese, and germanium, as well as nanocrystalline and bulk intermetallic compounds containing germanium, gallium, tin, indium, zinc, bismuth, and lithium. New chemical tools were developed to help target desired phases in complex binary intermetallic and metal chalcogenide systems that contain multiple stable phases, including direct synthesis methods and chemical routes that permit post-synthetic modification. Several phases that are metastable in bulk systems were targeted, synthesized, and characterized as nanocrystalline solids and bulk powders, including the L12-type intermetallic compounds Au3Fe, Au3Ni, and Au3Co, as well as wurtzite-type MnSe. Methods for accessing crystalline metal borides and carbides using direct solution chemistry methods were also developed, with an emphasis on Ni3B and Ni3C, which revealed useful correlations of composition and magnetic properties. Methods for scale-up and nanoparticle purification were explored, providing access to centimeter-scale pressed pellets of polyol-synthesized nanopowders and a bacteriophage-mediated method for separating impure nanoparticle mixtures into their components. Several advances were made in the synthesis of iron selenide and related superconducting materials, including the production of colloidal FeSe nanosheets and a post-synthetic method for selectively leaching excess selenium from chalcogen-rich Fe-Se samples to precisely target the desired superconducting FeSe polymorph. The insights into FeSe nanosheet formation were applied to other metal chalcogenide systems, including SnSe, SnS, GeSe, and GeS, which led to advances in the synthesis and characterization of 0D, 1D, 2D, and 3D metal chalcogenide nanostructures, including morphology-dependent crystal structures in the SnS system.

Download or read book Methods of Synthesis of Colloidal Nanoparticles written by Jeffrey A. Gerbec and published by . This book was released on 2006 with total page 356 pages. Available in PDF, EPUB and Kindle. Book excerpt: Colloidal semiconductor nanocrystals, with unique size-dependent optical properties, have great promise for integration into next generation technologies including solid-state lighting and biological labeling. A general method of reproducible, large scale and environmentally safe synthetic preparation becomes crucial for integration in commercial devices. In addition to the synthetic protocol, an understanding of the surfaces of the as prepared material is critical for obtaining a high quantum yield that is stable for long periods of time in ambient conditions. In this dissertation, a new synthetic approach to general colloidal nanocrystals is presented. Microwave heating of molecular precursors increases the rate of reaction from days to minutes for a host of nanomaterials. The most relevant for the study of inorganic phosphors is CdSe and InP and their respective ternary analogs. Post synthetic surface treatment of the as prepared material show a tremendous increase in the QY for as prepared InP and InGaP. Post synthetic surface treatment is carried out by photoactivated etching with dilute HF. In the case of InGaP, the QY reaches 0.80 from 0.05 in a matter of minutes. Other surface treatment strategies that address the stability is carried out by forming epitaxial core shell structures. It is shown that using ZnS as a wide band gap shelling material, the QY of InP reaches 0.42 in solution and is stable for months. These are significant steps toward the engineering of semiconductor quantum dot phosphors for solid state lighting and biological labeling.

Download or read book Nanocrystals written by C.N.R. Rao and published by Springer Science & Business Media. This book was released on 2007-04-03 with total page 187 pages. Available in PDF, EPUB and Kindle. Book excerpt: This is the most comprehensive book on nanocrystals on the market. It is an up-to-date monograph on an important aspect of nanoscience and technology. It opens with an elegant introduction including a brief historical account. Emphasis is then given to diverse synthetic methods, both chemical and physical, in addition to modern hybrid methods. Tables providing information at a glance, cartoons and schematic diagrams, make the monograph appealing to read.

Download or read book Perovskite Materials written by Likun Pan and published by BoD – Books on Demand. This book was released on 2016-02-03 with total page 652 pages. Available in PDF, EPUB and Kindle. Book excerpt: The book summarizes the current state of the know-how in the field of perovskite materials: synthesis, characterization, properties, and applications. Most chapters include a review on the actual knowledge and cutting-edge research results. Thus, this book is an essential source of reference for scientists with research fields in energy, physics, chemistry and materials. It is also a suitable reading material for graduate students.

Download or read book Synthesis of Inorganic Nanomaterials written by Sneha Bhagyaraj and published by Woodhead Publishing. This book was released on 2018-06-29 with total page 314 pages. Available in PDF, EPUB and Kindle. Book excerpt: Synthesis of Inorganic Nanomaterials: Advances and Key Technologies discusses the latest advancements in the synthesis of various types of nanomaterials. The book's main objective is to provide a comprehensive review regarding the latest advances in synthesis protocols that includes up-to-date data records on the synthesis of all kinds of inorganic nanostructures using various physical and chemical methods. The synthesis of all important nanomaterials, such as carbon nanostructures, Core-shell Quantum dots, Metal and metal oxide nanostructures, Nanoferrites, polymer nanostructures, nanofibers, and smart nanomaterials are discussed, making this a one-stop reference resource on research accomplishments in this area. Leading researchers from industry, academia, government and private research institutions across the globe have contributed to the book. Academics, researchers, scientists, engineers and students working in the field of polymer nanocomposites will benefit from its solutions for material problems. - Provides an up-to-date data record on the synthesis of all kinds of organic and inorganic nanostructures using various physical and chemical methods - Presents the latest advances in synthesis protocols - Includes the latest techniques used in the physical and chemical characterization of nanomaterials - Covers the characterization of all the important materials groups, such as carbon nanostructures, core-shell quantum dots, metal and metal oxide nanostructures, Nano ferrites, polymer nanostructures and nanofibers

Download or read book Colloidal Quantum Dot Optoelectronics and Photovoltaics written by Gerasimos Konstantatos and published by Cambridge University Press. This book was released on 2013-11-07 with total page 329 pages. Available in PDF, EPUB and Kindle. Book excerpt: Captures the most up-to-date research in the field, written in an accessible style by the world's leading experts.

Download or read book Halide Perovskites written by Tze-Chien Sum and published by John Wiley & Sons. This book was released on 2019-03-25 with total page 312 pages. Available in PDF, EPUB and Kindle. Book excerpt: Real insight from leading experts in the field into the causes of the unique photovoltaic performance of perovskite solar cells, describing the fundamentals of perovskite materials and device architectures. The authors cover materials research and development, device fabrication and engineering methodologies, as well as current knowledge extending beyond perovskite photovoltaics, such as the novel spin physics and multiferroic properties of this family of materials. Aimed at a better and clearer understanding of the latest developments in the hybrid perovskite field, this is a must-have for material scientists, chemists, physicists and engineers entering or already working in this booming field.

Download or read book NASA Glenn Coefficients for Calculating Thermodynamic Properties of Individual Species written by Bonnie J. McBride and published by . This book was released on 2002 with total page 300 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Oxide Electronics written by Asim K. Ray and published by John Wiley & Sons. This book was released on 2021-04-12 with total page 628 pages. Available in PDF, EPUB and Kindle. Book excerpt: Oxide Electronics Multiple disciplines converge in this insightful exploration of complex metal oxides and their functions and properties Oxide Electronics delivers a broad and comprehensive exploration of complex metal oxides designed to meet the multidisciplinary needs of electrical and electronic engineers, physicists, and material scientists. The distinguished author eschews complex mathematics whenever possible and focuses on the physical and functional properties of metal oxides in each chapter. Each of the sixteen chapters featured within the book begins with an abstract and an introduction to the topic, clear explanations are presented with graphical illustrations and relevant equations throughout the book. Numerous supporting references are included, and each chapter is self-contained, making them perfect for use both as a reference and as study material. Readers will learn how and why the field of oxide electronics is a key area of research and exploitation in materials science, electrical engineering, and semiconductor physics. The book encompasses every application area where the functional and electronic properties of various genres of oxides are exploited. Readers will also learn from topics like: Thorough discussions of High-k gate oxide for silicon heterostructure MOSFET devices and semiconductor-dielectric interfaces An exploration of printable high-mobility transparent amorphous oxide semiconductors Treatments of graphene oxide electronics, magnetic oxides, ferroelectric oxides, and materials for spin electronics Examinations of the calcium aluminate binary compound, perovoksites for photovoltaics, and oxide 2Degs Analyses of various applications for oxide electronics, including data storage, microprocessors, biomedical devices, LCDs, photovoltaic cells, TFTs, and sensors Suitable for researchers in semiconductor technology or working in materials science, electrical engineering, and physics, Oxide Electronics will also earn a place in the libraries of private industry researchers like device engineers working on electronic applications of oxide electronics. Engineers working on photovoltaics, sensors, or consumer electronics will also benefit from this book.

Download or read book Thermoelectric Materials and Devices written by Iris Nandhakumar and published by Royal Society of Chemistry. This book was released on 2017 with total page 269 pages. Available in PDF, EPUB and Kindle. Book excerpt: Authoritative account of recent developments in thermoelectric materials and devices for power energy harvesting applications, ideal for researchers and industrialists in materials science.