Download or read book Colloidal Nanocrystal Assemblies written by Brian William Goodfellow and published by . This book was released on 2011 with total page 510 pages. Available in PDF, EPUB and Kindle. Book excerpt: Colloidal nanocrystal assemblies offer an attractive opportunity for designer metamaterials. The ability to permute chemical composition, size, shape, and arrangement of nanocrystals leads to an astounding number of unique materials properties that find use in an extensive array of applications---ranging from solar cells to medicine. However, to take full advantage of these materials in useful applications, the nature of their assembly and their behavior under external stimuli must be well understood. Additionally, the assembly of colloidal nanocrystals into thin films provides a promising pathway to the solution-processing of inorganic materials that are prohibitively too expensive and/or difficult to deposit by conventional methods. Nanocrystal superlattices (NCSLs) of sterically stabilized nanocrystals were assembled by slow evaporation of colloidal dispersions on various substrates. Detailed analysis of the NCSL structures was carried out using transmission and scanning electron microscopy (TEM and SEM) and small-angle x-ray scattering (SAXS). Body-centered cubic (bcc) NCSLs, in particular, were studied in detail and ligand packing frustration was proposed as a significant driving force for their assembly. The behavior of NCSLs was also studied by SAXS under mild heating and solvent vapor exposure revealing several remarkable order-order, order-disorder, and amorphous-crystalline structural transitions. Colloidal Cu(In [subscript 1-x] Ga [subscript x])Se2 (CIGS) nanocrystals were synthesized by arrested precipitation and formulated into inks. These inks were spray deposited into thin films under ambient conditions to serve as the active light absorbing material in printed low-cost photovoltaic (PV) devices. These devices, which were fabricated without the need for high temperature processes, have achieved power conversion efficiencies above 3 % under AM1.5 illumination. While the efficiencies of these devices are still too low for commercial viability, this work does provide a proof of concept that reasonable efficient solar cells can be created with a low-cost printable process using nanocrystal inks. Since high temperatures are not used to form the light-absorbing layer, nanocrystal-based solar cells were built on flexible light weight plastic substrates. The main obstacle to achieving high power conversation efficiencies was found to be the ability to extract the photo induced charge carriers. Nanocrystal films suffer from poor transport that leads to high recombination rates in thicker films. To date, the best efficiencies have been achieved with thin light absorber layers that only absorb a fraction of the incident light.

Download or read book Crystallization and Growth of Colloidal Nanocrystals written by Edson Roberto Leite and published by Springer Science & Business Media. This book was released on 2011-11-17 with total page 101 pages. Available in PDF, EPUB and Kindle. Book excerpt: Since the size, shape, and microstructure of nanocrystalline materials strongly impact physical and chemical properties, the development of new synthetic routes to nanocrystals with controlled composition and morphology is a key objective of the nanomaterials community. This objective is dependent on control of the nucleation and growth mechanisms that occur during the synthetic process, which in turn requires a fundamental understanding of both classical nucleation and growth and non-classical growth processes in nanostructured materials. Recently, a novel growth process called Oriented Attachment (OA) was identified which appears to be a fundamental mechanism during the development of nanoscale materials. OA is a special case of aggregation that provides an important route by which nanocrystals grow, defects are formed, and unique—often symmetry-defying—crystal morphologies can be produced. This growth mechanism involves reversible self-assembly of primary nanocrystals followed by reorientation of the assembled nanoparticles to achieve structural accord at the particle-particle interface, the removal of adsorbates and solvent molecules, and, finally, the irreversible formation of chemical bonds to produce new single crystals, twins, and intergrowths. Crystallization and Growth of Colloidal Nanocrystals provides a current understanding of the mechanisms related to nucleation and growth for use in controlling nanocrystal morphology and physical-chemical properties, and is essential reading for any chemist or materials scientist with an interest in using nanocrystals as building blocks for larger structures. This book provides a compendium for the expert reader as well as an excellent introduction for advanced undergraduate and graduate students seeking a gateway into this dynamic area of research.

Download or read book Oriented Self Assembly of Colloidal Semiconductor Nanoplatelets on Liquid Interfaces written by Onur Erdem and published by Springer Nature. This book was released on 2022-10-27 with total page 79 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book highlights the fabrication of orientation-controlled colloidal quantum well (nanoplatelet) thin films using liquid interface self-assembly. The book details methods for orientation-controlled deposition of CdSe core nanoplatelets for characterization of directional energy transfer in nanoplatelets and layer-by-layer construction of CdSe/CdZnS core/shell nanoplatelets to create optically active waveguides with precisely tunable thickness and excellent uniformity across device scale. It also provides a future outlook for construction of large-scale two- and three-dimensional nanoplatelet superstructures and their incorporation into device fabrication.

Download or read book Atomically Precise Nanochemistry written by Rongchao Jin and published by John Wiley & Sons. This book was released on 2023-06-12 with total page 533 pages. Available in PDF, EPUB and Kindle. Book excerpt: Explore recent progress and developments in atomically precise nanochemistry Chemists have long been motivated to create atomically precise nanoclusters, not only for addressing some fundamental issues that were not possible to tackle with imprecise nanoparticles, but also to provide new opportunities for applications such as catalysis, optics, and biomedicine. In Atomically Precise Nanochemistry, a team of distinguished researchers delivers a state-of-the-art reference for researchers and industry professionals working in the fields of nanoscience and cluster science, in disciplines ranging from chemistry to physics, biology, materials science, and engineering. A variety of different nanoclusters are covered, including metal nanoclusters, semiconductor nanoclusters, metal-oxo systems, large-sized organometallic nano-architectures, carbon clusters, and supramolecular architectures. The book contains not only experimental contributions, but also theoretical insights into the atomic and electronic structures, as well as the catalytic mechanisms. The authors explore synthesis, structure, geometry, bonding, and applications of each type of nanocluster. Perfect for researchers working in nanoscience, nanotechnology, and materials chemistry, Atomically Precise Nanochemistry will also benefit industry professionals in these sectors seeking a practical and up-to-date resource.

Download or read book Direct Observation of Colloidal Nanocrystals by Using Liquid Cell Transmission Electron Microscopy written by Jungwon Park and published by . This book was released on 2012 with total page 156 pages. Available in PDF, EPUB and Kindle. Book excerpt: Colloidal semiconductor and metal nanocyrstals receive attention from studying their physical properties to application in biology, electronics, optics, and catalyst. In addition, colloidal nanocrystals as artificial building blocks construct assemblies in solution phase and on substrate to exploit coupled properties of individual nanocrystals. A facile control of physical properties by tuning size, shape, and composition of nanocrystals can be achieved in solution phase synthetic protocols and now we have a library of literatures about them. However, most of nanocrystal synthesis and their use are developed empirically, perhaps in a lack of fundamental understanding. Growth kinetics during synthesis, motion and behavior of nanocrystals in liquid and at interfaces include many questions which await mechanistic studies. This dissertation explores direct observation of nanocrystals in liquid by using liquid cell transmission electron microscopy. Growth of nanocrystals from molecular precursor in solvent requires observation in atomistic resolution of a single particle level. Chapter 1 describes single particle growth trajectories of metal nanocrystals investigated by using graphene liquid cell in transmission electron microscopy. This cell is employed to achieve high-resolution imaging of colloidal platinum nanocrystal growth. The ability to directly image and resolve critical steps at atomistic resolution provides new insights into colloidal nanocrystal growth. Control of nanocrystal interaction and drying condition of solvent determines the final morphology of nanocrystal self-assembly. Chapter 2 presents direct imaging of nanocrystal motions in solution and real-time formation of two-dimensional nanocrystal superlattices by using liquid phase transmission electron microscopy. Nucleation and growth processes are introduced accompanying with detailed mechanistic steps and single particle trajectories. The important role of solvent fluctuation for self-assembly of nanocrystals is explored in experiment and coarse-grained lattice gas modeling. Concluding remarks are presented in Chapter 3.

Download or read book Interactions and Assemblies of Polymeric Materials and Colloidal Nanocrystals written by Teresa Elaine Williams and published by . This book was released on 2017 with total page 208 pages. Available in PDF, EPUB and Kindle. Book excerpt: Our need to reduce global energy use is well known and without question, not just from an economic standpoint but also to decrease human impact on climate change. Emerging advances in this area result from the ability to tailor-make materials and energy-saving devices using solution-phase chemistry and deposition techniques. Colloidally synthesized nanocrystals, with their tunable size, shape, and composition, and unusual optical and electronic properties, are leading candidates in these efforts. Because of recent advances in colloidal chemistries, the inventory of monodisperse nanocrystals has expanded to now include metals, semiconductors, magnetic materials, and dielectric materials. For a variety of applications, an active layer composed of a thin film of randomly close-packed nanocrystals is not ideal for optimized device performance; here, the ability to arrange these nano building units into mesoporous (2 nm

Download or read book Self Assembly of Nano and Micro structured Materials Using Colloidal Engineering written by Dwaipayan Chakrabarti and published by Elsevier. This book was released on 2019-04-25 with total page 184 pages. Available in PDF, EPUB and Kindle. Book excerpt: Self-assembly of Nano- and Micro-structured Materials Using Colloidal Engineering, Volume 12, covers the recent breakthroughs in the design and manufacture of functional colloids at the micro- and nanoscale level. In addition, it provides analyses on how these functionalities can be exploited to develop self-assembly pathways towards nano- and micro-structured materials. As we seek increasingly complex functions for colloidal superstructures, in silico design will play a critical role in guiding experimental fabrication by reducing the element of trial-and-error that would otherwise be involved. In addition to novel experimental approaches, recent developments in computational modelling are also presented, along with an overview of the arsenal of designing tools that are available to the modern materials scientist. Focuses on promoting feedback between experiment, theory and computation in this cross-disciplinary research area Shows how colloid science plays a crucial role in the bottom-up fabrication of nanostructured materials Presents recent developments in computational modelling

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 Semiconductor Nanocrystal Quantum Dots written by Andrey Rogach and published by Springer Science & Business Media. This book was released on 2008-09-02 with total page 374 pages. Available in PDF, EPUB and Kindle. Book excerpt: This is the first book to specifically focus on semiconductor nanocrystals, and address their synthesis and assembly, optical properties and spectroscopy, and potential areas of nanocrystal-based devices. The enormous potential of nanoscience to impact on industrial output is now clear. Over the next two decades, much of the science will transfer into new products and processes. One emerging area where this challenge will be very successfully met is the field of semiconductor nanocrystals. Also known as colloidal quantum dots, their unique properties have attracted much attention in the last twenty years.

Download or read book Nanoparticle Assemblies and Superstructures written by Nicholas A. Kotov and published by CRC Press. This book was released on 2016-04-19 with total page 648 pages. Available in PDF, EPUB and Kindle. Book excerpt: Cubes, triangular prisms, nano-acorn, nano-centipedes, nanoshells, nano-whiskers. . . . Now that we can create nanoparticles in a wide variety of shapes and morphologies, comes the next challenge: finding ways to organize this collection of particles into larger and more complex systems. Nanoparticle Assemblies and Superstructures, edit

Download or read book Assembly of Colloidal Nanocrystals Into Porous Nanomaterials written by Taisiia Berestok and published by . This book was released on 2018 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: This thesis focuses on different aspects of NCs colloidal synthesis, the exploration of the relevant surface chemistries that afford NC assembly and the NC implementation into porous nanomaterials. The work is divided into two blocks. The first block is devoted to developing and optimizing the synthesis of NCs followed by the examination of their suitability for potential applications in catalysis and photocatalysis. The second block is dedicated to establish procedures to fabricate single-component or multicomponent porous nanomaterials from NC building blocks. To embrace the use of the developed strategies in different application fields, several kind of materials were under research. Namely, metals (e.g. Au), metal oxides (e.g. CeO2, TiO2, Fe2O3), metal chalcogenides (e.g. In2S3, ZnS, PbS, CuGaS2 and Cu2ZnSnSe4), and their composites. CeO2 NCs synthesis was deeply investigated with the aim to achieve a proper control on the NCs morphology, facets exposed, crystal phase, composition, etc., required for application. Overall, CeO2 NCs with spherical, octapod-like branched, cubic hyperbranched, and kite-like morphology with sizes in the range 7 to 45 nm were produced by adjusting experimental conditions of the synthetic protocol. Branched and hyperbranched NCs showed higher surface areas, porosities and oxygen capacity storage values compared to quasi-spherical NCs. The NCs morphology-controlled synthesis has been extended to quaternary Cu2ZnSnSe4 (CZTSe). CZTSe NCs with narrow size distribution and controlled composition were produced. It was shown how off-stoichiometric CZTSe compositions were characterized by higher charge carrier concentrations and thus electrical conductivities. The strategy to functionalize the metal oxide NC surface composition by applying different ligands is proposed. This enables to develop a novel approach to assemble metal oxide NCs into porous gel and aerogel structures. Propylene oxide has been found to trigger the gelation process of glutamine functionalized NCs. The detailed investigation of the gelation mechanism is demonstrated for the case of ceria. The method is applied for NCs with different morphologies. Eventually, the versatility of the concept is proved by using of the proposed approach for the TiO2 and Fe2O3 nanocrystals. The assembly method has been extended to metal chalcogenides - In2S3 NCs - starting from the NCs synthesis, with further surface chemistry manipulation and eventually follows by the NC assembly into gels and aerogels. The optimization of NC surface chemistry was achieved by testing different ligand exchange approaches via applying short-chain organic and inorganic ligands. The assembly method based on ligand desorption from the NC surface and chalcogenide-chalcogenide bond formation has been established for In2S3. The comparison of the different ligands impact on the NC performance in colloidal form, when assembled into gels and when supported onto substrate is investigated towards photoelectrocatalysis. The oxidative ligand desorption assembly approach has been extended for multicomponent NCs for the case of CuGaS2 and CuGaS2-ZnS. Optimization of spin-coating process of the formed NCs inks followed by applying of sol-gel chemistry led to formation of highly porous layers from TGA-CuGaS2 and TGA-ZnS. Applied results of CuGaS2/ZnS nanocrystal-based bilayers and CuGaS2–ZnS nanocrystal-based composite layers have been shown by testing their photoelectrochemical energy conversion capabilities. The approach to adjust NC surface chemistry has been proposed and tested for performing multicomponent NC assemblies. Applying of different ligands for NC surface functionalization endows their surface with different charges which usually provides colloidal NCs stabilization. It has been found that mixing of oppositely charged NCs with certain concentration enabled their assembly/gelation via electrostatic interaction. The proposed approach has been applied and optimized to produce multicomponent NC gels and aerogels. The detailed investigation of the gelation mechanism is shown for combination of metal-metal oxide and metal oxide-metal chalcogenide NCs (Au-CeO2, CeO2-PbS). Applied results of the Au-CeO2 aerogels were demonstrated for CO-oxidation.

Download or read book Surface Chemistry of Colloidal Nanocrystals written by Ana Luísa Daniel-da-Silva and published by Royal Society of Chemistry. This book was released on 2021-02-08 with total page 221 pages. Available in PDF, EPUB and Kindle. Book excerpt: The chemistry of nanomaterials has developed considerably in the past two decades, and concepts that have emerged from these developments are now well established. The surface modification of nanoparticles is a subject of intense research interest given its importance for many applications across a number of disciplines. This comprehensive guide is the first to be devoted to the surface chemistry of inorganic nanocrystals. Following an introduction to the physical chemistry of surfaces, chapters cover topics such as the surface modification of nanoparticles, water compatible, polymer-based, and inorganic nanocomposites, as well as relevant applications in catalysis, biotechnology and nanomedicine. Highlighting recent advances, Surface Chemistry of Colloidal Nanocrystals provides an integrated approach to chemical aspects related to the surface of nanocrystals. Written by prestigious scientists, this will be a useful resource for students and researchers working in surface science, nanoscience and materials science as well as those interested in the applications of the nanomaterials in areas such as health science, biology, and environmental engineering.

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 Colloids and Colloid Assemblies written by Frank Caruso and published by John Wiley & Sons. This book was released on 2006-12-13 with total page 621 pages. Available in PDF, EPUB and Kindle. Book excerpt: Written by outstanding experts in the colloids field, this book deals with the recent developments in the synthesis, modification, utilization and application of colloids. The types covered range from metal nanoparticles through to inorganic particles and polymer latexes. Strategies for their modification to impart new properties will be outlined and ordered assemblies derived from colloid particles and some applications for colloids are shown. A multidisciplinary audience spread throughout academia and industry alike will certainly appreciate this first concise collection of knowledge in book form for this topic.

Download or read book Metal Nanocrystals written by Kallum M. Koczkur and published by American Chemical Society. This book was released on 2020-07-31 with total page 164 pages. Available in PDF, EPUB and Kindle. Book excerpt: Our society depends heavily on metals. They are ubiquitous construction materials, critical interconnects in integrated circuits, common coinage materials, and more. Excitingly, new uses for metals are emerging with the advent of nanoscience, as metal crystals with nanoscale dimensions can display new and tunable properties. The optical and photothermal properties of metal nanocrystals have led to cancer diagnosis and treatment platforms now in clinical trials, while, at the same time, the ability to tune the surface features of metal nanocrystals is giving rise to designer catalysts that enable more sustainable use of precious resources. These are just two examples of how metal nanocrystals are addressing important social needs.

Download or read book Semiconductor and Metal Nanocrystals written by Victor I. Klimov and published by CRC Press. This book was released on 2003-11-07 with total page 479 pages. Available in PDF, EPUB and Kindle. Book excerpt: The vast technological potential of nanocrystalline materials, as well as current intense interest in the physics and chemistry of nanoscale phenomena, has led to explosive growth in research on semiconductor nanocrystals, also known as nanocrystal quantum dots, and metal nanoparticles. Semiconductor and Metal Nanocrystals addresses current topics impacting the field including synthesis and assembly of nanocrystals, theory and spectroscopy of interband and intraband optical transitions, single-nanocrystal optical and tunneling spectroscopies, electrical transport in nanocrystal assemblies, and physical and engineering aspects of nanocrystal-based devices. Written by experts who have contributed pioneering research, this reference comprises key advances in the field of semiconductor nanocrystal quantum dots and metal nanoparticles over the past several years. Focusing specifically on nanocrystals generated through chemical techniques, Semiconductor and Metal Nanocrystals Merges investigative frontiers in physics, chemistry, and engineering Documents advances in nanocrystal synthesis and assembly Explores the theory of electronic excitations in nanoscale particles Presents comprehensive information on optical spectroscopy of interband and intraband optical transitions Reviews data on single-nanocrystal optical and tunneling spectroscopies Weighs controversies related to carrier relaxation dynamics in ultrasmall nanoparticles Discusses charge carrier transport in nanocrystal assemblies Provides examples of lasing and photovoltaic nanocrystal-based devices Semiconductor and Metal Nanocrystals is a must read for scientists, engineers, and upper-level undergraduate and graduate students interested in the physics and chemistry of nanoscale semiconductor and metal particles, as well as general nanoscale science. About the Editor: VICTOR I. KLIMOV is Team Leader, Softmatter Nanotechnology and Advanced Spectroscopy Team, Chemistry Division, Los Alamos National Laboratory, New Mexico. The recipient of the Los Alamos Fellows Prize (2000), he is a Fellow of the Alexander von Humboldt Foundation, leader of the Nanophotonics and Nanoelectronics Thrust of the Center for Integrated Nanotechnologies (U.S. Department of Energy), a member of the Los Alamos Board of Governors of the Institute for Complex Adaptive Matter, and a member of the Steering Committee for the Los Alamos Quantum Institute. He received the M.S. (1978), Ph.D. (1981), and Dr. Sci. (1993) degrees from Moscow State University, Russia.

Download or read book Optical and Structural Studies of Shape controlled Semiconductor Nanocrystals and Their Self assembled Solids written by Benjamin Tavenner Diroll and published by . This book was released on 2015 with total page 414 pages. Available in PDF, EPUB and Kindle. Book excerpt: Colloidal nanocrystals are prominent candidates to displace current electronic active layers in solid-state device technologies and offer a body of physics which diverges from those of bulk materials and discreet molecules. Realizing the potential of colloidal nanocrystals may transform the costs and performance of common technologies, but understanding of the relationship between particle size, shape, uniformity, and composition and outputs like physical properties or device performance is often incomplete. This work uses the controlled synthesis of anisotropic colloidal nanocrystals to implement characterization techniques including X-ray diffraction and simulation, which allows an ensemble-level description of particle structure, as well as polarized and time-resolved spectroscopy, which demonstrates subtle synthetic control over the properties of quantum-mechanical wavefunctions. Time- and temperature-resolved optical spectroscopy is employed to analyze the behavior of nanocrystal samples under more realistic device operating conditions and to determine the structure/property relationships that underpin improved performance. Highly-uniform samples of colloidal nanocrystals are self-assembled into large-area thin films. Discussion of self-assembly is placed within the context the fundamentals of self-assembly processes and the roadmap to high-performance devices based upon colloidal nanocrystals. X-ray diffraction and microscopic analysis are performed to analyze and qualify the structure of self-assembled films. These measurement techniques provide figures of merit for nanocrystal assemblies including the sample crystallinity and purity, surface coverage, homogeneity. Diffraction analysis is further used to measure alignment of nanocrystal assemblies with respect to a substrate and the orientation of individual particles within assemblies. Monodisperse anisotropic building blocks encode the unique optoelectronic properties of isolated nanocrystals into solid state materials with long-range structural orientation.