Download or read book First principles Studies of Defects in Colloidal Nanocrystals written by Yun Liu (Ph.D.) and published by . This book was released on 2019 with total page 102 pages. Available in PDF, EPUB and Kindle. Book excerpt: Solar energy is one of the few renewable, low-carbon sources with both the maturity and accessibility to meet the ever-increasing global demand for energy. There are also accounting for an increasing percentage of our energy output due to increased adoption in both industrial and residential areas. Wafer based silicon photovolatics (PV) technology has dominated the solar market, whereby its price has increased significantly over the last decades. In order to fully capture the solar energy from the sun and extend the flexibility of PV technology, there is a need for constant innovation for new materials. Currently, there is a class pf emerging PV technologies that offer the potential of increased scalability, flexibility and lower prices. They include hybrid organic-inorganic lead halide perovskite PV, organic PV and colloidal quantum dot (CQD) PV. Colloidal quantum dots are semiconducting nanocrystals that exhibit size tunable electronic and optical properties. Owing to their versatility and facile synthesis, they have seen wide application photovoltaics, light emitting diodes, solar concentrators and bio-imaging. In particular, their PV power conversion efficiency has grown rapidly over the last 9 years from 3% to 16.6%. Despite the rapid progress, the search for better PV materials has been carried out almost exclusively through tremendous numbers of trial and error experiments. This is due to the fact that many fundamental aspects of the materials has not been fully understood, especially the role of defects and trap states. Due to the nature of wet chemistry synthesis, vacancies, intersitial and other extended defects inevitably form. These defects often cause in gap states within the semiconductor bandgap, which sensitively impact the performance of the PV devices. In addition, defects are difficult to measure directly using experimental techniques, and we often rely on spectroscopic and imaging to probe their properties indirectly. The core of the work described in this thesis deals with the theoretical understanding of nanocrystals with the goal of achieving a deeper and more fundamental understanding of the material's properties at the atomic scale, focusing on the roles of defects. To this end, we employ a technique of computational electronic structure calculation methods, namely density functional theory (DFT) calculations. In this thesis we will use DFT to investigate and find the role that defects play at controlling the 1) Stokes shift and 2) trap states in PbS quantum dot, as well as the 3) luminescent properties of CuAlS2 nanocrystals. While we show that points defects can cause excessive Stokes shift in single PbS CQDs, and dimer defects are a source of detrimental trap states in PbS CQD solids, the presence of point defects are the source of high luminescence in CuAl2 nanocrystals. We have also provided insights and design guidelines to control defects to design ever more efficient PV devices at an atomic level. This thesis document is organized as follows: Chapter 1 introduce CQD and their applications in PV and other optoelectronic devices. Chapter 2 summarizes the computational techniques employed in this thesis work. Chapter 3 focuses on the origins of the Stokes shift in PbS nanocrystal. Chapter 4 focuses on the PbS superlattice solids, and highlight the origin of trap states in these solids as due to the presence of dimers. Chapter 5 studies the defect physics of CuAlS2, and identifies the defect states responsible for the high photoluminescene.
Download or read book Defects in Nanocrystals written by Sergio Pizzini and published by CRC Press. This book was released on 2020-05-11 with total page 295 pages. Available in PDF, EPUB and Kindle. Book excerpt: Defects in Nanocrystals: Structural and Physico-Chemical Aspects discusses the nature of semiconductor systems and the effect of the size and shape on their thermodynamic and optoelectronic properties at the mesoscopic and nanoscopic levels. The nanostructures considered in this book are individual nanometric crystallites, nanocrystalline films, and nanowires of which the thermodynamic, structural, and optical properties are discussed in detail. The work: Outlines the influence of growth processes on their morphology and structure Describes the benefits of optical spectroscopies in the understanding of the role and nature of defects in nanostructured semiconductors Considers the limits of nanothermodynamics Details the critical role of interfaces in nanostructural behavior Covers the importance of embedding media in the physico-chemical properties of nanostructured semiconductors Explains the negligible role of core point defects vs. surface and interface defects Written for researchers, engineers, and those working in the physical and physicochemical sciences, this work comprehensively details the chemical, structural, and optical properties of semiconductor nanostructures for the development of more powerful and efficient devices.
Download or read book First principles Studies of Defect Dynamics in Crystalline Solids written by Anthony Yoshimura and published by . This book was released on 2020 with total page 40 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Principles and Applications of Chemical Defects written by Richard J.D. Tilley and published by CRC Press. This book was released on 1998-06-30 with total page 326 pages. Available in PDF, EPUB and Kindle. Book excerpt: The aim of this text is to provide some insight into chemical defects in crystalline solids. Chemical defects, which are mistakes or changes in the atomic make-up of the crystals, have far-reaching effects on the composition, optical properties and electronic properties of materials. The area is therefore of relevance to chemists, physicists, materials scientists and engineers. The book has been designed to be read by students with no prior knowledge of the subject, but with a background in basic chemistry and physics. It begins with relatively simple ideas but progresses into a discussion of complex materials, at the forefront of research in the field. The links between principles and applications have been strengthened in the text by the inclusion of a series of case studies. In addition, the crystal structures that are of most importance have been described throughout the book in a series of boxes, to provide a crystallographic reference within the text.
Download or read book Semiconductor Nanocrystals written by Alexander L. Efros and published by Springer Science & Business Media. This book was released on 2013-06-29 with total page 277 pages. Available in PDF, EPUB and Kindle. Book excerpt: A physics book that covers the optical properties of quantum-confined semiconductor nanostructures from both the theoretical and experimental points of view together with technological applications. Topics to be reviewed include quantum confinement effects in semiconductors, optical adsorption and emission properties of group IV, III-V, II-VI semiconductors, deep-etched and self assembled quantum dots, nanoclusters, and laser applications in optoelectronics.
Download or read book Functional Metal Oxides written by Satishchandra Balkrishna Ogale and published by John Wiley & Sons. This book was released on 2013-11-08 with total page 478 pages. Available in PDF, EPUB and Kindle. Book excerpt: Functional oxides are used both as insulators and metallic conductors in key applications across all industrial sectors. This makes them attractive candidates in modern technology ? they make solar cells cheaper, computers more efficient and medical instrumentation more sensitive. Based on recent research, experts in the field describe novel materials, their properties and applications for energy systems, semiconductors, electronics, catalysts and thin films. This monograph is divided into 6 parts which allows the reader to find their topic of interest quickly and efficiently. * Magnetic Oxides * Dopants, Defects and Ferromagnetism in Metal Oxides * Ferroelectrics * Multiferroics * Interfaces and Magnetism * Devices and Applications This book is a valuable asset to materials scientists, solid state chemists, solid state physicists, as well as engineers in the electric and automotive industries.
Download or read book Monte Carlo Methods for Radiation Transport written by Oleg N. Vassiliev and published by Springer. This book was released on 2016-10-17 with total page 292 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book is a guide to the use of Monte Carlo techniques in radiation transport. This topic is of great interest for medical physicists. Praised as a "gold standard" for accurate radiotherapy dose calculations, Monte Carlo has stimulated a high level of research activity that has produced thousands of papers within the past few years. The book is designed primarily to address the needs of an academically inclined medical physicist who wishes to learn the technique, as well as experienced users of standard Monte Carlo codes who wish to gain insight into the underlying mathematics of Monte Carlo algorithms. The book focuses on the fundamentals—giving full attention to and explaining the very basic concepts. It also includes advanced topics and covers recent advances such as transport of charged particles in magnetic fields and the grid-based solvers of the Boltzmann equation.
Download or read book Defects In Functional Materials written by Chi-chung Francis Ling and published by World Scientific. This book was released on 2020-08-21 with total page 338 pages. Available in PDF, EPUB and Kindle. Book excerpt: The research of functional materials has attracted extensive attention in recent years, and its advancement nitrifies the developments of modern sciences and technologies like green sciences and energy, aerospace, medical and health, telecommunications, and information technology. The present book aims to summarize the research activities carried out in recent years devoting to the understanding of the physics and chemistry of how the defects play a role in the electrical, optical and magnetic properties and the applications of the different functional materials in the fields of magnetism, optoelectronic, and photovoltaic etc.
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 Defects and Impurities in Silicon Materials written by Yutaka Yoshida and published by Springer. This book was released on 2016-03-30 with total page 498 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book emphasizes the importance of the fascinating atomistic insights into the defects and the impurities as well as the dynamic behaviors in silicon materials, which have become more directly accessible over the past 20 years. Such progress has been made possible by newly developed experimental methods, first principle theories, and computer simulation techniques. The book is aimed at young researchers, scientists, and technicians in related industries. The main purposes are to provide readers with 1) the basic physics behind defects in silicon materials, 2) the atomistic modeling as well as the characterization techniques related to defects and impurities in silicon materials, and 3) an overview of the wide range of the research fields involved.
Download or read book Liquid Crystal Colloids written by Igor Muševič and published by Springer. This book was released on 2017-05-14 with total page 313 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book brings together the many concepts and discoveries in liquid crystal colloids contributed over the last twenty years and scattered across numerous articles and book chapters. It provides both a historical overview of the development of the field and a clear perspective on the future applications in photonics. The book covers all phenomena observed in liquid crystal colloids with an emphasis on experimental tools and applications of topology in condensed matter, as well as practical micro-photonics applications. It includes a number of spectacular manifestations of new topological phenomena not found or difficult to observe in other systems. Starting from the early works on nematic colloids, it explains the basics of topological defects in ordered media, charge and winding, and the elastic forces between colloidal particles in nematics. Following a detailed description of experimental methods, such as optical tweezing and particle tracking, the book eases the reader into the theoretical part, which deals with elastic deformation of nematic liquid crystals due to inclusions and surface alignment. This is discussed in the context of basic mean field Landau-de Gennes Q-tensor theory, with a brief explanation of the free-energy minimization numerical methods. There then follows an excursion into the topology of complex nematic colloidal structures, colloidal entanglement, knotting and linking. Nematic droplets, shells, handlebodies and chiral topological structures are addressed in separate chapters. The book concludes with an extensive chapter on the photonic properties of nematic dispersions, presenting the concept of integrated soft matter photonics and discussing the concepts of nematic and chiral nematic microlasers, surface-sensitive photonic devices and smectic microfibers. The text is complemented by a large bibliography, explanatory sketches and beautiful micrographs.
Download or read book Metal Oxide Nanoparticles 2 Volume Set written by Oliver Diwald and published by John Wiley & Sons. This book was released on 2021-09-14 with total page 903 pages. Available in PDF, EPUB and Kindle. Book excerpt: Metal Oxide Nanoparticles A complete nanoparticle resource for chemists and industry professionals Metal oxide nanoparticles are integral to a wide range of natural and technological processes—from mineral transformation to electronics. Additionally, the fields of engineering, electronics, energy technology, and electronics all utilize metal oxide nanoparticle powders. Metal Oxide Nanoparticles: Formation, Functional Properties, and Interfaces presents readers with the most relevant synthesis and formulation approaches for using metal oxide nanoparticles as functional materials. It covers common processing routes and the assessment of physical and chemical particle properties through comprehensive and complementary characterization methods. This book will serve as an introduction to nanoparticle formulation, their interface chemistry and functional properties at the nanoscale. It will also act as an in-depth resource, sharing detailed information on advanced approaches to the physical, chemical, surface, and interface characterization of metal oxide nanoparticle powders and dispersions. Addresses the application of metal oxide nanoparticles and its economic impact Examines particle synthesis, including the principles of selected bottom-up strategies Explores nanoparticle formulation—a selection of processing and application routes Discusses the significance of particle surfaces and interfaces on structure formation, stability and functional materials properties Covers metal oxide nanoparticle characterization at different length scales With this valuable resource, academic researchers, industrial chemists, and PhD students can all gain insight into the synthesis, properties, and applications of metal oxide nanoparticles.
Download or read book Nanocrystal Quantum Dots written by Victor I. Klimov and published by CRC Press. This book was released on 2017-12-19 with total page 485 pages. Available in PDF, EPUB and Kindle. Book excerpt: A review of recent advancements in colloidal nanocrystals and quantum-confined nanostructures, Nanocrystal Quantum Dots is the second edition of Semiconductor and Metal Nanocrystals: Synthesis and Electronic and Optical Properties, originally published in 2003. This new title reflects the book’s altered focus on semiconductor nanocrystals. Gathering contributions from leading researchers, this book contains new chapters on carrier multiplication (generation of multiexcitons by single photons), doping of semiconductor nanocrystals, and applications of nanocrystals in biology. Other updates include: New insights regarding the underlying mechanisms supporting colloidal nanocrystal growth A revised general overview of multiexciton phenomena, including spectral and dynamical signatures of multiexcitons in transient absorption and photoluminescence Analysis of nanocrystal-specific features of multiexciton recombination A review of the status of new field of carrier multiplication Expanded coverage of theory, covering the regime of high-charge densities New results on quantum dots of lead chalcogenides, with a focus studies of carrier multiplication and the latest results regarding Schottky junction solar cells Presents useful examples to illustrate applications of nanocrystals in biological labeling, imaging, and diagnostics The book also includes a review of recent progress made in biological applications of colloidal nanocrystals, as well as a comparative analysis of the advantages and limitations of techniques for preparing biocompatible quantum dots. The authors summarize the latest developments in the synthesis and understanding of magnetically doped semiconductor nanocrystals, and they present a detailed discussion of issues related to the synthesis, magneto-optics, and photoluminescence of doped colloidal nanocrystals as well. A valuable addition to the pantheon of literature in the field of nanoscience, this book presents pioneering research from experts whose work has led to the numerous advances of the past several years.
Download or read book Energy Landscapes of Nanoscale Systems written by David J. Wales and published by Elsevier. This book was released on 2022-06-08 with total page 368 pages. Available in PDF, EPUB and Kindle. Book excerpt: Energy Landscapes of Nanoscale Systems provides a snapshot of the state-of-the-art in energy landscapes theory and applications. The book's chapters reflect diversity and knowledge transfer that is a key strength of the energy landscape approach. To reflect the breadth of this field, contributions include applications for clusters, biomolecules, crystal structure prediction and glassy materials. Chapters highlighting new methodologies, especially enhanced sampling techniques are included. In particular, the development and application of global optimization for structure prediction, methods for treating broken ergodicity on multifunnel landscapes, and treatment of rare event dynamics that reflect the state-of-the-art are featured. This book is an important reference source for materials scientists and energy engineers who want to understand more about how nanotechnology applies to the energy landscape approach. This volume is dedicated to Prof. Roy L. Johnston, who was formerly Co-Editor of the Frontiers of Nanoscience series, and who passed away in 2019. - Outlines applications and advances in theory and simulation of energy systems at the nanoscale - Explores how the energy landscapes approach is being applied to nanoscale materials - Assesses major challenges in applying nanomaterials for energy applications on an industrial scale
Download or read book Handbook of Nanophysics written by Klaus D. Sattler and published by CRC Press. This book was released on 2016-04-19 with total page 718 pages. Available in PDF, EPUB and Kindle. Book excerpt: In the 1990s, nanoparticles and quantum dots began to be used in optical, electronic, and biological applications. Now they are being studied for use in solid-state quantum computation, tumor imaging, and photovoltaics. Handbook of Nanophysics: Nanoparticles and Quantum Dots focuses on the fundamental physics of these nanoscale materials and struct
Download or read book Ordered Porous Solids written by Valentin Valtchev and published by Elsevier. This book was released on 2011-08-11 with total page 813 pages. Available in PDF, EPUB and Kindle. Book excerpt: The developments in the area of ordered nanoporous solids have moved beyond the traditional catalytic and separation uses and given rise to a wide variety of new applications in different branches of chemistry, physics, material science, etc. The activity in this area is due to the outstanding properties of nanoporous materials that have attracted the attention of researchers from different communities. However, recent achievements in a specific field often remain out of the focus of collaborating communities. This work summarizes the latest developments and prospects in the area of ordered porous solids, including synthetic layered materials (clays), microporous zeolite-type materials, ordered mesoporous solids, metal-organic-framework compounds (MOFs), carbon, etc. All aspects, from synthesis via comprehensive characterization to the advanced applications of ordered porous materials, are presented. The chapters are written by leading experts in their respective fields with an emphasis on recent progress and the state of the art. - Summarizes the latest developments in the field of ordered nanoporous solids - Presents state-of-the-art coverage of applications related to porous solids - Incorporates 28 contributions from experts across the disciplines
Download or read book Colloidal Metal Oxide Nanoparticles written by and published by Elsevier. This book was released on 2019-10-16 with total page 612 pages. Available in PDF, EPUB and Kindle. Book excerpt: Colloidal Metal Oxide Nanoparticles: Synthesis, Characterization and Applications is a one-stop reference for anyone with an interest in the fundamentals, synthesis and applications of this interesting materials system. The book presents a simple, effective and detailed discussion on colloidal metal oxide nanoparticles. It begins with a general introduction of colloidal metal oxide nanoparticles, then delves into the most relevant synthesis pathways, stabilization procedures, and synthesis and characterization techniques. Final sections discuss promising applications, including bioimaging, biosensing, diagnostic, and energy applications—i.e., solar cells, supercapacitors and environment applications—i.e., the treatment of contaminated soil, water purification and waste remediation. - Provides the most comprehensive resource on the topic, from fundamentals, to synthesis and characterization techniques - Presents key applications, including biomedical, energy, electronic and environmental - Discusses the most relevant techniques for synthesis, patterning and characterization
