Download or read book Transition Metal Doped Semiconductor Quantum Dot Alloys written by Khalid M. Hanif and published by . This book was released on 2004 with total page 472 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Theoretical Insight Into the Manipulation of the Optical and Magnetic Properties of Transition metal doped II VI Semiconductor Quantum Dots written by Joseph William May and published by . This book was released on 2014 with total page 107 pages. Available in PDF, EPUB and Kindle. Book excerpt: The ability to tune the electronic, magnetic, and optical properties of II-VI semiconductor quantum dots (QDs) makes these materials ideal candidates in the fabrication of new solar energy, spin electronic, and phosphorescent devices. This dissertation makes use of electronic structure theory to provide insight into the physical underpinnings of magnetic exchange and photoexcitation in Mn2[superscript +]- and Co2[superscript +]-doped CdSe and ZnO QDs. Specifically, new methods for controlling these physical effects via the incorporation of various dopants or changes in the QD's size and shape are presented. Several examples of these control techniques are discussed in this dissertation. Ferromagnetic alignment of multiple unpaired Mn2[superscript +] 3d electrons is predicted when the p-type defect N2[superscript - ] is present in ZnO QDs. Control over the magnetic exchange interactions between charge carriers and TM2[superscript] dopants that give rise to ferromagnetism is achieved by distorting the QD's shape along one or two dimensions. Aliovalent doping with Al3[superscript +] produces QDs that are spectroscopically identical to photochemically charged QDs, yet exhibit different reactivities. A unique temperature dependence of the luminescence and photoconductivity in large Co2[superscript +] -doped ZnO QDs is predicted upon excitation of its mid-gap excited state. Lastly, a new method for the optimization of transition state molecular geometries is shown to exhibit fast optimization and to be advantageous for difficult optimizations where the reaction path is flat, ideal for optimizing large QD structures.
Download or read book Rare Earth and Transition Metal Doping of Semiconductor Materials written by Volkmar Dierolf and published by Woodhead Publishing. This book was released on 2016-01-23 with total page 472 pages. Available in PDF, EPUB and Kindle. Book excerpt: Rare Earth and Transition Metal Doping of Semiconductor Material explores traditional semiconductor devices that are based on control of the electron's electric charge. This book looks at the semiconductor materials used for spintronics applications, in particular focusing on wide band-gap semiconductors doped with transition metals and rare earths. These materials are of particular commercial interest because their spin can be controlled at room temperature, a clear opposition to the most previous research on Gallium Arsenide, which allowed for control of spins at supercold temperatures. Part One of the book explains the theory of magnetism in semiconductors, while Part Two covers the growth of semiconductors for spintronics. Finally, Part Three looks at the characterization and properties of semiconductors for spintronics, with Part Four exploring the devices and the future direction of spintronics. - Examines materials which are of commercial interest for producing smaller, faster, and more power-efficient computers and other devices - Analyzes the theory behind magnetism in semiconductors and the growth of semiconductors for spintronics - Details the properties of semiconductors for spintronics
Download or read book Atomic scale Modeling of Transition metal Doping of Semiconductor Nanocrystals written by Tejinder Singh and published by . This book was released on 2011 with total page 225 pages. Available in PDF, EPUB and Kindle. Book excerpt: Doping in bulk semiconductors (e.g., n- or p- type doping in silicon) allows for precise control of their properties and forms the basis for the development of electronic and photovoltaic devices. Recently, there have been reports on the successful synthesis of doped semiconductor nanocrystals (or quantum dots) for potential applications in solar cells and spintronics. For example, nanocrystals of ZnSe (with zinc-blende lattice structure) and CdSe and ZnO (with wurtzite lattice structure) have been doped successfully with transition-metal (TM) elements (Mn, Co, or Ni). Despite the recent progress, however, the underlying mechanisms of doping in colloidal nanocrystals are not well understood. This thesis reports a comprehensive theoretical analysis toward a fundamental kinetic and thermodynamic understanding of doping in ZnO, CdSe, and ZnSe quantum dots based on first-principles density-functional theory (DFT) calculations. The theoretical predictions of this thesis are consistent with experimental measurements and provide fundamental interpretations for the experimental observations. The mechanisms of doping of colloidal ZnO nanocrystals with the TM elements Mn, Co, and Ni is investigated. The dopant atoms are found to have high binding energies for adsorption onto the Zn-vacancy site of the (0001) basal surface and the O-vacancy site of the (0001) basal surface of ZnO nanocrystals; therefore, these surface vacancies provide viable sites for substitutional doping, which is consistent with experimental measurements. However, the doping efficiencies are affected by the strong tendencies of the TM dopants to segregate at the nanocrystal surface facets, as indicated by the corresponding computed dopant surface segregation energy profiles. Furthermore, using the Mn doping of CdSe as a case study, the effect of nanocrystal size on doping efficiency is explored. It is shown that Mn adsorption onto small clusters of CdSe is characterized by high binding energies, which, in conjunction with the Mn surface segregation characteristics on CdSe nanocrystals, explains experimental reports of high doping efficiency for small-size CdSe clusters. In addition, this thesis presents a systematic analysis of TM doping in ZnSe nanocrystals. The analysis focuses on the adsorption and surface segregation of Mn dopants on ZnSe nanocrystal surface facets, as well as dopant-induced nanocrystal morphological transitions, and leads to a fundamental understanding of the underlying mechanisms of dopant incorporation into growing nanocrystals. Both surface kinetics (dopant adsorption onto the nanocrystal surface facets) and thermodynamics (dopant surface segregation) are found to have a significant effect on the doping efficiencies in ZnSe nanocrystals. The analysis also elucidates the important role in determining the doping efficiency of ZnSe nanocrystals played by the chemical potentials of the growth precursor species, which determine the surface structure and morphology of the nanocrystals.
Download or read book Transition Metal Compounds written by Sajjad Haider and published by BoD – Books on Demand. This book was released on 2021-06-09 with total page 121 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book explores synthesis, structural changes, properties, and potential applications of transition metal (TM) compounds. Over three sections, chapters cover such topics as the synthesis of pentoxide vanadium (V2O5), the effect of TM compounds on structural, dielectric properties and high-temperature superconductors, and TM-doped nanocrystals (NCs).
Download or read book Quantum Dots written by Rakshit Ameta and published by Elsevier. This book was released on 2022-09-20 with total page 393 pages. Available in PDF, EPUB and Kindle. Book excerpt: Quantum Dots: Fundamentals, Synthesis and Applications compiles key information, along with practical guidance on quantum dot synthesis and applications. Beginning with an introduction, Part One highlights such foundational knowledge as growth mechanisms, shape and composition, electrochemical properties, and production scale-up for quantum dots. Part Two goes on to provide practical guides to key chemical, physical and biological methods for the synthesis of quantum dots, with Part Three reviewing the application of quantum dots and a range of important use cases, including photocatalysis, energy cells and medical imaging. Drawing on the knowledge of its expert authors, this comprehensive book provides practical guidance for all those who already study, develop or use quantum dots in their work. - Presents the foundational information needed to effectively understand and manipulate quantum dot properties - Consolidates key methods of quantum dot synthesis in a single volume - Reviews both current and future practical applications of quantum dots across a range of important fields
Download or read book Tuning Semiconducting and Metallic Quantum Dots written by Christian von Borczyskowski and published by CRC Press. This book was released on 2017-03-27 with total page 231 pages. Available in PDF, EPUB and Kindle. Book excerpt: Nanotechnology is one of the growing areas of this century, also opening new horizons for tuning optical properties. This book introduces basic tuning schemes, including those on a single quantum object level, with an emphasis on surface and interface manipulation of semiconducting and metallic quantum dots. There are two opposing demands in current forefront applications of quantum dots as optical labels, namely high luminescence stability (suppression of luminescence intermittency) and controllable intermittency and bleaching on a single-particle level to facilitate super-resolution optical microscopy (for which Eric Betzig, Stefan W. Hell, and William E. Moerner were awarded the 2014 Nobel Prize in Chemistry). The book discusses these contradictory demands with respect to both an understanding of the basic processes and applications. The chapters are a combination of scholarly presentation and comprehensive review and include case studies from the authors’ research, including unpublished results. Special emphasis is on a detailed understanding of spectroscopic and dynamic properties of semiconducting quantum dots. The book is suitable for senior undergraduates and researchers in the fields of optical nanoscience, materials science, and nanotechnology.
Download or read book Dissertation Abstracts International written by and published by . This book was released on 2007 with total page 924 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Simple Models of Magnetism written by Ralph Skomski and published by Oxford University Press on Demand. This book was released on 2008-01-17 with total page 366 pages. Available in PDF, EPUB and Kindle. Book excerpt: This volume presents introductory appendices and panels on quantum mechanics, statistical mechanics, and other topics.
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 Photoactive Semiconductor Nanocrystal Quantum Dots written by Alberto Credi and published by Springer. This book was released on 2017-01-20 with total page 179 pages. Available in PDF, EPUB and Kindle. Book excerpt: The series Topics in Current Chemistry Collections presents critical reviews from the journal Topics in Current Chemistry organized in topical volumes. The scope of coverage is all areas of chemical science including the interfaces with related disciplines such as biology, medicine and materials science. The goal of each thematic volume is to give the non-specialist reader, whether in academia or industry, a comprehensive insight into an area where new research is emerging which is of interest to a larger scientific audience. Each review within the volume critically surveys one aspect of that topic and places it within the context of the volume as a whole. The most significant developments of the last 5 to 10 years are presented using selected examples to illustrate the principles discussed. The coverage is not intended to be an exhaustive summary of the field or include large quantities of data, but should rather be conceptual, concentrating on the methodological thinking that will allow the non-specialist reader to understand the information presented. Contributions also offer an outlook on potential future developments in the field.
Download or read book Handbook of Semiconductors written by Ram K. Gupta and published by CRC Press. This book was released on 2024-07-10 with total page 396 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book provides readers with state-of-the-art knowledge of established and emerging semiconducting materials, their processing, and the fabrication of chips and microprocessors. In addition to covering the fundamentals of these materials, it details the basics and workings of many semiconducting devices and their role in modern electronics and explores emerging semiconductors and their importance in future devices. • Provides readers with latest advances in semiconductors. • Covers diodes, transistors, and other devices using semiconducting materials. • Covers advances and challenges in semiconductors and their technological applications. • Discusses fundamentals and characteristics of emerging semiconductors for chip manufacturing. This book provides directions to scientists, engineers, and researchers in materials engineering and related disciplines to help them better understand the physics, characteristics, and applications of modern semiconductors.
Download or read book Transition Metals Doped Nanocrystals written by Anielle Almeida Christine Almeida Silva and published by . This book was released on 2020 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: Doping is a technique that makes it possible to incorporate substitutional ions into the crystalline structure of materials, generating exciting properties. This book chapter will comment on the transition metals (TM) doped nanocrystals (NCs) and how doping and concentration influence applications and biocompatibility. In the NCs doped with TM, there is a strong interaction of sp-d exchange between the NCs,Äô charge carriers and the unpaired electrons of the MT, generating new and exciting properties. These doped NCs can be nanopowders or be embedded in glass matrices, depending on the application of interest. Therefore, we show the group results of synthesis, characterization, and applications of iron or copper-doped ZnO nanopowders and chromium-doped Bi2S3, nickel-doped ZnTe, and manganese-doped CdTe quantum dots in the glass matrices.
Download or read book Graphene Nanotubes and Quantum Dots Based Nanotechnology written by Yarub Al-Douri and published by Woodhead Publishing. This book was released on 2022-07-28 with total page 978 pages. Available in PDF, EPUB and Kindle. Book excerpt: A comprehensive look combining experimental and theoretical approaches to graphene, nanotubes, and quantum dots-based nanotechnology evaluation and development are including a review of key applications. Graphene, nanotubes, and quantum dots-based nanotechnology review the fundamentals, processing methods, and applications of this key materials system. The topics addressed are comprehensive including synthesis, preparation, both physical and chemical properties, both accepted and novel processing methods, modeling, and simulation. The book provides fundamental information on key properties that impact performance, such as crystal structure and particle size, followed by different methods to analyze, measure, and evaluate graphene, nanotubes, and quantum dots-based nanotechnology and particles. Finally, important applications are covered, including different applications of biomedical, energy, electronics, etc. Graphene, nanotubes, and quantum dots-based nanotechnology is appropriate for those working in the disciplines of nanotechnology, materials science, chemistry, physics, biology, and medicine. - Provides a comprehensive overview of key topics both on the experimental side and the theoretical - Discusses important properties that impact graphene, nanotubes, and quantum dots performance, processing methods both novel and accepted and important applications - Reviews the most relevant applications, such as biomedical, energy, electronics, and materials ones
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 Quantum Dots written by Ameenah Al-Ahmadi and published by BoD – Books on Demand. This book was released on 2012-04-04 with total page 294 pages. Available in PDF, EPUB and Kindle. Book excerpt: The book “Quantum dots: A variety of a new applications” provides some collections of practical applications of quantum dots. This book is divided into four sections. In section 1 a review of the thermo-optical characterization of CdSe/ZnS core-shell nanocrystal solutions was performed. The Thermal Lens (TL) technique was used, and the thermal self-phase Modulation (TSPM) technique was adopted as the simplest alternative method. Section 2 includes five chapters where novel optical and lasing application are discussed. In section 3 four examples of quantum dot system for different applications in electronics are given. Section 4 provides three examples of using quantum dot system for biological applications. This is a collaborative book sharing and providing fundamental research such as the one conducted in Physics, Chemistry, Biology, Material Science, Medicine with a base text that could serve as a reference in research by presenting up-to-date research work on the field of quantum dot systems.
Download or read book Transition Metal Doped Colloidal Semiconductor Nanocrystals written by Franziska Muckel and published by . This book was released on 2018 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
