Download or read book Charge Carrier Dynamics in Transition Metal Oxides Studied by Femtosecond Transient Extreme Ultraviolet Absorption Spectroscopy written by Chang-Ming Jiang and published by . This book was released on 2015 with total page 176 pages. Available in PDF, EPUB and Kindle. Book excerpt: With the ability to disentangle electronic transitions that occur on different elements and local electronic structures, time-resolved extreme ultraviolet (XUV) spectroscopy has emerged as a powerful tool for studying ultrafast dynamics in condensed phase systems. In this dissertation, a visible-pump/XUV-probe transient absorption apparatus with femtosecond resolution was constructed to investigate the carrier relaxation dynamics in semiconductors after photo-excitation. This includes timescales for carrier thermalization by carrier-carrier and carrier-phonon scattering. The 30 - 72 eV photon energy coverage (17 - 40 nm wavelength) generated by a table-top XUV light source is suitable for probing the 3p-to-3d core level absorptions of various transition metal oxides (TMOs) with specificities to elements and oxidation states. In Chapter 1, a brief introduction to charge carrier dynamics in semiconductor-based materials is given. In addition, fundamentals of core-level spectroscopy and the high harmonic generation (HHG) process are also addressed in this introductory chapter. Specifications of the experimental apparatus that was constructed are summarized in Chapter 2, including the design concepts and characterization of performance. Chapter 3 presents the spectral tunability of the XUV pulses generated from a semi-infinite gas cell (SIGC), as well as the data acquisition procedures. Charge carrier relaxation dynamics in Co3O4 following the charge transfer excitation pathway at 400 nm are documented in Chapter 4. In Chapter 5, various visible pump wavelengths are used to excite Co3O4 and the differences in the carrier dynamics versus excitation wavelength are considered. After selectively photoexciting a Si/TiO2 heterojunction, the resulted electron transfer process is observed and reported in Chapter 6. The concluding remarks of the dissertation are made in Chapter 7, while several ongoing time-resolved experiments are addressed in the Appendix sections.
Download or read book Ultrafast Photophysics of Transition Metal Coordination Complexes Studied with Femtosecond Extreme Ultraviolet Transient Absorption Spectroscopy written by Elizabeth S. Ryland 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 Watching Electrons Move in Metal Oxide Catalysts written by Somnath Biswas and published by . This book was released on 2020 with total page 170 pages. Available in PDF, EPUB and Kindle. Book excerpt: One of the most important steps in solar energy conversion process is to understand the interfacial charge separation. I have investigated interfacial charge transfer between Fe2O3 and NiO, two earth-abundant semiconductors. This study provides a first direct observation of exciton dissociation and charge separation. The details of this study had been described in Chapter 5.
Download or read book Ultrafast Transient Absorption Spectroscopy of Valley Carrier Dynamics in Atomically Thin Transition Metal Dichalcogenides written by Cong Mai and published by . This book was released on 2018 with total page 107 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Heterogeneous Photocatalysis written by Jennifer Strunk and published by John Wiley & Sons. This book was released on 2021-08-23 with total page 386 pages. Available in PDF, EPUB and Kindle. Book excerpt: Discover the latest research in photocatalysis combined with foundational topics in basic physical and chemical photocatalytic processes In Heterogeneous Photocatalysis: From Fundamentals to Applications in Energy Conversion and Depollution, distinguished researcher and editor Jennifer Strunk delivers a rigorous discussion of the two main topics in her field—energy conversion and depollution reactions. The book covers topics like water splitting, CO2 reduction, NOx abatement and harmful organics degradation. In addition to the latest research on these topics, the reference provides readers with fundamental information about elementary physical and chemical processes in photocatalysis that are extremely practical in this interdisciplinary field. It offers an excellent overview of modern heterogeneous photocatalysis and combines concepts from different viewpoints to allow researchers with backgrounds as varied as electrochemistry, material science, and semiconductor physics to begin developing solutions with photocatalysis. In addition to subjects like metal-free photocatalysts and photocarrier loss pathways in metal oxide absorber materials for photocatalysis explored with time-resolved spectroscopy, readers will also benefit from the inclusion of: Thorough introductions to kinetic and thermodynamic considerations for photocatalyst design and the logic, concepts, and methods of the design of reliable studies on photocatalysis Detailed explorations of in-situ spectroscopy for mechanistic studies in semiconductor photocatalysis and the principles and limitations of photoelectrochemical fuel generation Discussions of photocatalysis, including the heterogeneous catalysis perspective and insights into photocatalysis from computational chemistry Treatments of selected aspects of photoreactor engineering and defects in photocatalysis Perfect for photochemists, physical and catalytic chemists, electrochemists, and materials scientists, Heterogeneous Photocatalysis will also earn a place in the libraries of surface physicists and environmental chemists seeking up-to-date information about energy conversion and depollution reactions.
Download or read book X Ray Absorption and X Ray Emission Spectroscopy written by Jeroen A. van Bokhoven and published by John Wiley & Sons. This book was released on 2016-03-21 with total page 940 pages. Available in PDF, EPUB and Kindle. Book excerpt: During the last two decades, remarkable and often spectacular progress has been made in the methodological and instrumental aspects of x–ray absorption and emission spectroscopy. This progress includes considerable technological improvements in the design and production of detectors especially with the development and expansion of large-scale synchrotron reactors All this has resulted in improved analytical performance and new applications, as well as in the perspective of a dramatic enhancement in the potential of x–ray based analysis techniques for the near future. This comprehensive two-volume treatise features articles that explain the phenomena and describe examples of X–ray absorption and emission applications in several fields, including chemistry, biochemistry, catalysis, amorphous and liquid systems, synchrotron radiation, and surface phenomena. Contributors explain the underlying theory, how to set up X–ray absorption experiments, and how to analyze the details of the resulting spectra. X-Ray Absorption and X-ray Emission Spectroscopy: Theory and Applications: Combines the theory, instrumentation and applications of x-ray absorption and emission spectroscopies which offer unique diagnostics to study almost any object in the Universe. Is the go-to reference book in the subject for all researchers across multi-disciplines since intense beams from modern sources have revolutionized x-ray science in recent years Is relevant to students, postdocurates and researchers working on x-rays and related synchrotron sources and applications in materials, physics, medicine, environment/geology, and biomedical materials
Download or read book Two Dimensional Transition Metal Dichalcogenides written by Alexander V. Kolobov and published by Springer. This book was released on 2016-07-26 with total page 545 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book summarizes the current status of theoretical and experimental progress in 2 dimensional graphene-like monolayers and few-layers of transition metal dichalcogenides (TMDCs). Semiconducting monolayer TMDCs, due to the presence of a direct gap, significantly extend the potential of low-dimensional nanomaterials for applications in nanoelectronics and nano-optoelectronics as well as flexible nano-electronics with unprecedented possibilities to control the gap by external stimuli. Strong quantum confinement results in extremely high exciton binding energies which forms an interesting platform for both fundamental studies and device applications. Breaking of spatial inversion symmetry in monolayers results in strong spin-valley coupling potentially leading to their use in valleytronics. Starting with the basic chemistry of transition metals, the reader is introduced to the rich field of transition metal dichalcogenides. After a chapter on three dimensional crystals and a description of top-down and bottom-up fabrication methods of few-layer and single layer structures, the fascinating world of two-dimensional TMDCs structures is presented with their unique atomic, electronic, and magnetic properties. The book covers in detail particular features associated with decreased dimensionality such as stability and phase-transitions in monolayers, the appearance of a direct gap, large binding energy of 2D excitons and trions and their dynamics, Raman scattering associated with decreased dimensionality, extraordinarily strong light-matter interaction, layer-dependent photoluminescence properties, new physics associated with the destruction of the spatial inversion symmetry of the bulk phase, spin-orbit and spin-valley couplings. The book concludes with chapters on engineered heterostructures and device applications such as a monolayer MoS2 transistor. Considering the explosive interest in physics and applications of two-dimensional materials, this book is a valuable source of information for material scientists and engineers working in the field as well as for the graduate students majoring in materials science.
Download or read book 4D Electron Microscopy written by Ahmed H. Zewail and published by World Scientific. This book was released on 2010 with total page 359 pages. Available in PDF, EPUB and Kindle. Book excerpt: Structural phase transitions, mechanical deformations, and the embryonic stages of melting and crystallization are examples of phenomena that can now be imaged in unprecedented structural detail with high spatial resolution, and ten orders of magnitude as fast as hitherto. No monograph in existence attempts to cover the revolutionary dimensions that EM in its various modes of operation nowadays makes possible. The authors of this book chart these developments, and also compare the merits of coherent electron waves with those of synchrotron radiation. They judge it prudent to recall some important basic procedural and theoretical aspects of imaging and diffraction so that the reader may better comprehend the significance of the new vistas and applications now afoot. This book is not a vade mecum - numerous other texts are available for the practitioner for that purpose.
Download or read book Crystal Structure Electronic and Optical Properties of Epitaxial Alkaline Earth Niobate Thin Films written by Dongyang Wan and published by Springer. This book was released on 2017-09-18 with total page 133 pages. Available in PDF, EPUB and Kindle. Book excerpt: This impressive thesis offers a comprehensive scientific study of the alkaline earth niobates and describes their nonlinear optical properties for the first time. It explores the crystal structure, electrical properties, optical absorption properties, hot carrier dynamics, nonlinear optical property and strain-induced metal to insulator transition of alkaline earth niobates using advanced experimental techniques. These alkaline earth niobates can have a strong plasmon resonance in the visible range due to their large carrier density, and this unique property gives rise to the emergent phenomenon of photocatalysis and nonlinear optical properties. This series of intrinsic plasmonic materials based on niobates, can be used as a photocatalyst to split water under sunlight, a novel saturable absorber in the high-power ultrashort pulsed laser system, and as a sensor in microelectromechanical systems.
Download or read book Organic Solar Cells written by Wallace C.H. Choy and published by Springer Science & Business Media. This book was released on 2012-11-19 with total page 268 pages. Available in PDF, EPUB and Kindle. Book excerpt: Organic solar cells have emerged as new promising photovoltaic devices due to their potential applications in large area, printable and flexible solar panels. Organic Solar Cells: Materials and Device Physics offers an updated review on the topics covering the synthesis, properties and applications of new materials for various critical roles in devices from electrodes, interface and carrier transport materials, to the active layer composed of donors and acceptors. Addressing the important device physics issues of carrier and exciton dynamics and interface stability and novel light trapping structures, the potential for hybrid organic solar cells to provide high efficiency solar cells is examined and discussed in detail. Specific chapters covers key areas including: Latest research and designs for highly effective polymer donors/acceptors and interface materials Synthesis and application of highly transparent and conductive graphene Exciton and charge dynamics for in-depth understanding of the mechanism underlying organic solar cells. New potentials and emerging functionalities of plasmonic effects in OSCs Interface Degradation Mechanisms in organic photovoltaics improving the entire device lifetime Device architecture and operation mechanism of organic/ inorganic hybrid solar cells for next generation of high performance photovoltaics This reference can be practically and theoretically applied by senior undergraduates, postgraduates, engineers, scientists, researchers, and project managers with some fundamental knowledge in organic and inorganic semiconductor materials or devices.
Download or read book NEXAFS Spectroscopy written by Joachim Stöhr and published by Springer Science & Business Media. This book was released on 2013-04-17 with total page 415 pages. Available in PDF, EPUB and Kindle. Book excerpt: This is the first ever comprehensive treatment of NEXAFS spectroscopy. It is suitable for novice researchers as an introduction to the field, while experts will welcome the detailed description of state-of-the-art instrumentation and analysis techniques, along with the latest experimental and theoretical results.
Download or read book Lithium Niobate written by Tatyana Volk and published by Springer Science & Business Media. This book was released on 2008-09-13 with total page 258 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book covers new research on LiNbO3 including current studies on intrinsic and extrinsic point defects and the contribution of intrinsic defects to photoinduced charge transport. Applications of this material are also discussed.
Download or read book Charge and Energy Transfer Dynamics in Molecular Systems written by Volkhard May and published by John Wiley & Sons. This book was released on 2011-04-27 with total page 600 pages. Available in PDF, EPUB and Kindle. Book excerpt: This 3rd edition has been expanded and updated to account for recent developments, while new illustrative examples as well as an enlarged reference list have also been added. It naturally retains the successful concept of its predecessors in presenting a unified perspective on molecular charge and energy transfer processes, thus bridging the regimes of coherent and dissipative dynamics, and establishing a connection between classic rate theories and modern treatments of ultrafast phenomena. Among the new topics are: - Time-dependent density functional theory - Heterogeneous electron transfer, e.g. between molecules and metal or semiconductor surfaces - Current flows through a single molecule. While serving as an introduction for graduate students and researchers, this is equally must-have reading for theoreticians and experimentalists, as well as an aid to interpreting experimental data and accessing the original literature.
Download or read book Visualizing Chemistry written by National Research Council and published by National Academies Press. This book was released on 2006-06-01 with total page 222 pages. Available in PDF, EPUB and Kindle. Book excerpt: Scientists and engineers have long relied on the power of imaging techniques to help see objects invisible to the naked eye, and thus, to advance scientific knowledge. These experts are constantly pushing the limits of technology in pursuit of chemical imagingâ€"the ability to visualize molecular structures and chemical composition in time and space as actual events unfoldâ€"from the smallest dimension of a biological system to the widest expanse of a distant galaxy. Chemical imaging has a variety of applications for almost every facet of our daily lives, ranging from medical diagnosis and treatment to the study and design of material properties in new products. In addition to highlighting advances in chemical imaging that could have the greatest impact on critical problems in science and technology, Visualizing Chemistry reviews the current state of chemical imaging technology, identifies promising future developments and their applications, and suggests a research and educational agenda to enable breakthrough improvements.
Download or read book Advanced Computing written by Michael Bader and published by Springer Science & Business Media. This book was released on 2013-09-26 with total page 255 pages. Available in PDF, EPUB and Kindle. Book excerpt: This proceedings volume collects review articles that summarize research conducted at the Munich Centre of Advanced Computing (MAC) from 2008 to 2012. The articles address the increasing gap between what should be possible in Computational Science and Engineering due to recent advances in algorithms, hardware, and networks, and what can actually be achieved in practice; they also examine novel computing architectures, where computation itself is a multifaceted process, with hardware awareness or ubiquitous parallelism due to many-core systems being just two of the challenges faced. Topics cover both the methodological aspects of advanced computing (algorithms, parallel computing, data exploration, software engineering) and cutting-edge applications from the fields of chemistry, the geosciences, civil and mechanical engineering, etc., reflecting the highly interdisciplinary nature of the Munich Centre of Advanced Computing.
Download or read book Fundamentals of Semiconductors written by Peter YU and published by Springer Science & Business Media. This book was released on 2007-05-08 with total page 651 pages. Available in PDF, EPUB and Kindle. Book excerpt: Excellent bridge between general solid-state physics textbook and research articles packed with providing detailed explanations of the electronic, vibrational, transport, and optical properties of semiconductors "The most striking feature of the book is its modern outlook ... provides a wonderful foundation. The most wonderful feature is its efficient style of exposition ... an excellent book." Physics Today "Presents the theoretical derivations carefully and in detail and gives thorough discussions of the experimental results it presents. This makes it an excellent textbook both for learners and for more experienced researchers wishing to check facts. I have enjoyed reading it and strongly recommend it as a text for anyone working with semiconductors ... I know of no better text ... I am sure most semiconductor physicists will find this book useful and I recommend it to them." Contemporary Physics Offers much new material: an extensive appendix about the important and by now well-established, deep center known as the DX center, additional problems and the solutions to over fifty of the problems at the end of the various chapters.
Download or read book Heterogeneous Photocatalysis Using Inorganic Semiconductor Solids written by Umar Ibrahim Gaya and published by Springer Science & Business Media. This book was released on 2013-11-08 with total page 222 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book underscores the essential principles of photocatalysis and provides an update on its scientific foundations, research advances, and current opinions, and interpretations. It consists of an introduction to the concepts that form the backbone of photocatalysis, from the principles of solid-state chemistry and physics to the role of reactive oxidizing species. Having recognised the organic link with chemical kinetics, part of the book describes kinetic concepts as they apply to photocatalysis. The dependence of rate on the reaction conditions and parameters is detailed, the retrospective and prospective aspects of the mechanism of photocatalysis are highlighted, and the adsorption models, photocatalytic rate expressions, and kinetic disguises are examined. This book also discusses the structure, property, and activity relationship of prototypical semiconductor photocatalysts and reviews how to extend their spectral absorption to the visible region to enable the effective use of visible solar spectrum. Lastly, it presents strategies for deriving substantially improved photoactivity from semiconductor materials to support the latest applications and potential trends.
