Download or read book Spectroscopy of Molecular Excitons written by Vladimir L. Broude and published by Springer. This book was released on 1985 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: Low-temperature spectroscopy of organic molecular crystals came into being in the late 20s, just when quantum physics of solids as a whole began to de velop vigorously. Already in the early works, two experimental facts of prime importance were discovered: the presence of a multitude of narrow bands in the low-temperature spectrum of a crystal, and a close relationship between the spectrum of the crystal and that of the constituent molecules. These findings immediately preceded the celebrated paper of Frenkel in which he went beyond the framework of Bloch's scheme and advanced the exciton concept. Subsequent investigations showed that the most interesting features of the spectra of molecular crystals are associated with excitons, and then the spectroscopy of molecular excitons began to form gradually on the basis of the spectroscopy of organic crystals. The molecular exciton became synonymous to the Frenkel exciton in a molecular crystal. In view of the difficulties involved in the analysis of rich spectra con taining many tens of bands, the spectroscopy of molecular crystals had long been connected most closely with the spectroscopy of molecules. It had deve loped independently, to a large extent, from the other branches of solid state physics. This was also emphasized by the difference in experimental techniques, the specific properties of the objects, etc. As a result, there was some lag in ideas and concepts.
Download or read book Spectroscopy of Molecular Excitons written by Vladimir L. Broude and published by Springer. This book was released on 1985-09-01 with total page 274 pages. Available in PDF, EPUB and Kindle. Book excerpt: Low-temperature spectroscopy of organic molecular crystals came into being in the late 20s, just when quantum physics of solids as a whole began to de velop vigorously. Already in the early works, two experimental facts of prime importance were discovered: the presence of a multitude of narrow bands in the low-temperature spectrum of a crystal, and a close relationship between the spectrum of the crystal and that of the constituent molecules. These findings immediately preceded the celebrated paper of Frenkel in which he went beyond the framework of Bloch's scheme and advanced the exciton concept. Subsequent investigations showed that the most interesting features of the spectra of molecular crystals are associated with excitons, and then the spectroscopy of molecular excitons began to form gradually on the basis of the spectroscopy of organic crystals. The molecular exciton became synonymous to the Frenkel exciton in a molecular crystal. In view of the difficulties involved in the analysis of rich spectra con taining many tens of bands, the spectroscopy of molecular crystals had long been connected most closely with the spectroscopy of molecules. It had deve loped independently, to a large extent, from the other branches of solid state physics. This was also emphasized by the difference in experimental techniques, the specific properties of the objects, etc. As a result, there was some lag in ideas and concepts.
Download or read book Dynamics of Molecular Excitons written by Seogjoo J. Jang and published by Elsevier. This book was released on 2020-05-13 with total page 242 pages. Available in PDF, EPUB and Kindle. Book excerpt: Dynamics of Molecular Excitons provides a comprehensive, but concise description of major theories on the dynamics of molecular excitons, intended to serve as a self-contained resource on the topic. Designed to help those new to this area gain proficiency in this field, experts will also find the book useful in developing a deeper understanding of the subject. The starting point of the book is the standard microscopic definition of molecular Hamiltonians presented in commonly accepted modern quantum mechanical notations. Major assumptions and approximations involved in constructing Frenkel-type exciton Hamiltonians, which are well established, but are often hidden under arcane notations and approximations of old publications, are presented in detail. This will help quantum chemists understand the major assumptions involved in the definition of commonly used exciton models. Rate theories of exciton dynamics, such as Förster and Dexter theories and their modern generalizations, are presented in a unified and detailed manner. In addition, important aspects that are often neglected, such as local field effect and the role of fluctuating environments, are discussed. Various quantum dynamics methods allowing coherent dynamics of excitons are presented in a systematic manner in the context of quantum master equations or path integral formalisms. The author also provides a detailed theoretical explanation for the major spectroscopic techniques probing exciton dynamics, including modern two-dimensional electronic spectroscopy, with a critical assessment of the implications of these spectroscopic measurements. Finally, the book includes a brief overview of major applications including an explanation of organic photovoltaic materials and natural light harvesting complexes. Covers major theories of exciton dynamics in a consciously concise and easily readable way Bridges the gap between quantum dynamics working with phenomenological exciton Hamiltonian and quantum chemistry construct reliable models amenable for dynamics calculations from ab initio calculations Explores modern nonlinear electronic spectroscopy techniques to probe exciton dynamics, showing how it is applied
Download or read book Theory of Molecular Excitons written by A. Davydov and published by Springer. This book was released on 2013-11-11 with total page 319 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Spectroscopy of the Excited State written by Baldassare Di Bartolo and published by Springer Science & Business Media. This book was released on 2012-12-06 with total page 423 pages. Available in PDF, EPUB and Kindle. Book excerpt: These proceedings report the lectures and seminars presented at the NATO Advanced Study Institute on "The Spectroscopy of the Excited State," held at Erice, Italy, June 9-24, 1975. This Institute was an activity of the International School of Atomic and Molecular Spectroscopy of the "Ettore Majorana" Centre for Scientific Culture. The Institute consisted of a series of lectures on the spectroscopic properties of materials in excited electronic states, that, starting at a fundamental level, finally reached the current level of research. The sequence of lectures and the organization of the material taught were in keeping with a didac tical presentation. In essence the course had the two-fold pur pose of organizing what was known on the subject, and updating the knowledge in the field. The formal lectures were complemented by seminars whose abstracts are also included in these proceedings. The proceedings report also the contributions sent by Professors R.G.W. Norrish and S. C1aesson who, unfortunately, were not able to come because of illness. A total of 62 participants and 7 lecturers came from the following countries: Belgium, Canada, Czechoslovakia, France, Germany, Israel, Italy, Japan, Netherlands, Norway, Pakistan, Poland, Sweden, Switzerland, the United Kingdom, the United States and Venezuela. The secretaries of the course were: A. La Francesca for the administrative aspects of the meeting and P.Papagiannakopou10s for the scientific aspects of the meeting.
Download or read book Spectroscopy Relaxation and Transport of Molecular Excitons in Noisy and Disordered Environments written by Chern Chuang and published by . This book was released on 2018 with total page 150 pages. Available in PDF, EPUB and Kindle. Book excerpt: In this thesis contribution we theoretically investigate the spectroscopy, relaxation, and transport properties of Frenkel excitons in molecular aggregates, with extensive comparison to or prediction of experimental observables. Particular emphasis is devoted to the effects of thermal noise, static disorder, and system dimensionality. Our key contributions are summarized as the following. We study the spectroscopic signatures of excitonic molecular aggregates of dimensionality larger than unity as functions of temperature and disorder strength. These findings are applied to the determination of essential system characteristics and quantitatively explain the spectroscopic traits seen in experiments where either the temperature or disorder strength is altered. A classification scheme generalized from Kasha's seminal work on J- and H-aggregates is proposed that is compatible with experimental observations previously unexplained. We recognize the importance of long-wavelength approximations in understanding the density of states in two-dimensional excitonic aggregates. And for tubular aggregates this leads to a simple expression for the energy gap between the parallel- and the perpendicular-polarized peaks useful in inferring key system parameters. This long-wavelength approach is then extended to the analysis of 2D excitonic molecular aggregates in general. A universal scaling relation concerning the steady-state diffusive transport of excitons in molecular tubes is predicted and analyzed, where the key order parameter is identified as the ratio between the localization length of the exciton wavefunctions and the tube circumference. A unified theoretical framework is proposed to explain the relaxation of hot excitons generated in emissive conjugated polymers across three orders of magnitude in timescale, with quantitative agreements with experiments.
Download or read book Spectroscopy of Molecular Excitons written by Vladimir Lʹvovich Broude and published by Springer. This book was released on 1985 with total page 296 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Dynamics of Molecular Excitons written by Seogjoo J. Jang and published by Elsevier. This book was released on 2020-04-25 with total page 242 pages. Available in PDF, EPUB and Kindle. Book excerpt: Dynamics of Molecular Excitons provides a comprehensive, but concise description of major theories on the dynamics of molecular excitons, intended to serve as a self-contained resource on the topic. Designed to help those new to this area gain proficiency in this field, experts will also find the book useful in developing a deeper understanding of the subject. The starting point of the book is the standard microscopic definition of molecular Hamiltonians presented in commonly accepted modern quantum mechanical notations. Major assumptions and approximations involved in constructing Frenkel-type exciton Hamiltonians, which are well established, but are often hidden under arcane notations and approximations of old publications, are presented in detail. This will help quantum chemists understand the major assumptions involved in the definition of commonly used exciton models. Rate theories of exciton dynamics, such as Förster and Dexter theories and their modern generalizations, are presented in a unified and detailed manner. In addition, important aspects that are often neglected, such as local field effect and the role of fluctuating environments, are discussed. Various quantum dynamics methods allowing coherent dynamics of excitons are presented in a systematic manner in the context of quantum master equations or path integral formalisms. The author also provides a detailed theoretical explanation for the major spectroscopic techniques probing exciton dynamics, including modern two-dimensional electronic spectroscopy, with a critical assessment of the implications of these spectroscopic measurements. Finally, the book includes a brief overview of major applications including an explanation of organic photovoltaic materials and natural light harvesting complexes. Covers major theories of exciton dynamics in a consciously concise and easily readable way Bridges the gap between quantum dynamics working with phenomenological exciton Hamiltonian and quantum chemistry construct reliable models amenable for dynamics calculations from ab initio calculations Explores modern nonlinear electronic spectroscopy techniques to probe exciton dynamics, showing how it is applied
Download or read book Two dimensional Spectroscopy of Molecular Excitons in a Model Dimer System written by H. Alexei Halpin and published by . This book was released on 2014 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Primary Photoexcitations In Conjugated Polymers Molecular Exciton Versus Semiconductor Band Model written by Niyasi Serdar Sariciftci and published by World Scientific. This book was released on 1998-01-02 with total page 641 pages. Available in PDF, EPUB and Kindle. Book excerpt: This volume concentrates on the controversy within the scientific community over how to explain, understand and describe the photophysics/photochemistry of this class of materials.This controvery is of such a fundamental nature that the solution of the problem might be in a unification of the semiconductor and metal physics with the molecular quantum chemistry. Thus, a wide-ranging and comprehensive discussion of this very crucial issue has not been written down yet.This volume brings together the most prominent scientists specializing in this controversial topic. Each contributor addresses the opponents' arguments. After short introductory chapters, the contributors discuss their own speciality area and compare the results with both models and explain their position on why one of the models is more appropriate. Special emphasis is given to comparative discussions with other conjugated molecular systems as well as inorganic semiconductors.
Download or read book Molecular Spectroscopy XI written by O. Sild and published by Elsevier. This book was released on 2017-01-31 with total page 255 pages. Available in PDF, EPUB and Kindle. Book excerpt: Molecular Spectroscopy–XI provides information pertinent to the fundamental aspects of molecular spectroscopy. This book discusses the modifications of molecular spectra when the density varies as a function of temperature and pressure. Organized into 15 chapters, this book begins with an overview of the several processes concerning triplet excitons leading to magnetic-field sensitive luminescence in organic crystals and related compounds. This text then examines the methods of investigation of the exciton band structures in molecular crystals. Other chapters consider the conditions for the equivalence of Fourier spectroscopy and of slow passage experiments in nuclear magnetic resonance. This book discusses as well the application of computer technology in carbon-13 magnetic resonance spectroscopy. The final chapter deals with the application of high-resolution proton and carbon-13 n.m.r. spectroscopy for the investigation of the molecular conformations in proteins. This book is a valuable resource for organic chemists, biologists, microbiologists, scientists, and research workers.
Download or read book Photosynthetic Excitons written by Herbert van Amerongen and published by World Scientific. This book was released on 2000 with total page 612 pages. Available in PDF, EPUB and Kindle. Book excerpt: Excitons are considered as the basic concept used by describing the spectral properties of photosynthetic pigment-protein complexes and excitation dynamics in photosynthetic light-harvesting antenna and reaction centers. Following the recently obtained structures of a variety of photosynthetic pigment-protein complexes from plants and bacteria our interest in understanding the relation between structure, function and spectroscopy has strongly increased. These data demonstrate a short interpigment distance (of the order of 1 nm or even smaller) and/or a highly symmetric (ring-like) arrangement of pigment molecules in peripheral light-harvesting complexes of photosynthetic bacteria. Books which were devoted to the exciton problem so far mainly considered the spectral properties of molecular crystals. However, the small size of these pigment aggregates in the pigment-protein complexes as well as the role of the protein, which is responsible for the structural arrangement of the complex, clearly will have a dramatic influence on the pigment spectra and exciton dynamics. All these aspects of the problem are considered in this book. Exciton theory is mainly considered for small molecular aggregates (dimers, ring-like structures etc.). Together with the theoretical description of the classical conceptual approach, which mainly deals with polarization properties of the absorption and fluorescence spectra, the nonlinear femtosecond spectroscopy which is widely used for investigations now is also discussed. A large part of the book demonstrates the excitonic effects in a multitude of photosynthetic pigment-protein complexes and how we can understand these properties on the basis of the exciton concept.
Download or read book Spectroscopy and Excitation Dynamics of Condensed Molecular Systems written by Vladimir Moiseevich Agranovich and published by North-Holland. This book was released on 1983 with total page 724 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Formation and Dynamics of Molecular Excitons and Their Fingerprints in Nonlinear Optical Spectroscopy written by Pär Kjellberg and published by . This book was released on 2006 with total page 45 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Spectroscopy of Excitons in Semiconductor Quantum Dot Molecules written by Gerhard Ortner and published by . This book was released on 2004 with total page 128 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Physical Processes in Radiation Biology written by Leroy Augenstein and published by Academic Press. This book was released on 2013-10-22 with total page 395 pages. Available in PDF, EPUB and Kindle. Book excerpt: Physical Processes in Radiation Biology covers the proceedings of an International Symposium on Physical Processes in Radiation Biology, held at the Kellogg Center for Continuing Education, Michigan State University on May 6-8, 1963, sponsored by the U.S. Atomic Energy Commission. The symposium aims to address the core problems of radiation biology concerning the absorption, distribution, and utilization of high energy packets in biological systems. This book is composed of 21 chapters, and begins with an introduction to the absorption, excitation, and transfer processes in molecular solids. The subsequent chapters discuss the nature of exciton processes; the mechanisms of charge transport in biological materials; the interactions of fast and slow electrons with model systems; the importance of liquid structures in determining the development of radiation damage; and the nature of the metastable species formed. The concluding chapters explore the importance of charge migration in energy transfer processes in different biological systems and the significance of higher excited levels in charge migration and energy transfer. These chapters also describe the nature of the hydration of electrons and protons in aqueous systems. This book will be of great value to radiation biologists, biophysicists, physical chemists, and physicists.
Download or read book Molecular Excitation Dynamics and Relaxation written by Leonas Valkunas and published by John Wiley & Sons. This book was released on 2013-10-04 with total page 414 pages. Available in PDF, EPUB and Kindle. Book excerpt: This work brings together quantum theory and spectroscopy to convey excitation processes to advanced students and specialists wishing to conduct research and understand the entire fi eld rather than just single aspects. Written by experienced authors and recognized authorities in the field, this text covers numerous applications and offers examples taken from different disciplines. As a result, spectroscopists, molecular physicists, physical chemists, and biophysicists will all fi nd this a must-have for their research. Also suitable as supplementary reading in graduate level courses.
