Download or read book Electronic Structure and Electron Dynamics at Molecule metal Interfaces written by X.-Y. Zhu and published by . This book was released on 2004 with total page 84 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Electronic structure and electron dynamics at molecule metal interfaces written by X.-Y. Zhu and published by . This book was released on 2004 with total page 84 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book The Molecule Metal Interface written by Norbert Koch and published by John Wiley & Sons. This book was released on 2013-02-08 with total page 257 pages. Available in PDF, EPUB and Kindle. Book excerpt: Reviewing recent progress in the fundamental understanding of the molecule-metal interface, this useful addition to the literature focuses on experimental studies and introduces the latest analytical techniques as applied to this interface. The first part covers basic theory and initial principle studies, while the second part introduces readers to photoemission, STM, and synchrotron techniques to examine the atomic structure of the interfaces. The third part presents photoelectron spectroscopy, high-resolution UV photoelectron spectroscopy and electron spin resonance to study the electronic structure of the molecule-metal interface. In the closing chapter the editors discuss future perspectives. Written as a senior graduate or senior undergraduate textbook for students in physics, chemistry, materials science or engineering, the book's interdisciplinary approach makes it equally relevant for researchers working in the field of organic and molecular electronics.
Download or read book Electronic Structure and Ultrafast Dynamics in Molecular Films on Metal Surfaces written by Gregory John Dutton and published by . This book was released on 2006 with total page 300 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Energy Level Alignment and Electron Transport Through Metal Organic Contacts written by Enrique Abad and published by Springer Science & Business Media. This book was released on 2012-09-16 with total page 211 pages. Available in PDF, EPUB and Kindle. Book excerpt: In recent years, ever more electronic devices have started to exploit the advantages of organic semiconductors. The work reported in this thesis focuses on analyzing theoretically the energy level alignment of different metal/organic interfaces, necessary to tailor devices with good performance. Traditional methods based on density functional theory (DFT), are not appropriate for analyzing them because they underestimate the organic energy gap and fail to correctly describe the van der Waals forces. Since the size of these systems prohibits the use of more accurate methods, corrections to those DFT drawbacks are desirable. In this work a combination of a standard DFT calculation with the inclusion of the charging energy (U) of the molecule, calculated from first principles, is presented. Regarding the dispersion forces, incorrect long range interaction is substituted by a van der Waals potential. With these corrections, the C60, benzene, pentacene, TTF and TCNQ/Au(111) interfaces are analyzed, both for single molecules and for a monolayer. The results validate the induced density of interface states model.
Download or read book Electron Dynamics and Symmetries at the Metal Molecule Interface Probed by Two Photon Photoemission written by Eric Anton Muller and published by . This book was released on 2012 with total page 206 pages. Available in PDF, EPUB and Kindle. Book excerpt: Femtosecond, angle resolved two photon photoemission spectroscopy is used as a probe of the metal-molecule interface. In four related investigations, monolayer or submonolayer coverages of a molecule are adsorbed onto an Ag(111) surface under ultrahigh vacuum conditions. Studies use a an optically excited electronic probe to investigate to probe the energetic landscape experienced and the response of a molecular adsorbate to an excess charge. Energy levels, electronic population, and band structure reveal molecular structure and mechanisms of dynamic response to an injected charge. Room temperature ionic liquids (RTIL), consisting of charge separated anions and cations, represent a new and poorly understood class of electrochemical solvents. The mechanism of electron solvation has been proposed to be vastly different at the electrode interface than has been observed in bulk studies. Optical excitation into the RTIL conduction band results in a localized excess charge, as measured by band dispersions. Electron solvation is measured directly as the photoemitted kinetic energy. Solvation by 200-540 meV is found to occur rapidly on the timescale of 350 fs, supporting previous predictions of fast charge solvation at the interface. Further, a previously proposed phase transition is observed between a low temperature ordered phase and high temperature disordered phase. This phase transition, which occurs at 250 K, is quantified by both the change in workfunction and a change in the energy of solvation between the two phases. The image state is often used as a sensitive probe of molecular films, however, the electronic potential experienced by the image state electron is poorly understood. Theoretical predictions of image state energy in molecular films with a positive electron affinity are often wrong by 1-3 eV, and descriptions of the band structure typically remain limited to a measurement of effective mass. An image state is investigated within a film of metallated phthalocyanines. Phthalocyanines crystallize laying flat on the substrate, with a nearly square unit cell of 14 - 15 Å on a side. Angle resolved measurements into the second Brillouin zone reveal folding of the image state due to interactions with the screened potential energy surface within the molecule. The bandgap, measured to be 150 meV, can be used to estimate the corrugation of the energy landscape. Further, a Kronig Penney model is quantitatively compared to the first several backfolded image bands. Comparision between theory and experiment reveals the effects of the fourfold symmetry of lattice on the image state bandstructure. The morphology and crystal structure of thin film molecular semiconductors is well known to directly influence the band structure and electronic properties of the material. Further, several morphologies and crystal structures can result from epitaxial growth of a single molecule on a metal surface. Although phase transitions in 2D-atomic systems have been well studied for over 80 years, molecular systems are less well understood due to their larger size and the complex interplay of relatively weak forces that govern the crystalline packing. Three phases of metallated phthalocyanines are studied as a function of substrate temperature and submonolayer coverage. Three phases, the 2D-gas phase, the low temperature commensurate phase, and the high temperature incommensurate phase, are each studied using TPPE and low energy electron diffraction. The image state is found to be an excellent probe of the local crystal structure and local workfunction. Preliminary studies focus on the temperature and coverage dependent energies and intensities of the image state peak in domains of each phase. Temperature dependent studies reveal a pseudo-isosbestic point in the transition from the low temperature commensurate to the high temperature incommensurate phases. Coverage dependence reveals a redshift of the image state with increasing molecular density and decreasing workfunction, and low temperature studies reveal long time scale kinetics of reorganization. Preliminary experimental results are interpreted with the aid of kinetic monte carlo simulations. Further studies will aim to obtain quantitative thermodynamics of these submonolayer coverages. Two photon photoemission spectrscopy has proven to be a powerful tool for understanding basic surface physics of atomic and molecular systems. In particular, the image state has proven to be a powerful probe of the first 1-2 ML coverage of a molecular system. In order to improve the applicability of TPPE to answer device relevant questions, the technique will need to resolve, identify, and characterize molecularly derived bands and excitonic states. The basic selection rules for metal-molecule charge transfer excitations and exciton formation at a surface are understood, but it is not agreed upon whether hot-electrons or interfacial electronic coupling allow for excitations that break normal selection rules. Further, classical dipole quenching is expected to play a strong role in the exciton lifetimes in molecules adsorbed on metal or semiconductor surfaces, though no TPPE study up to this point has been able to observe the expected distance dependent lifteimes. In this final chapter, selection rules and classical dipole quenching are briefly discussed, and general trends are derived for molecular systems adsorbed on highly oriented metal surfaces. Our work up to this point suggests that selection rules are followed rigourously in molecular adsorbates on Ag(111).
Download or read book Ultrafast Dynamics of Electrons at Interfaces written by Jason Douglas McNeill and published by . This book was released on 1999 with total page 382 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Electronic Structure written by Richard M. Martin and published by Cambridge University Press. This book was released on 2020-08-27 with total page 791 pages. Available in PDF, EPUB and Kindle. Book excerpt: The study of electronic structure of materials is at a momentous stage, with new computational methods and advances in basic theory. Many properties of materials can be determined from the fundamental equations, and electronic structure theory is now an integral part of research in physics, chemistry, materials science and other fields. This book provides a unified exposition of the theory and methods, with emphasis on understanding each essential component. New in the second edition are recent advances in density functional theory, an introduction to Berry phases and topological insulators explained in terms of elementary band theory, and many new examples of applications. Graduate students and research scientists will find careful explanations with references to original papers, pertinent reviews, and accessible books. Each chapter includes a short list of the most relevant works and exercises that reveal salient points and challenge the reader.
Download or read book Ultrafast Studies of Electron Dynamics at Metal dielectric Interfaces written by Nien-Hui Ge and published by . This book was released on 1998 with total page 372 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Electronic Structure of Metal Phthalocyanines on Ag 100 written by Cornelius Krull and published by Springer Science & Business Media. This book was released on 2013-11-19 with total page 158 pages. Available in PDF, EPUB and Kindle. Book excerpt: The application of molecules in technological devices hinges on the proper understanding of their behavior on metallic electrodes or substrates. The intrinsic molecular electronic and magnetic properties are modified at a metallic interface, and greatly depend on the atomic configuration of the molecule-metal bond. This poses certain problems, such as the lack of reproducibility in the transport properties of molecular junctions, but also offers the possibility to induce new charge and spin configurations that are only present at the interface. The results presented in this thesis address this issue, providing a comprehensive overview of the influence of molecule-metal and molecule-molecule interactions on the electronic and magnetic properties of molecules adsorbed on metallic substrates. Using metal-phthalocyanines (MePc), a commonly used metal-organic complex as a model system, each chapter explores different aspects of the interaction with silver surfaces: the local adsorption geometry, self-assembly, the modifications of the electronic and magnetic characteristics due to hybridization and charge transfer, and finally the manipulation of molecular charge and spin states by electron doping using alkali atoms moved with the STM tip.
Download or read book Two Photon photoemission Studies of Metal molecule Interfaces written by Chadwick D. Lindstrom and published by . This book was released on 2006 with total page 306 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Electronic Structure Correlation Effects and Physical Properties of D and F metals and Their Compounds written by Valentin Yu Irkhin and published by Cambridge Int Science Publishing. This book was released on 2007 with total page 464 pages. Available in PDF, EPUB and Kindle. Book excerpt: The book includes all main physical properties of d- and f-transition-metal systems and corresponding theoretical concepts. Special attention is paid to the theory of magnetism and transport phenomena. Some examples of non-traditional questions which are treated in detail in the book: the influence of density of states singularities on electron properties; many-electron description of strong itinerant magnetism; mechanisms of magnetic anisotropy; microscopic theory of anomalous transport phenomena in ferromagnets. Besides considering classical problems of solid state physics as applied to transition metals, modern developments in the theory of correlation effects in d- and f-compounds are considered within many-electron models. The book contains, where possible, a simple physical discussion. More difficult questions are considered in Appendices.
Download or read book Chemical Bonding at Surfaces and Interfaces written by Anders Nilsson and published by Elsevier. This book was released on 2011-08-11 with total page 533 pages. Available in PDF, EPUB and Kindle. Book excerpt: Molecular surface science has made enormous progress in the past 30 years. The development can be characterized by a revolution in fundamental knowledge obtained from simple model systems and by an explosion in the number of experimental techniques. The last 10 years has seen an equally rapid development of quantum mechanical modeling of surface processes using Density Functional Theory (DFT). Chemical Bonding at Surfaces and Interfaces focuses on phenomena and concepts rather than on experimental or theoretical techniques. The aim is to provide the common basis for describing the interaction of atoms and molecules with surfaces and this to be used very broadly in science and technology. The book begins with an overview of structural information on surface adsorbates and discusses the structure of a number of important chemisorption systems. Chapter 2 describes in detail the chemical bond between atoms or molecules and a metal surface in the observed surface structures. A detailed description of experimental information on the dynamics of bond-formation and bond-breaking at surfaces make up Chapter 3. Followed by an in-depth analysis of aspects of heterogeneous catalysis based on the d-band model. In Chapter 5 adsorption and chemistry on the enormously important Si and Ge semiconductor surfaces are covered. In the remaining two Chapters the book moves on from solid-gas interfaces and looks at solid-liquid interface processes. In the final chapter an overview is given of the environmentally important chemical processes occurring on mineral and oxide surfaces in contact with water and electrolytes. Gives examples of how modern theoretical DFT techniques can be used to design heterogeneous catalysts This book suits the rapid introduction of methods and concepts from surface science into a broad range of scientific disciplines where the interaction between a solid and the surrounding gas or liquid phase is an essential component Shows how insight into chemical bonding at surfaces can be applied to a range of scientific problems in heterogeneous catalysis, electrochemistry, environmental science and semiconductor processing Provides both the fundamental perspective and an overview of chemical bonding in terms of structure, electronic structure and dynamics of bond rearrangements at surfaces
Download or read book Electrons in Molecules written by Jean-Pierre Launay and published by Oxford University Press. This book was released on 2018 with total page 605 pages. Available in PDF, EPUB and Kindle. Book excerpt: The purpose of this book is to provide the reader with essential keys to a unified understanding of the rapidly expanding field of molecular materials and devices: electronic structures and bonding, magnetic, electrical and photo-physical properties, and the mastering of electrons in molecular electronics.
Download or read book Electronic Structure of Metal Semiconductor Contacts written by Winfried Mönch and published by Springer Science & Business Media. This book was released on 2012-12-06 with total page 302 pages. Available in PDF, EPUB and Kindle. Book excerpt: Interface and surface science have been important in the development of semicon ductor physics right from the beginning on. Modern device concepts are not only based on p-n junctions, which are interfaces between regions containing different types of dopants, but take advantage of the electronic properties of semiconductor insulator interfaces, heterojunctions between distinct semiconductors, and metal semiconductor contacts. The latter ones stood almost at the very beginning of semi conductor physics at the end of the last century. The rectifying properties of metal-semiconductor contacts were first described by Braun in 1874. A physically correct explanation of unilateral conduction, as this deviation from Ohm's law was called, could not be given at that time. A prerequisite was Wilson's quantum theory of electronic semi-conductors which he published in 1931. A few years later, in 1938, Schottky finally explained the rectification at metal-semiconductor contacts by a space-
Download or read book Workshop on the Interface Between Electronic Structure and Dynamics written by Workshop on the Interface Between Electronic Structure and Dynamics. 1986, Snowbird, Utah and published by . This book was released on 1987 with total page 184 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Femtosecond Studies of Interband and Intraband Electron Dynamics at Dielectric metal Interfaces written by Chung-Ming Wong and published by . This book was released on 2000 with total page 278 pages. Available in PDF, EPUB and Kindle. Book excerpt:
