Crystallographic and Quantum Chemical Studies of Materials for Organic Electronics Applications PDF Download

Author: Xu Wang
Publisher:
ISBN:
Category : Crystal growth
Languages : en
Pages : 210

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Book Description
Charge-transfer complexes/co-crystals are promising organic semiconducting materials for electronics applications. However, the understanding of their fundamental structureƯ property relations still needs more explorations. In this project we studied three series of materials which are (1) co-crystals of cis-bis(trifluoromethylethylene-1,2- dithiolato)nickel (Ni(tfd)z) (acceptor) and four different aromatic donor molecules, (2) crystals of four different derivatives of dithienophenazines (DTPhz), and (3) crystals of 5,6-bis(9H-carbazol-9-yl)benzo[c]-[1,2,5] thiadiazole (DCBT). Single crystals of these materials were characterized using single crystal X-ray diffraction (XRD). A total of four co-crystals of series (I) and nine samples of series of (2) and (3) were structurally characterized. The XRD results had shown that different crystal growth conditions could result in different structure and stoichiometry (polymorphs). Furthermore, electronic structure calculations based on the results of XRD have shown that, for the same material, the degree of charge transfer and HOMO/LUMO levels gaps were different due to the difference in structure and stoichiometry of the crystals.

Author: D.S. Chemla
Publisher: Elsevier
ISBN: 0323148158
Category : Science
Languages : en
Pages : 497

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Book Description
Nonlinear Optical Properties of Organic Molecules and Crystals, Volume 1 discusses the nonlinear optical effects in organic molecules and crystals, providing a classical distinction between quadratic and cubic processes. This book begins with a general overview of the basic properties of organic matter, followed by a review on the benefits derived from quantum-chemistry-based models and growth and characterization of high quality, bulk organic crystals and waveguided structures. A case study focusing on a specific material, namely urea, which exemplifies a situation in which transparency in the UV region has been purposely traded for nonlinear efficiency is also deliberated. This text concludes with a description of a type of trade-off between the unpredictable orientation of molecules in crystalline media, polarity of liquid-crystalline structures, and dominant electronic contribution to the electro-optic effect. This publication is beneficial to solid-state physicists and chemists concerned with nonlinear optical properties of organic molecules and crystals.

Author: Anna V. Vologzhanina
Publisher: MDPI
ISBN: 3039361708
Category : Science
Languages : en
Pages : 144

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Book Description
Unravelling an intricate network of interatomic interactions and their relations to different behaviors of chemical compounds is key to the successful design of new materials for both existing and novel applications, from medicine to innovative concepts of molecular electronics and spintronics. X-ray crystallography has proven to be very helpful in addressing many important chemical problems in modern materials science and biosciences. Intertwined with computational techniques, it provides insights into the nature of chemical bonding and the physicochemical properties (including optical, magnetic, electrical, mechanical, and others) of crystalline materials, otherwise accessible by experimental techniques that are not so readily available to chemists. In addition to the advanced approaches in charge density analysis made possible by X-ray diffraction, the information collected over the years through this technique (which is easily mined from huge databases) has tremendous use in the design of new materials for medicine, gas storage, and separation applications as well as for electronic devices. This Special Issue contains two reviews and five articles that cover very different aspects of ‘composition–structure’ and ‘structure–property’ relations identified by X-ray diffraction and complementary techniques (from conventional IR and Raman spectroscopies to cutting-edge quantum chemical calculations) and their use in crystal engineering and materials science.

Author: Masako Kato
Publisher: Springer Nature
ISBN: 9819902606
Category : Science
Languages : en
Pages : 265

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Book Description
This open access book introduces the science of the new materials, soft crystals, by showing various interesting examples. Different from conventional hard and stable crystals, the soft crystals respond to gentle stimuli such as vapor exposure and rubbing but maintain their structural order. In this book, their exhibition of remarkable visual changes in their shape, color, and luminescence is described. Through the chapters, historical background, recent remarkable developments, and future prospects are described concisely. This book helps readers to understand a new concept of materials that have the characteristics of stimulus-sensitive soft matter and finely controlled crystals and to design novel materials with the characteristics. The English translation of this book from its Japanese language original manuscript was done with the help of artificial intelligence (machine translation by the service DeepL.com). The text has subsequently been revised further by a professional copy editor in order to refine the work stylistically.

Author: Angelo Gavezzotti
Publisher: Elsevier
ISBN: 0128237481
Category : Science
Languages : en
Pages : 304

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Book Description
The Crystalline States of Organic Compounds is a broad survey of the techniques by which molecular crystals are investigated, modeled, and applied, starting with the fundamentals of intra- and intermolecular bonding supplemented by a concise tutorial on present-day diffraction methods, then proceeding to an examination of crystallographic databases with their statistics and of such fundamental and fast-growing topics as intermolecular potentials, polymorphism, co-crystallization, and crystal structure prediction by computer. A substantial part of the book is devoted to the techniques of choice in modern simulation, Monte Carlo and molecular dynamics, with their most recent developments and application to formed crystals and to the concomitant phases involved in nucleation and growth. Drawing on the decades-long experience of its author in teaching and research in the field of organic solid state, The Crystalline States of Organic Compounds is an indispensable source of key insights and future directions for students and researchers at any level, in academia and in industry. Condenses theoretical information and practical methods in a single resource Provides a guide on the use of crystallographic databases, structure statistics, and molecular simulations Includes a large number of worked examples and tutorials, with extensive graphics and multimedia

Author: Emil Kalered
Publisher: Linköping University Electronic Press
ISBN: 9176853330
Category :
Languages : en
Pages : 73

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Book Description
Quantum chemical calculations have been used to model chemical reactions in epitaxial growth of silicon carbide by chemical vapor deposition (CVD) processes and to study heterogeneous catalytic reactions for methanol synthesis. CVD is a common method to produce high-quality materials and e.g. thin films in the semiconductor industry, and one of the many usages of methanol is as a promising future renewable and sustainable energy carrier. To optimize the chemical processes it is essential to understand the reaction mechanisms. A comprehensive theoretical model for the process is therefore desired in order to be able to explore various variables that are difficult to investigate in situ. In this thesis reaction paths and reaction energies are computed using quantum chemical calculations. The quantum-chemical results can subsequently be used as input for thermodynamic, kinetic and computational fluid dynamics modelling in order to obtain data directly comparable with the experimental observations. For the CVD process, the effect of halogen addition to the gas mixture is studied by modelling the adsorption and diffusion of SiH2, SiCl2 and SiBr2 on the (0001?) 4H-SiC surface. SiH2 was found to bind strongest to the surface and SiBr2 binds slightly stronger than the SiCl2 molecule. The diffusion barrier is shown to be lower for SiH2 than for SiBr2 and SiCl2 which have similar barriers. SiBr2 and SiCl2 are found to have similar physisorption energies and bind stronger than the SiH2 molecule. Gibbs free-energy calculations also indicate that the SiC surface is not fully hydrogen terminated at CVD conditions since missing-neighboring pair of surface hydrogens is found to be common. Calculations for the (0001) surface show that SiCl, SiCl2, SiHCl, SiH, and SiH2 likely adsorb on a methylene site, but the processes are thermodynamically less favorable than their reverse reactions. However, the adsorbed products may be stabilized by subsequent surface reactions to form a larger structure. The formation of these larger structures is found to be fast enough to compete with the desorption processes. Also the Gibbs free energies for adsorption of Si atoms, SiX, SiX2, and SiHX where X is F or Br are presented. Adsorption of Si atoms is shown to be the most thermodynamically favorable reaction followed by SiX, SiHX, and SiX2, X being a halide. The results in this study suggest that the major Si contributors in the SiC–CVD process are Si atoms, SiX and SiH. Methanol can be synthesized from gaseous carbon dioxide and hydrogen using solid metal-metal oxide mixtures acting as heterogeneous catalysts. Since a large surface area of the catalyst enhances the speed of the heterogeneous reaction, the use of nanoparticles (NP) is expected to be advantageous due to the NPs’ large area to surface ratio. The plasma-induced creation of copper NPs is investigated. One important element during particle growth is the charging process where the variation of the work function (W) with particle size is a key quantity, and the variation becomes increasingly pronounced at smaller NP sizes. The work functions are computed for a set of NP charge numbers, sizes and shapes, using copper as a case study. A derived analytical expression for W is shown to give quite accurate estimates provided that the diameter of the NP is larger than about a nanometer and that the NP has relaxed to close to a spherical shape. For smaller sizes W deviates from the approximative expression, and also depends on the charge number. Some consequences of these results for NP charging process are outlined. Key reaction steps in the methanol synthesis reaction mechanism using a Cu/ZrO2 nanoparticle catalyst is investigated. Two different reaction paths for conversion of CO2 to CO is studied. The two paths result in the same complete reaction 2 CO2 ? 2 CO + O2 where ZrO2 (s) acts as a catalyst. The highest activation energies are significantly lower compared to that of the gas phase reaction. The presence of oxygen vacancies at the surface appear to be decisive for the catalytic process to be effective. Studies of the reaction kinetics show that when oxygen vacancies are present on the ZrO2 surface, carbon monoxide is produced within a microsecond. The IR spectra of CO2 and H2 interacting with ZrO2 and Cu under conditions that correspond to the catalyzed CH3OH production process is also studied experimentally and compared to results from the theoretical computations. Surface structures and gas-phase molecules are identified through the spectral lines by matching them to specific vibrational modes from the literature and from the new computational results. Several surface structures are verified and can be used to pin point surface structures in the reaction path. This gives important information that help decipher how the reaction mechanism of the CO2 conversion and ultimately may aid to improve the methanol synthesis process.

Author: Piero Macchi
Publisher: Springer Nature
ISBN: 3030956415
Category : Science
Languages : en
Pages : 98

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Book Description
This book explores the potential of quantum crystallography. The field accompanied the major milestones of x-ray diffraction and it has undergone a rapid evolution in the past few years. For this reason, some reflections are necessary in order to scrutinize the next steps and anticipate the future developments. After a short survey of the historical background and in depth description of the state of the art, some examples are provided of current and future applications of the know-how in this discipline. This implies attracting readership of both experts in the field and neophytes. The former will test their own views with the one exposed in the book; the newcomers, instead, will learn both what has been done and what could be done with quantum crystallography.

Author: Markus Schwoerer
Publisher: John Wiley & Sons
ISBN: 3527405402
Category : Science
Languages : en
Pages : 451

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Book Description
This is the first comprehensive textbook on the physical aspects of organic solids. All phenomena which are necessary in order to understand modern technical applications are being dealt with in a way which makes the concepts of the topics accessible for students. The chapters - from the basics, production and characterization of organic solids and layers to organic semiconductors, superconductors and opto-electronical applications - have been arranged in a logical and well thought-out order.

Author: Wei Gao
Publisher: World Scientific Publishing Company
ISBN: 9813107790
Category : Technology & Engineering
Languages : en
Pages : 563

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Book Description
An Introduction to Electronic Materials for Engineers aims to give a basic understanding and comprehensive overview of a wide range of materials, such as conducting materials, semiconductors, magnetic materials, optical materials, dielectric materials, superconductors, thermoelectric materials and ionic materials. The new chapters added into this latest edition include thin film electronic materials, organic electronic materials and nanostructured materials. These chapters aim to reflect the new developments made in electronic materials and nanotechnology research towards the design and fabrication of modern equipment and electronic devices.This book is designed for undergraduate engineering and technology students who have background knowledge of physics and chemistry, as well as for engineers who work on materials processing or application, or electric/electronic engineering.It emphasizes on the synthesis, performance and application of electronic materials and will enable readers to understand and relate to the devices and materials.

Author: Cesare Pisani
Publisher: Springer
ISBN: 9783642614798
Category : Science
Languages : en
Pages : 332

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Book Description
A number of general-purpose, reasonably accurate and well-tested ab-initio codes for crystals are discussed in this book. The aim is to expand competence of their application in material sciences and solid-state physics. The book addresses particularly readers with a general knowledge in quantum chemistry and intends to give a deeper insight into the special algorithms and computational techniques in ab-initio computer codes for crystals. Three different programs which are available to all interested potential users on request are presented.