Download or read book Theoretical Studies of Electronic Properties in Graphene related Systems Using Thermally assisted occupation Density Functional Theory written by 黃家政 and published by . This book was released on 2012 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Graphene Chemistry written by De-en Jiang and published by John Wiley & Sons. This book was released on 2013-10-14 with total page 496 pages. Available in PDF, EPUB and Kindle. Book excerpt: What are the chemical aspects of graphene as a novel 2D material and how do they relate to the molecular structure? This book addresses these important questions from a theoretical and computational standpoint. Graphene Chemistry: Theoretical Perspectives presents recent exciting developments to correlate graphene’s properties and functions to its structure through state-of-the-art computational studies. This book focuses on the chemistry aspect of the structure-property relationship for many fascinating derivatives of graphene; various properties such as electronic structure, magnetism, and chemical reactivity, as well as potential applications in energy storage, catalysis, and nanoelectronics are covered. The book also includes two chapters with significant experimental portions, demonstrating how deep insights can be obtained by joint experimental and theoretical efforts. Topics covered include: Graphene ribbons: Edges, magnetism, preparation from unzipping, and electronic transport Nanographenes: Properties, reactivity, and synthesis Clar sextet rule in nanographene and graphene nanoribbons Porous graphene, nanomeshes, and graphene-based architecture and assemblies Doped graphene: Theory, synthesis, characterization and applications Mechanisms of graphene growth in chemical vapor deposition Surface adsorption and functionalization of graphene Conversion between graphene and graphene oxide Applications in gas separation, hydrogen storage, and catalysis Graphene Chemistry: Theoretical Perspectives provides a useful overview for computational and theoretical chemists who are active in this field and those who have not studied graphene before. It is also a valuable resource for experimentalist scientists working on graphene and related materials, who will benefit from many concepts and properties discussed here.
Download or read book First principles Study of Electronic and Topological Properties of Graphene and Graphene like Materials written by Priyamvada Jadaun and published by . This book was released on 2013 with total page 236 pages. Available in PDF, EPUB and Kindle. Book excerpt: This dissertation includes work done on graphene and related materials, examining their electronic and topological properties using first-principles methods. Ab-initio computational methods, like density functional theory (DFT), have become increasingly popular in condensed matter and material science. Motivated by the search for novel materials that would help us devise fast, low-power, post-CMOS transistors, we explore the properties of some of these promising materials. We begin by studying graphene and its interaction with dielectric oxides. Graphene has recently inspired a flurry of research activity due to its interesting electronic and mechanical properties. For the device community, graphene's high charge carrier mobility and continuous gap tunability can have immense use in novel transistors. In Chapter 3 we examine the properties of graphene placed on two oxides, namely quartz and alumina. We find that oxygen-terminated quartz is a useful oxide for the purpose of graphene based FETs. Inspired by a recent surge of interest in topological insulators, we then explore the topological properties of two-dimensional materials. We conduct a theoretical study to examine the relationship between crystal space group symmetry and the electric polarization of a two-dimensional crystal. We show that the presence of symmetry restricts the polarization values to a small number of distinct groups. There groups in turn are topologically inequivalent, making polarization a topological index. We also conduct density functional theory calculations to obtain actual polarization values of materials belonging to C3 symmetry and show that our results are consistent with our theoretical analysis. Finally we prove that any transformation from one class of polarization to another is a topological phase transition. In Chapter 5 we use density functional theory to examine the electronic properties of graphene intercalation compounds. Bilayer pseudospin field effect transistor (BiSFET) has been proposed as an interesting low-power, efficient post-CMOS switch. In order to implement this device we need bilayer graphene with reduced interlayer interaction. One way of achieving that is by inserting foreign molecules between the layers, a process which is called intercalation. In this chapter we examine the electronic properties of bilayer graphene intercalated with iodine monochloride and iodine monobromide molecules. We find that intercalation of graphene indeed makes it promising for the implementation of BiSFET, by reducing interlayer interaction. As an interesting side problem, we also use hybrid, more extensive approaches in DFT, to examine the electronic and optical properties of dilute nitrides. Dilute nitrides are highly promising and interesting materials for the purposes of optoelectronic applications. Together, we hope this work helps in elucidating the electronic properties of promising material systems as well as act as a guide for experimentalists.
Download or read book Geometric and Electronic Properties of Graphene Related Systems written by Ngoc Thanh Thuy Tran and published by CRC Press. This book was released on 2017-11-22 with total page 316 pages. Available in PDF, EPUB and Kindle. Book excerpt: Due to its physical, chemical, and material properties, graphene has been widely studied both theoretically and experimentally since it was first synthesized in 2004. This book explores in detail the most up-to-date research in graphene-related systems, including few-layer graphene, sliding bilayer graphene, rippled graphene, carbon nanotubes, and adatom-doped graphene, among others. It focuses on the structure-, stacking-, layer-, orbital-, spin- and adatom-dependent essential properties, in which single- and multi-orbital chemical bondings can account for diverse phenomena. Geometric and Electronic Properties of Graphene-Related Systems: Chemical Bonding Schemes is excellent for graduate students and researchers, but understandable to undergraduates. The detailed theoretical framework developed in this book can be used in the future characterization of emergent materials.
Download or read book Electronic and Thermal Properties of Graphene written by Kyong Yop Rhee and published by Mdpi AG. This book was released on 2020-07 with total page 322 pages. Available in PDF, EPUB and Kindle. Book excerpt: This Special Issue includes recent research articles and extensive reviews on graphene-based next-generation electronics, bringing together perspectives from different branches of science and engineering. The papers presented in this volume cover experimental, computational and theoretical aspects of the electrical and thermal properties of graphene and its applications in batteries, electrodes, sensors and ferromagnetism. In addition, this Special Issue covers many important state-of-the-art technologies and methodologies regarding the synthesis, fabrication, characterization and applications of graphene-based nanocomposites.
Download or read book Graphene Simulation written by Jian Ru Gong and published by IntechOpen. This book was released on 2011-08-01 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: Graphene, a conceptually new class of materials in condensed-matter physics, has been the interest of many theoretical studies due to the extraordinary thermal, mechanical and electrical properties for a long time. This book is a collection of the recent theoretical work on graphene from many experts, and will help readers to have a thorough and deep understanding in this fast developing field.
Download or read book Electronic Properties of Graphene written by and published by . This book was released on 2014 with total page 240 pages. Available in PDF, EPUB and Kindle. Book excerpt: Graphene is a single atomic layer of hexagonally arranged carbon atoms. Since the experimental discovery of graphene in 2004, a wealth of research has been conducted on studying its electronic and optical properties, as well as on developing novel applications. To explaining the typically observed electronic properties of graphene and to evaluate its potential in novel applications it is vital to quantitatively examine the intrinsic limits and the influence of the dominant extrinsic factors on the electromagnetic response of this material. The two-dimensional nature of graphene makes it vulnerable to the influence of a host of extrinsic factors, such as the interface phonons from the supporting substrate and trapped charged impurities near the interface between graphene and the substrate. In this dissertation, the electronic transport properties of graphene are examined in detail using multiphysics numerical simulations. Specifically, the following three aspects are studied: electron-phonon scattering rates and the intrinsic mobility, effect of clustered impurities on carrier transport, and substrate-dependent THz-frequency carrier transport. To calculate the electron-phonon scattering rates and predict the intrinsic mobility of graphene, the overlap between the electronic tight-binding Bloch wave functions (TB BWF), up to the third nearest neighbors, are used. Room-temperature carrier dynamics in suspended and supported graphene in the presence of different impurity distributions and densities is simulated using a numerical method that combines semiclassical carrier transport, using ensemble Monte-Carlo (EMC), with electrodynamics, using the finite-difference time-domain (FDTD) technique and molecular dynamics (MD). The electron-phonon scattering rates calculated using TB BWFs provide a better estimate of the ``bare'' acoustic and optical deformation potential constants ($D_{ac}=\SI[mode=text]{12}{\electronvolt}$, $D_{op}=\SI[mode=text]{5e9}{\electronvolt\per\centi\meter}$), while the intrinsic mobility calculated exceeds experimentally observed values and agrees with theoretical predictions based on density functional theory. Clustered impurities (average cluster size between $\SIrange[mode=text,range-phrase=-]{40}{50}{\nano\meter}$) are shown to have a significant effect on carrier transport in graphene and explain the experimentally observed average electron-hole puddle size of $\SI[mode=text]{20}{\nano\meter}$. In addition, the residual conductivity and the linear-region slope of the conductvity versus carrier density dependence are found to be determined by the impurity distribution and density, while the high-carrier-density sublinearity in the conductivity is shown to stem from carrier-carrier interactions. There is excellent agreement between the THz-conductivity calculated with clustered impurities and the experimentally measured frequency-dependent conductivity. Moreover, the choice of the substrate ($\textrm{SiO}_2$ or $h$-BN) is shown to be important below $\SI[mode=text]{4}{\tera\hertz}$ provided the ratio of impurity to carrier density ($N_i/n$) is less than $0.1$, where carrier scattering with substrate phonons dominates transport. Electron-impurity interactions govern transport for $0.1N_i/n
Download or read book Advances in Density Functional Theory and Beyond for Computational Chemistry written by Wei Hu and published by Frontiers Media SA. This book was released on 2021-09-13 with total page 116 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Coulomb Excitations and Decays in Graphene Related Systems written by Chiun-Yan Lin and published by CRC Press. This book was released on 2019-06-14 with total page 416 pages. Available in PDF, EPUB and Kindle. Book excerpt: Coulomb Excitations and Decays in Graphene-Related Systems provides an overview of the subject under the effects of lattice symmetries, layer numbers, dimensions, stacking configurations, orbital hybridizations, intralayer and interlayer hopping integrals, spin-orbital couplings, temperatures, electron/hole dopings, electric field, and magnetic quantization while presenting a new theoretical framework of the electronic properties and the electron-electron interactions together. This book presents a well-developed theoretical model and addresses important advances in essential properties and diverse excitation phenomena. Covering plenty of critical factors related to the field, the book also addresses the theoretical model which is applicable to various dimension-enriched graphene-related systems and other 2D materials, including layered graphenes, graphites, carbon nanotubes, silicene, and germanene. The text is aimed at professionals in materials science, physics, physical chemistry, and upper level students in these fields.
Download or read book Electronic Properties of Graphene Heterostructures with Hexagonal Crystals written by John R. Wallbank and published by Springer. This book was released on 2014-06-13 with total page 101 pages. Available in PDF, EPUB and Kindle. Book excerpt: The last decade has witnessed the discovery of, and dramatic progress in understanding the physics of graphene and related two-dimensional materials. The development of methods for manufacturing and aligning high-quality two-dimensional crystals has facilitated the creation of a new generation of materials: the heterostructures of graphene with hexagonal crystals, in which the graphene electrons acquire new, qualitatively different properties. This thesis provides a comprehensive theoretical framework in which to understand these heterostructures, based on the tight binding model, perturbation theory, group theory and the concept of the moire superlattice (all of which are elucidated). It explains how graphene heterostructures provide new opportunities for tailoring band structure, such as creating additional Dirac points or opening band gaps and how they manifest themselves in transport measurements, optical absorption spectra and the fractal Hofstadter spectra. Also considered are the heterostructures of bilayer graphene and resonant tunneling in aligned graphene/insulator/graphene devices.
Download or read book Structural and Electronic Properties of Graphene by DFT written by Gaurav Raj and published by . This book was released on 2020 with total page 47 pages. Available in PDF, EPUB and Kindle. Book excerpt: Understanding the structural and electronic properties of graphene is one of the major areas of focus in materials science research. The electronic properties of graphene can be altered by chemical manipulations such as doping and adsorption of impurities, therefore understanding the mechanism and energetics of doping and adsorption has a crucial role in modifying the electronic properties of graphene. In this work, using the density functional theory, we calculate the doping formation energy and adsorption energy as a function of system size and pseudopotential. We find that the adsorption energy of graphene remains constant as a function of system size. Furthermore, we observe a switch in semiconducting behavior of graphene (say from p- to n-type) when an impurity atom is added as a dopant instead of added an adsorbent on the surface of a graphene sheet. In addition, we find that N and B doped graphene flips it’s semiconducting behavior when adsorbed on graphene while O and Be show pristine-like behavior when adsorbed. Be-adsorbed graphene behaves like pure graphene because it gets adsorbed far above the graphene plane, making the interactions between graphene and Be negligible. Finally, this work clarifies the underlying reasons for large quantitative and qualitative inconsistencies in literature in terms of structural and electronic properties of graphene predicted from electronic structure calculations.
Download or read book Geometric and Electronic Properties of Graphene Related Systems written by Ngoc Thanh Thuy Tran and published by CRC Press. This book was released on 2019-12-18 with total page 214 pages. Available in PDF, EPUB and Kindle. Book excerpt: Due to its physical, chemical, and material properties, graphene has been widely studied both theoretically and experimentally since it was first synthesized in 2004. This book explores in detail the most up-to-date research in graphene-related systems, including few-layer graphene, sliding bilayer graphene, rippled graphene, carbon nanotubes, and adatom-doped graphene, among others. It focuses on the structure-, stacking-, layer-, orbital-, spin- and adatom-dependent essential properties, in which single- and multi-orbital chemical bondings can account for diverse phenomena. Geometric and Electronic Properties of Graphene-Related Systems: Chemical Bonding Schemes is excellent for graduate students and researchers, but understandable to undergraduates. The detailed theoretical framework developed in this book can be used in the future characterization of emergent materials.
Download or read book Graphene Electrolyte Interfaces written by Hualin Zhan and published by CRC Press. This book was released on 2020-04-07 with total page 156 pages. Available in PDF, EPUB and Kindle. Book excerpt: Graphene–electrolyte systems are commonly found in cutting-edge research on electrochemistry, biotechnology, nanoelectronics, energy storage, materials engineering, and chemical engineering. The electrons in graphene intimately interact with ions from an electrolyte at the graphene–electrolyte interface, where the electrical or chemical properties of both graphene and electrolyte could be affected. The electronic behavior therefore determines the performance of applications in both Faradaic and non-Faradaic processes, which require intensive studies. This book systematically integrates the electronic theory and experimental techniques for both graphene and electrolytes. The theoretical sections detail the classical and quantum description of electron transport in graphene and the modern models for charges in electrolytes. The experimental sections compile common techniques for graphene growth/characterization and electrochemistry. Based on this knowledge, the final chapter reviews a few applications of graphene–electrolyte systems in biosensing, neural recording, and enhanced electronic devices, in order to inspire future developments. This multidisciplinary book is ideal for a wide audience, including physicists, chemists, biologists, electrical engineers, materials engineers, and chemical engineers.
Download or read book Electronic Properties of Rhombohedral Graphite written by Servet Ozdemir and published by Springer Nature. This book was released on 2021-10-25 with total page 142 pages. Available in PDF, EPUB and Kindle. Book excerpt: This thesis presents the first systematic electron transport investigation of rhombohedral graphite (RG) films and thus lies at the interface of graphene physics, vdW heterostructure devices and topological matter. Electron transport investigation into the rhombohedral phase of graphite was limited to a few layers of graphene due to the competing hexagonal phase being more abundant. This work reports that in exfoliated natural graphite films, rhombohedral domains of up to 50 layers can be found. In the low energy limit, these domains behave as an N-layer generalisation of graphene. Moreover, being a potential alternative to twisted bilayer graphene systems, RG films show a spontaneous metal-insulator transition, with characteristic symmetry properties that could be described by mean-field theory where superconductivity is also predicted in these low energy bands. A nodal-line semimetal in the bulk limit, RG thin films are a 3D generalisation of the simplest topological insulator model: the Su-Schrieffer-Heeger chain. Similar to the more usual topological insulators, RG films exhibit parallel conduction of bulk states, which undergo three-dimensional quantum transport that reflects bulk topology.
Download or read book Experimental and Theoretical Studies on Electronic Properties of Graphene written by Jie Pan and published by . This book was released on 2016 with total page 138 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Theoretical Studies of Structural Electronic and Optical Properties of Graphene Based Systems written by Celal Yelgel and published by . This book was released on 2013 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Electronic Properties of Heterostructures of 2D Materials written by Wafa Hadadi and published by . This book was released on 2020 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Researchers have recently become interested in two-dimensional materials such as graphene, hexagonal boron nitride (h-BN), Transition Metal Dichalcogenides (TMDs), etc. Their 2D hexagonal structures result in unique properties, which make these materials attractive for scientists and engineers. In this work, we investigated the electronic properties of graphene, h-BN, and MoS2 based on density functional theory (DFT). We first studied the electronic properties of monolayers of different materials. We found a zero bandgap and observed massless Dirac Hamiltonian in graphene. For h-BN, a large bandgap at K-point was observed. Also, we observed the bandgap opening in MoS2 and a strong splitting of its bands. Then, we extended these studies to graphene and h-BN bilayers. For graphene bilayer, we observed a gapless material and massive Dirac fermions. For h-BN bilayer, an indirect bandgap was observed, smaller in comparison with its monolayer. The main focus of this study was the investigation of graphene/h-BN heterostructures for different stacking configurations. The suitability of h-BN as a substrate for graphene is due to its small lattice constant mismatch with graphene and its high insulating gap (~ 5 eV). Another important aspect to be observed in graphene/h-BN heterostructures is the gap opening brought by the h-BN layer proximity to the initially gapless graphene layer. We found the effect of bandgap opening in graphene/h- BN and determined the most stable configuration which is the AB[CB]. This work supports the findings of many researchers who demonstrate that graphene/h-BN heterostructures are very useful as building blocks for nanodevices with desirable electronic properties.
