Download or read book Electronic Properties of Graphene and Boron Nitride Nanoribbon Junctions written by Gihan Uthpala Panapitiya and published by . This book was released on 2013 with total page 87 pages. Available in PDF, EPUB and Kindle. Book excerpt: Graphene, the most recently extracted allotrope of carbon has attracted the interest of the scientific community, due to its remarkable electronic properties. Even though the two dimensional undoped graphene is considered as a semiconductor without a band gap, its one dimensional counterpart, graphene nanoribbons, which are stripes of graphene with nanometer sized widths[1], posses a tunable band gap which depends on their widths. In this study, we mainly investigate the electronic properties of structures constructed using graphene nanoribbons to find the relationship between their band gaps and the corresponding structural and geometrical properties. The electronic band structures of both monolayer and bi-layer cross-like junctions are modeled using the p orbital tight binding method. It is shown that for a given structure, the shapes of the energy bands near the Fermi level depend on the dimensions of the structure to a considerable extent. Further, it is proven that the structural dimensions and the number of atoms on the zigzag edges of the nanoribbons have a significant effect on the magnitude of the direct band gap. This computational experiment is also extended to study the Borin Nitride-Boron Nitride and graphene-Boron Nitride bi-layer nano structures. It is shown that the patterns of band gap changes in Graphene-Boron Nitrde bi-layer systems with respect to certain geometrical parameters are similar to that in graphene-graphene systems. The results of this study provides a basis to fine tune the band gaps of monolayer and bi-layer junctions.

Download or read book The Electronic Properties of Hexagonal Boron Nitride and Graphene Nanoribbons written by Albert C. DiBenedetto and published by . This book was released on 2017 with total page 163 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Transport Studies of the Electronic Properties of Graphene on Hexagonal Boron Nitride written by Peng Wang and published by . This book was released on 2015 with total page 106 pages. Available in PDF, EPUB and Kindle. Book excerpt: Chapter 5 discusses measurements of short BN/G/BN cavities. The high quality BN/G/BN devices exhibit ballistic transport behavior - Fabry-Pérot oscillations. The effects of magnetic field on the system are also investigated, showing signatures of "pseudodiffussive" transport at the charge neutrality point for finite fields.

Download or read book Electronic Optical and Phononic Properties of Graphene Boron Nitride and Related Materials written by CHEOL HWAN. PARK and published by . This book was released on 2009 with total page 442 pages. Available in PDF, EPUB and Kindle. Book excerpt: Since the isolation of graphene, a single layer of carbon atoms in honeycomb structure, in 2004, this new material has gotten huge attention from communities in physics, chemistry, materials science, and engineering not only because the charge carriers of graphene show neutrino-like linear energy dispersion as well as chiral behavior near the Dirac point but also because graphene is considered to be a promising candidate for nano- and micro-scale electronic and spintronic device applications. On the other hand, a hexagonal sheet of boron nitride has a similar honeycomb-like structure, except that the two different sublattices are occupied by boron and nitrogen atoms, respectively. Notwithstanding its structural similarity to graphene, a hexagonal boron nitride sheet is an insulator with a large bandgap and is considered to be useful to optical applications such as ultra-violet lasers. In this work, we investigate the electronic, optical, and vibrational properties of graphene, hexagonal boron nitride, and related materials such as nanotubes or nanoribbons from first-principles calculations as well as from simple model considerations. In the first chapter, we briefly review the methodologies used in our work such as density functional theory, the GW approximation, the Bethe-Salpeter equation method, and density functional perturbation theory. In the following four chapters (2-5), we discuss the calculated spectral features of graphene and compare the results mainly with recent angle-resolved photoemission experiments. In our work, we have explicitly taken into account the effects of electron-electron and electron-phonon interactions from first-principles. Our calculations reproduce some of the key experimental observations related to many-body effects, including a mismatch between the upper and lower halves of the Dirac cone and the non-trivial energy dependence of carrier linewidths on the binding energy. The following three chapters (6-8) are on bilayer graphene. In chapters 6 and 7, we discuss the effects of many-body interactions on the dynamics of electrons and phonons in bilayer graphene, in similar ways as in chapters 2 to 5. We show that the interlayer interaction between the two graphene layers change electron-phonon and electron-electron interactions. In chapter 8, we discuss the excitons in biased bilayer graphene. We show that bound excitons qualitatively change the optical response of this novel material. In the following four chapters (9-12), we discuss the interesting behaviors of charge carriers in graphene subjected to an external periodic potential. For example, we show that the carrier group velocity is anisotropically reduced and that, under certain conditions, electrons can be supercollimated. We also discuss newly generated massless Dirac fermions in graphene superlattices as well as their signatures in quantum Hall conductance measurements. In chapter 13, we discuss the possibility of generating massless Dirac fermions in a conventional two-dimensional electron gas with an external periodic potential, i.e., a way of making artificial graphene. In the last four chapters, we discuss several different aspects of boron nitride compounds. In chapter 14, we present the calculated electronic energy bandgaps and effective masses of boron nitride nanoribbons and their changes in response to a transverse electric field. In chapters 15 and 16, we discuss excitons and optical response of boron nitride nanotubes and bulk hexagonal boron nitride, respectively. Finally, in the last chapter, we discuss a novel behavior of electric dipole moment reversal upon hydrogen passivation in boron nitride as well as other III-V or II-VI compound nanostructures.

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 Properties of Misoriented Two dimensional Materials written by Supeng Ge and published by . This book was released on 2017 with total page 94 pages. Available in PDF, EPUB and Kindle. Book excerpt: Van der Waals (vdW) heterostructures assembled from monolayers (one or a few) of graphene, hexagonal boron nitride (h-BN) are emerging as a new paradigm with which to attain desired electronic properties. Graphene/h-BN heterostructures have higher carrier mobility and better device performance when compared with traditional devices of graphene on SiO2/Si substrate. Vertical interlayer tunneling in Gr/BN/Gr structures display negative differential resistance (NDR). These exceptional electrical properties has attracted intense attentions for energy band engineering and device performance optimization. Interlayer electron transport through a graphene / hexagonal boron-nitride (h-BN) / graphene heterostructure is strongly affected by the misorientation angle & thetas; of the h-BN with respect to the graphene layers with different physical mechanisms governing the transport in different regimes of angle, Fermi level, and bias. The different mechanisms and their resulting signatures in resistance and current are analyzed using two different models, a tight-binding, non-equilibrium Green function model and an effective continuum model, and the qualitative features resulting from the two different models compare well. In the large-angle regime (& thetas;> 4°), the change in the effective h-BN bandgap seen by an electron at the K point of the graphene causes the resistance to monotonically increase with angle by several orders of magnitude reaching a maximum at & thetas; = 30°. It does not affect the peak-to-valley current ratios in devices that exhibit negative differential resistance. In the small-angle regime (& thetas;

Download or read book Phosphorene Physical Properties Synthesis and Fabrication written by Yongqing Cai and published by CRC Press. This book was released on 2019-09-16 with total page 293 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book is the first attempt to systematically present the knowledge and research progress of phosphorene, another elemental 2D material that can be exfoliated by mechanical or liquid methods as the intensively studied graphene. The book provides a comprehensive overview of the synthesis, growth, characterization, and applications of phosphorene. It also compiles cutting-edge research in the related field with respect to thermal conduction, transistors, and electrochemical applications and encompasses the intrinsic properties (structural, electronic, defective, and phononic) of phosphorene. This book provides detailed mechanisms of phenomena observed for phosphorene. It will benefit graduate students of physics, chemistry, electrical and electronics engineering, and materials science and engineering; researchers in nanoscience working on phosphorene and similar 2D materials; and engineers and anyone involved in nanotechnology, nanoelectronics, materials preparation, and device fabrication based on layered materials.

Download or read book Structure and Adatom Enriched Essential Properties of Graphene Nanoribbons written by Shih-Yang Lin and published by CRC Press. This book was released on 2018-11-19 with total page 444 pages. Available in PDF, EPUB and Kindle. Book excerpt: Structure- and Adatom-Enriched Essential Properties of Graphene Nanoribbons offers a systematic review of the feature-rich essential properties in emergent graphene nanoribbons, covering mainstream theoretical and experimental research. It includes a wide range of 1D systems; namely, armchair and zigzag graphene nanoribbons with and without hydrogen terminations, curved and zipped graphene nanoribbons, folded graphene nanoribbons, carbon nanoscrolls, bilayer graphene nanoribbons, edge-decorated graphene nanoribbons, and alkali-, halogen-, Al-, Ti, and Bi-absorbed graphene nanoribbons. Both multiorbital chemical bondings and spin arrangements, which are responsible for the diverse phenomena, are explored in detail. First-principles calculations are developed to thoroughly describe the physical, chemical, and material phenomena and concise images explain the fundamental properties. This book examines in detail the application and theory of graphene nanoribbons, offering a new perspective on up-to-date mainstream theoretical and experimental research.

Download or read book 2D Materials written by Phaedon Avouris and published by Cambridge University Press. This book was released on 2017-06-29 with total page 521 pages. Available in PDF, EPUB and Kindle. Book excerpt: Learn about the most recent advances in 2D materials with this comprehensive and accessible text. Providing all the necessary materials science and physics background, leading experts discuss the fundamental properties of a wide range of 2D materials, and their potential applications in electronic, optoelectronic and photonic devices. Several important classes of materials are covered, from more established ones such as graphene, hexagonal boron nitride, and transition metal dichalcogenides, to new and emerging materials such as black phosphorus, silicene, and germanene. Readers will gain an in-depth understanding of the electronic structure and optical, thermal, mechanical, vibrational, spin and plasmonic properties of each material, as well as the different techniques that can be used for their synthesis. Presenting a unified perspective on 2D materials, this is an excellent resource for graduate students, researchers and practitioners working in nanotechnology, nanoelectronics, nanophotonics, condensed matter physics, and chemistry.

Download or read book Ultrathin Two Dimensional Semiconductors for Novel Electronic Applications written by Mohammad Karbalaei Akbari and published by CRC Press. This book was released on 2020-07-30 with total page 277 pages. Available in PDF, EPUB and Kindle. Book excerpt: Offering perspective on both the scientific and engineering aspects of 2D semiconductors, Ultrathin Two-Dimensional Semiconductors for Novel Electronic Applications discusses how to successfully engineer 2D materials for practical applications. It also covers several novel topics regarding 2D semiconductors which have not yet been discussed in any other publications. Features: Provides comprehensive information and data about wafer-scale deposition of 2D semiconductors, ranging from scientific discussions up to the planning of experiments and reliability testing of the fabricated samples Precisely discusses wafer-scale ALD and CVD of 2D semiconductors and investigates various aspects of deposition techniques Covers the new group of 2D materials synthesized from surface oxide of liquid metals and also explains the device fabrication and post-treatment of these 2D nanostructures Addresses a wide range of scientific and practical applications of 2D semiconductors and electronic and optoelectronic devices based on these nanostructures Offers novel coverage of 2D heterostructures and heterointerfaces and provides practical information about fabrication and application of these heterostructures Introduces the latest advancement in fabrication of novel memristors, artificial synapses and sensorimotor devices based on 2D semiconductors This work offers practical information valuable for engineering applications that will appeal to researchers, academics, and scientists working with and interested in developing an array of semiconductor electronic devices.

Download or read book Chemical Vapor Deposition Growth and Characterization of Two Dimensional Hexagonal Boron Nitride written by Roland Yingjie Tay and published by Springer. This book was released on 2018-06-20 with total page 152 pages. Available in PDF, EPUB and Kindle. Book excerpt: This thesis focuses on the growth of a new type of two-dimensional (2D) material known as hexagonal boron nitride (h-BN) using chemical vapor deposition (CVD). It also presents several significant breakthroughs in the authors’ understanding of the growth mechanism and development of new growth techniques, which are now well known in the field. Of particular importance is the pioneering work showing experimental proof that 2D crystals of h-BN can indeed be hexagonal in shape. This came as a major surprise to many working in the 2D field, as it had been generally assumed that hexagonal-shaped h-BN was impossible due to energy dynamics. Beyond growth, the thesis also reports on synthesis techniques that are geared toward commercial applications. Large-area aligned growth and up to an eightfold reduction in the cost of h-BN production are demonstrated. At present, all other 2D materials generally use h-BN as their dielectric layer and for encapsulation. As such, this thesis lays the cornerstone for using CVD 2D h-BN for this purpose.

Download or read book Graphene Science Handbook written by Mahmood Aliofkhazraei and published by CRC Press. This book was released on 2016-04-27 with total page 719 pages. Available in PDF, EPUB and Kindle. Book excerpt: Discover the Unique Electron Transport Properties of GrapheneThe Graphene Science Handbook is a six-volume set that describes graphene's special structural, electrical, and chemical properties. The book considers how these properties can be used in different applications (including the development of batteries, fuel cells, photovoltaic cells, and s

Download or read book Electronic Properties of Graphene Nanoribbons with AA stacking Order written by and published by . This book was released on 2015 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Graphene Science Handbook Six Volume Set written by Mahmood Aliofkhazraei and published by CRC Press. This book was released on 2016-04-26 with total page 3379 pages. Available in PDF, EPUB and Kindle. Book excerpt: Graphene is the strongest material ever studied and can be an efficient substitute for silicon. This six-volume handbook focuses on fabrication methods, nanostructure and atomic arrangement, electrical and optical properties, mechanical and chemical properties, size-dependent properties, and applications and industrialization. There is no other major reference work of this scope on the topic of graphene, which is one of the most researched materials of the twenty-first century. The set includes contributions from top researchers in the field and a foreword written by two Nobel laureates in physics. Volumes in the set: K20503 Graphene Science Handbook: Mechanical and Chemical Properties (ISBN: 9781466591233) K20505 Graphene Science Handbook: Fabrication Methods (ISBN: 9781466591271) K20507 Graphene Science Handbook: Electrical and Optical Properties (ISBN: 9781466591318) K20508 Graphene Science Handbook: Applications and Industrialization (ISBN: 9781466591332) K20509 Graphene Science Handbook: Size-Dependent Properties (ISBN: 9781466591356) K20510 Graphene Science Handbook: Nanostructure and Atomic Arrangement (ISBN: 9781466591370)

Download or read book Geometry induced Rich Electronic Properties in Graphene Nanoribbon written by 張勝琳 and published by . This book was released on 2014 with total page 85 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Physics and Chemistry of Graphene Second Edition written by Toshiaki Enoki and published by CRC Press. This book was released on 2019-11-01 with total page 660 pages. Available in PDF, EPUB and Kindle. Book excerpt: Graphene has been attracting growing attentions in physics, chemistry, and device applications after the discovery of micromechanically cleaved graphene sheet by A. Geim and K. Novoselov, who were awarded the 2010 Nobel Prize in Physics. The electronic structure of graphene, which is described in terms of massless Dirac fermions, brings about unconventional electronic properties, which are not only an important basic issue in condensed matter physics but also a promising target of cutting-edge electronics/spintronics device applications. Meanwhile, from chemistry aspect, graphene is the extreme of condensed polycyclic hydrocarbon molecules extrapolated to infinite size. Here, the concept on aromaticity, which organic chemists utilize, is applicable. Interesting issues appearing between physics and chemistry are pronounced in nanosized graphene (nanographene), as we recognize the importance of the shape of nanographene in understanding its electronic structure. This book comprehensively discusses the fundamental issues related to the electronic, magnetic, and chemical properties of condensed polycyclic hyodrocarbon molecules, nanographene, and graphene.

Download or read book Engineering the Electronic Structure of Atomically precise Graphene Nanoribbons written by Giang Duc Nguyen and published by . This book was released on 2006 with total page 102 pages. Available in PDF, EPUB and Kindle. Book excerpt: Graphene nanoribbons (GNRs) have recently attracted great interest because of their novel electronic and magnetic properties, as well as their significant potential for device applications. Although several top-down techniques exist for fabricating GNRs, only bottom-up synthesis of GNRs from molecular precursors yields nanoribbons with atomic-scale structural control. Furthermore, precise incorporation of dopant species into GNRs, which is possible with bottom-up synthesis, is a potentially powerful way to control the electronic structure of GNRs. However, it is not well understood how these dopants affect the electronic structure of GNRs. Are these effects dependent on the dopant site? Can the band gap be tuned by doping? This dissertation helps to answer these questions through studying the electronic structure of bottom-up grown GNRs with controlled atomic dopants. The effects of edge and interior doping with different atomic species such as sulfur, boron and ketone were investigated and showed significant site dependence. Topographic and local electronic structure characterization was performed via scanning tunneling microscopy & spectroscopy (STM & STS) and compared to first-principle calculations. The chemical structure of GNRs and GNR heterojunctions was characterized by CO-tip-functionalized non-contact atomic force microscopy (nc-AFM) as well as by a newly developed technique of bond-resolved STM (BRSTM). In an effort to develop a new method for directly synthesizing GNRs on an insulating substrate, we also studied light-induced photo-isomerization of azobenzene molecules adsorbed on an insulating surface of CVD-grown monolayer boron nitride (BN) on Cu(111). This study provides important insights into molecular behavior on an insulating surface, how to couple light to an STM system, and how to utilize local field enhancement effects due to surface plasmon resonance.