Download or read book Electronic and Optical Properties of Two Dimensional Transition Metal Dichalcogenide Nanoribbons written by Santosh Neupane and published by . This book was released on 2023 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: Two-dimensional (2D) layered materials, such as transition metal dichalcogenides (TMDs), are the subject of intense research interest as platforms for both developing atomically-thin devices and exploring novel physics. Nanoribbons are intriguing, reduced forms of 2D layered materials. They exhibit more spatial confinement effects and rich edge states than their 2D counterparts, which can result in drastic changes in electronic and optical properties. This dissertation presents an investigation of the electronic structure properties of bent TMDs nanoribbons using density functional theory (DFT) and explores their optical absorption and excitonic states through many-body perturbation GW and BSE (Bethe-Salpeter equation) methods.The band structures, band gaps, and projected spin polarization of semiconducting armchair tungsten diselenide (WSe2) nanoribbons are calculated under various bending curvatures and electron/hole doping using density functional approximations (DFAs). Additionally, optical absorption and excitonic states are analyzed using the many-body perturbation GW-BSE approach. The findings reveal that the band gap of the nanoribbon can be modified from direct to indirect or vice versa under appropriate bending curvatures. Furthermore, doping or bending the nanoribbons with proper curvatures leads to spin polarization anisotropy within the bands around the Fermi level. This suggests their potential utilization in compact and controllable magnetic nanodevices and spintronics. The exciton states exhibit mixed or various spin configurations in the electron and hole pairs, which are controlled by the bending, and hold promise for applications in spin-based quantum information processes. Defects are commonly present in 2D TMD materials and significantly alter their properties. The interaction between edge states and defect states in tungsten disulfide (WS2) nanoribbons with line defects under different bending curvatures is investigated using density functional theory (DFT). The results are compared with quasiparticle GW calculations to gain insights into the limitations of DFAs for band gaps and energies of defect states. The investigations uncover interesting semiconducting-to-metallic phase transitions, indicating potential applications in nano-electronics or molecular electronics. Moreover, optical absorption of the bent and defective nanoribbons is calculated using the many-body GW-BSE approach, revealing a tunable optical spectrum and diverse exciton states in the defective WS2 nanoribbons.
Download or read book Two Dimensional Transition Metal Dichalcogenides written by Alexander V. Kolobov and published by Springer. This book was released on 2016-07-26 with total page 545 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book summarizes the current status of theoretical and experimental progress in 2 dimensional graphene-like monolayers and few-layers of transition metal dichalcogenides (TMDCs). Semiconducting monolayer TMDCs, due to the presence of a direct gap, significantly extend the potential of low-dimensional nanomaterials for applications in nanoelectronics and nano-optoelectronics as well as flexible nano-electronics with unprecedented possibilities to control the gap by external stimuli. Strong quantum confinement results in extremely high exciton binding energies which forms an interesting platform for both fundamental studies and device applications. Breaking of spatial inversion symmetry in monolayers results in strong spin-valley coupling potentially leading to their use in valleytronics. Starting with the basic chemistry of transition metals, the reader is introduced to the rich field of transition metal dichalcogenides. After a chapter on three dimensional crystals and a description of top-down and bottom-up fabrication methods of few-layer and single layer structures, the fascinating world of two-dimensional TMDCs structures is presented with their unique atomic, electronic, and magnetic properties. The book covers in detail particular features associated with decreased dimensionality such as stability and phase-transitions in monolayers, the appearance of a direct gap, large binding energy of 2D excitons and trions and their dynamics, Raman scattering associated with decreased dimensionality, extraordinarily strong light-matter interaction, layer-dependent photoluminescence properties, new physics associated with the destruction of the spatial inversion symmetry of the bulk phase, spin-orbit and spin-valley couplings. The book concludes with chapters on engineered heterostructures and device applications such as a monolayer MoS2 transistor. Considering the explosive interest in physics and applications of two-dimensional materials, this book is a valuable source of information for material scientists and engineers working in the field as well as for the graduate students majoring in materials science.
Download or read book Two Dimensional Transition Metal Dichalcogenides written by Narayanasamy Sabari Arul and published by Springer. This book was released on 2019-07-30 with total page 355 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book presents advanced synthesis techniques adopted to fabricate two-dimensional (2D) transition metal dichalcogenides (TMDs) materials with its enhanced properties towards their utilization in various applications such as, energy storage devices, photovoltaics, electrocatalysis, electronic devices, photocatalysts, sensing and biomedical applications. It provides detailed coverage on everything from the synthesis and properties to the applications and future prospects of research in 2D TMD nanomaterials.
Download or read book Two Dimensional Transition Metal Dichalcogenides written by Chi Sin Tang and published by John Wiley & Sons. This book was released on 2023-11-14 with total page 357 pages. Available in PDF, EPUB and Kindle. Book excerpt: Two-Dimensional Transition-Metal Dichalcogenides Comprehensive resource covering rapid scientific and technological development of polymorphic two-dimensional transition-metal dichalcogenides (2D-TMDs) over a range of disciplines and applications Two-Dimensional Transition-Metal Dichalcogenides: Phase Engineering and Applications in Electronics and Optoelectronics provides a discussion on the history of phase engineering in 2D-TMDs as well as an in-depth treatment on the structural and electronic properties of 2D-TMDs in their respective polymorphic structures. The text addresses different forms of in-situ synthesis, phase transformation, and characterization methods for 2D-TMD materials and provides a comprehensive treatment of both the theoretical and experimental studies that have been conducted on 2D-TMDs in their respective phases. Two-Dimensional Transition-Metal Dichalcogenides includes further information on: Thermoelectric, fundamental spin-orbit structures, Weyl semi-metallic, and superconductive and related ferromagnetic properties that 2D-TMD materials possess Existing and prospective applications of 2D-TMDs in the field of electronics and optoelectronics as well as clean energy, catalysis, and memristors Magnetism and spin structures of polymorphic 2D-TMDs and further considerations on the challenges confronting the utilization of TMD-based systems Recent progress of mechanical exfoliation and the application in the study of 2D materials and other modern opportunities for progress in the field Two-Dimensional Transition-Metal Dichalcogenides provides in-depth review introducing the electronic properties of two-dimensional transition-metal dichalcogenides with updates to the phase engineering transition strategies and a diverse range of arising applications, making it an essential resource for scientists, chemists, physicists, and engineers across a wide range of disciplines.
Download or read book Electronic Structure and Mechanical Properties of Two Dimensional Transition Metal Dichalcogenides written by Oday Kadhim and published by . This book was released on 2020 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Properties of Synthetic Two Dimensional Materials and Heterostructures written by Yu-Chuan Lin and published by Springer. This book was released on 2018-10-23 with total page 150 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book represents a significant advance in our understanding of the synthesis and properties of two-dimensional (2D) materials. The author’s work breaks new ground in the understanding of a number of 2D crystals, including atomically thin transition metal dichalcogenides, graphene, and their heterostructures, that are technologically important to next-generation electronics. In addition to critical new results on the direct growth of 2D heterostructures, it also details growth mechanisms, surface science, and device applications of “epi-grade” 2D semiconductors, which are essential to low-power electronics, as well as for extending Moore’s law. Most importantly, it provides an effective alternative to mechanically exfoliate 2D layers for practical applications.
Download or read book Electronic and Optical Properties of Graphene like Two dimensional Materials written by and published by . This book was released on 2023 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Engineering Optical and Thermal Properties of Two Dimensional Transition Metal Dichalcogenide Monolayer written by Lujun Huang and published by . This book was released on 2017 with total page 120 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Crystallization of Two dimensional Transition Metal Dichalcogenides for Tailored Optical Properties written by Rachel H. Rai and published by . This book was released on 2019 with total page 123 pages. Available in PDF, EPUB and Kindle. Book excerpt: Two dimensional (2D) semiconducting transition metal dichalcogenides (TMD) are new materials that exhibit unique and useful combinations of physical properties, such as photoluminescence (PL) in the visible to NIR frequencies coupled with mechanical flexibility. Such properties make 2D TMDs attractive candidates for the next generation of compact, unobtrusive, and low-cost opto-electronic technologies. However, the incorporation of 2D TMDs in commercial applications and products is currently limited by the absence of synthesis approaches yielding uniform, large area films with desired properties. Thus, this work encompasses innovative techniques to tailor optical properties of TMD thin films by controlling their area, thickness, grain size, defect density and uniformity during and after processing. These new approaches start with magnetron sputtering of ultra-thin amorphous TMD films on either flexible or rigid substrates. The amorphous precursor films were then subjected to illumination with energy beams to induce crystallization, including laser light, broadband radiation from a xenon lamp, and nanoscale electron beams. Magnetron sputtering was selected as the precursor deposition technique due to the large area capability coupled with low processing temperatures, allowing deposition directly on polymer substrates. Furthermore, modulation of the energy flux to the growing film during magnetron sputtering (by controlling the flux of incident energetic particles) provided an opportunity to control the density of pre-existing nuclei in the amorphous material for an added measure of structural control upon illumination. The structure, composition and optical properties of crystalline 2D TMD materials on flexible and rigid substrates after illumination, were then correlated to the pre-existing amorphous structure and process conditions for selected TMD compositions. Important conclusions from the work include significant insight on the mechanisms of crystallization kinetics, as well as new correlations of structure to optical properties, including a dependence on photoluminescence intensity accompanied by a change in crystal edge density, correlating well to theory. In summary, this work employs various crystallization techniques to understand nucleation and growth of 2D TMD materials, and application of nucleation and growth mechanisms to control optical properties.
Download or read book Optical Properties of 2D Transition Metal Dichalcogenides Enhanced by Plasmonic Nanostructures written by Zhuo Wang and published by . This book was released on 2017 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
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 2D Semiconductor Materials and Devices written by Dongzhi Chi and published by Elsevier. This book was released on 2019-10-19 with total page 339 pages. Available in PDF, EPUB and Kindle. Book excerpt: 2D Semiconductor Materials and Devices reviews the basic science and state-of-art technology of 2D semiconductor materials and devices. Chapters discuss the basic structure and properties of 2D semiconductor materials, including both elemental (silicene, phosphorene) and compound semiconductors (transition metal dichalcogenide), the current growth and characterization methods of these 2D materials, state-of-the-art devices, and current and potential applications. - Reviews a broad range of emerging 2D electronic materials beyond graphene, including silicene, phosphorene and compound semiconductors - Provides an in-depth review of material properties, growth and characterization aspects—topics that could enable applications - Features contributions from the leading experts in the field
Download or read book A Study of Transition Metal Dichalcogenides written by Sarah Michelle Bobek and published by . This book was released on 2016 with total page 123 pages. Available in PDF, EPUB and Kindle. Book excerpt: Highly photosensitive, tunable direct band gap materials of subnanometer thickness represent an important path forward in minimization of opto-electronic devices. It is inevitable that the scale of devices will soon move beyond the 2 nm node. With the ever decreasing scale of devices, two dimensional transition metal dichalcogenides (TMDs) offer a promising avenue towards reduced dimensionality and unveil novel direct-indirect band gap shift tuning capabilities by means of thickness, and composition. A primary goal of this work is to investigate bottom-up approaches to fabrication of integrated materials systems using chemical vapor deposition (CVD) grown TMDs. In that vein, this thesis presented examines the methods for growth of the transition metal dichalcogenide materials on a variety of metal oxide terminated substrates, graphene and directly onto an economical photocathode for the hydrogen evolution reaction in water splitting. Where the limits of CVD process preclude bottom-up fabrication, the research presents methods to vertically stack CVD-grown two dimensional materials and deposit them on arbitrary substrates via physical transfer techniques allowing for a single step process to obtain CVD grown TMDs on flexible substrates. Executing physical transfer allows us to reach the final goal of this work, to investigate a third type of optical tuning, that of uniaxial mechanical strain. The thesis probes a mechanical strain induced shift in the optical behavior of the MX2 (M=Mo, W; X=S, Se) materials.
Download or read book Investigation of Two Dimensional Transition Metal Dichalcogenides by Optical and Scanning Tunneling Spectroscopy written by and published by . This book was released on 2016 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: The latter portion of this dissertation will cover the nanoscopic dynamics of TMDC heterostructures. The Kramers-Kronig relations will be derived and discussed in detail. Data and results regarding the electronic structure of these materials, their heterostructures, and their custom alloys measured via scanning tunneling microscopy will be presented. Coupled with the measured optical properties, significant numerical quantities that characterize these materials are extracted. There will be several appendices that offer some supplementary information and basic summaries about all the projects that were initiated.
Download or read book Optical and Electrical Characterization of Two dimensional Transition Metal Dichalcogenides written by 陈曦 and published by . This book was released on 2016 with total page 228 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book 2D Metal Carbides and Nitrides MXenes written by Babak Anasori and published by Springer Nature. This book was released on 2019-10-30 with total page 534 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book describes the rapidly expanding field of two-dimensional (2D) transition metal carbides and nitrides (MXenes). It covers fundamental knowledge on synthesis, structure, and properties of these new materials, and a description of their processing, scale-up and emerging applications. The ways in which the quickly expanding family of MXenes can outperform other novel nanomaterials in a variety of applications, spanning from energy storage and conversion to electronics; from water science to transportation; and in defense and medical applications, are discussed in detail.
Download or read book Two dimensional Materials written by Pramoda Kumar Nayak and published by BoD – Books on Demand. This book was released on 2016-08-31 with total page 282 pages. Available in PDF, EPUB and Kindle. Book excerpt: There are only a few discoveries and new technologies in materials science that have the potential to dramatically alter and revolutionize our material world. Discovery of two-dimensional (2D) materials, the thinnest form of materials to ever occur in nature, is one of them. After isolation of graphene from graphite in 2004, a whole other class of atomically thin materials, dominated by surface effects and showing completely unexpected and extraordinary properties, has been created. This book provides a comprehensive view and state-of-the-art knowledge about 2D materials such as graphene, hexagonal boron nitride (h-BN), transition metal dichalcogenides (TMD) and so on. It consists of 11 chapters contributed by a team of experts in this exciting field and provides latest synthesis techniques of 2D materials, characterization and their potential applications in energy conservation, electronics, optoelectronics and biotechnology.
