Download or read book Tailored Growth of Transition Metal Dichalcogenide Monolayers and Heterostructures for Electronic and Optoelectronic Applications written by Ziyang Gan and published by . This book was released on 2024* with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: 2D transition metal dichalcogenides (TMDs) and their heterostructures have shown great potential for next-generation device applications due to their unique and versatile electronic, optical and chemical properties. However, to exploit their potential in applications, it is crucial to establish reliable and reproducible synthesis methods for these atomically thin materials. In addition, efficient strategies for their synthesis with tailored properties must be developed. This work focuses on developing chemical vapor deposition (CVD) growth techniques for a range of TMD monolayers and their heterostructures, understanding the underlying growth mechanism, investigating their structure-property relationships, and exploring their functional applications. The work starts with the development of MoSe2-WSe2 lateral heterostructures, demonstrating the formation of high-quality atomically sharp p-n junctions. The synthesis of Janus SeMoS TMDs, with their unique asymmetric atomic configurations, presents the emergence of novel optical phenomena such as valley Zeeman splitting. The work also innovates in the direct growth of TMD monolayers on curved photonic structures, expanding the potential for photonic applications. In addition, a novel area selective growth technique using micromolding in capillaries (MIMIC) is introduced, leading to high-quality TMD patterns for advanced electronic and optoelectronic devices.

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 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 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 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 Catalytic and Electronic Activity of Transition Metal Dichalcogenides Heterostructures written by Baichang Li and published by . This book was released on 2021 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: The synthesis of transition metal dichalcogenides (TMDs) are crucial to realization of their real-world applications in electronic, optoelectronic and chemical devices. However, the fabrication yield in terms of material quality, crystal size, defect density are poorly controlled. In this work, by employing the up-to-date stack-and-transfer and nano fabrication techniques, synthetic TMDs that obtained from different growth methods with various crystal qualities were studied. In most of the cases, better crystals with lower defect densities and larger crystal domain sizes are preferred. Self-flux method was developed to obtain better quality crystals comparing to the traditional chemical vapor transport, as characterized by lower defect densities. BN encapsulating graphene device platform was utilized and TMDs monolayers with different defect densities was inserted in between the BN/graphene interface, where intrinsic defects from the TMDs disturbed the electronic environment of graphene.

Download or read book Direct Synthesis of Semiconducting Transition Metal Dichalcogenide Monolayers and Heterojunctions by Chemical Vapor Deposition written by Jonathan Caplette Shaw and published by . This book was released on 2016 with total page 105 pages. Available in PDF, EPUB and Kindle. Book excerpt: Since the isolation of graphene in 2004, interest regarding two-dimensional materials properties and their synthesis has exploded. Group VIb transition metal dichalcogenides (MX2: M=Mo, W; X = S, Se) are a class of layered semiconductors that show unique layer-number dependent electronic and optical properties. For example, bulk three-dimensional MoS2 is an indirect band gap semiconductor with a 1.2 eV band gap, while monolayer MoS2 nanohseet is a direct band gap semiconductor with a 1.8 eV energy gap. This exciting change in electronic structure opens several possibilities towards implementing these materials in novel device assemblies such as field effect transistors, electroluminescent devices, and flexible optoelectronic devices. While these materials offer great promise, isolating transition metal dichalcogenide monolayers requires tedious mechanical exfoliations using scotch tape, which is neither practical nor scalable for production. In the first part of my dissertation, we investigated the synthesis of MoS2 and WS2 monolayers using chemical vapor deposition. The isolated nanosheets were single crystal, triangular, and had edge lengths up to 100 m. In the next chapter, by utilizing H2 gas in a chemical vapor deposition apparatus, MoSe2 monolayers and few-layers were also synthesized. The MoSe2 nanosheets exhibited thickness-dependent vibrational and optical properties, and a notable intense photoluminescence emission from the direct band gap monolayer region. In the following chapter, we describe an alternative method to produce WSe2 nanosheets by physically vaporizing of WSe2 powder at a high temperature. Using WSe2 powder directly is advantageous since under optimal conditions we can selectively grow single-layer WSe2 domains or single-layer films up to several square centimeters. Lastly, we combine the synthesis of the transition metal chalcogenides previously described into lateral and vertical heterostructures grown in situ by chemical vapor deposition. The lateral MoS2-MoSe2 and WS2-WSe2 heterostructures formed stitched monolayer heterojunctions confirmed, as confirmed by photoluminescence and Raman spectroscopy studies. Vertical MoS2-MoSe2 and WS2-WSe2 heterojunctions were two layers thick and had vibrational and emission confirmations of their composition. This dissertation lays the foundation for the rational synthesis of two-dimensional transition metal dichalcogenide monolayer and heterostructure, which represents the key challenge to apply these exciting materials systems into functional optoelectronic devices.

Download or read book Two Dimensional Electronics and Optoelectronics written by and published by . This book was released on 2017 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Annotation The discovery of monolayer graphene led to a Nobel Prize in Physics being awarded in 2010. This has stimulated further research on a wide variety of two-dimensional (2D) layered materials. The coupling of metallic graphene, semiconducting 2D transition metal dichalcogenides (TMDCs) and black phosphorus have attracted a tremendous amount of interest in new electronic and optoelectronic applications. Together with other 2D materials, such as the wide band gap boron nitride nanosheets (BNNSs), all these 2D materials have led towards an emerging field of van der Waal 2D heterostructures. The papers in this book were originally published by Electronics (MDPI) in a Special Issue on "Two-Dimensional Electronics and Optoelectronics." The book consists of eight papers, including two review articles, covering various pertinent and fascinating issues concerning 2D materials and devices. Further, the potential and the challenges of 2D materials are discussed, which provide up to date guidance for future research and development.

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 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 Chemical Vapor Deposition Growth of Transition Metal Dichalcogenides and Their Heterostructure Integration written by Sajeevi Sankalpani Withanage and published by . This book was released on 2021 with total page 147 pages. Available in PDF, EPUB and Kindle. Book excerpt: Two-dimensional transition metal dichalcogenides (TMDs) are of great interest for the discovery of many novel physics owing to their extraordinary electrical, optical, mechanical properties as well as many promising applications including heterojunctions. To realize the overreaching goals of these materials, it is important to develop scalable growth techniques and investigate the role of different growth parameters on the resulting material properties. In this dissertation, I study, (i) controllable and reproducible growth of monolayer molybdenum disulfide (MoS2) via chemical vapor deposition (CVD), (ii) the role of growth temperature on the properties of large area MoS2 thin films grown via thermal vapor sulfurization route, and (iii) low temperature growth of palladium diselenide (PdSe2) thin films, their doping and integration into heterojunctions. In particular, for the growth of MoS2 monolayer crystals, I modified the CVD process by using molybdenum trioxide thin films as a precursor addressing the difficulty of controlling the local variations of the precursor concentrations in the conventional method resulting in highly reproducible MoS2 crystal growth. For large area MoS2 thin films, I show that the electrical properties of the samples change significantly with growth temperature and discuss the challenges in using Si/SiO2 substrates for the direct growth of these films, specially at high temperature. For PdSe2 thin films, I studied the changes in electrical, chemical, and crystalline quality of the PdSe2 films grown under low pressure CVD conditions below 400 °C and showed its integration with molybdenum diselenide to fabricate a vertical heterojunction diode with a high rectification ratio. I have also investigated the surface charge transfer doping of PdSe2 devices and used it toward fabrication of lateral heterojunction diode by selective area doping. The TMD synthesis, doping, and heterojunction integrations shown in this study is a significant step forward for the scalable fabrication of photodetectors, sensors, logic circuits, and other high-performance electronic devices.

Download or read book Transition Metal Dichalcogenides Heterostructure based Electronic and Optoelectronic Devices written by Omar Badr Mohammed and published by . This book was released on 2019 with total page 124 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book 2D Monoelemental Materials Xenes and Related Technologies written by Zongyu Huang and published by CRC Press. This book was released on 2022-04-19 with total page 166 pages. Available in PDF, EPUB and Kindle. Book excerpt: Monoelemental 2D materials called Xenes have a graphene-like structure, intra-layer covalent bond, and weak van der Waals forces between layers. Materials composed of different groups of elements have different structures and rich properties, making Xenes materials a potential candidate for the next generation of 2D materials. 2D Monoelemental Materials (Xenes) and Related Technologies: Beyond Graphene describes the structure, properties, and applications of Xenes by classification and section. The first section covers the structure and classification of single-element 2D materials, according to the different main groups of monoelemental materials of different components and includes the properties and applications with detailed description. The second section discusses the structure, properties, and applications of advanced 2D Xenes materials, which are composed of heterogeneous structures, produced by defects, and regulated by the field. Features include: Systematically detailed single element materials according to the main groups of the constituent elements Classification of the most effective and widely studied 2D Xenes materials Expounding upon changes in properties and improvements in applications by different regulation mechanisms Discussion of the significance of 2D single-element materials where structural characteristics are closely combined with different preparation methods and the relevant theoretical properties complement each other with practical applications Aimed at researchers and advanced students in materials science and engineering, this book offers a broad view of current knowledge in the emerging and promising field of 2D monoelemental materials.

Download or read book Electronic Transport in Synthetic Transition Metal Dichalcogenides and Novel Graphene metal Heterostructures written by Brian Bersch and published by . This book was released on 2019 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Two-dimensional (2D) and layered materials are atomically thin sheets of materials whose monolayer forms range from single to few atoms in thickness and which display fundamentally anisotropic bonding configurations characterized by strong in-plane (intralayer) bonding and weak out-of-plane (interlayer) van der Waals bonding. Pristine 2D materials lack dangling bonds and are inherently thickness-scalable, representing the thinnest stable material systems in science. Additionally, the 2D materials sandbox encompasses the entire range of electronic classification of materials from insulators to semiconductors to conductors (and superconductors) and are also truly quantum in nature. Thus, 2D materials and their heterostructures are poised to revolutionize conventional electronics, optoelectronics, and quantum technologies. In order to demonstrate technological readiness, however, 2D materials must be synthesized on the wafer-scale with ultimate control over film properties, defects, film morphology, and thickness. In a similar vein, 2D-superconductors will be essential components in future quantum devices, and they will also need to be synthesized and integrated into robust wafer-scale platforms if they are to become technologically relevant. Over the years, the Robinson group has been a pioneer in the metal organic chemical vapor deposition of transition metal dichalcogenides (TMDs) for realization of large-area and scalable electronic-grade 2D-semiconductors, as well as the synthesis of wafer-scale epitaxial graphene (EG) on SiC. This thesis is fundamentally about understanding the electronic transport of charge carriers in synthetic two-dimensional layers and graphene-based heterostructures, elucidated by field-effect transistor and other electrical measurements and correlated to materials characterization of as-grown films. We strive to understand the impact of growth substrate, growth conditions, and dopants on the electronic properties of epitaxial 2D-semiconductors including molybdenum disulfide (MoS2) and tungsten disulfide (WSe2). Additionally, we have pioneered a new synthesis technique for stabilizing 2D-allotropes of traditionally 3D metals and nitrides at the interface of epitaxial graphene and SiC in a process termed confinement heteroepitaxy (CHet). These graphene/2D-metal heterostructures are inherently air-stable, highly crystalline, non-centrosymmetric, and exhibit the potential for tunable superconductivity, topological states, and extreme non-linear optical properties. As a result, this thesis is broken up into two main sections. First, after a short introduction to 2D-materials, devices and procedures (Chapters 1-2), chapters 3-5 investigate the transport and transistor performance in single to few-layer MoS2 and WSe2 synthesized on engineered sapphire substrates, including a novel technique for the selective-area deposition and growth of TMDs in chapter 5. Chapter 6 introduces the concept of confinement heteroepitaxy and discusses the optimization of this process to achieve large-area uniform EG/2D-Ga and EG/GaN heterostructures. Within, we discuss the structure and material properties of 2D-Ga films at the interface of graphene and SiC, and we discuss considerations and impacts of the nitridation process on graphene overlayers. Chapter 7 specifically deals with the superconductivity in these graphene/2D-Ga heterostructures and helps to shed light on the origin of the critical temperature (Tc) enhancement in hexagonal 2D-Ga/SiC. Chapter 8 will present ongoing and future work with a summary of findings in this thesis.

Download or read book Advanced Biosensors for Health Care Applications written by Dr. Inamuddin and published by Elsevier. This book was released on 2019-06-15 with total page 432 pages. Available in PDF, EPUB and Kindle. Book excerpt: Advanced Biosensors for Health Care Applications highlights the different types of prognostic and diagnostic biomarkers associated with cancer, diabetes, Alzheimer's disease, brain and retinal diseases, cardiovascular diseases, bacterial infections, as well as various types of electrochemical biosensor techniques used for early detection of the potential biomarkers of these diseases. Many advanced nanomaterials have attracted intense interests with their unique optical and electrical properties, high stability, and good biocompatibility. Based on these properties, advanced nanoparticles have been used as biomolecular carriers, signal producers, and signal amplifiers in biosensor design. Recent studies reported that there are several diagnostic methods available, but the major issue is the sensitivity and selectivity of these approaches. This book outlines the need of novel strategies for developing new systems to retrieve health information of patients in real time. It explores the potential of nano-multidisciplinary science in the design and development of smart sensing technology using micro-nanoelectrodes, novel sensing materials, integration with MEMS, miniaturized transduction systems, novel sensing strategy, that is, FET, CMOS, System-on-a-Chip (SoC), Diagnostic-on-a-Chip (DoC), and Lab-on-a-Chip (LOC), for diagnostics and personalized health-care monitoring. It is a useful handbook for specialists in biotechnology and biochemical engineering. Describes advanced nanomaterials for biosensor applications Relates the properties of available nanomaterials to specific biomarkers applications Includes diagnosis and electrochemical studies based on biosensors Explores the potential of nano-multidisciplinary science to design and develop smart sensing technologies Describes novel strategies for developing a new class of assay systems to retrieve the desired health information

Download or read book Defects in Two Dimensional Materials written by Rafik Addou and published by Elsevier. This book was released on 2022-02-14 with total page 434 pages. Available in PDF, EPUB and Kindle. Book excerpt: Defects in Two-Dimensional Materials addresses the fundamental physics and chemistry of defects in 2D materials and their effects on physical, electrical and optical properties. The book explores 2D materials such as graphene, hexagonal boron nitride (h-BN) and transition metal dichalcogenides (TMD). This knowledge will enable scientists and engineers to tune 2D materials properties to meet specific application requirements. The book reviews the techniques to characterize 2D material defects and compares the defects present in the various 2D materials (e.g. graphene, h-BN, TMDs, phosphorene, silicene, etc.). As two-dimensional materials research and development is a fast-growing field that could lead to many industrial applications, the primary objective of this book is to review, discuss and present opportunities in controlling defects in these materials to improve device performance in general or use the defects in a controlled way for novel applications. Presents the theory, physics and chemistry of 2D materials Catalogues defects of 2D materials and their impacts on materials properties and performance Reviews methods to characterize, control and engineer defects in 2D materials

Download or read book Defect driven Processing of Two dimensional Transition Metal Dichalcogenides written by Kevin Christopher Bogaert and published by . This book was released on 2019 with total page 161 pages. Available in PDF, EPUB and Kindle. Book excerpt: Two-dimensional transition metal dichalcogenides (TMDs) are an emerging class of semiconductor materials that offer exciting new properties for future electronic and optoelectronic applications. However, many ongoing challenges related to synthesis and processing must be overcome before this nascent technology can become industrially viable. In this thesis, processing-related phenomena relevant to the fabrication of TMD heterostructures, alloys, and nanoporous membranes are presented. This thesis begins with an investigation of the role of substrate temperature in two-step chemical vapor deposition (CVD) growth of MoS2/WS2 heterostructures. We demonstrate diffusion-mediated synthesis of inverted lateral heterostructures following low MoS2 growth temperatures in the second CVD step and homogeneous Mo[subscript x]W[subscript 1-x]S2 alloyed crystals following higher MoS2 growth temperatures. Investigating the nature of this diffusion-mediated process, we identify an energetically favorable atomistic model proposing that transition metal diffusion is driven by a heterogeneous distribution of sulfur vacancies. This model is corroborated by the synthesis of a composition-graded Mo[subscript x]W[subscript 1-x]S2 alloy crystals in which the final-stage spatial distribution of transition metal atoms correlates with intermediate-stage distribution of point defects. These heterogeneous crystals allow for correlation of the local optical properties with the local composition, demonstrating a variation in photoluminescence intensity spanning two orders of magnitude and reaching the maximum value for equicompositional alloy Mo0.5W0.5S2 (x=0.5). Furthermore, the correlation between intermediate-stage distribution of point defects and final-stage spatial distribution of transition metal atoms enables the opportunity for bespoke patterning. Utilizing a laser annealing technique, we demonstrate the ability to locally induce defects that define the regions of preferential nucleation during subsequent CVD growth. Finally, defect processing is also demonstrated in nanoporous TMD membrane applications. Combining modeling with experimentation, we demonstrate the relationship between vacuum annealing time and temperature with nanopore properties such as average radius and edge structure. Control of these properties is essential for the fabrication of functional nanoporous membrane devices for sensing, filtration, and energy applications. This thesis motivates further work on TMD processing in pursuit of developing a fundamental understanding of the defect-driven diffusion mechanism, a larger library of interesting TMD compositions and structures, as well as industrially viable TMD devices.