Graphene Optoelectronics

Author: Abdul Rashid bin M. Yusoff
Publisher: John Wiley & Sons
ISBN: 3527677801
Size: 64.80 MB
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This first book on emerging applications for this innovative material gives an up-to-date account of the many opportunities graphene offers high-end optoelectronics. The text focuses on potential as well as already realized applications, discussing metallic and passive components, such as transparent conductors and smart windows, as well as high-frequency devices, spintronics, photonics, and terahertz devices. Also included are sections on the fundamental properties, synthesis, and characterization of graphene. With its unique coverage, this book will be welcomed by materials scientists, solid-state chemists and solid-state physicists alike.

Optoelectronics Of Graphene Based Van Der Waals Heterostructures

Author: Qiong Ma (Ph. D.)
Publisher:
ISBN:
Size: 54.87 MB
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Research on van der Waals (vdW) materials (homo- or hetero-) is a rapidly emerging field in condensed matter physics. They are layered structures with strong chemical bonding within layers and relatively weak van der Waals force to combine layers together. This unique layer-bylayer nature makes it easy to exfoliate layers out and at the same time to re-assemble in arbitrary sequences with different combinations. The versatility, flexibility, and relatively low cost of production make the scientific community enthusiastic about their future. In this thesis, I investigate the fundamental physical processes of light-matter interactions in these layered structures, including graphene, boron nitride, transition metal dichalcogenides and heterostructures formed from these materials. My research involves state-of-the-art nanoscale fabrication and microscale photocurrent spectroscopy and imaging. In Chapter 1, 1 will briefly discuss basic physical properties of the vdW materials involved in this thesis and introduce the main nanofabrication and measurement techniques. Chapter 2-4 are about hot electron dynamics and electron-phonon coupling in intrinsic graphene systems, among which Chapter 2 is focusing on the generation mechanism of the photocurrent at the p-n interface, which is demonstrated to have a photothermoelectric origin. This indicates a weak electron-phonon coupling strength in graphene. Chapter 3 is a direct experimental follow-up of the work in Chapter 2 and reveals the dominant electron-phonon coupling mechanism at different temperature and doping regimes. In Chapter 4, I present the observation of anomalous geometric photocurrent patterns in various devices at the charge neutral point. The spatial pattern can be understood as a local photo-generated current near edges being collected by remote electrodes. The anomalous behavior as functions of change density and temperature indicates an interesting regime of energy and charge dynamics. In Chapter 5 and 6, 1 will show the photoresponse of graphene-BN heterostuctures. In graphene-BN stack directly on SiO2, we observed strong photo-induced doping phenomenon, which can be understood as charge transfer from graphene across BN and eventually trapped at the interface between BN and SiO2. By inserting another layer of graphene between BN and SiO2 , we can measure an electrical current after photoexcitation due to such charge transfer. We further studied the competition between this vertical charge transfer and in-plane carrier-carrier scattering in different regimes. In Chapter 7, I will briefly summarize collaborated work with Prof. Dimitri Basov's group on near-field imaging of surface polariton in two-dimensional materials. This technique provides a complementary tool to examine the intriguing light-matter interaction (for large momentum excitations) in low-dimensional materials. Chapter 8 is the outlook, from my own point of view, what more can be done following this thesis.

Graphene Based Polymer Nanocomposites In Electronics

Author: Kishor Kumar Sadasivuni
Publisher: Springer
ISBN: 3319138758
Size: 74.64 MB
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This book covers graphene reinforced polymers, which are useful in electronic applications, including electrically conductive thermoplastics composites, thermosets and elastomers. It systematically introduces the reader to fundamental aspects and leads over to actual applications, such as sensor fabrication, electromagnetic interference shielding, optoelectronics, superconductivity, or memory chips. The book also describes dielectric and thermal behaviour of graphene polymer composites - properties which are essential to consider for the fabrication and production of these new electronic materials. The contributions in this book critically discuss the actual questions in the development and applications of graphene polymer composites. It will thus appeal to chemists, physicists, materials scientists as well as nano technologists, who are interested in the properties of graphene polymer composites.

Issues In Nanotechnology And Micotechnology Electronic And Photonic Research 2013 Edition

Author:
Publisher: ScholarlyEditions
ISBN: 1490110275
Size: 16.25 MB
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Issues in Nanotechnology and Micotechnology—Electronic and Photonic Research: 2013 Edition is a ScholarlyEditions™ book that delivers timely, authoritative, and comprehensive information about Microstructures. The editors have built Issues in Nanotechnology and Micotechnology—Electronic and Photonic Research: 2013 Edition on the vast information databases of ScholarlyNews.™ You can expect the information about Microstructures in this book to be deeper than what you can access anywhere else, as well as consistently reliable, authoritative, informed, and relevant. The content of Issues in Nanotechnology and Micotechnology—Electronic and Photonic Research: 2013 Edition has been produced by the world’s leading scientists, engineers, analysts, research institutions, and companies. All of the content is from peer-reviewed sources, and all of it is written, assembled, and edited by the editors at ScholarlyEditions™ and available exclusively from us. You now have a source you can cite with authority, confidence, and credibility. More information is available at http://www.ScholarlyEditions.com/.

Functional Graphene Synthesis Characterization And Application In Optoelectronics

Author: Van Chuyen Pham
Publisher:
ISBN:
Size: 17.85 MB
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Zusammenfassung: Graphene has recently attracted enormous attention within the scientific community due to its outstanding optical, electrical and mechanical properties, and is highly promising for various applications. Also, semiconducting CdSe quantum dots (QDs), with easily tunable optical and electrical properties, have already demonstrated their potential for application in various applications such as photovoltaics. In this thesis, the transparency, high carrier mobility and high specific surface area of graphene were combined with the optical properties of CdSe QDs in a novel hybrid material, CdSe QD decorated graphene. Based on the synergetic properties, the hybrid material has been successfully characterized by various methods and was introduced in the active layer of hybrid solar cells, remarkably enhancing the power conversion efficiency of the solar cells. Graphene oxide (GO) was synthesized by a modified Hummers method. Then, oxygen-containing groups within GO were reduced and partially transformed into thiol- functionalities. As a result, thiol-functionalized reduced graphene oxide (TrGO) was obtained. This was achieved by refluxing GO with phosphorus pentasulfide in dimethylformamide solvent. The thiol groups serve as anchor points for the attachment of nanoparticles. This was realized with CdSe QDs and ZnO nanoparticles, respectively via a self-assembly process, whereby novel hybrid materials were obtained: nanoparticle decorated TrGO. Various techniques and methods such as SEM, TEM, XPS, FTIR, UV-Vis absorption spectroscopy were used to characterize GO, rGO, TrGO and QD-TrGO hybrid materials. Based on the results, the materials were further modified and developed to obtain the desired properties and functionalities. Graphenes with different functionalities and reduction degrees were also investigated in comparison with carbon nanotubes using electron paramagnetic resonance (EPR) spectroscopy. For application in photovoltaics, CdSe QD-TrGO hybrid material was mixed with semiconducting polymers to form photoactive thin films which were utilized in hybrid solar cells. The photovoltaic cells showed significantly enhanced solar power conversion efficiencies. The graphene-based hybrid solar cells achieved a PCE of up to 4.24%, which is 46% higher than graphene-free cells and is in the range of the best efficiencies of hybrid quantum dot-polymer solar cells so far. Additionally, CdSe QD decorated rGO was tested regarding its utilization in photoconductors. Preliminary results proved that photo-induced charge transfer from QDs to graphene occurs, resulting in a measurable photocurrent contribution. This finding is consistent with those obtained from PL quenching experiments and the quenching of EPR signals for CdSe QD-TrGO hybrid materials. This finding further demonstrates the high potential of nanoparticle-graphene hybrid materials for optoelectronic applications

Carbon Nanotubes And Graphene For Photonic Applications

Author: Shinji Yamashita
Publisher: Elsevier
ISBN: 0857098624
Size: 29.49 MB
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The optical properties of carbon nanotubes and graphene make them potentially suitable for a variety of photonic applications. Carbon nanotubes and graphene for photonic applications explores the properties of these exciting materials and their use across a variety of applications. Part one introduces the fundamental optical properties of carbon nanotubes and graphene before exploring how carbon nanotubes and graphene are synthesised. A further chapter focusses on nonlinearity enhancement and novel preparation approaches for carbon nanotube and graphene photonic devices. Chapters in part two discuss carbon nanotubes and graphene for laser applications and highlight optical gain and lasing in carbon nanotubes, carbon nanotube and graphene-based fiber lasers, carbon-nanotube-based bulk solid-state lasers, electromagnetic nonlinearities in graphene, and carbon nanotube-based nonlinear photonic devices. Finally, part three focusses on carbon-based optoelectronics and includes chapters on carbon nanotube solar cells, a carbon nanotube-based optical platform for biomolecular detection, hybrid carbon nanotube-liquid crystal nanophotonic devices, and quantum light sources based on individual carbon nanotubes. Carbon nanotubes and graphene for photonic applications is a technical resource for materials scientists, electrical engineers working in the photonics and optoelectronics industry and academics and researchers interested in the field. Covers the properties and fabrication of carbon nanotubes and graphene for photonic applications Considers the uses of carbon nanotubes and graphene for laser applications Explores numerous carbon-based light emitters and detectors

Study Of Graphene Bandgap Engineering And Betavoltaic And Optoelectronic Devices

Author:
Publisher:
ISBN:
Size: 43.72 MB
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Three aspects covering new material, long lasting energy and innovative heterojunction optoelectronics, which are graphene, betavoltaic microbatteries and group IV/III-V photodiodes, have been systematically studied in this thesis. By a first-principles study, we find that local strain with a proper range and strength along the zigzag direction results in opening of significant band gaps in graphene, with the maximum band gap of 1.0 eV; whereas, local strain along the armchair direction fails to open a band gap in graphene. There is a band gap opening in rippled graphene by a first-principles calculation. Generally, the value of the band gap increases as the amplitudes of ripples increase, while it decreases as the periodicities of ripples enlarge. The maximum band gap opened in rippled graphene can reach several hundred meV. To optimize the device design and improve the energy conversion efficiency of betavoltaic microbatteries, a comprehensive theoretical modeling and analysis have been performed. By employing the Monte Carlo method and Synopsys℗ʼ Medici device simulator, we investigate the performance of 4H-SiC p-n junction based betavoltaic microbatteries under exposure to a practical Ni-63 source with considering isotope impurities, self-absorption, and the full beta energy spectra. From simulating the effects of both the p-n junction configuration and the isotope source thickness on the battery performance, we propose that a p-n junction betavoltaic cell with a thicker and heavily doped p- layer under exposure to a practical Ni-63 source of a proper thickness could produce the optimal energy conversion efficiency up to 13% in 4H-SiC. Through the nanomembrane transfer-printing technique, we demonstrate the formation and characteristics of hetero p-n junction photodiodes formed between the single-crystal silicon nanomembrane (SiNM) or germanium nanomembrane (GeNM) and the gallium arsenide (GaAs) substrate. Excellent rectifying characteristics are obtained from both types of heterogeneous p-n photodiodes. The SiNM/GaAs photodiode exhibits photosensitivity at visible wavelengths with a photo-to-dark current ratio exceeding five orders and an external quantum efficiency of 29.6% at 633 nm of wavelength. For the GeNM/GaAs photodiode, a photo-to-dark current ratio exceeds six orders and an external quantum efficiency of 22.3% at 633 nm is observed.

Cmoset 2012 Final Program

Author: CMOS Emerging Technologies Research
Publisher: CMOS Emerging Technologies Research
ISBN: 1927500605
Size: 44.45 MB
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Final program for the CMOSET 2012 conference

Graphene Based Materials

Author: Subbiah Alwarappan
Publisher: CRC Press
ISBN: 1439884455
Size: 47.95 MB
Format: PDF
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Continuously studied since its discovery, graphene offers truly unique opportunities, because unlike most semiconductor systems, its 2D electronic states are not buried deep under the surface and it can be easily accessed directly by tunneling or by other local probes. An in-depth analysis of recent advances in graphene research, Graphene-Based Materials: Science and Technology discusses synthesis, properties, and their important applications in several fields. It examines methods for synthesis of graphene as well as surface characterization, properties, and application in biosensors and energy storage. The book begins with a brief review of the history of graphene and a discussion of its important properties. It then presents the different methods of graphene synthesis available and a brief overview of a few important characterization techniques that distinguishes graphene from its allotropes. The authors detail the applications of graphene in high-speed electronics, field-effect transistors, biosensors, gas-sensors, ultra-capacitors, photonics, optoelectronics, and drug delivery. They conclude with coverage of the toxicity properties of graphene and the future of graphene research. Written by experts with more than a decade of experience in nanotechnology research, the book incorporates the latest literature and findings in the field. Its emphasis on applications, especially biomedical/electrochemical and energy storage applications, sets it apart from other books on this topic. It provides those working in graphene and related materials a resource that helps initiate new thinking.

Graphene

Author: Viera Skakalova
Publisher: Elsevier
ISBN: 0857099337
Size: 18.70 MB
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Graphene: Properties, Preparation, Characterisation and Devices reviews the preparation and properties of this exciting material. Graphene is a single-atom-thick sheet of carbon with properties, such as the ability to conduct light and electrons, which could make it potentially suitable for a variety of devices and applications, including electronics, sensors, and photonics. Chapters in part one explore the preparation of , including epitaxial growth of graphene on silicon carbide, chemical vapor deposition (CVD) growth of graphene films, chemically derived graphene, and graphene produced by electrochemical exfoliation. Part two focuses on the characterization of graphene using techniques including transmission electron microscopy (TEM), scanning tunneling microscopy (STM), and Raman spectroscopy. These chapters also discuss photoemission of low dimensional carbon systems. Finally, chapters in part three discuss electronic transport properties of graphene and graphene devices. This part highlights electronic transport in bilayer graphene, single charge transport, and the effect of adsorbents on electronic transport in graphene. It also explores graphene spintronics and nano-electro-mechanics (NEMS). Graphene is a comprehensive resource for academics, materials scientists, and electrical engineers working in the microelectronics and optoelectronics industries. Explores the graphene preparation techniques, including epitaxial growth on silicon carbide, chemical vapor deposition (CVD), chemical derivation, and electrochemical exfoliation Focuses on the characterization of graphene using transmission electron microscopy (TEM), scanning tunneling microscopy (STM), and Raman spectroscopy A comprehensive resource for academics, materials scientists, and electrical engineers