The book presents a detailed study on GRAPHENE Nanoelectronics’. Comprehensive analyses of energy band structures and charge transport behaviors among various types of the Graphene based Nanostructures are presented. Especially, the Armchair (AC) and Zigzag (ZZ) shaped graphene nanoribbons (GNRs) have been used in nanodevices. Various approaches for tricky samples’ modeling are discussed in detail. The density of states, transmission spectra and current-voltage characteristics are examined for the Graphene nanodevices. The observance of transmission eigenstate conduction channels and strong couplings among various sections of the nano-device are also rightly elucidated, which helps in understanding of different modes of the charge transport. To finish with the work, a Z junction nanotransistor is simulated and the I-V characteristics are studied. Finally yet importantly, the book is very helpful in understanding the intrinsic properties of the Graphene based nanomaterials for futuristic Nanotechnology applications.
Heat transfer in nanostructures differ significantly from that in the bulk materials since the characteristic length scales associated with heat carriers, i.e., the mean free path and the wavelength, are comparable to the characteristic length of the nanostructures. Nanostructure materials hold the promise of novel phenomena,properties, and functions in the areas of thermal management and energy conversion. Three important topics are studied with respect to energy transport in nanostructure materials for micro/nano electronic and thermoelectric applications: 1) the role of nanocomposites in improving the thermal efficiency of thermoelectric devices, 2) the interfacial thermal resistance for the semiconductor/metal contacts in thermoelectric devices and for metallic interconnects in micro/nano electronic devices, 3) the interaction between the energy carriers namely electrons/carriers with phonons which lead to a significant non-equilibrium at the semiconductor-metal contacts.
Graphene has recently become the focus of enormous attention for experimentalists and theorists alike mainly due to its unique electronic properties. However, the limited way in which one can control these properties is a major obstacle for device applications. This book proposes and thoroughly justifies ways to control the electronic properties of graphene and carbon nanotubes by light or static electric and magnetic fields and to harness these properties for optoelectronic applications. The background theory of the optical selection rules of graphene and its one-dimensional counterpart the carbon nanotube is introduced and applied to a variety of Terahertz applications. The phenomena of momentum alignment: the ability to steer the direction of electrons in graphene by light is discussed and together with the depolarization of hot photoluminescence is used to study relaxation processes in graphene. Not only can the electrons in graphene be steered by light, but they can also be confined and steered by electrostatic potentials. The theory of confinement in smooth electron waveguides in graphene is introduced and its electronic applications are discussed.
Currently, the humanity is encountering two major crises: energy deficiency and global warming. In order to resolve these crises, we should consider maximizing energy efficiency and minimizing its usage. Furthermore, we should develop alternative energy sources (e.g. wind, solar, biomass), instead of hydrocarbon products. Moreover, we need to commercialize well-known techniques such as fuel cells, which are environment-friendly and high efficiency systems for various applications, such as power generation and transportation. In addition, we need to continue research on CO2 capture and separation processes. This study presents the synthesis and characterization of CO2 selective hydrotalcite (HT) membranes with several techniques. In addition, this study explores the possibility of using HT materials as inorganic fillers for conductive membranes in direct methanol fuel cells (DMFC). Due to their properties, hydrotalcites also known as layered double hydroixde compounds, are a potentially good candidate as CO2-selective membranes and inorganic filler of conductive membrane.
The book covers recent hot topics of condensed matter physics, such as topological insulators and graphene, through a pedagogical approach. Starting from the treatment of energy bands in solids through advanced mathematical instruments, the transport properties of surface states in three-dimensional topological insulators and graphene are analyzed. The application of Dirac equation on curved space time to condensed matter systems is also treated, with the study of topological defects and local curvatures as possible applications. A study of the possible use of condensed matter system to the relevation of gravitational waves concludes the book, together with a detailed treatment of all the mathematical prerequisites needed to follow the calculations in the book.
The study of solute transport phenomena in laminar and turbulent flow situations has a wide range of applications in different fields of engineering sciences and this is the reason that modern fluid dynamics has become a common platform of mathematicians, physicists, chemists, biologists, physiologists, geologists and engineers. Since the pioneer work of Sir G. I. Taylor in 1953, the study of solute transport in longitudinal direction has been extensively studied by different researchers. This book is written for the researchers and post graduate students who are working in the field of time-dependent convection-diffusion problems. A clear view on basic fluid dynamics is given in the first chapter of the book. Three research problems have been carefully chosen to understand the basic mechanism of solute transport phenomena in longitudinal direction, and to predict the dispersion coefficient, mean concentration distribution for all time period using finite-difference technique.
The design of a polymer electrolyte fuel cell (PEFC) stack requires careful consideration of thermal, water, and gas management to ensure high stack performance in operation. This work aims to develop a mathematical and numerical model for PEFC stacks that serves two objectives: the first involves a study of the fundamental aspects of the PEFC and the associated transport phenomena, electrochemical processes and multiphase flow for a single cell as well as a stack. The second objective concerns the development and integration of applied research for the PEFC single cell and stack, including new designs and related management issues (thermal, gas, and water) to achieve an enhanced fuel cell performance. This book provides basic guidelines for fuel cell engineers to design and enhance fuel cell performance.
In 2004, Novoselov, Geim, and co-workers at the University of Manchester fabricated graphene by mechanical exfoliation. Many extraordinary properties have been reported, such as extremely high electron mobility. More important,graphene, with a monolayer of carbon atoms arranged in a two-dimensional honeycomb lattice, exhibits a variety of transport phenomena that are characteristic of 2D Dirac fermions, such as specific integer and fractional quantum Hall effects, ambipolar behavior. Graphene has been considered a promising candidate material for post-silicon electronics and likely to have the greatest impact on geometric scaling in semiconductors due to its high mobility. The nanoelectronics with graphene have been studied, widely. However, there are few books discussed graphene digital devices and radio frequency (RF) devices, comprehensively, and presented the latest advancements in these fields. the book presents the critical progress of science and technology of graphene nanoelectronics. We believe the book will bring comprehensive and valuable information on graphene nanoelectronics and help their developments.
This book reflects on methods of determining the exact solutions for the velocity and shear stress corresponding to motion of Oldroyd-B and second grade fluids in different geometric scenarios. Retarded and advanced quantum Green's functions have also been used to derive new forms of kadanoff-Baym equations for a system of interacting particles in Quantum Statistical Mechanics to analyze the question to what extent Landau-Silin kinetic equations for Neutral Fermi liquid take into account quickly varying disturbances. This book introduces new results in the area of fluid dynamics and Quantum Fermi liquids.
This book consists of six chapters: In the first chapter, electrical and material properties and charge transport in organic and graphene based FETs are introduced. In the second chapter, device architectures of amorphous copolymer FETs are discussed. The combination of recessed electrodes and surface treatments on electrical contact is investigated. In the third chapter, device physics and charge transport of donor-acceptor copolymer based FETs are discussed. Charge transport measurements in steady-state and under non-quasi-static conditions reveal device physics in dual-gate configuration. In the fourth chapter, device characteristics of ambipolar copolymer based FETs are focused. Those possess balanced electron and hole mobilities which are both > 0.5 cm2/V-s. The trap DOS is calculated using two analytical methods. In the fifth chapter, charge transport in copolymer based FETs employing 4-point-probe configuration is studied. Such polymer FETs possess the mobilities of up to 3 cm2/V-s. In the sixth chapter, transformation of electrical characteristics of graphene FETs with an interacting capping layer of fluoropolymers and pi-conjugated organic semiconductors is investigated.
The growing World energy demand is setting new challenges toward the use of alternative and green resources as well as for the development of more efficient and low-power consuming devices. Thanks to their unique optical properties, group IV nanostructures (NS) show promising applications for cheap multi-junction solar cells and, in general, for efficient energy-tunable light harvesting devices. Among them, Ge reveals interesting optical properties due to its large absorption coefficient that make it intrinsically more suitable than Si for what concerns light harvesting applications. Moreover, the larger exciton Bohr radius of Ge (~24 nm) with respect to Si, gives the chance to easily tune the optical properties of Ge NSs by varying their size. Discerning the role of these parameters and controlling their effects in the light absorption process represents a key-factor toward the implementation of Ge NS in any type of light harvesting device. This work reports a detailed study on the synthesis, structural and optical properties of Ge nanostructures the investigation of photo-conduction properties in prototypal light harvesting devices.
Over the years, the numerical modeling of transport phenomena has been obtained a great portion in the solution of scientific and industrial problems. One of the new numerical techniques is Lattice Boltzmann Method. This method has a lot of advantages like easy implementation, flexible boundary condition, and fast convergence. Also, t is appropriate for simulation of complex geometries and domains like porous media, multiphase flow and etc. The present book provides an investigation of the transport phenomenon in porous media within a computational geometry using LBM. This book should help shed some light on the industrial and educational investigations of porous media and should be particularly useful to professionals in LBM modeling, or anyone else who may be considering employing of numerical techniques for porous and non-porous mediums.
Mashelkar: ?transport? Phenomena In Polymeric Syst Ems