Download or read book Studying Phonon Mean Free Paths at the Nanoscale written by Lingping Zeng and published by . This book was released on 2016 with total page 119 pages. Available in PDF, EPUB and Kindle. Book excerpt: Heat conduction in semiconductors and dielectrics involves cumulative contributions from phonons with different frequencies and mean free paths (MFPs). Knowing the phonon MFP distribution allows us to gain insight into the fundamental microscopic transport physics and has important implications for many energy applications. The key metric that quantifies the relative contributions of different phonon MFPs to thermal conductivity is termed thermal conductivity accumulation function. In this thesis, we advance a thermal conductivity spectroscopy technique based upon experimental observation of non-diffusive thermal transport using wire grid linear polarizer in conjunction with time-domain thermoreflectance (TDTR) pump-and-probe measurement setup. Consistent algorithm based on solution from the phonon Boltzmann transport equation (BTE) is also developed to approximately extract the thermal conductivity accumulation functions in materials studied. The heat flux suppression function appropriate for the experimental sample geometry relates the measured apparent thermal conductivities to the material's phonon MFP distributions. We develop a multi-dimensional thermal transport model based on the gray phonon BTE to find the suppression function relevant to our spectroscopy experiment. The simulation results reveal that the suppression function depends upon both the heater size and the heater array period. We also find that the suppression function depends significantly on the location of the temperature measurement. Residual suppression effect is observed for finite filling fractions (ratio of heater size to heater array period) due to the transport coupling in the underlying substrate induced by the neighboring heaters. Prior phonon MFP spectroscopy techniques suffer from one or several of the following limitations: (1) diffraction limited to micrometer lengthscales by focusing optics, (2) applying only to transparent materials, or (3) involving complex micro-fabrications. We explore an alternate approach here using wire grid linear polarizer in combination with TDTR measurement. The wire grid polarizer is designed with sub-wavelength gaps between neighboring heaters to prevent direct photo-excitation in the substrate while simultaneously functioning as heaters and thermometers during the measurement. The spectroscopy technique is demonstrated in crystalline silicon by studying length-dependent thermal transport across a range of lengthscales and temperatures. We utilize the calculated heat flux suppression functions and the measured size-dependent effective thermal conductivities to reconstruct the phonon MFPs in silicon and achieve reasonably good agreement with calculation results from first principle density function theory. Knowledge of phonon MFP distributions in thermoelectric materials will help design nanostructures to further reduce lattice thermal conductivity to achieve better thermoelectric performance in the next-generation thermoelectric devices. We apply the developed wire grid polarizer spectroscopy technique to study phonon MFP distributions in two thermoelectric materials: Nb0.95 Ti0.05FeSb and boron-doped nanocrystalline Si80Ge20B. We find that the dominant phonon MFPs that contribute to thermal conductivity in those two materials are in the a few tens to a few hundreds of nanometers. The measurement results also shed light on why nanostructuring is an effective approach to scattering phonons and improve the thermoelectric behavior.

Download or read book Measuring Phonon Mean Free Path Distributions by Probing Quasiballistic Phonon Transport in Grating Nanostructures written by and published by . This book was released on 2015 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Heat conduction in semiconductors and dielectrics depends upon their phonon mean free paths that describe the average travelling distance between two consecutive phonon scattering events. Nondiffusive phonon transport is being exploited to extract phonon mean free path distributions. Here, we describe an implementation of a nanoscale thermal conductivity spectroscopy technique that allows for the study of mean free path distributions in optically absorbing materials with relatively simple fabrication and a straightforward analysis scheme. We pattern 1D metallic grating of various line widths but fixed gap size on sample surfaces. The metal lines serve as both heaters and thermometers in time-domain thermoreflectance measurements and simultaneously act as wiregrid polarizers that protect the underlying substrate from direct optical excitation and heating. We demonstrate the viability of this technique by studying length-dependent thermal conductivities of silicon at various temperatures. The thermal conductivities measured with different metal line widths are analyzed using suppression functions calculated from the Boltzmann transport equation to extract the phonon mean free path distributions with no calibration required. Furthermore, this table-top ultrafast thermal transport spectroscopy technique enables the study of mean free path spectra in a wide range of technologically important materials.

Download or read book Nanoscale Energy Transport and Harvesting written by Zhang Gang and published by CRC Press. This book was released on 2015-02-04 with total page 222 pages. Available in PDF, EPUB and Kindle. Book excerpt: Energy transport and conversion in nanoscale structures is a rapidly expanding area of science. It looks set to make a significant impact on human life and, with numerous commercial developments emerging, will become a major academic topic over the coming years. Owing to the difficulty in experimental measurement, computational simulation has becom

Download or read book 21st Century Nanoscience A Handbook written by Klaus D. Sattler and published by CRC Press. This book was released on 2019-11-21 with total page 371 pages. Available in PDF, EPUB and Kindle. Book excerpt: This up-to-date reference is the most comprehensive summary of the field of nanoscience and its applications. It begins with fundamental properties at the nanoscale and then goes well beyond into the practical aspects of the design, synthesis, and use of nanomaterials in various industries. It emphasizes the vast strides made in the field over the past decade – the chapters focus on new, promising directions as well as emerging theoretical and experimental methods. The contents incorporate experimental data and graphs where appropriate, as well as supporting tables and figures with a tutorial approach.

Download or read book 21st Century Nanoscience written by Klaus D. Sattler and published by CRC Press. This book was released on 2022-01-18 with total page 4153 pages. Available in PDF, EPUB and Kindle. Book excerpt: This 21st Century Nanoscience Handbook will be the most comprehensive, up-to-date large reference work for the field of nanoscience. Handbook of Nanophysics, by the same editor, published in the fall of 2010, was embraced as the first comprehensive reference to consider both fundamental and applied aspects of nanophysics. This follow-up project has been conceived as a necessary expansion and full update that considers the significant advances made in the field since 2010. It goes well beyond the physics as warranted by recent developments in the field. Key Features: Provides the most comprehensive, up-to-date large reference work for the field. Chapters written by international experts in the field. Emphasises presentation and real results and applications. This handbook distinguishes itself from other works by its breadth of coverage, readability and timely topics. The intended readership is very broad, from students and instructors to engineers, physicists, chemists, biologists, biomedical researchers, industry professionals, governmental scientists, and others whose work is impacted by nanotechnology. It will be an indispensable resource in academic, government, and industry libraries worldwide. The fields impacted by nanoscience extend from materials science and engineering to biotechnology, biomedical engineering, medicine, electrical engineering, pharmaceutical science, computer technology, aerospace engineering, mechanical engineering, food science, and beyond.

Download or read book Phonon Focusing and Phonon Transport written by Igor Gaynitdinovich Kuleyev and published by Walter de Gruyter GmbH & Co KG. This book was released on 2020-06-08 with total page 221 pages. Available in PDF, EPUB and Kindle. Book excerpt: The monograph is devoted to the investigation of physical processes that govern the phonon transport in bulk and nanoscale single-crystal samples of cubic symmetry. Special emphasis is given to the study of phonon focusing in cubic crystals and its influence on the boundary scattering and lattice thermal conductivity of bulk materials and nanostructures.

Download or read book Nanoscale Thermoelectrics written by Xiaodong Wang and published by Springer Science & Business Media. This book was released on 2013-11-18 with total page 520 pages. Available in PDF, EPUB and Kindle. Book excerpt: For the efficient utilization of energy resources and the minimization of environmental damage, thermoelectric materials can play an important role by converting waste heat into electricity directly. Nanostructured thermoelectric materials have received much attention recently due to the potential for enhanced properties associated with size effects and quantum confinement. Nanoscale Thermoelectrics describes the theory underlying these phenomena, as well as various thermoelectric materials and nanostructures such as carbon nanotubes, SiGe nanowires, and graphene nanoribbons. Chapters written by leading scientists throughout the world are intended to create a fundamental bridge between thermoelectrics and nanotechnology, and to stimulate readers' interest in developing new types of thermoelectric materials and devices for power generation and other applications. Nanoscale Thermoelectrics is both a comprehensive introduction to the field and a guide to further research, and can be recommended for Physics, Electrical Engineering, and Materials Science departments.

Download or read book Thermal and Electro thermal System Simulation 2020 written by Márta Rencz and published by MDPI. This book was released on 2021-01-12 with total page 310 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book, edited by Prof. Marta Rencz and Prof Andras Poppe, Budapest University of Technology and Economics, and by Prof. Lorenzo Codecasa, Politecnico di Milano, collects fourteen papers carefully selected for the “thermal and electro-thermal system simulation” Special Issue of Energies. These contributions present the latest results in a currently very “hot” topic in electronics: the thermal and electro-thermal simulation of electronic components and systems. Several papers here proposed have turned out to be extended versions of papers presented at THERMINIC 2019, which was one of the 2019 stages of choice for presenting outstanding contributions on thermal and electro-thermal simulation of electronic systems. The papers proposed to the thermal community in this book deal with modeling and simulation of state-of-the-art applications which are highly critical from the thermal point of view, and around which there is great research activity in both industry and academia. In particular, contributions are proposed on the multi-physics simulation of families of electronic packages, multi-physics advanced modeling in power electronics, multiphysics modeling and simulation of LEDs, batteries and other micro and nano-structures.

Download or read book Heat Transport in Micro and Nanoscale Thin Films written by Bekir Sami Yilbas and published by Elsevier. This book was released on 2017-08-23 with total page 437 pages. Available in PDF, EPUB and Kindle. Book excerpt: Heat Transport in Micro- and Nanoscale Thin Films presents aspects and applications of the principle methods of heat transport in relation to nanoscale films. Small-scale parts and thin films are widely used in the electronics industry. However, the drastic change in the thermal conductivity with reducing device size and film thickness modifies the energy transport by heat-carrying phonons in the film. Energy transfer in small-sized devices and thin films deviate from the classical diffusion to radiative transport. This book deals with micro/nano scale heat transfer in small scale devices and the thin films, including interface properties of cross-plane transport. The book fills the gap between applications of the physical fundamentals and energy transport at the micro- and nano scale, which will be valuable for academics, researchers and students in the fields of materials science and energy transport. Offers a specialist focus on nanoscale thin films, allowing the reader to create more efficient heat transfer systems Includes in-depth coverage of the formulation of transient energy transport for short durations of heating, which is valuable those working in electronics Focuses on applications and real-life case studies to clearly illustrate how the theories explained in the book can be used in industry

Download or read book Transport Phenomena in Micro and Nanoscale Functional Materials and Devices written by Joao B. Sousa and published by Elsevier. This book was released on 2021-03-26 with total page 484 pages. Available in PDF, EPUB and Kindle. Book excerpt: Transport Phenomena in Micro- and Nanoscale Functional Materials and Devices offers a pragmatic view on transport phenomena for micro- and nanoscale materials and devices, both as a research tool and as a means to implant new functions in materials. Chapters emphasize transport properties (TP) as a research tool at the micro/nano level and give an experimental view on underlying techniques. The relevance of TP is highlighted through the interplay between a micro/nanocarrier's characteristics and media characteristics: long/short-range order and disorder excitations, couplings, and in energy conversions. Later sections contain case studies on the role of transport properties in functional nanomaterials. This includes transport in thin films and nanostructures, from nanogranular films, to graphene and 2D semiconductors and spintronics, and from read heads, MRAMs and sensors, to nano-oscillators and energy conversion, from figures of merit, micro-coolers and micro-heaters, to spincaloritronics. Presents a pragmatic description of electrical transport phenomena in micro- and nanoscale materials and devices from an experimental viewpoint Provides an in-depth overview of the experimental techniques available to measure transport phenomena in micro- and nanoscale materials Features case studies to illustrate how each technique works Highlights emerging areas of interest in micro- and nanomaterial transport phenomena, including spintronics

Download or read book Heat and Fluid Flow in Microscale and Nanoscale Structures written by Mohammad Faghri and published by Witpress. This book was released on 2004 with total page 402 pages. Available in PDF, EPUB and Kindle. Book excerpt: This research book gives a general introduction to gas turbine heat transfer topics and also specialises in topics such as external and internal blade cooling, combuster wall cooling, leading and trailing edge cooling and recuperators.

Download or read book Microscale and Nanoscale Heat Transfer written by C.B. Sobhan and published by CRC Press. This book was released on 2008-06-12 with total page 440 pages. Available in PDF, EPUB and Kindle. Book excerpt: Through analyses, experimental results, and worked-out numerical examples, Microscale and Nanoscale Heat Transfer: Fundamentals and Engineering Applications explores the methods and observations of thermophysical phenomena in size-affected domains. Compiling the most relevant findings from the literature, along with results from their own re

Download or read book Rhythmic Advantages in Big Data and Machine Learning written by Anirban Bandyopadhyay and published by Springer Nature. This book was released on 2022-01-10 with total page 270 pages. Available in PDF, EPUB and Kindle. Book excerpt: The book discusses various aspects of biophysics. It starts from the popular article on neurobiology to quantum biology and ends up with the consciousness of a human being and in the universe. The authors have covered eight nine different aspects of natural intelligence, starting from time crystal found in the chemical biology to the vibrations and the resonance of proteins. They have covered a wide spectrum of hierarchical communication among different biological systems. Most importantly, authors have taken an utmost care that even school-level students fall in love with biophysics; it is simple and more of a textbook and definitely bring the readers to a world of biology and physics like never before. Most authors are experienced academicians, and they have used lucid and simple language to make the content interesting for the readers.

Download or read book Nanoscale Energy Transport written by LIAO and published by IOP Publishing Limited. This book was released on 2020-03-20 with total page 440 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book brings together leading names in the field of nanoscale energy transport to provide a comprehensive and insightful review of this developing topic. The text covers new developments in the scientific basis and the practical relevance of nanoscale energy transport, highlighting the emerging effects at the nanoscale that qualitatively differ from those at the macroscopic scale. Throughout the book, microscopic energy carriers are discussed, including photons, electrons and magnons. State-of-the-art computational and experimental nanoscale energy transport methods are reviewed, and a broad range of materials system topics are considered, from interfaces and molecular junctions to nanostructured bulk materials. Nanoscale Energy Transport is a valuable reference for researchers in physics, materials, mechanical and electrical engineering, and it provides an excellent resource for graduate students.

Download or read book Future Trends in Microelectronics written by Serge Luryi and published by John Wiley & Sons. This book was released on 2010-08-03 with total page 448 pages. Available in PDF, EPUB and Kindle. Book excerpt: In the summer of 2009, leading professionals from industry, government, and academia gathered for a free-spirited debate on the future trends of microelectronics. This volume represents the summary of their valuable contributions. Providing a cohesive exploration and holistic vision of semiconductor microelectronics, this text answers such questions as: What is the future beyond shrinking silicon devices and the field-effect transistor principle? Are there green pastures beyond the traditional semiconductor technologies? This resource also identifies the direction the field is taking, enabling microelectronics professionals and students to conduct research in an informed, profitable, and forward-looking fashion.

Download or read book Length Scale Dependent Phonon Interactions written by Subhash L. Shindé and published by Springer Science & Business Media. This book was released on 2013-10-29 with total page 304 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book presents a comprehensive description of phonons and their interactions in systems with different dimensions and length scales. Internationally-recognized leaders describe theories and measurements of phonon interactions in relation to the design of materials with exotic properties such as metamaterials, nano-mechanical systems, next-generation electronic, photonic, and acoustic devices, energy harvesting, optical information storage, and applications of phonon lasers in a variety of fields. The emergence of techniques for control of semiconductor properties and geometry has enabled engineers to design structures in which functionality is derived from controlling electron behavior. As manufacturing techniques have greatly expanded the list of available materials and the range of attainable length scales, similar opportunities now exist for designing devices whose functionality is derived from controlling phonon behavior. However, progress in this area is hampered by gaps in our knowledge of phonon transport across and along arbitrary interfaces, the scattering of phonons with crystal defects, interface roughness and mass-mixing, delocalized electrons/collective electronic excitations, and solid acoustic vibrations when these occur in structures with small physical dimensions. This book provides a comprehensive description of phonons and their interactions in systems with different dimensions and length scales. Theories and measurements of phonon interactions are described in relation to the design of materials with exotic properties such as metamaterials, nano-mechanical systems, next-generation electronic, photonic, and acoustic devices, energy harvesting, optical information storage, and applications of phonon lasers in a variety of fields.

Download or read book Computational Nanoscience written by Elena Bichoutskaia and published by Royal Society of Chemistry. This book was released on 2011 with total page 445 pages. Available in PDF, EPUB and Kindle. Book excerpt: Nanoscience is one of the most exciting scientific disciplines as it is concerned with materials and systems, which exhibit novel and significantly improved physical, chemical and biological properties due to their small nanoscale size. It stretches across the whole spectrum of modern science including medicine and health, physics, engineering and chemistry. Providing a deep understanding of the behaviour of matter at the scale of individual atoms and molecules, it takes a crucial step towards future applications of nanotechnology. The remarkable improvements in both theoretical methods and computational techniques make it possible for computational nanoscience to achieve a new level of accuracy. Computational nanoscience is now a discipline capable of leading and guiding experimental efforts. Computational Nanoscience addresses modern challenges in computational science, within the context of the rapidly evolving field of nanotechnology. It satisfies the need for a comprehensive, yet concise and up-to-date, survey of new developments and applications presented by the world's leading academics. It documents major, recent advances in scientific computation, mathematical models and theory development that specifically target the applications in nanotechnology. Suitable for theoreticians, experimental researchers and students, the book shows readers what computational nanoscience can achieve, and how it may be applied in their own work. The twelve chapters cover topics including the concepts behind recent breakthroughs in nanoscience, the development of cutting edge simulation tools, and the variety of new applications.