Thermal Transport in Heterogeneous Nanostructures PDF Download
Are you looking for read ebook online? Search for your book and save it on your Kindle device, PC, phones or tablets. Download Thermal Transport in Heterogeneous Nanostructures PDF full book. Access full book title Thermal Transport in Heterogeneous Nanostructures by Man Li. Download full books in PDF and EPUB format.
Author: Man Li Publisher: ISBN: Category : Languages : en Pages : 0
Book Description
Heterogeneous nanostructures involve nanoscale interfaces with different materials components, such as matrix and fillers in composites, stacking planer structures in electronics, and aggregates of nanomaterials. Thermal transport in heterogenous nanostructures is critical to the safety and performance of various applications ranging from high temperature turbines, microelectronics, solar cells, thermoelectrics, buildings' thermal management and so on. However, it remains challenging to achieve rational control of the thermal properties in heterogeneous nanostructures due to limitations in current characterization techniques and fundamental understandings of interface thermal transport. My PhD research focuses on developing new thermal measurement techniques and investigating fundamental interface transport mechanisms through the combination of experiments and modeling, to provide rational control over heterogeneous nanostructures for better addressing practical heat management and energy conversion problems using nanoengineering. The study of thermal transport in heterogeneous nanostructures in my dissertation spans from technical development of new tools, experimental measurements at nanoscale interfaces and porous structures, and atomistic modelling of fundamental transport physics to practical device applications. First, I have developed a new metrology based on asymmetric beam time-domain thermoreflectance (AB-TDTR) that enables accurate measurements over three-dimensional thermal transport. Through the design of an asymmetric laser beam with controlled elliptical ratio and spot size, the experimental signals can be exploited to be dominantly sensitive to measure anisotropic thermal conductivity along the cross-plane or any specific in-plane directions. I have further applied this new approach to investigate anisotropic transport phenomena that enables unique applications. Second, I have explored the effects of crystal orientations and dipole-dipole interactions on interface thermal transport. In particular, for the first time, we have observed a record-high anisotropy ratio of 3.25 in the thermal boundary resistance across a prototype two-dimensional material, i.e., black phosphorus. Moreover, my study has resulted in the first observation of strong effects from long-range molecular dipole-dipole interactions on interface thermal transport. In addition, I have also investigated the heterogeneous integration of our recently developed new high thermal conductivity materials with prototyped high-power semiconductor, i.e., gallium nitride. Our in-situ measurement demonstrated substantially reduced hot-spot temperatures in devices using boron arsenide cooling substrates, beyond the best state-of-the-art HEMTs using diamond or silicon carbide. Lastly, I have investigated thermal transport in porous and mesoporous structures, including super-hydrophobic polymer aerogel, transparent mesoporous silica, and flexible tin selenide nanosheet films for applications in buildings, windows, and thermoelectric energy conversion.
Author: Man Li Publisher: ISBN: Category : Languages : en Pages : 0
Book Description
Heterogeneous nanostructures involve nanoscale interfaces with different materials components, such as matrix and fillers in composites, stacking planer structures in electronics, and aggregates of nanomaterials. Thermal transport in heterogenous nanostructures is critical to the safety and performance of various applications ranging from high temperature turbines, microelectronics, solar cells, thermoelectrics, buildings' thermal management and so on. However, it remains challenging to achieve rational control of the thermal properties in heterogeneous nanostructures due to limitations in current characterization techniques and fundamental understandings of interface thermal transport. My PhD research focuses on developing new thermal measurement techniques and investigating fundamental interface transport mechanisms through the combination of experiments and modeling, to provide rational control over heterogeneous nanostructures for better addressing practical heat management and energy conversion problems using nanoengineering. The study of thermal transport in heterogeneous nanostructures in my dissertation spans from technical development of new tools, experimental measurements at nanoscale interfaces and porous structures, and atomistic modelling of fundamental transport physics to practical device applications. First, I have developed a new metrology based on asymmetric beam time-domain thermoreflectance (AB-TDTR) that enables accurate measurements over three-dimensional thermal transport. Through the design of an asymmetric laser beam with controlled elliptical ratio and spot size, the experimental signals can be exploited to be dominantly sensitive to measure anisotropic thermal conductivity along the cross-plane or any specific in-plane directions. I have further applied this new approach to investigate anisotropic transport phenomena that enables unique applications. Second, I have explored the effects of crystal orientations and dipole-dipole interactions on interface thermal transport. In particular, for the first time, we have observed a record-high anisotropy ratio of 3.25 in the thermal boundary resistance across a prototype two-dimensional material, i.e., black phosphorus. Moreover, my study has resulted in the first observation of strong effects from long-range molecular dipole-dipole interactions on interface thermal transport. In addition, I have also investigated the heterogeneous integration of our recently developed new high thermal conductivity materials with prototyped high-power semiconductor, i.e., gallium nitride. Our in-situ measurement demonstrated substantially reduced hot-spot temperatures in devices using boron arsenide cooling substrates, beyond the best state-of-the-art HEMTs using diamond or silicon carbide. Lastly, I have investigated thermal transport in porous and mesoporous structures, including super-hydrophobic polymer aerogel, transparent mesoporous silica, and flexible tin selenide nanosheet films for applications in buildings, windows, and thermoelectric energy conversion.
Author: Tadeh Avanessian Publisher: ISBN: Category : Electronic dissertations Languages : en Pages : 149
Book Description
Thermal diodes and switches are systems that enable us to control thermal transport, preferentially in one direction, and switch "on"/"off" on demand. The main challenges of existing thermal diodes and switches are poor steady-state performance, limited operation conditions, slow transient response, and/or extremely difficult manufacturing. In this study, adsorption-controlled and capillary-controlled thermal diodes and switches are examined by employing argon gas-filled heterogeneous nanostructures using molecular simulations. For the adsorption-controlled mechanism, asymmetric adsorption onto the heterogeneous nanogap with respect to the different temperature gradient direction results in the asymmetric gas pressure and thermal accommodation coefficients (TACs), giving a maximum degree of diode, Rmax ~ 7. For a thermal switch, Ar-filled nanogaps with two heterogeneous surfaces are designed to demonstrate a fast thermal switch mechanism without having extra mechanical controlling system with the maximum degree of thermal switch, Smax ~ 13. In order to achieve higher magnitudes of R and S, the adsorption and capillary transition on the heterogeneous nanostructures are elucidated using Ar-filled Pt-based nanogaps with one surface having nanoposts using Grand Canonical Monte Carlo Simulation (GCMC). The study shows that the nanoposts decrease capillary transition pressure at given temperature (or increase temperature at given pressure). The large thermal conductivity contrast between the controlled adsorption and capillary states using the structural and/or material heterogeneity is shown to allow for Rmax ~ 140 in a demonstrated thermal diode with operating temperatures -40 K
Author: Jihong Al-Ghalith Publisher: Springer ISBN: 3319738828 Category : Science Languages : en Pages : 88
Book Description
The book introduces modern atomistic techniques for predicting heat transfer in nanostructures, and discusses the applications of these techniques on three modern topics. The study of heat transport in screw-dislocated nanowires with low thermal conductivity in their bulk form represents the knowledge base needed for engineering thermal transport in advanced thermoelectric and electronic materials, and suggests a new route to lower thermal conductivity that could promote thermoelectricity. The study of high-temperature coating composite materials facilitates the understanding of the role played by composition and structural characterization, which is difficult to approach via experiments. And the understanding of the impact of deformations, such as bending and collapsing on thermal transport along carbon nanotubes, is important as carbon nanotubes, due to their exceptional thermal and mechanical properties, are excellent material candidates in a variety of applications, including thermal interface materials, thermal switches and composite materials.
Author: Hai-Peng Li Publisher: Springer ISBN: 9811326371 Category : Science Languages : en Pages : 86
Book Description
In this Brief, authors introduce the advance in theoretical and experimental techniques for determining the thermal conductivity in nanomaterials, and focus on review of their recent theoretical studies on the thermal properties of silicon–based nanomaterials, such as zero–dimensional silicon nanoclusters, one–dimensional silicon nanowires, and graphenelike two–dimensional silicene. The specific subject matters covered include: size effect of thermal stability and phonon thermal transport in spherical silicon nanoclusters, surface effects of phonon thermal transport in silicon nanowires, and defects effects of phonon thermal transport in silicene. The results obtained are supplemented by numerical calculations, presented as tables and figures. The potential applications of these findings in nanoelectrics and thermoelectric energy conversion are also discussed. In this regard, this Brief represents an authoritative, systematic, and detailed description of the current status of phonon thermal transport in silicon–based nanomaterials. This Brief should be a highly valuable reference for young scientists and postgraduate students active in the fields of nanoscale thermal transport and silicon-based nanomaterials.
Author: Xiaodong Wang Publisher: Springer Science & Business Media ISBN: 3319020129 Category : Technology & Engineering Languages : en Pages : 520
Book Description
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.
Author: Zhang Gang Publisher: CRC Press ISBN: 9814463035 Category : Science Languages : en Pages : 222
Book Description
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
Author: Stefano Lepri Publisher: Springer ISBN: 3319292617 Category : Science Languages : en Pages : 418
Book Description
Understanding non-equilibrium properties of classical and quantum many-particle systems is one of the goals of contemporary statistical mechanics. Besides its own interest for the theoretical foundations of irreversible thermodynamics(e.g. of the Fourier's law of heat conduction), this topic is also relevant to develop innovative ideas for nanoscale thermal management with possible future applications to nanotechnologies and effective energetic resources. The first part of the volume (Chapters 1-6) describes the basic models, the phenomenology and the various theoretical approaches to understand heat transport in low-dimensional lattices (1D e 2D). The methods described will include equilibrium and nonequilibrium molecular dynamics simulations, hydrodynamic and kinetic approaches and the solution of stochastic models. The second part (Chapters 7-10) deals with applications to nano and microscale heat transfer, as for instance phononic transport in carbon-based nanomaterials, including the prominent case of nanotubes and graphene. Possible future developments on heat flow control and thermoelectric energy conversion will be outlined. This volume aims at being the first step for graduate students and researchers entering the field as well as a reference for the community of scientists that, from different backgrounds (theoretical physics, mathematics, material sciences and engineering), has grown in the recent years around those themes.
Author: Xinwei Wang Publisher: John Wiley & Sons ISBN: 1118310233 Category : Technology & Engineering Languages : en Pages : 278
Book Description
This book covers the new technologies on micro/nanoscale thermal characterization developed in the Micro/Nanoscale Thermal Science Laboratory led by Dr. Xinwei Wang. Five new non-contact and non-destructive technologies are introduced: optical heating and electrical sensing technique, transient electro-thermal technique, transient photo-electro-thermal technique, pulsed laser-assisted thermal relaxation technique, and steady-state electro-Raman-thermal technique. These techniques feature significantly improved ease of implementation, super signal-to-noise ratio, and have the capacity of measuring the thermal conductivity/diffusivity of various one-dimensional structures from dielectric, semiconductive, to metallic materials.
Author: Sebastian Volz Publisher: Springer Science & Business Media ISBN: 3642042589 Category : Science Languages : en Pages : 597
Book Description
Heat transfer laws for conduction, radiation and convection change when the dimensions of the systems in question shrink. The altered behaviours can be used efficiently in energy conversion, respectively bio- and high-performance materials to control microelectronic devices. To understand and model those thermal mechanisms, specific metrologies have to be established. This book provides an overview of actual devices and materials involving micro-nanoscale heat transfer mechanisms. These are clearly explained and exemplified by a large spectrum of relevant physical models, while the most advanced nanoscale thermal metrologies are presented.
Author: Zlatan Aksamija Publisher: CRC Press ISBN: 1351609440 Category : Science Languages : en Pages : 234
Book Description
Heat in most semiconductor materials, including the traditional group IV elements (Si, Ge, diamond), III–V compounds (GaAs, wide-bandgap GaN), and carbon allotropes (graphene, CNTs), as well as emerging new materials like transition metal dichalcogenides (TMDCs), is stored and transported by lattice vibrations (phonons). Phonon generation through interactions with electrons (in nanoelectronics, power, and nonequilibrium devices) and light (optoelectronics) is the central mechanism of heat dissipation in nanoelectronics. This book focuses on the area of thermal effects in nanostructures, including the generation, transport, and conversion of heat at the nanoscale level. Phonon transport, including thermal conductivity in nanostructured materials, as well as numerical simulation methods, such as phonon Monte Carlo, Green’s functions, and first principles methods, feature prominently in the book, which comprises four main themes: (i) phonon generation/heat dissipation, (i) nanoscale phonon transport, (iii) applications/devices (including thermoelectrics), and (iv) emerging materials (graphene/2D). The book also covers recent advances in nanophononics—the study of phonons at the nanoscale. Applications of nanophononics focus on thermoelectric (TE) and tandem TE/photovoltaic energy conversion. The applications are augmented by a chapter on heat dissipation and self-heating in nanoelectronic devices. The book concludes with a chapter on thermal transport in nanoscale graphene ribbons, covering recent advances in phonon transport in 2D materials. The book will be an excellent reference for researchers and graduate students of nanoelectronics, device engineering, nanoscale heat transfer, and thermoelectric energy conversion. The book could also be a basis for a graduate special topics course in the field of nanoscale heat and energy.
Author: Man Li
Author: Man Li
Author: Tadeh Avanessian
Author: Jihong Al-Ghalith
Author: Hai-Peng Li
Author: Xiaodong Wang
Author: Zhang Gang
Author: Stefano Lepri
Author: Xinwei Wang
Author: Sebastian Volz
Author: Zlatan Aksamija