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Showing 1 to 20 of 51 for “"Boltzmann transport equation"”.
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Semiconductor device simulation : a spectral method for solution of the Boltzmann transport equation
Thesis (Ph. D.)--Massachusetts Institute of Technology, Dept. of Electrical Engineering and Computer Science, 1988.
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Variational approach to solving the phonon Boltzmann transport equation for analyzing nanoscale thermal transport experiments
… smaller length scales, and as a result the heat transport in these systems has entered the nanoscale regime. With increasing computational speed and power consumption, there is a need to efficiently dissipate the heat generated for proper thermal management of computer chips. The ability to …
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An inverse problem framework for reconstruction of phonon properties using solutions of the Boltzmann transport equation
… experimental results and the one calculated by a Boltzmann transport equation (BTE)-based model of the experimental process, with the desired material property treated as the unknown in the optimization process. Crucially, the proposed approach makes no assumption of an underlying Fourier …
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An efficient method for the solution of the energy dependent integral Boltzmann transport equation in the resolved resonance energy region
… the two spatial region energy dependent integral transport equation is developed. This solution, denoted the "Broad Group Integral Method'' (BGIM), uses escape probabilities to obtain the spatial coupling between regions and uses an analytical flux shape within a multigroup to obtain weighted …
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Low variance methods for Monte Carlo simulation of phonon transport
Computational studies in kinetic transport are of great use in micro and nanotechnologies. In this work, we focus on Monte Carlo methods for phonon transport, intended for studies in microscale heat transfer. After reviewing the theory of phonons, we use scientific literature to write a Monte Carlo …
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Thermal transport at the nanoscale : from fourier diffusion to phonon hydrodynamics
… to construct an accurate picture of thermal transport at small length and time scales. In this work, we employ and contribute to this modern toolset by testing and pushing the limits of our understanding. First, we experimentally examine the effects of domain walls and crystal structure in …
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Numerical models for the simulation of nonstationary effects in submicron semiconductor devices
Numerical modeling of nonstationary transport effects using partial differential equations derived from the Boltzmann Transport Equation (BTE) is investigated. Augmented drift-diffusion (ADD) models and improved energy transport (ET) models for submicron device simulation are constructed and …
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Electronic Transport in Thermoelectric Bismuth Telluride
… experimental investigation of the electronic transport properties of bismuth telluride nanocomposite materials is presented. The primary transport measurements are electrical conductivity, Seebeck coefficient and Hall effect. An experimental apparatus for measuring Hall effect and electrical …
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ATOMISTIC MODELING OF PHONON BANDSTRUCTURE AND TRANSPORT FOR OPTIMAL THERMAL MANAGEMENT IN NANOSCALE DEVICES
… Carlo based statistical approach to solve Boltzmann Transport Equation (BTE) has become a norm to investigate heat transport in semiconductors at sub-micron regime, owing mainly to its ability to characterize realistically sized device geometries qualitatively. One of the primary issues …
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A two-dimensional numerical model of the high electron mobility transistor
… by solving Schrodinger's and Poisson's equations self-consistently. The Boltzmann transport equation in the form of a current continuity equation and an energy transport equation is solved to obtain the transient transport behavior. Transport of carriers takes place in two layers in the …
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Thermoelectric cooling devices: thermodynamic modelling and their application in adsorption cooling cycles
On the basis of the Boltzmann Transport Equation, the thesis presents a universal thermodynamic framework for modeling the solid state cooling devices namely thermoelectric cooler, the pulsed thermoelectric cooler, thin film thermoelectric device, and an electro-adsorption chiller (EAC) such that …
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Experimental and numerical investigation of phonon mean free path distribution
… sapphire at room temperature. A multidimensional transport model based on the grey phonon Boltzmann equation is developed and solved to study the quasi-ballistic transport occurring in the spectroscopy experiments. To account for the nonlinear dispersion relation, we present a variance reduced …
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Mathematical Modelling of Semi Conductor Devices and Processes
… using the nearly isotropic approximation to the Boltzmann transport equation. The formalism treats the steady state inhomogeneous cases and an electric field is included in the analysis. As well as developing the equations to describe the charge transport appropriate boundary value problems are …
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Thermoelectric properties of polysilicon inverse opals
… over electrons. Using solutions to the Boltzmann transport equation for electrons and phonons, we show that the gure of merit at 300 K is fteen times that of bulk single-crystal silicon. Our models predict that grain boundaries are more e ective than surfaces in enhancing the figure of …
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Ferrite characterization techniques & particle simulations for semiconductor devices
… develops a particle simulator, based on the Boltzmann transport equation (BTE) and Monte Carlo (MC) methods, for studying semiconductor devices with submicron feature sizes. Particle simulations are advantageous because full-wave simulators based purely on Maxwell's equations are not able to …
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Nonlinear transport in semiconductor superlattices
"We develop a semiclassical balance equation model for transport through a single miniband of a semiconductor superlattice subject to a spatially uniform, time-dependent external electric field and/or a constant external magnetic field. The balance equations are derived from the semiclassical …
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Electronic properties of bilayer graphene in a steady magnetic field
… tunable non–linear properties. Using the Boltzmann transport equation, we determine the intraband contribution to the dc current, known as the magnetic ratchet effect, and the second harmonic current. We also take into account a perpendicular magnetic field component, which produces …
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Design and modeling of a high flux cooling device based on thin film evaporation from thin nanoporous membranes
… to the thinness of the membrane. The interfacial transport has been re-investigated where we use the moment method to solve the Boltzmann Transport Equation. The pore-level transport has been modeled coupling liquid transport, vapor transport and the interfacial balance. The interfacial transport …
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Understanding the origins of metastability in thin film growth; tantalum and the early group VB-VIB metals
… Approximation (LOVA) for the solution of the Boltzmann transport equation have been used to calculate the temperature dependent resistivity for the studied metals and reveal that substrate-induced film strain is not by itself sufficient to cause the formation of ss-Ta. Fermi surface …
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Efficient simulation of molecular gas transport for micro- and nanoscale applications
… validate an efficient method for simulating the Boltzmann transport equation in regimes typically encountered in nanotechnology applications. These transport regimes are characterized by non-vanishing Knudsen numbers, preventing simple analyses based on the Navier-Stokes equations; and also by …
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