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Engineering Commons

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Electrical and Computer Engineering

Purdue University

Department of Electrical and Computer Engineering Faculty Publications

2011

Articles 1 - 2 of 2

Full-Text Articles in Engineering

Computational Study Of The Seebeck Coefficient Of One-Dimensional Composite Nanostructures, Raseong Kim, Mark S. Lundstrom Jan 2011

Computational Study Of The Seebeck Coefficient Of One-Dimensional Composite Nanostructures, Raseong Kim, Mark S. Lundstrom

Department of Electrical and Computer Engineering Faculty Publications

The Seebeck coefficient (S) of composite nano-structures is theoretically explored within a self-consistent electro-thermal transport simulation framework using the non-equilibrium Green’s function method and a heat diffusion equation. Seebeck coefficients are determined using numerical techniques that mimic experimental measurements. Simulation results show that, without energy relaxing scattering, the overall S of a composite structure is determined by the highest barrier within the device. For a diffusive, composite structure with energy relaxation due to electron-phonon scattering, however, the measured Sis an average of the position-dependent values with the weighting factor being the lattice temperature gradient. The results stress …


Full Dispersion Vs. Debye Model Evaluation Of Lattice Thermal Conductivity With A Landauer Approach, Changwook Jeong, Supriyo Datta, Mark S. Lundstrom Jan 2011

Full Dispersion Vs. Debye Model Evaluation Of Lattice Thermal Conductivity With A Landauer Approach, Changwook Jeong, Supriyo Datta, Mark S. Lundstrom

Department of Electrical and Computer Engineering Faculty Publications

Using a full dispersion description of phonons, the thermal conductivities of bulk Si and Bi2Te3 are evaluated using a Landauer approach and related to the conventional approach based on the Boltzmann transport equation. A procedure to extract a well-defined average phonon mean-free-path from the measured thermal conductivity and given phonon-dispersion is presented. The extracted mean-free-path has strong physical significance and differs greatly from simple estimates. The use of simplified dispersion models for phonons is discussed, and it is shown that two different Debye temperatures must be used to treat the specific heat and thermal conductivity (analogous to the two different …