Materials Science & Engineering

“Mode Resolved Modeling of Phonon-structure Interactions in Semiconductor Nanocomposites”

Dr. Joe Feser
Professor of Mechanical Engineering
University of Delaware

Introducing nanoscale inhomogeneities into semiconductor alloys is a known route to enhance the scattering of long wavelength phonons and to subsequently reduce thermal conductivity. For key applications such as thermoelectric energy conversion materials, this must be done efficiently to avoid harming electronic functionality. Thus, key questions arise such as what type (i.e. contrast mechanisms), shape, size, and number density of particles should be used. This talk presents two new theoretical developments in this area from our group: (1) The use of continuum mechanics to analytically calculate exact phonon scattering cross sections of cylindrical and spherical shaped elastic discontinuities across the Mie regime, and their subsequent use in Boltzmann transport models of thermal transport and (2) the development of a new frequency-domain atomistic approach to simulate the scattering cross section of nanoparticles of arbitrary complexity for wavevectors spanning the entire Brillouin zone, and which can accommodate very large atomistic systems. Its advantages compared to atomistic Green’s functions (AGF) and molecular dynamics wave-packet analysis will be discussed.

Joseph P. Feser is an assistant professor in the Department of Mechanical Engineering at the University of Delaware with an expertise in theoretical and experimental microscale heat transfer. He received his Ph.D in Mechanical Engineering in 2010 from the University of California, Berkeley under the co-advisement of Arun Majumdar and Rachel Segalman. In 2013, he completed a post-doctoral position in the Materials Science and Engineering Department at the Univeristy of Illinois, Urbana-Champaign with David G. Cahill.

Christine Williamson
Materials Science & Engineering
201 DuPont Hall
(302) 831-2062

322 ISE Lab
221 Academy Street
Newark, DE 19716

Hosting Organization:
Materials Science & Engijneering
University of Delaware

February 17, 2016

10:30 a.m.