Publications in Scientific Journals:

G. Romano, A. M. Kolpak, J. Carrete:
"Parameter-free model to estimate thermal conductivity in nanostructured materials";
Physical Review B, 100 (2019), 4.

English abstract:
Achieving low thermal conductivity and good electrical properties is a crucial condition for thermal energy
harvesting materials. Nanostructuring offers a very powerful tool to address both requirements: in nanostructured
materials, boundaries preferentially scatter phonons compared to electrons. The computational screening for
low-thermal-conductivity nanostructures is typically limited to materials with simple crystal structures, such as
silicon, because of the complexity arising from modeling branch- and wave-vector-dependent nanoscale heat
transport. The phonon mean-free-path (MFP) dependent Boltzmann transport equation (MFP-BTE) approach is
a model that overcomes this limitation. To illustrate this, we analyze thermal transport in 75 nanoporous half-
Heusler compounds for different pore sizes. Our calculations demonstrate that, in most cases, the optimization
of thermal transport in nanostructures should take into account both bulk thermal properties and geometrydependent
size effects, two aspects that are typically engineered separately. To enable efficient calculations within
this paradigm we derive a model, based on the "gray" formulation of the BTE, that can decouple the influence
of the geometry and the material on the effective thermal conductivity with relatively little loss in accuracy
compared to the MFP-BTE. Our study motivates the need for a holistic approach to engineering thermal transport
and provides a method for high-throughput low-thermal conductivity materials discovery.

"Official" electronic version of the publication (accessed through its Digital Object Identifier - DOI)

Created from the Publication Database of the Vienna University of Technology.