Dresden 2017 – wissenschaftliches Programm
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HL: Fachverband Halbleiterphysik
HL 71: Transport Properties
HL 71.4: Vortrag
Donnerstag, 23. März 2017, 10:15–10:30, POT 112
Ab-initio phonon scattering by dislocations using Atomic-Green's function approach — •Tao Wang1, Jesus Carrete Montaña2, Natalio Mingo2, and Georg K. H. Madsen1, 3 — 1ICAMS, Bochum, Germany — 2CEA-Grenoble, Grenoble, France — 3Institute of Materials Chemistry, Wien, Austria
Predicting the thermal conductivity of modern semi-conductor architectures is an inherent multi-scale problem. It requires the quantification of phonon scattering strength caused by various types of defects e.g. vacancies, interfaces and dislocations, inside the materials. We introduce the atomic-Green's-function approach as an efficient way to evaluate the phonon scattering of dislocations with ab-initio precision. The three-dimensional Brillouin Zone (BZ) is divided into parallel planes perpendicular to the defect line direction. A triangulation mesh is adopted to discretize each of the two-dimensional BZ planes. By summing the Green's function results of all the linearly interpolated triangular elements on the planar sub-domains, the T-matrix and scattering cross section are obtained.
We will illustrate this strategy by setting up an atomic model of a quadrupolar arrangement of edge dislocations in silicon using linear elasticity theory. The frequency dependence of the scattering rate is calculated and discussed. Dislocation density influenced thermal conductivity evaluated from the Boltzmann-transport-equation is further analyzed to reveal how the long range elastic deformation field and short range dislocation core will modify lattice thermal transport behavior.