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MM: Fachverband Metall- und Materialphysik

MM 3: Development of Computational Methods: Evaporation, Growth and Oxidation – Density Functional, Tight Binding

MM 3.9: Vortrag

Montag, 27. März 2023, 12:30–12:45, SCH A 251

A DFTB-based approach to calculating electron-phonon couplings — •Alexander Croy¹, Elif Unsal², Gianaurelio Cuniberti², and Alessandro Pecchia³ — ¹Institute of Physical Chemistry, FSU Jena, Germany — ²Institute of Materials Science, TU Dresden, Germany — ³Institute of Nanostructured Materials, CNR, Italy

The calculation of electron-phonon couplings from first principles is computationally very challenging and remains mostly out of reach for systems with a large number of atoms. Resorting to semi-empirical methods, like density-functional based tight-binding (DFTB), has been shown to be a viable approach for obtaining quantitative results at moderate computational costs. In this contribution, we present a method for calculating the electron-phonon coupling matrix within the DFTB approach and demonstrate its implementation which is based on dftb+ and phonopy. It further allows the calculation of relaxation times and interfaces with BoltzTrap2 to compute transport properties. Exemplarily, we show results for γ-graphyne which was recently synthesized. Consistent with earlier predictions we obtain mobilities on the order of 10⁴ cm² V⁻¹ s⁻¹ at room temperature.