Berlin 2024 – scientific programme
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HL: Fachverband Halbleiterphysik
HL 7: Transport properties I
HL 7.6: Talk
Monday, March 18, 2024, 16:30–16:45, ER 325
Charge Carrier Mobilities in 2D Carbon Allotropes — •Elif Ünsal1, Alexander Croy2, Alessandro Pecchia3, and Gianaurelio Cuniberti1 — 1Institute for Materials Science and Max Bergmann Center of Biomaterials, TU Dresden, Dresden, Germany — 2Institute of Physical Chemistry, Friedrich-Schiller-Universität, Jena, Germany — 3CNR-ISMN, Monterotondo Stazione, Rome, Italy
Calculation of electron-phonon couplings from first principles is computationally very challenging and remains mostly out of reach particularly for systems with a large number of atoms. Semi-empirical methods, like DFTB, offer a framework to obtain quantitative results at reasonable computational costs. Herein, we are modelling charge transport properties by combining state-of-the-art electron-phonon coupling calculations and semi-classical Boltzmann transport theory. We are using our own code DFTBephy [Croy et al. J. Comput. Electron., 2023] whose implementation is based on DFTB+ [Elstner et al, Phys. Rev. B, 1998] and phonopy [Togo et al, Scr. Mater., 2015] and it interfaces with BoltzTrap2 [Madsen et al., Comput. Phys. Commun., 2018] to calculate transport properties. Our results are bechmarked against state-of-the-art EPW [Poncé et al., Comput. Phys. Comm., 2016] calculations. As a test case, we focused 2D carbon allotropes like graphyne and graphdiyne, and investigated the mechanisms underlying carrier scattering and mobilities within these materials. Our results align with the literature, affirming that the DFTBephy method gives consistent results.
Keywords: charge carrier transport; dftb+; dftbephy; 2D carbon allotropes; ab-initio