26ème Congrès Général de la SFP

Ab initio description of electron-phonon and phonon-phonon scattering processes in density functional theory for the calculation of charge and heat transports

Non programmé

20m

Centre des Congrès de la Villette (Cité des sciences et de l'Industrie, Paris)

Poster MC19 Hétérostructures et interfaces de basse dimensionnalité Mini-colloques: MC19 Hétérostructures et interfaces de basse dimensionnalité

Orateur

Dr nathalie VAST (Laboratoire des Solides Irradiés - CEA-DRF-IRAMIS (CNRS, Institut Polytechnique de Paris))

Description

The future sparsity of carbon-based fuels, the increasing energy cost, together with the growing concern of society over environmental problems, make the performance improvement of energy conversion devices – thermoelectricity, photovoltaics – a topic of high importance. Such devices are mainly designed by using macroscopic models -the drift-diffusion for electronic transport, or the Fourier formalism for heat/energy transport- which assume local equilibrium and simplified (averaged) material properties for the carrier relaxation times. Huge progress has however been achieved in the description of scattering processes with methods based on the density functional perturbation theory (DFPT). We will show that electron transport characteristics of bulk semiconductors are well described within the approach that couples DFPT electron-phonon scattering rates with the semi-classical Boltzmann transport equation (BTE), and the same is true for DFPT phonon-phonon scattering rates and BTE for phonon that yield the thermal conductivity, with bismuth as an example. We will also discuss the electron and phonon coupled equations for thermoelectricity – the so-called phonon-drag effect -as well as the effect of nano-structuring on the Seebeck coefficient.

Acknowledgements:
Calculations have been performed using the QUANTUM ESPRESSO [1] and EPW [2] softwares modified by us.. We acknowledge access to high performance computing (HPC) resources by the Partnership for Advanced Computing in Europe (PRACE Project No. 2019204962), by the French HPC centers of TGCC, CINES and IDRIS (GENCI Project 2210) as well as to the 3L-hpc local computer cluster partly supported by the DIM SIRTEQ (région Île de France) and École Polytechnique. Financial supports are also acknowledged: CEA ANCRE program (project Thermoint), Labex Nanosaclay ANR-10-LABX-0035 (Flagship project MaCaCQu), and ANR-21-CE50-0008 (project Placho).

[1] P. Giannozzi et al., Advanced capabilities for materials modelling with QUANTUM ESPRESSO. J. Phys.: Condens. Matter, 29:465901, 2017.

[2] S. Ponce, E. R. Margine, C. Verdi, and F. Giustino. EPW: Electron-phonon coupling, transport and superconducting properties using maximally localized Wannier functions. Comp. Phys. Comm., 209:116, 2016.