Phonon-driven exciton scattering and dissociation from first principles

ORAL

Abstract

Understanding the processes governing exciton dissociation is of central importance for optoelectronic devices such as solar cells. Recently, we have introduced a new ab initio approach to compute temperature-dependent phonon-driven exciton dissociation rates in optoelectronic materials [1,2]. In this talk, we will present a rigorous theoretical framework that unifies many-body perturbation theory (MBPT) and Fermi's golden rule (FGR), allowing us to derive rigorous expressions for phonon-driven exciton scattering rates. We will show how the formalism of rearrangement collision theory [3] can be applied to extend the usual FGR approach to describe phonon-driven exciton dissociation, as well as the FGR exciton-to-exciton and exciton-to-uncorrelated charge carrier scattering [4,5]. We will apply this framework to a model involving Wannier-Mott excitons in the limit of Fröhlich electron-phonon coupling [6] to demonstrate the relative importance of exciton dissociation and exciton-exciton scattering channels in polar materials.



[1] Coveney, Haber, Alvertis, Neaton & Filip, In prep. (2023).

[2] Alvertis, Haber, Li, Coveney, Louie, Filip & Neaton, Submitted (2023).

[3] Sunakawa, Progr. Theo. Phys. 24, (1960).

[4] Antonius & Louie, PRB 105, 085111 (2022).

[5] Marini, PRL 101, 106405 (2008).

[6] Filip, Haber & Neaton, PRL 127, 067401 (2021).

* We acknowledge funding from the UK-EPSRC and computation resources from TACC (Frontera) at UT Austin, and from DOE via the Theory FWP and C2SEPEM at LBNL.

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Publication: Coveney, Haber, Alvertis, Neaton & Filip, In prep. (2023).
Alvertis, Haber, Li, Coveney, Louie, Filip & Neaton, Submitted (2023).

Presenters

  • Christopher J Coveney

    University of Oxford

Authors

  • Christopher J Coveney

    University of Oxford

  • Jonah B Haber

    Stanford University, Lawrence Berkeley National Laboratory

  • Antonios M Alvertis

    KBR, Inc, NASA Ames Research Center, Moffett Field, Californ, Lawrence Berkeley National Laboratory and NASA Ames Research Center, Lawrence Berkeley National Laboratory, KBR Inc, NASA Ames Research Center, Moffett Field, Materials Science Division, LBNL

  • Jeffrey B Neaton

    Lawrence Berkeley National Laboratory and UC-Berkeley

  • Marina R Filip

    University of Oxford