BEGIN:VCALENDAR
VERSION:2.0
PRODID:-//Talks.cam//talks.cam.ac.uk//
X-WR-CALNAME:Talks.cam
BEGIN:VEVENT
SUMMARY:Exciton (De)Localization and Dissociation in Heterogeneous Semicon
 ductors from First Principles Computational Modeling - Prof. Marina Filip 
 (Oxford)
DTSTART:20250612T130000Z
DTEND:20250612T143000Z
UID:TALK229378@talks.cam.ac.uk
CONTACT:Bo Peng
DESCRIPTION:Understanding the physics of how excitons form\, delocalize an
 d dissociate is of key importance to the functionality of a wide range of 
 applications\, such as photovoltaics\, lighting and lasing. Development of
  new computational modeling techniques based on density functional theory 
 (DFT) and many body perturbation theory capable to describe interactions b
 etween excitons and other quasiparticles constitutes a frontier first prin
 ciples computational modeling of materials. The GW+Bethe-Salpeter Equation
  (BSE) approach [1\,2] is the state-of-the-art approach to compute optical
  excitation energies in semiconductors and insulators and provides the fou
 ndation of new methods aimed at describing complex excited state phenomena
 . \n\nIn the first part of my talk\, I will present a new methodological d
 evelopment that generalizes the BSE to include the impact of ionic vibrati
 ons on the dielectric screening of excitons [3\,4]\, and show how this all
 ows us to compute temperature dependent exciton binding energies\, as well
  the rate of dissociation of excitons upon scattering with phonons in seve
 ral examples of semiconductors and insulators including III-V semiconducto
 rs and the ternary oxide BiVO4 [4\,5]. In the second part of my talk (as t
 ime allows)\, I will present our recent study of layered halide perovskite
 s and hetero-structures [6-9]. In particular\, I will discuss our recent w
 ork focused on understanding the mechanism for tuning the inter-layer exci
 ton de-localization in these complex heterogeneous semiconductors\, as pre
 dicted by our first principles calculations.\n\n\n\n\n\n\n\n\n\n1. Hyberts
 en & Louie\, Phys. Rev. B 34\, 5390 (1986).\n2. Rohlfing & Louie\, Phys. R
 ev. Lett. 81\, 2312 (1998).\n3. Filip\, Haber & Neaton\, Phys. Rev. Lett. 
 127\, 67401 (2021).\n4. Alvertis\, Haber\, Li\, Coveney\, Louie\, Filip & 
 Neaton\, Proc. Natl. Acad. Sci 121 (30)\,  e2403434121 (2024).\n5. Gant\, 
 Alvertis\, Coveney\, Haber\, Filip & Neaton\, arXiv:2504.00110 (2025). \n6
 . Coveney\, Haber\, Alvertis\, Neaton & Filip\, Phys. Rev. B 110 (5)\, 054
 307 (2023). \n7. Filip\, Qiu\, Del Ben & Neaton\, Nano Lett. 22 (12)\, 487
 0-4878 (2022).\n8. McArthur\, Filip & Qiu\, Nano Lett. 23 (9)\, 3796-3802 
 (2023).\n9. Chen & Filip\, J. Phys. Chem. Lett. 14\, 47\, 10634-10641 (202
 3).\n
LOCATION:Seminar Room 3\, RDC
END:VEVENT
END:VCALENDAR