[Crib-list] VIRTUAL Event... SPEAKER: Dipti Jasrasaria (UC, Berkeley/ CRIBB Seminar / 12:00 PM - 1:00 PM / Friday, June 3, 2022 (fwd)
Shirley Entzminger
daisymae at math.mit.edu
Thu Jun 2 15:24:25 EDT 2022
VIRTUAL Talk...
COMPUTATIONAL RESEARCH in BOSTON and BEYOND SEMINAR
(CRIBB)
ZOOM meeting info...
https://mit.zoom.us/j/96155042770
Meeting ID: 961 5504 2770
====================================
DATE: Friday, June 3, 2022
TIME: 12:00 PM - 1:00 PM
TITLE: Interplay of Surface and Interior Modes in Exciton-Phonon
Coupling at the Nanoscale
SPEAKER: Dipti Jasrasaria (UC, Berkeley)
ABSTRACT:
Quantum dots (QDs) are semiconducting nanocrystals that have been of much
interest due to their highly tunable optoelectronic properties. These
properties are greatly affected by coupling between excitons and phonons, or
lattice vibrations, in these systems. Despite this, a microscopic picture of
exciton-phonon coupling (EXPC) is still lacking, particularly regarding the
magnitude and scaling with QD size, the dependence on phonon frequency, and the
role of the QD surface. The computational complexity associated with accurately
describing excitons and phonons has limited previous theoretical studies of
EXPC to simplified models or very small QDs, which have limited transferability
to experimental systems. Here, I will describe an atomistic approach for
describing EXPC in QDs of experimentally relevant sizes. We validate our
approach by calculating the reorganization energies, a measure of EXPC, for
CdSe and CdSe-CdS core–shell QDs, finding good agreement with experimental
measurements. We demonstrate that exciton formation distorts the QD lattice
primarily along the coordinates of low-frequency acoustic modes. Modes at the
NC surface play a significant role in smaller QDs while interior modes dominate
for larger systems. This framework provides the foundation for ongoing work to
compute phonon-mediated exciton dynamics in QDs.
=======================================
For information about the "Computational Research in Boston and Beyond Seminar"
(CRIBB), please visit:
https://math.mit.edu/sites/crib/
=================
Shirley A. Entzminger
Administrative Assistant II
Department of Mathematics
Massachusetts Institute of Technology
77 Massachusetts Avenue
Building 2, Room 350A
Cambridge, MA 02139
PHONE: (617) 253-4994
E-mail: daisymae at math.mit.edu
-------------- next part --------------
A non-text attachment was scrubbed...
Name: CRIBB Seminar --Spk. Dipti Jasrasaria (Univ. of CA, Berkeley)) - June 3, 2022.pdf
Type: application/pdf
Size: 171204 bytes
Desc:
URL: <http://mailman.mit.edu/pipermail/crib-list/attachments/20220602/278614cf/attachment.pdf>
More information about the CRiB-list
mailing list