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Title: Unraveling Direct and Indirect Energy Transfer Pathways in a Light-Harvesting Dendrimer
Light-harvesting and intramolecular energy funneling are fundamental processes in natural photosynthesis. A comprehensive knowledge of the main structural, dynamic, and optical properties that regulate the efficiency of such processes can be deciphered through the study of artificial light-harvesting antennas, capable of mimicking natural systems. Dendrimers are some of the most explored artificial light-harvesting molecules. However, they have to be well-defined and highly branched conjugated structures, creating intramolecular energy gradients that guarantee efficient and unidirectional energy transfer. Herein, we explore the contributions of the different mechanisms responsible for the highly efficient energy funneling in a large, complex poly(phenylene–ethynylene) dendrimer, whose architecture was particularly designed to conduct the initially absorbed photons toward a spatially localized energy sink away from its surface, avoiding its quenching by the environment. For this purpose, the nonradiative photoinduced energy relaxation and redistribution are simulated by using nonadiabatic excited state molecular dynamics. In this way, the two possible direct and indirect pathways for exciton migrations, previously reported by time-resolved spectroscopy, are defined. Our results stimulate future developments of new synthetic dendrimers for applications in molecular-based photonic devices in which an enhancement in the photoemission efficiency can be predicted by changes in the detailed balance between the different intramolecular energy transfer pathways.  more » « less
Award ID(s):
1802240
PAR ID:
10472663
Author(s) / Creator(s):
; ; ; ;
Publisher / Repository:
ACS
Date Published:
Journal Name:
The Journal of Physical Chemistry C
Volume:
124
Issue:
41
ISSN:
1932-7447
Page Range / eLocation ID:
22383 to 22391
Format(s):
Medium: X
Sponsoring Org:
National Science Foundation
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