Interplay between structural hierarchy and exciton diffusion in artificial light harvesting

Bjorn Kriete, Julian Luettig, Tenzin Kunsel, Pavel Maly, Thomas L. C. Jansen, Jasper Knoester, Tobias Brixner, Maxim S. Pshenichnikov*

*Corresponding author for this work

Research output: Contribution to journalArticleAcademicpeer-review

19 Citations (Scopus)
112 Downloads (Pure)

Abstract

Unraveling the nature of energy transport in multi-chromophoric photosynthetic complexes is essential to extract valuable design blueprints for light-harvesting applications. Long-range exciton transport in such systems is facilitated by a combination of delocalized excitation wavefunctions (excitons) and exciton diffusion. The unambiguous identification of the exciton transport is intrinsically challenging due to the system's sheer complexity. Here we address this challenge by employing a spectroscopic lab-on-a-chip approach: ultrafast coherent two-dimensional spectroscopy and microfluidics working in tandem with theoretical modeling. We show that at low excitation fluences, the outer layer acts as an exciton antenna supplying excitons to the inner tube, while under high excitation fluences the former converts its functionality into an exciton annihilator which depletes the exciton population prior to any exciton transfer. Our findings shed light on the excitonic trajectories across different subunits of a multi-layered artificial light-harvesting complex and underpin their great potential for directional excitation energy transport.

Original languageEnglish
Article number4615
Number of pages11
JournalNature Communications
Volume10
DOIs
Publication statusPublished - 10-Oct-2019

Keywords

  • MOLECULAR NANOTUBES
  • ANTENNA COMPLEXES
  • FLUORESCENCE
  • SPECTROSCOPY
  • ANNIHILATION
  • MIGRATION
  • TRANSPORT
  • DYNAMICS
  • TRANSITIONS
  • RELAXATION

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