Cargando…

Population dynamics of multiple triplet excitons revealed from time-dependent fluorescence quenching of single conjugated polymer chains

The advent of multiple exciton harvesting schemes and prolonging exciton lifetimes to improve performance attributes of solar cells based on conjugated organic materials presents some interesting challenges that must be overcome in order to realize the full potential of these strategies. This is esp...

Descripción completa

Detalles Bibliográficos
Autores principales: Datko, Benjamin D., Grey, John K.
Formato: Online Artículo Texto
Lenguaje:English
Publicado: Nature Publishing Group UK 2019
Materias:
Acceso en línea:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6349865/
https://www.ncbi.nlm.nih.gov/pubmed/30692627
http://dx.doi.org/10.1038/s41598-018-37477-8
_version_ 1783390336629866496
author Datko, Benjamin D.
Grey, John K.
author_facet Datko, Benjamin D.
Grey, John K.
author_sort Datko, Benjamin D.
collection PubMed
description The advent of multiple exciton harvesting schemes and prolonging exciton lifetimes to improve performance attributes of solar cells based on conjugated organic materials presents some interesting challenges that must be overcome in order to realize the full potential of these strategies. This is especially important for applications involving multi-chromophoric conjugated polymers where interactions between multiple spin-forbidden triplet excitons can be significant and are mediated by chain conformation. We use single molecule spectroscopic techniques to investigate interactions between multiple triplet excitons and emissive singlets by monitoring time-dependent fluorescence quenching on time scales commensurate with the triplet lifetime. Structurally related conjugated polymers differing by heteroatom substitution were targeted and we use a stochastic photodynamic model to numerically simulate the evolution of multi-exciton populations following photoexcitation. Single chains of poly(3-hexylthiophene) (P3HT) exhibit longer-lived triplet dynamics and larger steady-state triplet occupancies compared to those of poly(3-hexylselenophene) (P3HS), which has a larger reported triplet yield. Triplet populations evolve and relax much faster in P3HS which only becomes evident when considering all kinetic factors governing exciton population dynamics. Overall, we uncover new guidelines for effectively managing multi-exciton populations and interactions in conjugated polymers and improving their light harvesting efficiency.
format Online
Article
Text
id pubmed-6349865
institution National Center for Biotechnology Information
language English
publishDate 2019
publisher Nature Publishing Group UK
record_format MEDLINE/PubMed
spelling pubmed-63498652019-01-30 Population dynamics of multiple triplet excitons revealed from time-dependent fluorescence quenching of single conjugated polymer chains Datko, Benjamin D. Grey, John K. Sci Rep Article The advent of multiple exciton harvesting schemes and prolonging exciton lifetimes to improve performance attributes of solar cells based on conjugated organic materials presents some interesting challenges that must be overcome in order to realize the full potential of these strategies. This is especially important for applications involving multi-chromophoric conjugated polymers where interactions between multiple spin-forbidden triplet excitons can be significant and are mediated by chain conformation. We use single molecule spectroscopic techniques to investigate interactions between multiple triplet excitons and emissive singlets by monitoring time-dependent fluorescence quenching on time scales commensurate with the triplet lifetime. Structurally related conjugated polymers differing by heteroatom substitution were targeted and we use a stochastic photodynamic model to numerically simulate the evolution of multi-exciton populations following photoexcitation. Single chains of poly(3-hexylthiophene) (P3HT) exhibit longer-lived triplet dynamics and larger steady-state triplet occupancies compared to those of poly(3-hexylselenophene) (P3HS), which has a larger reported triplet yield. Triplet populations evolve and relax much faster in P3HS which only becomes evident when considering all kinetic factors governing exciton population dynamics. Overall, we uncover new guidelines for effectively managing multi-exciton populations and interactions in conjugated polymers and improving their light harvesting efficiency. Nature Publishing Group UK 2019-01-28 /pmc/articles/PMC6349865/ /pubmed/30692627 http://dx.doi.org/10.1038/s41598-018-37477-8 Text en © The Author(s) 2019 Open Access This article is licensed under a Creative Commons Attribution 4.0 International License, which permits use, sharing, adaptation, distribution and reproduction in any medium or format, as long as you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons license, and indicate if changes were made. The images or other third party material in this article are included in the article’s Creative Commons license, unless indicated otherwise in a credit line to the material. If material is not included in the article’s Creative Commons license and your intended use is not permitted by statutory regulation or exceeds the permitted use, you will need to obtain permission directly from the copyright holder. To view a copy of this license, visit http://creativecommons.org/licenses/by/4.0/.
spellingShingle Article
Datko, Benjamin D.
Grey, John K.
Population dynamics of multiple triplet excitons revealed from time-dependent fluorescence quenching of single conjugated polymer chains
title Population dynamics of multiple triplet excitons revealed from time-dependent fluorescence quenching of single conjugated polymer chains
title_full Population dynamics of multiple triplet excitons revealed from time-dependent fluorescence quenching of single conjugated polymer chains
title_fullStr Population dynamics of multiple triplet excitons revealed from time-dependent fluorescence quenching of single conjugated polymer chains
title_full_unstemmed Population dynamics of multiple triplet excitons revealed from time-dependent fluorescence quenching of single conjugated polymer chains
title_short Population dynamics of multiple triplet excitons revealed from time-dependent fluorescence quenching of single conjugated polymer chains
title_sort population dynamics of multiple triplet excitons revealed from time-dependent fluorescence quenching of single conjugated polymer chains
topic Article
url https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6349865/
https://www.ncbi.nlm.nih.gov/pubmed/30692627
http://dx.doi.org/10.1038/s41598-018-37477-8
work_keys_str_mv AT datkobenjamind populationdynamicsofmultipletripletexcitonsrevealedfromtimedependentfluorescencequenchingofsingleconjugatedpolymerchains
AT greyjohnk populationdynamicsofmultipletripletexcitonsrevealedfromtimedependentfluorescencequenchingofsingleconjugatedpolymerchains