liu.seSearch for publications in DiVA
Change search
CiteExportLink to record
Permanent link

Direct link
Cite
Citation style
  • apa
  • harvard1
  • ieee
  • modern-language-association-8th-edition
  • vancouver
  • oxford
  • Other style
More styles
Language
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Other locale
More languages
Output format
  • html
  • text
  • asciidoc
  • rtf
Charge Generation via Relaxed Charge-Transfer States in Organic Photovoltaics by an Energy-Disorder-Driven Entropy Gain
Linköping University, Department of Physics, Chemistry and Biology, Surface Physics and Chemistry. Linköping University, Faculty of Science & Engineering.
Linköping University, Department of Physics, Chemistry and Biology, Biomolecular and Organic Electronics. Linköping University, Faculty of Science & Engineering.
Linköping University, Department of Physics, Chemistry and Biology. Linköping University, Faculty of Science & Engineering.
Linköping University, Department of Physics, Chemistry and Biology, Biomolecular and Organic Electronics. Linköping University, Faculty of Science & Engineering.ORCID iD: 0000-0002-2582-1740
Show others and affiliations
2018 (English)In: The Journal of Physical Chemistry C, ISSN 1932-7447, E-ISSN 1932-7455, Vol. 122, no 24, p. 12640-12646Article in journal (Refereed) Published
Abstract [en]

In organic photovoltaics, efficient charge generation relies on our ability to convert excitons into free charges. Efficient charge separation from "energetic excitons" has been understood to be governed by delocalization effects promoted by molecular aggregation. A remaining puzzle is, however, the mechanism underlying charge generation via relaxed interfacial charge-transfer (CT) excitons that also exhibit an internal quantum efficiency close to unity. Here, we provide evidence for efficient charge generation via CT state absorption over a temperature range of 50-300 K, despite an intrinsically strong Coulomb binding energy of about 400 meV that cannot be modified by fullerene aggregation. We explain our observation by entropy-driven charge separation, with a key contribution from energy disorder. The energy disorder reduces the charge generation barrier by substantially gaining the entropy as electron hole distance increases, resulting in efficient CT exciton dissociation. Our results underline an emerging consideration of energy disorder in thermodynamic stability of charge pairs and highlight the energy disorder as a dominant factor for generating charges via the CT state. A discussion for a trade-off in harvesting charges from relaxed CT excitons is also provided.

Place, publisher, year, edition, pages
AMER CHEMICAL SOC , 2018. Vol. 122, no 24, p. 12640-12646
National Category
Theoretical Chemistry
Identifiers
URN: urn:nbn:se:liu:diva-149714DOI: 10.1021/acs.jpcc.8b03432ISI: 000436381600008OAI: oai:DiVA.org:liu-149714DiVA, id: diva2:1234397
Note

Funding Agencies|Swedish Research Council [VR-2015-00436]; Wallenberg Scholar grant; Knut and Alice Wallenberg Foundation [KAW 2014.0041]

Available from: 2018-07-24 Created: 2018-07-24 Last updated: 2018-07-24

Open Access in DiVA

No full text in DiVA

Other links

Publisher's full text

Search in DiVA

By author/editor
Puttisong, YuttapoomXia, YuxinChen, X.Gao, FengBuyanova, IrinaInganäs, OlleChen, Weimin
By organisation
Surface Physics and ChemistryFaculty of Science & EngineeringBiomolecular and Organic ElectronicsDepartment of Physics, Chemistry and Biology
In the same journal
The Journal of Physical Chemistry C
Theoretical Chemistry

Search outside of DiVA

GoogleGoogle Scholar

doi
urn-nbn

Altmetric score

doi
urn-nbn
Total: 156 hits
CiteExportLink to record
Permanent link

Direct link
Cite
Citation style
  • apa
  • harvard1
  • ieee
  • modern-language-association-8th-edition
  • vancouver
  • oxford
  • Other style
More styles
Language
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Other locale
More languages
Output format
  • html
  • text
  • asciidoc
  • rtf