Delocalization Drives Free Charge Generation in Conjugated Polymer Films

Natalie A. Pace, Obadiah G. Reid, Garry Rumbles

Research output: Contribution to journalArticlepeer-review

22 Scopus Citations


We demonstrate that the product of photoinduced electron transfer between a conjugated polymer host and a dilute molecular sensitizer is controlled by the structural state of the polymer. Ordered semicrystalline solids exhibit free charge generation, while disordered polymers in the melt phase do not. We use photoluminescence (PL) and time-resolved microwave conductivity (TRMC) measurements to sweep through polymer melt transitions in situ. Free charge generation measured by TRMC turns off upon melting, whereas PL quenching of the molecular sensitizers remains constant, implying unchanged electron transfer efficiency. The key difference is the intermolecular order of the polymer host in the solid state compared to the melt. We propose that this order-disorder transition modulates the localization length of the initial charge-transfer state, which controls the probability of free charge formation.

Original languageAmerican English
Pages (from-to)735-741
Number of pages7
JournalACS Energy Letters
Issue number3
StatePublished - 2018

Bibliographical note

Publisher Copyright:
© 2018 American Chemical Society.

NREL Publication Number

  • NREL/JA-5900-70921


  • free charge generation
  • polymer microstructure
  • solar-photochemistry
  • time-resolved microwave conductivity


Dive into the research topics of 'Delocalization Drives Free Charge Generation in Conjugated Polymer Films'. Together they form a unique fingerprint.

Cite this