Photophysics of charge-transfer excitons in thin films of π -conjugated polymers

Zhendong Wang, Sumitendra Mazumdar, Alok Shukla

Research output: Contribution to journalArticle

23 Citations (Scopus)

Abstract

We develop a theory of the electronic structure and photophysics of interacting chains of π -conjugated polymers to understand the differences between solutions and films. While photoexcitation generates only the intrachain exciton in solutions, the optical exciton as well as weakly allowed charge-transfer excitons are generated in films. We extend existing theories of the lowest polaron pair and charge-transfer excitons to obtain descriptions of the excited states of these interchain species, and we show that a significant fraction of ultrafast photoinduced absorptions in films originates from the lowest charge-transfer exciton. Our proposed mechanism explains the simultaneous observation of polaronlike-induced absorption features peculiar to films in ultrafast spectroscopy and the absence of mobile charge carriers as deduced from other experiments. We also show that there is a 1:1 correspondence between the essential states that describe the photophysics of single chains and of interacting chains that constitute thin films.

Original languageEnglish (US)
Article number235109
JournalPhysical Review B - Condensed Matter and Materials Physics
Volume78
Issue number23
DOIs
StatePublished - Dec 1 2008

Fingerprint

Conjugated polymers
Excitons
Charge transfer
charge transfer
excitons
Thin films
polymers
thin films
Gene Conversion
Photoexcitation
Charge carriers
photoexcitation
Excited states
Electronic structure
charge carriers
LDS 751
Spectroscopy
electronic structure
spectroscopy
excitation

ASJC Scopus subject areas

  • Condensed Matter Physics
  • Electronic, Optical and Magnetic Materials

Cite this

Photophysics of charge-transfer excitons in thin films of π -conjugated polymers. / Wang, Zhendong; Mazumdar, Sumitendra; Shukla, Alok.

In: Physical Review B - Condensed Matter and Materials Physics, Vol. 78, No. 23, 235109, 01.12.2008.

Research output: Contribution to journalArticle

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