Photo-induced carrier generation and recombination dynamics probed by combining time-resolved microwave conductivity and transient absorption spectroscopy

Jaehong Park, Obadiah G. Reid, Gary Rumbles

Research output: Chapter in Book/Report/Conference proceedingConference contribution

Abstract

We examined photoinduced charge-generation dynamics of the poly(3-hexylthiophene) (P3HT)/titanyl phthalocyanine (TiOPc) bilayer and the P3HT/TiOPc/C60 trilayer using the combination of flash-photolysis time-resolved microwave conductivity experiments (fp-TRMC) and classic pump-probe transient absorption (TA) spectroscopy following dominant excitation of the P3HT layer. The superlinear increase of φΣμ for the P3HT/TiOPc bilayer, compared to the φΣμ sum of each P3HT and TiOPc layer suggest photoinduced carrier-generation. Furthermore, the superlinear increase of φΣμ of the P3HT/TiOPc/C60 trilayer with respect to the each P3HT/TiOPc and TiOPc/C60 bilayers evinces charge migration from one interface to the other interface. In addition, with selective photoexcitation on the P3HT layer, both amorphous and H-aggregated P3HT domains participate in electron transfer ([P3HT∗/TiOPc]→[P3HT•+/TiOPc•-]), contrasting to the previous observation where with selective excitation of the TiOPc layer, only the H-aggregated P3HT domain involves in hole transfer ([P3HT/TiOPc→[P3HT•+/TiOPc•-]) to produce P3HT•+/TiOPc•- in J. Phys. Chem. B 119(24), 7729 - 7739 (2015). These results under different excitation conditions are consistent with calculated energetic driving force (ΔECS) for charge generation which is -0.58 eV and -0.73 eV for amorphous and H-aggregated P3HT domains under the P3HT layer excitation, while 0.04 eV and -0.11 eV for amorphous and H-aggregated P3HT domains under the TiOPc layer excitation.

Original languageEnglish
Title of host publicationProceedings of SPIE - The International Society for Optical Engineering
PublisherSPIE
Volume9549
ISBN (Print)9781628417159
DOIs
Publication statusPublished - 2015
EventPhysical Chemistry of Interfaces and Nanomaterials XIV - San Diego, United States
Duration: Aug 9 2015Aug 12 2015

Other

OtherPhysical Chemistry of Interfaces and Nanomaterials XIV
CountryUnited States
CitySan Diego
Period8/9/158/12/15

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Keywords

  • and photoinduced electron transfer
  • carrier dynamics
  • excited-state dynamics
  • transient absorption spectroscopy
  • Transient microwave conductivity

ASJC Scopus subject areas

  • Applied Mathematics
  • Computer Science Applications
  • Electrical and Electronic Engineering
  • Electronic, Optical and Magnetic Materials
  • Condensed Matter Physics

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