Exciton diffusion in near-infrared absorbing solution-processed organic thin films

H. Y. Shin, J. H. Woo, M. J. Gwon, M. Barthelemy, M. Vomir, T. Muto, K. Takaishi, M. Uchiyama, D. Hashizume, T. Aoyama, D. W. Kim, S. Yoon, J. Y. Bigot, J. W. Wu, J. C. Ribierre

Research output: Contribution to journalArticle

13 Citations (Scopus)

Abstract

We report on singlet-singlet annihilation and exciton diffusion in as-prepared p-type and annealed n-type thin films of the low-bandgap quinoidal quaterthiophene [QQT(CN)4] using ultrafast transient absorption measurements. The decay dynamics of exciton populations are well described by a one-dimensional diffusion-limited bimolecular recombination, indicating that the singlet excitons migrate preferentially along the stacking direction. Our results show that the exciton diffusion constants in QQT(CN)4 films do not vary significantly upon thermal annealing. Exciton diffusion lengths are measured to be as high as 4 and 5 nm in as-prepared and annealed QQT(CN)4 films, respectively. We also observe an influence of the excitation densities on the singlet exciton diffusion, which is attributed to phonon scattering. Because of the possibility of patterning p-n regions in QQT(CN)4 films by thermal nanolithography techniques, this study provides important insight not only into the photophysical properties of quinoidal oligothiophene derivatives but also for their future integration into high-performance p-n nanostructured near infrared light-sensing devices.

Original languageEnglish
Pages (from-to)2868-2872
Number of pages5
JournalPhysical Chemistry Chemical Physics
Volume15
Issue number8
DOIs
Publication statusPublished - Feb 28 2013
Externally publishedYes

ASJC Scopus subject areas

  • Physics and Astronomy(all)
  • Physical and Theoretical Chemistry

Fingerprint Dive into the research topics of 'Exciton diffusion in near-infrared absorbing solution-processed organic thin films'. Together they form a unique fingerprint.

  • Cite this

    Shin, H. Y., Woo, J. H., Gwon, M. J., Barthelemy, M., Vomir, M., Muto, T., Takaishi, K., Uchiyama, M., Hashizume, D., Aoyama, T., Kim, D. W., Yoon, S., Bigot, J. Y., Wu, J. W., & Ribierre, J. C. (2013). Exciton diffusion in near-infrared absorbing solution-processed organic thin films. Physical Chemistry Chemical Physics, 15(8), 2868-2872. https://doi.org/10.1039/c2cp43705h