Chasing the “Killer” Phonon Mode for the Rational Design of Low-Disorder, High-Mobility Molecular Semiconductors

Guillaume Schweicher, Gabriele D'Avino, Michael T. Ruggiero, David J. Harkin, Katharina Broch, Deepak Venkateshvaran, Guoming Liu, Audrey Richard, Christian Ruzié, Jeff Armstrong, Alan R. Kennedy, Kenneth Shankland, Kazuo Takimiya, Yves H. Geerts, J. Axel Zeitler, Simone Fratini, Henning Sirringhaus

Research output: Contribution to journalArticle

12 Citations (Scopus)

Abstract

Molecular vibrations play a critical role in the charge transport properties of weakly van der Waals bonded organic semiconductors. To understand which specific phonon modes contribute most strongly to the electron–phonon coupling and ensuing thermal energetic disorder in some of the most widely studied high-mobility molecular semiconductors, state-of-the-art quantum mechanical simulations of the vibrational modes and the ensuing electron–phonon coupling constants are combined with experimental measurements of the low-frequency vibrations using inelastic neutron scattering and terahertz time-domain spectroscopy. In this way, the long-axis sliding motion is identified as a “killer” phonon mode, which in some molecules contributes more than 80% to the total thermal disorder. Based on this insight, a way to rationalize mobility trends between different materials and derive important molecular design guidelines for new high-mobility molecular semiconductors is suggested.

Original languageEnglish
Article number1902407
JournalAdvanced Materials
Volume31
Issue number43
DOIs
Publication statusPublished - 2019 Oct 1
Externally publishedYes

Keywords

  • charge transport
  • dynamic disorder
  • field-effect transistors
  • molecular design
  • organic electronics
  • transient localization scenario

ASJC Scopus subject areas

  • Materials Science(all)
  • Mechanics of Materials
  • Mechanical Engineering

Fingerprint Dive into the research topics of 'Chasing the “Killer” Phonon Mode for the Rational Design of Low-Disorder, High-Mobility Molecular Semiconductors'. Together they form a unique fingerprint.

  • Cite this

    Schweicher, G., D'Avino, G., Ruggiero, M. T., Harkin, D. J., Broch, K., Venkateshvaran, D., Liu, G., Richard, A., Ruzié, C., Armstrong, J., Kennedy, A. R., Shankland, K., Takimiya, K., Geerts, Y. H., Zeitler, J. A., Fratini, S., & Sirringhaus, H. (2019). Chasing the “Killer” Phonon Mode for the Rational Design of Low-Disorder, High-Mobility Molecular Semiconductors. Advanced Materials, 31(43), [1902407]. https://doi.org/10.1002/adma.201902407