Get access

Fused Thiophene Semiconductors: Crystal Structure–Film Microstructure Transistor Performance Correlations

Authors

  • Jangdae Youn,

    1. Department of Chemistry and the Materials Research Center, Northwestern University, 2145 Sheridan Rd., Evanston, IL 60208-3113, USA
    Search for more papers by this author
  • Sumit Kewalramani,

    1. Department of Materials Science and Engineering, Department of Physics and Astronomy, Northwestern University, 2220 Campus Dr., Evanston, IL 60208-3113, USA
    Search for more papers by this author
  • Jonathan D. Emery,

    1. Department of Materials Science and Engineering, Department of Physics and Astronomy, Northwestern University, 2220 Campus Dr., Evanston, IL 60208-3113, USA
    Search for more papers by this author
  • Yanrong Shi,

    1. Department of Chemistry and the Materials Research Center, Northwestern University, 2145 Sheridan Rd., Evanston, IL 60208-3113, USA
    Search for more papers by this author
  • Shiming Zhang,

    1. Department of Chemistry and the Materials Research Center, Northwestern University, 2145 Sheridan Rd., Evanston, IL 60208-3113, USA
    Search for more papers by this author
  • Hsiu-Chieh Chang,

    1. Department of Chemistry, National Central University, Jhong-Li, Taiwan, 32054, R.O.C.
    Search for more papers by this author
  • You-jhih Liang,

    1. Department of Chemistry, National Central University, Jhong-Li, Taiwan, 32054, R.O.C.
    Search for more papers by this author
  • Chia-Ming Yeh,

    1. Department of Chemistry, National Central University, Jhong-Li, Taiwan, 32054, R.O.C.
    Search for more papers by this author
  • Chieh-Yuan Feng,

    1. Department of Chemistry, National Central University, Jhong-Li, Taiwan, 32054, R.O.C.
    Search for more papers by this author
  • Hui Huang,

    1. Department of Chemistry and the Materials Research Center, Northwestern University, 2145 Sheridan Rd., Evanston, IL 60208-3113, USA
    Search for more papers by this author
  • Charlotte Stern,

    1. Department of Chemistry and the Materials Research Center, Northwestern University, 2145 Sheridan Rd., Evanston, IL 60208-3113, USA
    Search for more papers by this author
  • Liang-Hsiang Chen,

    1. Process Technology Division, Display Technology Center, Industrial Technology Research Institute, Chung Hsing Rd., Chutung, Hsinchu, Taiwan, 31040, R.O.C.
    Search for more papers by this author
  • Jia-Chong Ho,

    1. Process Technology Division, Display Technology Center, Industrial Technology Research Institute, Chung Hsing Rd., Chutung, Hsinchu, Taiwan, 31040, R.O.C.
    Search for more papers by this author
  • Ming-Chou Chen,

    Corresponding author
    1. Department of Chemistry, National Central University, Jhong-Li, Taiwan, 32054, R.O.C.
    • Department of Chemistry, National Central University, Jhong-Li, Taiwan, 32054, R.O.C.
    Search for more papers by this author
  • Michael J. Bedzyk,

    Corresponding author
    1. Department of Materials Science and Engineering, Department of Physics and Astronomy, Northwestern University, 2220 Campus Dr., Evanston, IL 60208-3113, USA
    • Department of Materials Science and Engineering, Department of Physics and Astronomy, Northwestern University, 2220 Campus Dr., Evanston, IL 60208-3113, USA
    Search for more papers by this author
  • Antonio Facchetti,

    Corresponding author
    1. Department of Chemistry and the Materials Research Center, Northwestern University, 2145 Sheridan Rd., Evanston, IL 60208-3113, USA
    • Department of Chemistry and the Materials Research Center, Northwestern University, 2145 Sheridan Rd., Evanston, IL 60208-3113, USA
    Search for more papers by this author
  • Tobin J. Marks

    Corresponding author
    1. Department of Chemistry and the Materials Research Center, Northwestern University, 2145 Sheridan Rd., Evanston, IL 60208-3113, USA
    • Department of Chemistry and the Materials Research Center, Northwestern University, 2145 Sheridan Rd., Evanston, IL 60208-3113, USA
    Search for more papers by this author

Abstract

The molecular packing motifs within crystalline domains should be a key determinant of charge transport in thin-film transistors (TFTs) based on small organic molecules. Despite this implied importance, detailed information about molecular organization in polycrystalline thin films is not available for the vast majority of molecular organic semiconductors. Considering the potential of fused thiophenes as environmentally stable, high-performance semiconductors, it is therefore of interest to investigate their thin film microstructures in relation to the single crystal molecular packing and OTFT performance. Here, the molecular packing motifs of several new benzo[d,d′]thieno[3,2-b;4,5-b′]dithiophene (BTDT) derivatives are studied both in bulk 3D crystals and as thin films by single crystal diffraction and grazing incidence wide angle X-ray scattering (GIWAXS), respectively. The results show that the BTDT derivative thin films can have significantly different molecular packing from their bulk crystals. For phenylbenzo[d,d′]thieno[3,2-b;4,5-b′]dithiophene (P-BTDT), 2-biphenylbenzo[d,d′]thieno-[3,2-b;4,5-b′]dithiophene (Bp-BTDT), 2-naphthalenylbenzo[d,d′]thieno[3,2-b;4,5-b′]dithiophene (Np-BTDT), and bisbenzo[d,d′]thieno[3,2-b;4,5-b′]dithiophene (BBTDT), two lattices co-exist, and are significantly strained versus their single crystal forms. For P-BTDT, the dominance of the more strained lattice relative to the bulk-like lattice likely explains the high carrier mobility. In contrast, poor crystallinity and surface coverage at the dielectric/substrate interface explains the marginal OTFT performance of seemingly similar PF-BTDT films.

Get access to the full text of this article

Ancillary