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A few-layer molecular film on polymer substrates to enhance the performance of organic devices

Nature Nanotechnologyvolume 13pages139144 (2018) | Download Citation


In organic electronics the functionalization of dielectric substrates with self-assembled monolayers is regarded as an effective surface modification strategy that may significantly improve the resulting device performance. However, this technique is not suitable for polymer substrates typically used in flexible electronics. Here, we report organic modifiers based on a paraffinic tripodal triptycene, which self-assembles into a completely oriented two-dimensional hexagonal triptycene array and one-dimensional layer stacking structure on polymer surfaces. Such few-layer films are analogous to conventional self-assembled monolayers on inorganic substrates in that they neutralize the polymer surface. Furthermore, the triptycene films significantly improve the crystallinity of an organic semiconductor and the overall performance of organic thin-film transistors, therefore enabling the fabrication of high-performance organic complementary circuits on polymer substrates with high oscillation speeds and low operation voltage.

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  1. 1.

    Zu Heringdorf, F. J. M., Reuter, M. C. & Tromp, R. M. Growth dynamics of pentacene thin films. Nature 412, 517–520 (2001).

  2. 2.

    Yang, S. Y., Shin, K. & Park, C. E. The effect of gate-dielectric surface energy on pentacene morphology and organic field-effect transistor characteristics. Adv. Funct. Mater. 15, 1806–1814 (2005).

  3. 3.

    Hu, Y., Qi, Q. & Jiang, C. Influence of different dielectrics on the first layer grain sizes and its effect on the mobility of pentacene-based thin-film transistors. Appl. Phys. Lett. 96, 133311 (2010).

  4. 4.

    Dinelli, F. et al. Spatially correlated charge transport in organic thin film transistors. Phys. Rev. Lett. 92, 116802 (2004).

  5. 5.

    Tanase, C., Meijer, E. J., Blom, P. W. M. & Leeuw, D. M. Local charge carrier mobility in disordered organic field-effect transistors. Org. Electron. 4, 33–37 (2003).

  6. 6.

    Chaki, N. K. & Vijayamohanan, K. Self-assembled monolayers as a tunable platform for biosensor applications. Biosens. Bioelectron. 17, 1–12 (2002).

  7. 7.

    Lim, S. C. et al. Surface-treatment effects on organic thin-film transistors. Synth. Met. 148, 75–79 (2005).

  8. 8.

    Seong, H., Pak, K., Joo, M., Choi, J. & Im, S. G. A low-voltage organic complementary inverter with high operation stability and flexibility using an ultrathin iCVD polymer dielectric and a hybrid encapsulation layer. Adv. Electron. Mater. 2, 1500209 (2016).

  9. 9.

    Prisawong, P. et al. Vacuum ultraviolet treatment of self-assembled monolayers: a tool for understanding growth and tuning charge transport in organic field-effect transistors. Adv. Mater. 28, 2049–2054 (2016).

  10. 10.

    Vanables, J. A., Spiler, G. D. T. & Hanbucken, M. Nucleation and growth of thin films. Rep. Prog. Phys. 47, 399–459 (1984).

  11. 11.

    McDowell, M., Hill, I. G., McDermott, J. E., Bernasek, S. L. & Schwartz, J. Improved organic thin-film transistor performance using novel self-assembled monolayers. Appl. Phys. Lett. 88, 073505 (2006).

  12. 12.

    Porter, M. D., Bright, T. B., Allara, D. L. & Chidsey, C. E. Spontaneously organized molecular assemblies. 4. Structural characterization of n-alkyl thiol monolayers on gold by optical ellipsometry, infrared spectroscopy, and electrochemistry. J. Am. Chem. Soc. 109, 3559–3568 (1987).

  13. 13.

    Fenter, P., Eberhardt, A. & Eisenberger, P. Self-assembly of n-alkyl thiols as disulfides on Au(111). Science 266, 1216–1218 (1994).

  14. 14.

    Marmont, P. et al. Improving charge injection in organic thin-film transistors with thiol-based self-assembled monolayers. Org. Electron. 9, 419–424 (2008).

  15. 15.

    Klauk, H., Zschieschang, U., Pflaum, J. & Halik, M. Low-voltage organic transistors with an amorphous molecular gate dielectric. Nature 445, 745–748 (2007).

  16. 16.

    Acton, O. et al. π-σ-Phosphonic acid organic monolayer/sol–gel hafnium oxide hybrid dielectrics for low-voltage organic transistors. Adv. Mater. 20, 3697–3701 (2008).

  17. 17.

    Park, Y. M., Daniel, J., Heeney, M. & Salleo, A. Room-temperature fabrication of ultrathin oxide gate dielectrics for low-voltage operation of organic field-effect transistors. Adv. Mater. 23, 971–974 (2011).

  18. 18.

    Seiki, N. et al. Rational synthesis of organic thin films with exceptional long-range structural integrity. Science 348, 1122–1126 (2015).

  19. 19.

    Shioya, H. et al. Raising the metal–insulator transition temperature of VO2 thin films by surface adsorption of organic polar molecules. Appl. Phys. Exp. 8, 121101 (2015).

  20. 20.

    Yamamoto, T. & Takimiya, K. Facile synthesis of highly π-extended heteroarenes, dinaphtho[2,3-b:2‘,3‘-f]chalcogenopheno[3,2-b]chalcogenophenes, and their application to field-effect transistors. J. Am. Chem. Soc. 129, 2224–2225 (2007).

  21. 21.

    Li, L. et al. High-performance and stable organic transistors and circuits with patterned polypyrrole electrodes. Adv. Mater. 24, 2159–2164 (2012).

  22. 22.

    Kraft, U. et al. Flexible low-voltage organic complementary circuits: finding the optimum combination of semiconductors and monolayer gate dielectrics. Adv. Mater. 27, 207–214 (2015).

  23. 23.

    Herlogsson, L., Cölle, M., Tierney, S., Crispin, X. & Berggren, M. Low-voltage ring oscillators based on polyelectrolyte-gated polymer thin-film transistors. Adv. Mater. 22, 72–76 (2010).

  24. 24.

    Bang, K. J. et al. High speeds complementary integrated circuits fabricated with all-printed polymeric semiconductors. J. Polym. Sci. B 49, 62–67 (2011).

  25. 25.

    Kronemeijer, A. J. et al. A selenophene-based low-bandgap donor–acceptor polymer leading to fast ambipolar logic. Adv. Mater. 24, 1558–1565 (2012).

  26. 26.

    Baeg, K. J. et al. Low-voltage, high speed inkjet-printed flexible complementary polymer electronic circuits. Org. Electron. 14, 1407–1418 (2013).

  27. 27.

    Sou, A. et al. Programmable logic circuits for functional integrated smart plastic systems. Org. Electron. 15, 3111–3119 (2014).

  28. 28.

    Hizu, K., Sekitani, T., Someya, T. & Otsuki, J. Reduction in operation voltage of complementary organic thin-film transistor inverter circuits using double-gate structures. Appl. Phys. Lett. 90, 093504 (2007).

  29. 29.

    Zschieschang, U. et al. Mixed self-assembled monolayer gate dielectrics for continuous threshold voltage control in organic transistors and circuits. Adv. Mater. 22, 4489–4493 (2010).

  30. 30.

    Yokota, T. et al. Control of threshold voltage in low-voltage organic complementary inverter circuits with floating gate structures. Appl. Phys. Lett. 98, 193302 (2011).

  31. 31.

    Shiwaku, R. et al. Control of threshold voltage in organic thin-film transistors by modifying gate electrode surface with MoO X aqueous solution and inverter circuit applications. Appl. Phys. Lett. 106, 053301 (2015).

  32. 32.

    Hammersley, A. FIT2D v.17.006 (European Synchrotron Radiation Facility, 2015);

  33. 33.

    Miura, H. CellCalc: A unit cell parameter refinement program on Windows computer. J. Cryst. Soc. Jpn. 45, 145–147 (2003).

  34. 34.

    Kwok, D. Y. & Neumann, A. W. Contact angle measurement and contact angle interpretation. Adv. Colloid Interface Sci. 81, 167 (1999).

  35. 35.

    Shimizu, R. N. & Demarquette, N. R. Evaluation of surface energy of solid polymers using different models. J. Appl. Polym. Sci. 76, 1831 (2000).

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This work was partly supported by the ‘Dynamic Alliance for Open Innovation Bridging Human, Environment and Materials’ from the Ministry of Education, Culture, Sports, Science and Technology of Japan (MEXT). The synchrotron GI-XRD experiments were performed at the BL45XU in the SPring-8 with the approval of the RIKEN SPring-8 Center (proposal nos. 20140056, 20150068 and 20160027). M.K. acknowledges funding through the LIT startup Grant LIT013144001SEL. The authors gratefully acknowledge N. Seiki and D. Ordinario for discussions.

Author information


  1. Electrical Engineering and Information Systems, The University of Tokyo, Tokyo, Japan

    • Tomoyuki Yokota
    • , Ren Shidachi
    • , Takeyoshi Tokuhara
    •  & Takao Someya
  2. Bio-Harmonized Electronics Project, Exploratory Research for Advanced Technology (ERATO), Japan Science and Technology Agency (JST), Tokyo, Japan

    • Tomoyuki Yokota
    • , Takashi Kajitani
    • , Martin Kaltenbrunner
    • , Tsuyoshi Sekitani
    • , Takanori Fukushima
    •  & Takao Someya
  3. Laboratory for Chemistry and Life Science, Institute of Innovative Research, Tokyo Institute of Technology, Yokohama, Japan

    • Takashi Kajitani
    • , Yoshiaki Shoji
    • , Fumitaka Ishiwari
    •  & Takanori Fukushima
  4. RIKEN SPring-8 Center, Hyogo, Japan

    • Takashi Kajitani
  5. Linz Institute of Technology (LIT), Johannes Kepler University Linz, Linz, Austria

    • Martin Kaltenbrunner
  6. The Institute of Scientific and Industrial Research (ISIR), Osaka University, Osaka, Japan

    • Tsuyoshi Sekitani


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T.Y., R.S., M.K., T.T., and T.Se. fabricated and characterized the transistors and circuits. T.K., Y.S., F.I. and T.F. performed the synthetic experiments and characterized thin films. T.Y., T.K., M.K., Y.S., F.I. and T.F. wrote the manuscript with comments from all authors. T.So. supervised the project.

Corresponding authors

Correspondence to Tomoyuki Yokota or Takanori Fukushima or Takao Someya.

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    Supplementary Methods, Supplementary Table 1 and Supplementary Figs. 1–13

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