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

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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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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.

Supplementary information

  1. Supplementary Information

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