A new electrode design for ambipolar carrier injection in organic semiconductors and its applications to light emitting diodes

ORAL

Abstract


Organic semiconductors (OSCs) have attracted much attention for low-cost, flexible and human-friendly optoelectronics. However, achieving high electron injection efficiency is difficult from air-stable electrodes and cannot be equivalent to that of holes. Here, we present a novel concept of electrode composed of a bilayer of tetratetracontane (TTC) and polycrystalline organic semiconductors (pc-OSC) covered by a metal (M) thin film layer. Field-effect transistors of single crystal organic semiconductors (sc-OSCs) with the new electrodes of M/pc-OSC/TTC (M: Ca or Au) show both highly-efficient electron and hole injection. Contact resistances of electron and hole injection from Ca/pc-OSC/TTC and Au/pc-OSC/TTC are lower than those from pure Ca for electrons and Au for holes, respectively. Equivalent high field-effect mobilities of holes (22 cm2V–1s–1) and electrons (5.0 cm2V–1s–1) were observed in a rubrene single crystal, which are the highest among field-effect transistors with electrodes so far proposed. The new electronde are useful in high performance and air stable lihgt emitting field-effect transistors.

*This work was partially supported by JSPS KAKENHI Grant Number JP17H05326, and the financial support for collarborative researches by AIMR, Tohohku University.

Presenters

  • Kasumi Tanigaki

    • Dept. of Physics, Tohoku Univ
    • Tohoku Univ

Authors

  • Kasumi Tanigaki

    • Dept. of Physics, Tohoku Univ
    • Tohoku Univ
  • Thangavel Kanagasekaran

    • Tohoku Univ
  • Hidekazu Shimotani

    • Tohoku Univ
  • Ryota Shimizu

    • Tokyo Institute of Technology
    • Chemistry, Tokyo Institue of Technology
  • Taro Hitosugi

    • Tokyo Institute of Technology
    • Chemistry, Tokyo Institue of Technology