Takashi Okubo

Faculty of Science and Engineering, Kindai University
Professor
A03

Research AreasCoordination Chemistry, Solid State Chemistry
Participating Group (2020-2021)

Development of Semiconducting Soft Crystals and Application to Opto-Electronic Devices

Keywords
Semiconducting Soft Crystal, Impedance Spectroscopy, Electroluminescence, Thin Film Solar Cell
Co-Researcher
Co-Researcher: Takayoshi Kuroda-Sowa (Department of Chemistry, Faculty of Science and Engineering, Kindai University, Professor)
Co-Researcher: Maekawa Masahiko (Research Institute for Science and Technology, Kindai University, Professor)

Research Outline

We have synthesized a variety of semiconducting coordination polymers with narrow band gap energy structures by combining copper halides and organic ligands, having similar energy levels of d-orbitals and HOMOs of the organic ligands. Recently, we are developing semiconducting soft crystals showing both conductivity and luminescence properties, and investigating the physical properties. In this project, we will try to develop a new semiconducting soft crystals and apply them to optoelectronic devices.  In particular, we will show new potentials of semiconducting soft crystals by applying them to optoelectronic devices such as organic light emitting diodes (OREDs), thin film solar cells, field effect transistors (FETs), secondary batteries and thermoelectric conversion devices.

Energy Diagram of Semiconducting Soft Crystals
Participating Group (2018-2019)

Application of Electrical Field Sensitive Soft Crystals to Optoelectronic Devices

Keywords
Electrical Field Sensitive Soft Crystal, Dielectric Property, Electrical Conducting Property, Impedance Spectroscopy, Field Effect Transistor, Organic Thin-Film Solar Cell
Co-Researcher
Co-Researcher: Takayoshi Kuroda-Sowa (Department of Chemistry, Faculty of Science and Engineering, Kindai University, Professor)
Co-Researcher: Maekawa Masahiko (Research Institute for Science and Technology, Kindai University, Professor)

Research Outline

Application of Electrical Field Sensitive Soft Crystals to Optoelectronic Devices

We have synthesized a variety of semiconducting coordination polymers with narrow band gap energy structures by combining copper halides and organic ligands, having similar energy levels of d-orbitals and HOMOs of the organic ligands. In these semiconducting coordination polymers, some coordination polymers exhibit ferroelectric behaviors due to the displacement of the copper ion. Such electric field sensitive soft crystals can be expected to develop new optoelectronic devices due to the huge dielectric constants. In this study, we will show new potentials of electrical field sensitive soft crystals with huge dielectric constants by applying them to optoelectronic devices such as field effect transistors (FET), capacitors, thermoelectric conversion devices.

Representative Achievements

  • T. Okubo, K. Himoto, K. Tanishima, S. Fukuda, Y. Noda, M. Nakayama, K. Sugimoto, M. Maekawa, T. Kuroda-Sowa, “Crystal Structure and Band-Gap Engineerign of Copper(I) Broide and a Bridging Acceptor Ligand”, Inorg. Chem., 2018, 57, 2373-2376.
    DOI: 10.1021/acs.inorgchem.7b02923.
  • K. Himoto, S. Suzuki, T. Okubo, M. Maekawa, T. Kuroda-Sowa “A new semiconducting 1D Cu(I)-Cu(II) mixed-valence coordination polymer with Cu(II) dimethylpiperidine-dithiocarbamate and a tetranuclear Cu(I)-Br cluster unit”, New J. Chem., 2018, 42, 3995-3998.
    DOI: 10.1039/c7nj04763k.
  • K. Himoto, T. Horii, T. Syoji, T. Okubo, M. Maekawa, T. Kuroda-Sowa, “A new semiconducting coordination polymer consisting of copper(I)-iodide and 3-pyridinecarboxaldehyde”, Inorg. Chem. Commun., 2018, 88, 34-37.
    DOI: 10.1016/j.inoche.2017.12.012.
  • Kenji Nakatani, Kento Himoto, Yuki Kono, Yuuki Nakahashi, Haruho Anma, Takashi Okubo, Masahiko Maekawa and Takayoshi Kuroda-Sowa, “Synthesis, Crystal Structure, and Electroconducting Properties of a 1D Mixed-Valence Cu(I)–Cu(II) Coordination Polymer with a Dicyclohexyl Dithiocarbamate Ligand”, Crystals, 5, 215-225, 2015.
    DOI: 10.3390/cryst5020215.
  • T. Okubo, H. Anma, Y. Nakahashi, M. Maekawa and T. Kuroda-Sowa “New one-dimensional mixed-valence coordination polymers including an iodine-bridged pentanuclear copper(I) cluster unit”, Polyhedron, 2014, 69, 103-109.
    DOI: 10.1016/j.poly.2013.11.026.
  • T. Okubo, H. Anma, N. Tanaka, K. Himoto, S. Seki, A. Saeki, M. Maekawa and T. Kuroda-Sowa, “Crystal structure and carrier transport properties of a new semiconducting 2D coordination polymer with a 3,5-dimethylpiperidine dithiocarbamate ligand”, Chem. Commun., 49, 4316-4318, 2013.
    DOI: 10.1039/C2CC37137E.
  • N. Tanaka, T. Okubo, H. Anma, K. H. Kim, Y. Inuzuka, M. Maekawa, T. Kuroda-Sowa, “New Halide-Bridged 1D Mixed-Valence CuI–CuII Coordination Polymers Bearing a Piperidine–1–carbodithioato Ligand: Crystal Structure, Magnetic and Conductive Properties, and Application in Dye-Sensitized Solar Cells”, Eur. J. Inorg. Chem., 2013, 3384-3391.
    DOI: 10.1002/ejic.201300188.

Publications


Related Website(s)
Contact
tokubo@kindai.ac.jp