KADOYA Tomofumi


Assistant Professor

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External Career 【 display / non-display

  • 兵庫県立大学大学院理学研究科

    2021.4 - 2022.3

  • 兵庫県立大学大学院物質理学研究科

    2015.4 - 2021.3

  • 日本学術振興会特別研究員(DC2)

    2013.4 - 2015.3

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Papers 【 display / non-display

  • Donor-Type Nickel–Dithiolene Complexes Fused with Bulky Cycloalkane Substituents and Their Application in Molecular Conductors

    Kazuya Kubo, Mamoru Sadahiro, Sonomi Arata, Norihisa Hoshino, Tomofumi Kadoya, Tomoyuki Akutagawa, Reizo Kato, Jun-ichi Yamada

    Crystals   11 ( 10 )   1154 - 1154   2021.9

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    Publisher:MDPI AG  

    The effects of substituents on the arrangement of metal–dithiolene complexes based on π-conjugated systems, which are extensively used to synthesize various functional materials, have not been studied adequately. New donor-type nickel–dithiolene complexes fused with bulky cycloalkane substituents [Ni(Cn-dddt)2] (C5-dddt = 4a,5,6,6a-pentahydro-1,4-benzodithiin-2,3-dithiolate; C6-dddt = 4a,5,6,7,8,8a-hexahydro-1,4-benzodithiin-2,3-dithiolate; C7-dddt = 4a,5,6,7,8,9,9a-heptahydro-1,4-benzodithiin-2,3-dithiolate; and C8-dddt = 4a,5,6,7,8,9,10,10a-octahydro-1,4-benzodithiin-2,3-dithiolate) were synthesized in this study. All the complexes were crystallized in cis-[Ni(cis-Cn-dddt)2] conformations with cis-oriented (R,S) conformations around the cycloalkylene groups in the neutral state. Unique molecular arrangements with a three-dimensional network, a one-dimensional column, and a helical molecular arrangement were formed in the crystals owing to the flexible cycloalkane moieties. New 2:1 cation radical crystals of [Ni(C5-dddt)2]2(X) (X = ClO4− or PF6−), obtained by electrochemical crystallization, exhibited semiconducting behaviors (ρrt = 0.8 Ω cm, Ea = 0.09 eV for the ClO4− crystal; 4.0 Ω cm, 0.13 eV for the PF6− crystal) under ambient pressure due to spin-singlet states between the dimers of the donor, which were in accordance with the conducting behaviors under hydrostatic pressure (ρrt = 0.2 Ω cm, Ea = 0.07 eV for the ClO4− crystal; 1.0 Ω cm, 0.12 eV for the PF6− crystal at 2.0 GPa).

    DOI: 10.3390/cryst11101154


  • Dihedral-Angle Dependence of Intermolecular Transfer Integrals in BEDT-BDT-Based Radical-Cation Salts with θ-Type Molecular Arrangements Invited Reviewed

    Tomofumi Kadoya, Shiori Sugiura, Toshiki Higashino, Keishiro Tahara, Kazuya Kubo, Takahiko Sasaki, Kazuo Takimiya, Jun-ichi Yamada

    Crystals   11 ( 8 )   868 - 868   2021.7

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    We report the structural and physical properties of a new organic Mott insulator (BEDT-BDT)AsF6 (BEDT-BDT: benzo[1,2-g:4,5-g′]bis(thieno[2,3-b][1,4dithiin). This AsF6 salt has the same structure as the PF6 salt. Although the anions are disordered, the donor molecules form a θ-type arrangement. The temperature dependence of the resistivity exhibits semiconducting behavior. The static magnetic susceptibility follows Curie–Weiss law over a wide temperature range; however, below 25 K, the magnetic susceptibility is in agreement with a one-dimensional chain model with the exchange coupling J = 7.4 K. No structural phase transition was observed down to 93 K. At 270 K, the Fermi surface calculated by the tight-binding approximation is a two-dimensional cylinder; however, it is significantly distorted at 93 K. This is because the dihedral angles between the BEDT-BDT molecules become larger due to lattice shrinkage at low temperatures, which results in a smaller transfer integral (t1) along the stack direction. This slight change in the dihedral angle gives rise to a significant change in the electronic structure of the AsF6 salt. Radical-cation salts using BEDT-BDT, in which the highest occupied molecular orbital does not have a dominant sign throughout the molecule, are sensitive to slight differences in the overlap between the molecules, and their electronic structures are more variable than those of conventional θ-type conductors.

    DOI: 10.3390/cryst11080868


  • Unique Solvatochromic Behavior of Unsymmetrical Platinum‐Dithiolene Complexes Coordinated by 4,4’‐Dinonyl‐2,2’‐Bipyridine

    Aoi Hori, Yuna Kim, Keishiro Tahara, Tomofumi Kadoya, Jun‐ichi Yamada, Kazuya Kubo

    European Journal of Inorganic Chemistry   2021 ( 11 )   1023 - 1027   2021.3

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  • Accumulated Charge Measurement: Control of the Interfacial Depletion Layer by Offset Voltage and Estimation of Band Gap and Electron Injection Barrier Reviewed

    Sunao Shimomoto, Tomofumi Kadoya, Toshiaki Tanimura, Kazusuke Maenaka, Tokuji Yokomatsu, Takeshi Komino, Hiroyuki Tajima

    The Journal of Physical Chemistry C   125 ( 3 )   1990 - 1998   2021.1

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    Authorship:Corresponding author   Publisher:American Chemical Society (ACS)  

    This study investigates the charge injection barrier at the phthalocyanine (H2Pc)/Pd using accumulated charge measurement (ACM). Because the hole injection barrier is relatively small, the voltage oscillation method in ACM is achieved at the highest occupied molecular orbital/Pd interface, and the hole injection barrier was determined to be 0.26 eV. A negative offset voltage was applied to determine the electron injection barrier at the lowest unoccupied molecular orbital (LUMO)/Pd interface. However, when the electron injection barrier was significantly large, the charge-injected thermal equilibrium state (CITES) could not be achieved at the interface, and an accurate injection barrier could not be determined. Surprisingly, by applying a positive offset voltage, a CITES of electrons was obtained at the LUMO/Pd interface, and the band gap was determined to be 2.75 eV. Furthermore, the electron injection barrier was found to be 2.49 eV. By applying a positive offset voltage, band bending occurred at the H2Pc/Pd interface, thereby reducing the depletion layer in the LUMO and enabling the determination of the band gap and electron injection barrier.

    DOI: 10.1021/acs.jpcc.0c04974


  • Chiral metal down to 4.2 K - a BDH-TTP radical-cation salt with spiroboronate anion B(2-chloromandelate)2− Reviewed

    Toby J. Blundell, Michael Brannan, Hiroshi Nishimoto, Tomofumi Kadoya, Jun-ichi Yamada, Hiroki Akutsu, Yasuhiro Nakazawa, Lee Martin

    Chemical Communications   57 ( 44 )   5406 - 5409   2021

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    Publisher:Royal Society of Chemistry (RSC)  

    <p>Synthesis of a chiral molecular metal which shows metallic behaviour down to at least 4.2 K.</p>

    DOI: 10.1039/d1cc01441b


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Review Papers (Misc) 【 display / non-display

  • Molecular conductors composed from Organic-Transistor Materials

    Tomofumi Kadoya

    Impact   2020 ( 4 )   38 - 39   2020.10

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    Authorship:Lead author, Corresponding author   Publishing type:Article, review, commentary, editorial, etc. (other)   Publisher:Science Impact, Ltd.  

    Assistant Professor Tomofumi Kadoya is part of a team within the Graduate School of Material Science at the University of Hyogo in Japan. He is engaged with a range of different investigations related to conductive organic materials. One of the main focuses of Kadoya's research is organic
    transistors and organic charge-transfer (CT) complexes. CT complexes achieve conductivity by chemical doping but in organic transistors, conduction carriers are generated by field effect, where an electric field is used to control the flow of current. Among the many goals of the research,
    Kadoya and his team want to increase the methods and types of organic doping.

    DOI: 10.21820/23987073.2020.4.38


  • 分子自由度と結合したモット転移の観測 Invited Reviewed

    竹原陵介, 中田耕平, 宮川和也, 角屋智史, 山田順一, 鹿野田一司

    固体物理   54 ( 7 )   353 - 362   2019

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  • Development of Precise Determination Method of Charge Injection Barrier by Accumulated Charge Measurement

    角屋智史, 田島裕之

    村田学術振興財団年報   ( 33 )   2019

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  • 蓄積電荷測定法による金/ペンタセン界面の電荷注入障壁測定

    大村祐一, 宮本裕太, 田島裕之, 小簑剛, 谷村利精, 下元純, 角屋智史, 前中一介, 横松得滋

    分子科学討論会講演プログラム&要旨(Web)   13th   2019

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  • 蓄積電荷測定法による有機半導体/電極界面の研究

    田島裕之, 角屋智史

    日本物理学会講演概要集(CD-ROM)   74 ( 2 )   2019

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Industrial property rights 【 display / non-display

  • 有機薄膜トランジスタの製造方法及び有機薄膜トランジスタ

    森健彦, 角屋智史

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    Application no:特願2013-34805

    Announcement no:特開2013-211534


Academic Awards Received 【 display / non-display

  • 平成27年度手島精一記念博士論文賞 材料工学関係部門

    2016.2   東京工業大学  


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Committee Memberships 【 display / non-display

  • 2018   有機固体若手の会  有機固体若手の会世話人

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  • 2017.2 - 2019.3   日本化学会  日本化学会近畿支部幹事

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