Band-shape engineering of thermoelectric materials for high thermoelectric efficiency

• Project/Area Number: 17K14108
• Research Category: Grant-in-Aid for Young Scientists (B)
• Allocation Type: Multi-year Fund
• Research Field: Applied materials
• Research Institution: Osaka University
• Principal Investigator: Usui Hidetomo 大阪大学, 理学研究科, 招へい研究員 (10722902)
• Project Period (FY): 2017-04-01 – 2019-03-31
• Project Status: Completed (Fiscal Year 2018)
• Budget Amount: ¥2,080,000 (Direct Cost: ¥1,600,000、Indirect Cost: ¥480,000); Fiscal Year 2018: ¥1,040,000 (Direct Cost: ¥800,000、Indirect Cost: ¥240,000); Fiscal Year 2017: ¥1,040,000 (Direct Cost: ¥800,000、Indirect Cost: ¥240,000)
• Keywords: 熱電効果 / 第一原理計算 / バンド構造 / 物性理論 / 再生可能エネルギー / 廃熱利用

Outline of Final Research Achievements

The thermoelectric effect is a direct conversion of heat to electricity or vice versa. In this study, we instigated new thermoelectric materials by means of band-shape engineering, which means that shape of electronic band structures is modified by substituting constituent elements of compounds in order to enhance thermoelectric efficiency. We found that LaOAsSe2, in which As and Se are hypothetically substituted with Bi and S of LaOBiS2, can exhibit large thermoelectric performance with the dimensionless figure of merit ZT > 2.

Academic Significance and Societal Importance of the Research Achievements

熱電効果の性能向上を目指した研究で、エネルギーバンドと呼ばれる電子状態を示す構造の形状を変化させることで高性能化を目指すという研究はこれまでほとんどなかった。本研究では、元素置換によりバンド構造の形状を制御できることを示し、仮想物質ではあるが、大きな熱電性能を生み出しうる物質を理論的に発見することが出来た。本研究により熱電物質開発の新しい指針を提案できたことから、既存の指針と組み合わせることで高性能物質開発の幅が広がることが期待される。

Research Products

• [Journal Article] Hidden kagome-lattice picture and origin of high conductivity in delafossite PtCoO2 (2019)
  • Author(s): Usui Hidetomo、Ochi Masayuki、Kitamura Sota、Oka Takashi、Ogura Daisuke、Rosner Helge、Haverkort Maurits W.、Sunko Veronika、King Philip D. C.、Mackenzie Andrew P.、Kuroki Kazuhiko
  • Journal Title: Physical Review Materials Volume: 3 Issue: 4
  • DOI: 10.1103/physrevmaterials.3.045002
  • Peer Reviewed / Int'l Joint Research
• [Journal Article] Thermoelectric properties of (Ba,K)Cd2As2 crystallized in the CaAl2Si2-type structure (2018)
  • Author(s): Kunioka H.、Kihou K.、Nishiate H.、Yamamoto A.、Usui H.、Kuroki K.、Lee C. H.
  • Journal Title: Dalton Transactions Volume: 47 Issue: 45 Pages: 16205-16210
  • DOI: 10.1039/c8dt02955e
  • Peer Reviewed
• [Journal Article] Retreat from Stress: Rattling in a Planar Coordination (2018)
  • Author(s): Koichiro Suekuni, Chul Ho Lee, Hiromi I. Tanaka, Eiji Nishibori, Atsushi Nakamura, Hidetaka Kasai, Hidetomo Usui, Masayuki Ochi, Takumi Hasegawa, Mitsutaka Nakamura, Seiko Ohira‐Kawamura, Tatsuya Kikuchi, Koji Kaneko, Hirotaka Nishiate, Katsuaki Hashikuni, Yasufumi Kosaka, Kazuhiko Kuroki, Toshiro Takabatake, 他1名
  • Journal Title: Advanced Materials Volume: 30 Issue: 13 Pages: 1706230-1706230
  • DOI: 10.1002/adma.201706230
  • Peer Reviewed
• [Journal Article] Enhanced power factor and reduced Lorenz number in the Wiedemann?Franz law due to pudding mold type band structures (2017)
  • Author(s): Hidetomo Usui, Kazuhiko Kuroki
  • Journal Title: Journal of Applied Physics Volume: 121 Issue: 16 Pages: 165101-165101
  • DOI: 10.1063/1.4981890
  • Peer Reviewed
• [Journal Article] Prediction of the High Thermoelectric Performance of Pnictogen Dichalcogenide Layered Compounds with Quasi-One-Dimensional Gapped Dirac-like Band Dispersion (2017)
  • Author(s): Masayuki Ochi, Hidetomo Usui, Kazuhiko Kuroki
  • Journal Title: Physical Review Applied Volume: 8 Issue: 6 Pages: 064020-064020
  • DOI: 10.1103/physrevapplied.8.064020
  • Peer Reviewed / Open Access
• [Journal Article] Temperature-and doping-dependent roles of valleys in the thermoelectric performance of SnSe: A first-principles study (2017)
  • Author(s): Hitoshi Mori, Hidetomo Usui, Masayuki Ochi, Kazuhiko Kuroki
  • Journal Title: Physical Review B Volume: 96 Issue: 8 Pages: 085113-085113
  • DOI: 10.1103/physrevb.96.085113
  • Peer Reviewed
• [Journal Article] Direct observation of double valence-band extrema and anisotropic effective masses of the thermoelectric material SnSe (2017)
  • Author(s): Takanobu Nagayama, Kensei Terashima, Takanori Wakita, Hirokazu Fujiwara, Tetsushi Fukura, Yuko Yano, Kanta Ono, Hiroshi Kumigashira, Osamu Ogiso, Aichi Yamashita, Yoshihiko Takano, Hitoshi Mori, Hidetomo Usui, Masayuki Ochi, Kazuhiko Kuroki, Yuji Muraoka, Takayoshi Yokoya
  • Journal Title: Japanese Journal of Applied Physics Volume: 57 Issue: 1 Pages: 010301-010301
  • DOI: 10.7567/jjap.57.010301
  • NAID: 210000148501
  • Peer Reviewed / Int'l Joint Research
• [Presentation] First principles study on the thermoelectric properties of delafossite compounds (2019)
  • Author(s): Hidetomo Usui、Kazuhiko Kuroki
  • Organizer: American Physical Society March Meeting 2019
  • Int'l Joint Research
• [Presentation] High thermoelectric properties of As-based 122-Zintl compounds Ba1-xKxCd2As2 (2019)
  • Author(s): Haruno Kunioka、Kunihiro Kihou、Hirotaka Nishiate、Hidetomo Usui、Kazuhiko Kuroki、Chul-Ho Lee、Atsushi Yamamoto、Tsutomu Iida、Haruhiko Obara
  • Organizer: American Physical Society March Meeting 2019
  • Int'l Joint Research
• [Presentation] First principles study on the thermoelectric properties of 122 Zintl phase compounds (2018)
  • Author(s): Hidetomo Usui、Kazuhiko Kuroki
  • Organizer: 37th International Conference on Thermoelectrics
  • Int'l Joint Research
• [Presentation] High thermoelectric properties of As-based 122-Zintl coupounds Ba1-xKxCd2As2 (2018)
  • Author(s): Haruno Kunioka、Kunihiro Kihou、Hirotaka Nishiate、Hidetomo Usui、Kazuhiko Kuroki、Chul-Ho Lee、Atsushi Yamamoto、Tsutomu Iida、Haruhiko Obara
  • Organizer: 37th International Conference on Thermoelectrics
  • Int'l Joint Research
• [Presentation] (Ba,K)Cd2As2 の熱電特性 (2018)
  • Author(s): 國岡春乃、 木方邦広、西当弘隆、臼井秀知、黒木和彦、李哲虎
  • Organizer: 第15回日本熱電学会学術講演会
• [Presentation] RZnAsOの電力因子の第一原理による解析 (2018)
  • Author(s): 徳永雄斗、臼井秀知、黒木和彦
  • Organizer: 第79回応用物理学会秋季学術講演会
• [Presentation] 特異なバンド構造が生み出す大きな熱電性能 (2018)
  • Author(s): 臼井秀知
  • Organizer: 日本磁気学会第 217 回研究会「シン・熱電変換材料」
  • Invited
• [Presentation] 122 系 Zintl 相化合物における熱電性能の第一原理計算による解析 (2018)
  • Author(s): 臼井秀知、黒木和彦
  • Organizer: 第 65 回応用物理学会春季学術講演会
• [Presentation] 第一原理計算による三元系カルコゲナイドの熱電特性の解析 (2018)
  • Author(s): 森仁志、越智正之、臼井秀知、黒木和彦
  • Organizer: 日本物理学会 第 73 回年次大会
• [Presentation] 複合アニオン化合物における低次元的電子状態を利用した高機能物性の理論設計 (2018)
  • Author(s): 越智正之、小倉大典、水野竜太、松本花梨、森仁志、加藤大智、臼井秀知、青木 秀夫、黒木和彦
  • Organizer: 新学術領域「複合アニオン化合物の創製と新機能」第3回公開シンポジウム
• [Presentation] First principles study and model analysis on thermoelectrics and superconductivity in layered Bi(S,Se)2-based compounds (2017)
  • Author(s): Hidetomo Usui
  • Organizer: Study of Matter at Extreme Conditions 2017
  • Int'l Joint Research / Invited
• [Presentation] Effect of Band Shape on the Lorenz Number and Thermoelectric Properties (2017)
  • Author(s): Hidetomo Usui、Kazuhiko Kuroki
  • Organizer: The 36th International Conference on Thermoelectrics
  • Int'l Joint Research
• [Presentation] BiS2系層状化合物の熱電性能に関する第一原理的解析 (2017)
  • Author(s): 越智正之、臼井秀知、黒木和彦
  • Organizer: 日本物理学会2017年秋季大会
• [Presentation] 第一原理マテリアルデザインに基づく BiCh2系層状化合物における熱電性能向上の可能性 (2017)
  • Author(s): 越智正之、臼井秀知、黒木和彦
  • Organizer: 第14回 日本熱電学会学術講演会
• [Presentation] カルコゲナイド系物質に隠れた擬1次元的な電子状態と熱電効果 (2017)
  • Author(s): 臼井秀知
  • Organizer: 日本熱電学会第22回研究会
  • Invited