Farbrication of polar superstructures to develop new photovoltaic materials

• Project/Area Number: 15H05426
• Research Category: Grant-in-Aid for Young Scientists (A)
• Allocation Type: Single-year Grants
• Research Field: Thin film/Surface and interfacial physical properties
• Research Institution: Institute of Physical and Chemical Research
• Principal Investigator: Nakamura Masao 国立研究開発法人理化学研究所, 創発物性科学研究センター, 上級研究員 (50525780)
• Project Period (FY): 2015-04-01 – 2017-03-31
• Project Status: Completed (Fiscal Year 2016)
• Budget Amount: ¥24,960,000 (Direct Cost: ¥19,200,000、Indirect Cost: ¥5,760,000); Fiscal Year 2016: ¥4,550,000 (Direct Cost: ¥3,500,000、Indirect Cost: ¥1,050,000); Fiscal Year 2015: ¥20,410,000 (Direct Cost: ¥15,700,000、Indirect Cost: ¥4,710,000)
• Keywords: 酸化物ヘテロ界面 / 自発分極 / バルク光起電力効果 / 太陽電池 / 酸化物ヘテロ接合 / 有機電荷移動錯体 / シフト電流 / 高効率太陽光発電材料 / 強相関エレクトロニクス / 表面・界面物性 / 酸化物界面

Outline of Final Research Achievements

The bulk photovoltaic effect observed in polar materials has a potential to be a photon-to-electron conversion mechanism to realize novel high efficiency solar cells. In this study, I investigated photovoltaic properties of heterojunctions composed of LaFeO3 and SrTiO3. Due to the polar discontinuity at the interface, the originally nonpolar insulator LaFeO3 becomes polar. The junctions exhibit anomalous photovoltaic properties driven by the induced polarization, such as the reversal of the sign of photocurrent depending on the thickness and interfacial termination layer. The photovoltaic efficiency of the LaFeO3 junctions exhibits large improvement compared to other Mott insulator junctions due to the bulk photovoltaic effect associated with the induced polarization.

Research Products

• [Journal Article] Nonlinear electron-phonon coupling in doped manganites (2017)
  • Author(s): V. Esposito, R. Mankowsky, M. Fechner, H. Lemke, M. Chollet, J.M. Glownia, M. Nakamura, M. Kawasaki, Y. Tokura, U. Staub, P. Beaud, and M. Forst
  • Journal Title: Phys. Rev. Lett. Volume: 印刷中
  • Peer Reviewed / Int'l Joint Research
• [Journal Article] Spontaneous Polarization and Bulk Photovoltaic Effect Driven by Polar Discontinuity in LaFeO3/SrTiO3 Heterojunctions (2016)
  • Author(s): M. Nakamura, F. Kagawa, T.Tanigaki, H. S. Park, T. Matsuda, D. Shindo, Y. Tokura, and M. Kawasaki
  • Journal Title: PHYSICAL REVIEW LETTERS Volume: in press Issue: 15
  • DOI: 10.1103/physrevlett.116.156801
  • Peer Reviewed / Open Access / Int'l Joint Research
• [Journal Article] Surface Ordering of Orbitals at Higher Temperature in LaCoO3 Thin Film (2016)
  • Author(s): Y. Yamasaki, J. Fujioka, H. Nakao, J. Okamoto, T. Sudayama, Y. Murakami, M. Nakamura, M. Kawasaki, T. Arima, and Y. Tokura
  • Journal Title: Journal of the Physical Society of Japan Volume: 85 Issue: 2 Pages: 023704-023704
  • DOI: 10.7566/jpsj.85.023704
  • NAID: 210000133819
  • Peer Reviewed
• [Journal Article] Band alignment and photovoltaic effect of epitaxial α-PbO thin films (2015)
  • Author(s): E. Majima, Y. Kozuka, M. Uchida, M. Nakamura, M. Kawasaki
  • Journal Title: Applied Physics Express Volume: 8 Issue: 7 Pages: 074001-074001
  • DOI: 10.7567/apex.8.074001
  • NAID: 210000137593
  • Peer Reviewed / Acknowledgement Compliant
• [Journal Article] Strain-sensitive spin-state ordering in thin films of perovskite LaCoO3 (2015)
  • Author(s): J. Fujioka, Y. Yamasaki, A. Doi, H. Nakao, R. Kumai,Y. Murakami, M. Nakamura, M. Kawasaki, T. Arima, Y. Tokura
  • Journal Title: Physical Review B Volume: 92 Issue: 19 Pages: 072103-072103
  • DOI: 10.1103/physrevb.92.195115
  • Peer Reviewed / Open Access
• [Journal Article] Direct Imaging of Dynamic Glassy Behavior in a Strained Manganite Film (2015)
  • Author(s): W. Kundhikanjana, Z. Sheng, Y. Yang, K. Lai, E. Ma, Y. Cui, M. Kelly, M. Nakamura, M. Kawasaki, Y. Tokura, Q. Tang, K. Zhang, X. Li, Z. Shen
  • Journal Title: Physical Review Letters Volume: 115 Issue: 26 Pages: 265701-265701
  • DOI: 10.1103/physrevlett.115.265701
  • Peer Reviewed / Int'l Joint Research
• [Journal Article] Thermal generation of spin current in an antiferromagnet (2015)
  • Author(s): S. Seki, T. Ideue, M. Kubota, Y. Kozuka, R. Takagi, M. Nakamura, Y.Kaneko, M. Kawasaki, Y. Tokura
  • Journal Title: Physical Review Letters Volume: 115 Issue: 26 Pages: 266601-266601
  • DOI: 10.1103/physrevlett.115.266601
  • Peer Reviewed
• [Presentation] Shift current photovoltaic effect in a quasi-one-dimensianl ferroelectric compound (2017)
  • Author(s): M. Nakamura, S. Horiuchi, S. Ishibashi, N. Ogawa, T. Kurumaji, F. Kagawa, Y. Tokura, and M. Kawasaki
  • Organizer: CEMS-QPEC Symposium on Emergent Quantum Materials
  • Place of Presentation: 理化学研究所、和光
  • Year and Date: 2017-01-18
  • Int'l Joint Research
• [Presentation] Spontaneous polarization and anomalous photovoltaic effect induced in oxide heterointerfaces (2017)
  • Author(s): Masao Nakamura
  • Organizer: 2016 MRS Spring meeting
  • Place of Presentation: Phoenix, USA
  • Int'l Joint Research / Invited
• [Presentation] Spontaneous polarization and bulk photovoltaic effect induced in designed interface of oxide heterojunctions (2015)
  • Author(s): M. Nakamura
  • Organizer: CEMS Topical Meeting on Oxide Interface
  • Place of Presentation: 理化学研究所(埼玉県和光市)
  • Int'l Joint Research / Invited
• [Presentation] Skyrmion formation in an epitaxial film of perovskite manganite with controlled magnetic anisotropy (2015)
  • Author(s): M. Nakamura, D. Morikawa, X. Z. Yu, F. Kagawa, T. Arima, M. Kawasaki, and Y. Tokura
  • Organizer: Workshop on “Topological Magnets”
  • Place of Presentation: 理研理化学研究所(埼玉県和光市)
  • Int'l Joint Research
• [Presentation] 酸化物ヘテロ接合における界面誘起の自発分極 (2015)
  • Author(s): 中村優男、賀川史敬、谷垣俊明、松田強、進藤大輔、十倉好紀、川﨑雅司
  • Organizer: 応用物理学会2015秋季学術講演会
  • Place of Presentation: 名古屋国際会議場(愛知県名古屋市)
• [Remarks] 理化学研究所 創発物性科学研究センター
  • URL: http://www.cems.riken.jp/jp/