Valence band electronic structures of heavily boron-doped superconducting diamond studied by synchrotron photoemission spectroscopy

Takayoshi Yokoya, Tetsuya Nakamura, Tomohiro Matsushita, Takayuki Muro, Eiji Ikenaga, Masaaki Kobata, Keisuke Kobayashi, Yoshihiko Takano, Masanori Nagao, Tomohiro Takenouchi, Hiroshi Kawarada, Tamio Oguchi

    Research output: Contribution to journalArticle

    3 Citations (Scopus)

    Abstract

    The valence band electronic structures of heavily boron-doped superconducting diamond films made by microwave plasma-assisted chemical vapor deposition (MPCVD) were investigated by hard X-ray photoemission spectroscopy (HXPES) and soft X-ray angle-resolved photoemission spectroscopy (SXARPES). The HXPES core-level spectrum of heavily boron-doped diamond shows a new feature at the lower binding energy side of the C 1s main peak. The HXPES valence band spectrum of a heavily boron-doped superconducting diamond film shows a broader spectral shape than that of a lightly doped non-superconducting sample. The SXARPES results of homoepitaxial CVD films show clear valence band dispersions with a bandwidth of ∼23 eV and the top of the valence band at the Γ point in the Brillouin zone, which are well explained by the calculated valence band dispersions of pure diamond. Boron concentration-dependent band dispersions near the Fermi level (EF) by SXARPES exhibit a systematic shift in EF, indicating electron depopulation due to hole doping, and an increase in the line shape corresponding to the broader density of states observed by HXPES. These results indicate that holes in the top of the valence band are responsible for the metallic states leading to superconductivity at low temperatures. The HXPES C 1s core-level spectra of lightly boron-doped non-superconducting and heavily boron-doped superconducting films are also shown.

    Original languageEnglish
    Pages (from-to)11-20
    Number of pages10
    JournalNew Diamond and Frontier Carbon Technology
    Volume17
    Issue number1
    Publication statusPublished - 2007

    Fingerprint

    Diamond
    Boron
    Photoelectron spectroscopy
    Valence bands
    Synchrotrons
    Electronic structure
    Diamonds
    synchrotrons
    boron
    photoelectric emission
    diamonds
    electronic structure
    valence
    X ray spectroscopy
    spectroscopy
    Superconducting films
    x rays
    Dispersions
    Core levels
    Diamond films

    Keywords

    • Band structure
    • Diamond
    • Heavily boron-doped
    • Hole
    • HXPES
    • Superconductivity
    • SXARPES

    ASJC Scopus subject areas

    • Surfaces, Coatings and Films
    • Surfaces and Interfaces
    • Materials Science(all)

    Cite this

    Yokoya, T., Nakamura, T., Matsushita, T., Muro, T., Ikenaga, E., Kobata, M., ... Oguchi, T. (2007). Valence band electronic structures of heavily boron-doped superconducting diamond studied by synchrotron photoemission spectroscopy. New Diamond and Frontier Carbon Technology, 17(1), 11-20.

    Valence band electronic structures of heavily boron-doped superconducting diamond studied by synchrotron photoemission spectroscopy. / Yokoya, Takayoshi; Nakamura, Tetsuya; Matsushita, Tomohiro; Muro, Takayuki; Ikenaga, Eiji; Kobata, Masaaki; Kobayashi, Keisuke; Takano, Yoshihiko; Nagao, Masanori; Takenouchi, Tomohiro; Kawarada, Hiroshi; Oguchi, Tamio.

    In: New Diamond and Frontier Carbon Technology, Vol. 17, No. 1, 2007, p. 11-20.

    Research output: Contribution to journalArticle

    Yokoya, T, Nakamura, T, Matsushita, T, Muro, T, Ikenaga, E, Kobata, M, Kobayashi, K, Takano, Y, Nagao, M, Takenouchi, T, Kawarada, H & Oguchi, T 2007, 'Valence band electronic structures of heavily boron-doped superconducting diamond studied by synchrotron photoemission spectroscopy', New Diamond and Frontier Carbon Technology, vol. 17, no. 1, pp. 11-20.
    Yokoya, Takayoshi ; Nakamura, Tetsuya ; Matsushita, Tomohiro ; Muro, Takayuki ; Ikenaga, Eiji ; Kobata, Masaaki ; Kobayashi, Keisuke ; Takano, Yoshihiko ; Nagao, Masanori ; Takenouchi, Tomohiro ; Kawarada, Hiroshi ; Oguchi, Tamio. / Valence band electronic structures of heavily boron-doped superconducting diamond studied by synchrotron photoemission spectroscopy. In: New Diamond and Frontier Carbon Technology. 2007 ; Vol. 17, No. 1. pp. 11-20.
    @article{38a292076a1e497d8aa8eca68f4a2d67,
    title = "Valence band electronic structures of heavily boron-doped superconducting diamond studied by synchrotron photoemission spectroscopy",
    abstract = "The valence band electronic structures of heavily boron-doped superconducting diamond films made by microwave plasma-assisted chemical vapor deposition (MPCVD) were investigated by hard X-ray photoemission spectroscopy (HXPES) and soft X-ray angle-resolved photoemission spectroscopy (SXARPES). The HXPES core-level spectrum of heavily boron-doped diamond shows a new feature at the lower binding energy side of the C 1s main peak. The HXPES valence band spectrum of a heavily boron-doped superconducting diamond film shows a broader spectral shape than that of a lightly doped non-superconducting sample. The SXARPES results of homoepitaxial CVD films show clear valence band dispersions with a bandwidth of ∼23 eV and the top of the valence band at the Γ point in the Brillouin zone, which are well explained by the calculated valence band dispersions of pure diamond. Boron concentration-dependent band dispersions near the Fermi level (EF) by SXARPES exhibit a systematic shift in EF, indicating electron depopulation due to hole doping, and an increase in the line shape corresponding to the broader density of states observed by HXPES. These results indicate that holes in the top of the valence band are responsible for the metallic states leading to superconductivity at low temperatures. The HXPES C 1s core-level spectra of lightly boron-doped non-superconducting and heavily boron-doped superconducting films are also shown.",
    keywords = "Band structure, Diamond, Heavily boron-doped, Hole, HXPES, Superconductivity, SXARPES",
    author = "Takayoshi Yokoya and Tetsuya Nakamura and Tomohiro Matsushita and Takayuki Muro and Eiji Ikenaga and Masaaki Kobata and Keisuke Kobayashi and Yoshihiko Takano and Masanori Nagao and Tomohiro Takenouchi and Hiroshi Kawarada and Tamio Oguchi",
    year = "2007",
    language = "English",
    volume = "17",
    pages = "11--20",
    journal = "New Diamond and Frontier Carbon Technology",
    issn = "1344-9931",
    publisher = "M Y U Scientific Publishing Division",
    number = "1",

    }

    TY - JOUR

    T1 - Valence band electronic structures of heavily boron-doped superconducting diamond studied by synchrotron photoemission spectroscopy

    AU - Yokoya, Takayoshi

    AU - Nakamura, Tetsuya

    AU - Matsushita, Tomohiro

    AU - Muro, Takayuki

    AU - Ikenaga, Eiji

    AU - Kobata, Masaaki

    AU - Kobayashi, Keisuke

    AU - Takano, Yoshihiko

    AU - Nagao, Masanori

    AU - Takenouchi, Tomohiro

    AU - Kawarada, Hiroshi

    AU - Oguchi, Tamio

    PY - 2007

    Y1 - 2007

    N2 - The valence band electronic structures of heavily boron-doped superconducting diamond films made by microwave plasma-assisted chemical vapor deposition (MPCVD) were investigated by hard X-ray photoemission spectroscopy (HXPES) and soft X-ray angle-resolved photoemission spectroscopy (SXARPES). The HXPES core-level spectrum of heavily boron-doped diamond shows a new feature at the lower binding energy side of the C 1s main peak. The HXPES valence band spectrum of a heavily boron-doped superconducting diamond film shows a broader spectral shape than that of a lightly doped non-superconducting sample. The SXARPES results of homoepitaxial CVD films show clear valence band dispersions with a bandwidth of ∼23 eV and the top of the valence band at the Γ point in the Brillouin zone, which are well explained by the calculated valence band dispersions of pure diamond. Boron concentration-dependent band dispersions near the Fermi level (EF) by SXARPES exhibit a systematic shift in EF, indicating electron depopulation due to hole doping, and an increase in the line shape corresponding to the broader density of states observed by HXPES. These results indicate that holes in the top of the valence band are responsible for the metallic states leading to superconductivity at low temperatures. The HXPES C 1s core-level spectra of lightly boron-doped non-superconducting and heavily boron-doped superconducting films are also shown.

    AB - The valence band electronic structures of heavily boron-doped superconducting diamond films made by microwave plasma-assisted chemical vapor deposition (MPCVD) were investigated by hard X-ray photoemission spectroscopy (HXPES) and soft X-ray angle-resolved photoemission spectroscopy (SXARPES). The HXPES core-level spectrum of heavily boron-doped diamond shows a new feature at the lower binding energy side of the C 1s main peak. The HXPES valence band spectrum of a heavily boron-doped superconducting diamond film shows a broader spectral shape than that of a lightly doped non-superconducting sample. The SXARPES results of homoepitaxial CVD films show clear valence band dispersions with a bandwidth of ∼23 eV and the top of the valence band at the Γ point in the Brillouin zone, which are well explained by the calculated valence band dispersions of pure diamond. Boron concentration-dependent band dispersions near the Fermi level (EF) by SXARPES exhibit a systematic shift in EF, indicating electron depopulation due to hole doping, and an increase in the line shape corresponding to the broader density of states observed by HXPES. These results indicate that holes in the top of the valence band are responsible for the metallic states leading to superconductivity at low temperatures. The HXPES C 1s core-level spectra of lightly boron-doped non-superconducting and heavily boron-doped superconducting films are also shown.

    KW - Band structure

    KW - Diamond

    KW - Heavily boron-doped

    KW - Hole

    KW - HXPES

    KW - Superconductivity

    KW - SXARPES

    UR - http://www.scopus.com/inward/record.url?scp=34547291804&partnerID=8YFLogxK

    UR - http://www.scopus.com/inward/citedby.url?scp=34547291804&partnerID=8YFLogxK

    M3 - Article

    AN - SCOPUS:34547291804

    VL - 17

    SP - 11

    EP - 20

    JO - New Diamond and Frontier Carbon Technology

    JF - New Diamond and Frontier Carbon Technology

    SN - 1344-9931

    IS - 1

    ER -