Okazaki, H. The Graduate School of Natural Science and Technology, Okayama University
Arakane, T. Department of Physics, Tohoku University
Sugawara, K. WPI Research Center, Advanced Institute for Materials Research, Tohoku University
Sato, T. Advanced Science Research Center, Japan Atomic Energy Agency
Takahashi, T. Department of Physics, Tohoku University
Wakita, T. The Graduate School of Natural Science and Technology, Okayama University
Hirai, M. The Graduate School of Natural Science and Technology, Okayama University
Muraoka, Y. The Graduate School of Natural Science and Technology, Okayama University 科研費研究者番号
Takano, Y. National Institute for Materials Science
Ishii, S. National Institute for Materials Science
Iriyama, S. School of Science and Engineering, Waseda University
Kawarada, H. School of Science and Engineering, Waseda University
We studied the electronic structure evolution of heavily B-doped diamond films across the metal-insulator transition (MIT) using ultraviolet photoemission spectroscopy (UPS). From high-temperature UPS, through which electronic states near the Fermi level (E(F)) up to similar to 5k(B)T can be observed (k(B) is the Boltzmann constant and T the temperature), we observed the carrier concentration dependence of spectral shapes near E(F). Using another carrier concentration dependent UPS, we found that the change in energy position of sp-band of the diamond valence band, which corresponds to the shift of E(F), can be explained by the degenerate semiconductor model, indicating that the diamond valence band is responsible for the metallic states for samples with concentrations above MIT. We discuss a possible electronic structure evolution across MIT.
Journal of Physics and Chemistry of Solids
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