Photoelectron spectroscopic study of electronic states and surface structure of an in situ cleaved In2O3 (111) single crystal

Takahiro Nagata, Oliver Bierwagen, Zbigniew Galazka, Masataka Imura, Shigenori Ueda, Yoshiyuki Yamashita, Toyohiro Chikyow

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6 Citations (Scopus)


Surface electronic states and band-bending behavior of a melt-grown (111)-plane In2O3 single crystal were investigated using X-ray photoelectron spectroscopy (XPES). The In2O3 single crystal was cleaved under vacuum conditions below 5 × 10-5 Pa, and loaded to a measurement chamber with a vacuum level of approximately 5 × 10-7 Pa. After cleaving, density reduction of in-gap states relating to oxygen vacancies was confirmed. Nevertheless, the cleaved surface had a surface electron accumulation layer with the surface Fermi level pinned at approximately 0.76 eV above the conduction band minimum. The bulk and surface carrier density were estimated as 3.9 × 1017 and 6.0 × 1019 cm-3 respectively by combining the XPES result and the Poisson-Schrödinger solutions. Scanning nonlinear dielectric microscopy indicated a higher carrier density at the (100) surface than that at the (111) surface, suggesting a crystallographic plane dependence which may originate in defects relating to the dipole and surface instability of the In2O3 surface.

Original languageEnglish
Article numberSDDG06
JournalJapanese journal of applied physics
Issue numberSD
Publication statusPublished - 2019
Externally publishedYes

ASJC Scopus subject areas

  • Engineering(all)
  • Physics and Astronomy(all)


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