Optoelectronic properties of valence-state-controlled amorphous niobium oxide

Takaki Onozato, Takayoshi Katase, Akira Yamamoto, Shota Katayama, Koichi Matsushima, Naho Itagaki, Hisao Yoshida, Hiromichi Ohta

Research output: Contribution to journalArticle

9 Citations (Scopus)

Abstract

In order to understand the optoelectronic properties of amorphous niobium oxide (a-NbOx), we have investigated the valence states, local structures, electrical resistivity, and optical absorption of a-NbOx thin films with various oxygen contents. It was found that the valence states of Nb ion in a-NbOx films can be controlled from 5+ to 4+ by reducing oxygen pressure during film deposition at room temperature, together with changing the oxide-ion arrangement around Nb ion from Nb2O5-like to NbO2-like local structure. As a result, a four orders of magnitude reduction in the electrical resistivity of a-NbOx films was observed with decreasing oxygen content, due to the carrier generation caused by the appearance and increase of an oxygen-vacancy-related subgap state working as an electron donor. The tunable optoelectronic properties of a-NbOx films by valence-state-control with oxygen-vacancy formation will be useful for potential flexible optoelectronic device applications.

Original languageEnglish
Article number255001
JournalJournal of Physics Condensed Matter
Volume28
Issue number25
DOIs
Publication statusPublished - May 10 2016

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Niobium oxide
niobium oxides
Optoelectronic devices
Oxide films
valence
oxygen
oxide films
Oxygen vacancies
Ions
Oxygen
ions
electrical resistivity
optoelectronic devices
Oxides
Light absorption
optical absorption
Thin films
oxides
Electrons
room temperature

All Science Journal Classification (ASJC) codes

  • Materials Science(all)
  • Condensed Matter Physics

Cite this

Optoelectronic properties of valence-state-controlled amorphous niobium oxide. / Onozato, Takaki; Katase, Takayoshi; Yamamoto, Akira; Katayama, Shota; Matsushima, Koichi; Itagaki, Naho; Yoshida, Hisao; Ohta, Hiromichi.

In: Journal of Physics Condensed Matter, Vol. 28, No. 25, 255001, 10.05.2016.

Research output: Contribution to journalArticle

Onozato, T, Katase, T, Yamamoto, A, Katayama, S, Matsushima, K, Itagaki, N, Yoshida, H & Ohta, H 2016, 'Optoelectronic properties of valence-state-controlled amorphous niobium oxide', Journal of Physics Condensed Matter, vol. 28, no. 25, 255001. https://doi.org/10.1088/0953-8984/28/25/255001
Onozato, Takaki ; Katase, Takayoshi ; Yamamoto, Akira ; Katayama, Shota ; Matsushima, Koichi ; Itagaki, Naho ; Yoshida, Hisao ; Ohta, Hiromichi. / Optoelectronic properties of valence-state-controlled amorphous niobium oxide. In: Journal of Physics Condensed Matter. 2016 ; Vol. 28, No. 25.
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AU - Itagaki, Naho

AU - Yoshida, Hisao

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