TY - JOUR
T1 - Large and constant absorption coefficient in Nb x Ti 1− x O 2 thin films throughout the visible range
AU - Shimabukuro, Adam E.
AU - Ishii, Akihiro
AU - Oikawa, Itaru
AU - Yamazaki, Yusuke
AU - Imura, Masaaki
AU - Kanai, Toshimasa
AU - Ohuchi, Fumio S.
AU - Takamura, Hitoshi
N1 - Funding Information:
This work has been financially supported in part by JSPS KAKENHI grant number 18H03832 . AS would like to thank the research placement done by Junior Year Programs in English (JYPE) at Tohoku University. AI would like to express his appreciation for the financial from the Grant-in-Aid for JSPS Research Fellows and the Interdepartmental Doctoral Degree Program for Multi-dimensional Materials Science Leaders in Tohoku University. The authors would like to acknowledge the vitally important encouragement and support made through the University of Washington-Tohoku University: Academic Open Space (UW-TU:AOS). They also would like to thank Ms. Y. Ohira and Mr. N. Akao for technical support in taking XPS measurements.
Publisher Copyright:
© 2018 Elsevier B.V.
PY - 2019/1/15
Y1 - 2019/1/15
N2 - We investigated the optical absorption properties of Nb x Ti 1−x O 2 thin films, a solid solution combining the reduced titanium and niobium oxide phases TiO 2 and NbO 2. The optical absorption properties of Nb x Ti 1−x O 2 thin films prepared by pulsed laser deposition at 600 °C were shown to be large in magnitude at an almost constant value of ≈17 µm −1 . Because this large absorption coefficient is nearly independent of incident photon energy in the visible range (400–700 nm), the Nb x Ti 1−x O 2 thin films appear optically black. Flat and homogenous, optically black coatings like these are desirable for color isolation in flat panel displays. The origin of flat wavelength dispersion in Nb x Ti 1−x O 2 is the coexistence of semiconducting absorption and metallic light absorption mechanisms. Localized Nb-Nb dimers in the metallic Nb x Ti 1−x O 2 phase open an optical band gap which gives rise to semiconducting behavior. We show here that reduction results in strong visible light sensitization in normally transparent Nb-Ti oxides.
AB - We investigated the optical absorption properties of Nb x Ti 1−x O 2 thin films, a solid solution combining the reduced titanium and niobium oxide phases TiO 2 and NbO 2. The optical absorption properties of Nb x Ti 1−x O 2 thin films prepared by pulsed laser deposition at 600 °C were shown to be large in magnitude at an almost constant value of ≈17 µm −1 . Because this large absorption coefficient is nearly independent of incident photon energy in the visible range (400–700 nm), the Nb x Ti 1−x O 2 thin films appear optically black. Flat and homogenous, optically black coatings like these are desirable for color isolation in flat panel displays. The origin of flat wavelength dispersion in Nb x Ti 1−x O 2 is the coexistence of semiconducting absorption and metallic light absorption mechanisms. Localized Nb-Nb dimers in the metallic Nb x Ti 1−x O 2 phase open an optical band gap which gives rise to semiconducting behavior. We show here that reduction results in strong visible light sensitization in normally transparent Nb-Ti oxides.
KW - Absorption coefficient
KW - NbO
KW - Non-dispersive media
KW - Pulsed laser deposition
KW - Ti O
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U2 - 10.1016/j.apsusc.2018.09.036
DO - 10.1016/j.apsusc.2018.09.036
M3 - Article
AN - SCOPUS:85053074084
VL - 464
SP - 61
EP - 67
JO - Applied Surface Science
JF - Applied Surface Science
SN - 0169-4332
ER -