TY - JOUR
T1 - Black titanium oxynitride thin films prepared by nitrogen plasma-assisted pulsed laser deposition for flat-panel displays
AU - Yamaguchi, Mina
AU - Ishii, Akihiro
AU - Oikawa, Itaru
AU - Takamura, Hitoshi
N1 - Funding Information:
This work was financially supported in part by JSPS ( 18H03832 ). MY would like to express her appreciation for support from GP-MS at Tohoku University. AI acknowledges his appreciation for the financial support from the Grant-in-Aid for JSPS Research Fellow and the Interdepartmental Doctoral Degree Program for Multi-dimensional Materials Science Leaders in Tohoku University. We are grateful to Dr. K. Kobayashi for technical support in taking EPMA and STEM measurements.
Publisher Copyright:
© 2020 Elsevier B.V.
PY - 2020/12/30
Y1 - 2020/12/30
N2 - Preference for a classy black turn-off appearance and for distinct dark colors on flat-panel displays has led to a high demand for optically black materials. Titanium oxynitrides and tungsten-doped oxynitrides were prepared using nitrogen plasma assisted pulsed laser deposition, and their optical absorption properties were investigated. A selection of Ti-O-N films were prepared with different compositions by controlling the emission current (Ie) and discharge voltage (Vd) of the ion source. It was found that the nitrogen content of the Ti(O,N)x could be adjusted by controlling the Ie. The large, flat absorption coefficient of approximately 40 μm−1 in the visible range (400–700 nm) attained for the samples deposited at high Vd was attributed to tungsten doping from a W filament in the ion source. The 4.1 mol%W-doped Ti(O,N)x, which had a rock-salt-type structure, was optically jet-black. The origin of the flat wavelength dispersion in the W-doped Ti(O,N)x was attributed to the coexistence of semiconducting absorption and metallic absorption mechanisms. DFT calculations suggest that the 5d states achieved when using doped tungsten provide high absorption in the mid-wavelength range, whereas undoped-Ti(O,N)x was characterized by weak absorption.
AB - Preference for a classy black turn-off appearance and for distinct dark colors on flat-panel displays has led to a high demand for optically black materials. Titanium oxynitrides and tungsten-doped oxynitrides were prepared using nitrogen plasma assisted pulsed laser deposition, and their optical absorption properties were investigated. A selection of Ti-O-N films were prepared with different compositions by controlling the emission current (Ie) and discharge voltage (Vd) of the ion source. It was found that the nitrogen content of the Ti(O,N)x could be adjusted by controlling the Ie. The large, flat absorption coefficient of approximately 40 μm−1 in the visible range (400–700 nm) attained for the samples deposited at high Vd was attributed to tungsten doping from a W filament in the ion source. The 4.1 mol%W-doped Ti(O,N)x, which had a rock-salt-type structure, was optically jet-black. The origin of the flat wavelength dispersion in the W-doped Ti(O,N)x was attributed to the coexistence of semiconducting absorption and metallic absorption mechanisms. DFT calculations suggest that the 5d states achieved when using doped tungsten provide high absorption in the mid-wavelength range, whereas undoped-Ti(O,N)x was characterized by weak absorption.
KW - Optical coatings
KW - Oxynitrides
KW - Pulsed laser deposition
KW - Visible light absorbers
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U2 - 10.1016/j.apsusc.2020.147616
DO - 10.1016/j.apsusc.2020.147616
M3 - Article
AN - SCOPUS:85089797696
VL - 534
JO - Applied Surface Science
JF - Applied Surface Science
SN - 0169-4332
M1 - 147616
ER -