Fabrication of Transparent and Conductive SWCNT/SiO2 Composite Thin-Film by Photo-Irradiation of Molecular Precursor Films

A single-walled carbon nanotube (SWCNT)-silica composite thin film on a quartz glass was formed by ultraviolet irradiation (20–40 °C) onto a spin-coated precursor film. With 7.4 mass% SWCNTs, the electrical resistivity reached 7.7 × 10−3 Ω·cm after UV-irradiation. The transmittance was >80% at 178–2600 nm, and 79%–73% at 220–352 nm. Heat treatment increased the transparency and pencil hardness, without affecting the low electrical resistivity. Raman spectroscopy and microscopic analyses revealed the excellent film morphology with good SWCNT dispersal. The low refractive index (1.49) and haze value (<1.5%) are invaluable for transparent windows for novel optoelectronic devices.

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Deep-Ultraviolet Transparent Conductive MWCNT/SiO2 Composite Thin Film Fabricated by UV Irradiation at Ambient Temperature onto Spin-Coated Molecular Precursor Film

Nanomaterials ◽

10.3390/nano11051348 ◽

2021 ◽

Vol 11 (5) ◽

pp. 1348

Author(s):

Hiroki Nagai ◽

Naoki Ogawa ◽

Mitsunobu Sato

Keyword(s):

Thin Film ◽

Thin Films ◽

Heat Treatment ◽

Uv Irradiation ◽

Composite Thin Film ◽

Precursor Film ◽

Mixed Solution ◽

Pencil Hardness ◽

Strong Base ◽

Deep Ultraviolet

Deep-ultraviolet (DUV) light-transparent conductive composite thin films, consisting of dispersed multiwalled carbon nanotubes (MWCNTs) and SiO2 matrix composites, were fabricated on a quartz glass substrate. Transparent and well-adhered amorphous thin films, with a thickness of 220 nm, were obtained by weak ultraviolet (UV) irradiation (4 mW cm−2 at 254 nm) for more than 6 h at 20−40 °C onto the precursor films, which were obtained by spin coating with a mixed solution of MWCNT in water and Si(IV) complex in ethanol. The electrical resistivity of MWCNT/SiO2 composite thin film is 0.7 Ω·cm, and transmittance in the wavelength region from DUV to visible light is higher than 80%. The MWCNT/SiO2 composite thin film showed scratch resistance at pencil hardness of 8H. Importantly, the resistivity of the MWCNT/SiO2 composite thin film was maintained at the original level even after heat treatment at 500 °C for 1 h. It was observed that the heat treatment of the composite thin film improved durability against both aqueous solutions involving a strong acid (HCl) and a strong base (NaOH).

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Facile Fabrication of Single-Walled Carbon Nanotube/Anatase Composite Thin Film on Quartz Glass Substrate for Translucent Conductive Photoelectrode

Nanomaterials ◽

10.3390/nano11123352 ◽

2021 ◽

Vol 11 (12) ◽

pp. 3352

Author(s):

Yutaka Suwazono ◽

Takuro Murayoshi ◽

Hiroki Nagai ◽

Mitsunobu Sato

Keyword(s):

Thin Film ◽

Carbon Nanotube ◽

Quartz Glass ◽

Glass Substrate ◽

Composite Thin Film ◽

Precursor Film ◽

Quartz Glass Substrate ◽

Single Walled Carbon Nanotube ◽

X Ray ◽

Single Walled Carbon

A single-walled carbon nanotube/anatase (SWCNT/anatase) composite thin film with a transmittance of over 70% in the visible-light region was fabricated on a quartz glass substrate by heat treating a precursor film at 500 °C in air. The precursor film was formed by spin coating a mixed solution of the titania molecular precursor and well-dispersed SWCNTs (0.075 mass%) in ethanol. The anatase crystals and Ti3+ ions in the composite thin films were determined by X-ray diffraction and X-ray photoelectron spectroscopy, respectively. The effect of the heating process on the SWCNTs was analyzed using Raman spectroscopy. The composite film showed an even surface with a scratch resistance of 4H pencil hardness, as observed using field-emission scanning electron microscopy and atomic force microscopy. The electrical resistivity and optical bandgap energy of the composite thin film with a thickness of 100 nm were 6.6 × 10−2 Ω cm and 3.4 eV, respectively, when the SWCNT content in the composite thin film was 2.9 mass%. An anodic photocurrent density of 4.2 μA cm−2 was observed under ultraviolet light irradiation (16 mW cm−2 at 365 nm) onto the composite thin film, thus showing excellent properties as a photoelectrode without conductive substrates.

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Single-walled carbon nanotube network/poly composite thin film for flow sensor

Microsystem Technologies ◽

10.1007/s00542-010-1055-3 ◽

2010 ◽

Vol 16 (6) ◽

pp. 955-959 ◽

Cited By ~ 10

Author(s):

Hui Cao ◽

Zhiyin Gan ◽

Qiang Lv ◽

Han Yan ◽

Xiaobin Luo ◽

...

Keyword(s):

Thin Film ◽

Carbon Nanotube ◽

Composite Thin Film ◽

Flow Sensor ◽

Single Walled Carbon Nanotube ◽

Single Walled Carbon ◽

Carbon Nanotube Network

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Selective formation of cubic or tetragonal zirconia thin films of transparent, with no use of metal ion stabilizer by heating molecular precursor films under mild conditions

Functional Materials Letters ◽

10.1142/s1793604721510127 ◽

2021 ◽

Vol 14 (02) ◽

pp. 2151012

Author(s):

Natangue Heita Shafudah ◽

Hiroki Nagai ◽

Mitsunobu Sato

Keyword(s):

Thin Film ◽

Thin Films ◽

Quartz Glass ◽

Glass Substrate ◽

Metal Ion ◽

Tetragonal Zirconia ◽

Precursor Film ◽

Quartz Glass Substrate ◽

Molecular Precursor ◽

Zirconia Thin Film

Cubic or tetragonal zirconia thin films of transparent and 100 nm thickness were selectively formed on a quartz glass substrate by heat-treating the molecular precursor films involving Zr(IV) complexes of nitrilotriacetic acid, at 500[Formula: see text]C in air for 1 h. A precursor solution was prepared by a reaction of the ligand and zirconium tetrabutoxide in alcohol under the presence of butylamine. By the addition of H2O2 or H2O into the solution, the spin-coated precursor films were converted to cubic zirconia thin films by the abovementioned procedure. Further, the identical phase was produced also in the case of the electro-sprayed precursor film which was formed by an addition of H2O2 into the solution. On the other hand, the tetragonal zirconia thin film was obtained from a precursor film formed by using a solution dissolving the original Zr(IV) complex of the ligand, without H2O2 nor H2O. The crystal structure of all thin films was determined by using both the X-ray diffraction (XRD) patterns and Raman spectra. Thus, the zirconia thin films of both crystals could be facilely and selectively obtained with no use of hetero-metal ion stabilizers. The XPS spectra of the thin films show that the O/Zr ratio of the cubic phase is 1.37 and slightly larger than tetragonal one (1.29), and also demonstrate that the nitrogen atoms, which may contribute to stabilize these metastable phases at room temperature, of about 5−7 atomic% was remained in the resultant thin films. The adhesion strengths of cubic zirconia thin film onto the quartz glass substrate was 68 MPa and larger than that of tetragonal one, when the precursor films were formed via a spin coating process. The optical and surface properties of the thin films were also examined in relation to the crystal systems.

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