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

Naoki Ogawa; Hiroki Nagai; Yukihiro Kudoh; Takeyoshi Onuma; Taichi Murayama; Akinobu Nojima; Mitsunobu Sato

doi:10.3390/nano11123404

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

Nanomaterials (Basel). 2021 Dec 16;11(12):3404. doi: 10.3390/nano11123404.

Authors

Naoki Ogawa¹, Hiroki Nagai², Yukihiro Kudoh³, Takeyoshi Onuma², Taichi Murayama¹, Akinobu Nojima⁴, Mitsunobu Sato²

Affiliations

¹ Electrical Engineering and Electronics Program, Graduate School, Kogakuin University, Tokyo 192-0015, Japan.
² Department of Applied Physics, School of Advanced Engineering, Kogakuin University, Tokyo 192-0015, Japan.
³ Department of Information and Communications Engineering, Faculty of Informatics, Kogakuin University, Tokyo 192-0015, Japan.
⁴ Advanced Products Development Center, Technology & Intellectual Property HQ, TDK Corporation, Nagano 385-8555, Japan.

Abstract

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.

Keywords: SWCNT/SiO2; conductive thin film; deep ultraviolet; heat resistance; molecular precursor method; near infrared; scratch resistance; transparent; vacuum ultraviolet.