FLAME SYNTHESIS OF MoO3 FILMS AND THEIR FLAME REDUCTION TO MoO3−x FILMS FOR NIR-SHIELDING APPLICATIONS

Abstract

Recently, defective metal oxides have attracted vast attention for their potential applications arising from their increased free carrier concentration. In this study, monoclinic MoO3 films have been grown on quartz glass substrates by hydrogen flame synthesis, as a fast and mass-productive method. The MoO3 films then were reduced to defective MoO[Formula: see text] by a flame-reduction treatment using a butane torch. After reduction, the localized surface plasmon resonance (LSPR) absorption band appeared in the NIR region that was employed for NIR-shielding applications. Films were reduced at a nozzle-to-sample distance ranging from 1 to 4[Formula: see text]cm, and the optical properties of these films were investigated at an optimum distance (2[Formula: see text]cm) as a function of reducing duration time ranging from 1 to 20[Formula: see text]s. The increase in the inner and outer temperatures were measured in the heat-shielding experiment and the optimum reducing condition was determined. Overall, we have developed a fast, mass-productive and cost-effective method for fabrication of heat-shielding devices based on LSPR effect.