2025 Volume 64 Issue 5 Pages 458-464
Invisible materials have attracted attention for anti-counterfeiting and traceability. We have focused on antimony-doped tin oxide (ATO) as an invisible material, which is transparent under visible light and can absorb near-infrared light by localized surface plasmon resonance. By controlling the amount of antimony doping, we have succeeded in preparing antimony tin oxide (ATO) inks with high transparency under visible light and high absorption under near-infrared light. In addition, by interpolating the color difference between the image to be given invisible information and the ATO inks, we have succeeded in imparting information on paper that is difficult to read in the visible region but readable in the near-infrared region.
