Plasmon-resonant optics on an indium-tin-oxide film for exciting a two-photon photochromic reaction

Abstract

Two-dimensional arrays of gold nanoparticles (AuNPs) as localized surface plasmon-resonant (LSPR) optics on a transparent conductive layer of indium-tin-oxide (ITO) were successfully fabricated. The typical surface coverage of the 10nm sized AuNPs is over 87% for on ITO film roughness of ±0.2 nm. The LSPR wavelength is tunable in the range of 622-905 nm. By adjusting the LSPR wavelength to 905nm at peak, twophoton photochromic reaction of diarylethene derivative in solution phase was demonstrated with irradiation by an incoherent near-infrared light in the range of 0.017-0.033W/cm2 instead of a laser, thanks to the AuNP two-dimensional array. © 2013 The Japan Society of Applied Physics.