Photochemistry of Bismuth- and Silver-Containing Glasses under Femtosecond Laser Irradiation: Energy Transfers and 3D-localized Background-Free Near-Infrared Fluorescence Emission

Abstract

The tunable fluorescence property from the visible to near-infrared (NIR) region of high-localized 3D architecture down to the diffraction limit thanks to femtosecond (fs) Direct Laser Writing (DLW) in bismuth-doped, silver-containing glass is performed. Absorption and photoluminescent spectroscopy showed evidence of the homogeneous dispersion of bismuth ions (Bi3+) and silver ions in the glass matrix before DLW. High repetition rate fs DLW simultaneously inducing the photochemistry of silver ions and the photoredox reaction of bismuth ions has been obtained. Femtosecond DLW allows the creation of 3D fluorescence patterns formed by colocalization of a silver cluster and low valence bismuth ions, exhibiting an emission band covering the whole visible to the NIR wave range. The phenomena of electron transfer from silver atoms to bismuth ions and the nonradiative energy transfer from silver clusters to NIR-emitting bismuth ions are demonstrated.