Dissolution of embedded gold nanoparticles in sol-gel glass film

Materials with metallic nanoparticles are widely investigated in order to fabricate plasmonic devices, for which the control of the material properties is required. A simple way to control the metal surface plasmon resonance in selected regions of the material is to dissolve the embedded metallic nanoparticles by means of d.c. electric field. Dissolution of embedded silver and copper nanoparticles has been demonstrated recently through poling-assisted bleaching of Ag-doped and Cu-doped nanocomposite glasses, respectively. The next challenge is the dissolution of other metallic nanoparticles, such as gold, which are more difficult to ionize. Here, we demonstrate the dissolution of gold nanoparticles (15 nm in diameter) by d.c. electric field thanks to a novel material design in which the nanoparticles were embedded in a high resistivity sol-gel film on top of a soda-lime-silicate glass substrate with a higher conductivity compared to the film. The role of the film resistivity is made obvious by studying two different film compositions. This result brings about the possibility to use other metallic nanoparticles for tailoring the region of transparency of glasses and opens perspectives for the fabrication of new plasmonic devices.