Fabrication of gold nanoparticles and their influence on optical properties of dye-doped sol-gel films

Au nanoparticles were generated in glass films by the sol-gel method. Au ions doped in silica/titania films were reduced by UV light or electron-beam irradiations resulting in Au nanoparticles with a diameter smaller than 20 nm. This method enabled us to produce any patterns of Au nanoparticles in thin films. Using two-beam interference of a UV laser and electron-beam lithography, periodic structures of An nanoparticles with submicrometer intervals were fabricated. Furthermore, doping of fluorescent dyes into the films containing An nanoparticles exhibited selective reactivation or quenching of the photoluminescence. By generation of An nanoparticles, the fluorescence of Rhodamine B was reactivated, whereas that of Coumarin 152 was quenched, depending on their electronic energy configurations with respect to the plasmon absorption band of the Au nanoparticles. This selective phenomenon also enabled us to make fluorescence patterning in the glass films. (C) 2003 Elsevier Science B.V. All rights reserved.