Controlled metallization of ion-exchanged glasses by thermal poling.

We present studies of the formation of silver nanoparticles (NPs) in silver-sodium ion-exchanged glasses by a combination of thermal poling and nanosecond pulsed laser irradiation at 355 nm. In poling, silver ions drift deeper into the glass and become separated from the glass surface by a poled layer depleted in cations. Performed measurements have indicated poling-induced broadening of silver ions depth distribution. Laser irradiation reduces silver ions to atomic silver via breaking silver-non-bridging oxygen (NBO) bonds, extraction of electrons from the NBO atoms and capturing these electrons and electrons generated via multi-photon absorption in the glass by silver ions. The depleted layer limits diffusion of silver atom towards glass surface and, as a consequence, formation of silver NPs on the surface of poled glasses. It is shown that thermal poling mode allows one to control formation of silver NPs of glass surface.