UV-light irradiation induced copper nanoclusters in a silicate glass

In this letter, copper nanoclusters formation was observed in Cu-doped silicate glasses after UV-light irradiation followed by thermal annealing. Spectroscopic data indicated that Cu+ transferred to Cu atoms after irradiation. The aggregation of Cu atoms appeared after heating at 500 °C for 30 min, resulting in an absorption band at about 560 nm, due to the surface plasmon resonance of Cu nanoclusters in glass. The band intensity of the absorption peak increases with heating time at 500 °C. The mean nanocluster size estimated based on Mie theory was ∼2.3 nm after heated at 500 °C for 120 min. The Cu nanoclusters only formed in the irradiated area of the glass.