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We show that ion beam assisted deposition (IBAD) can result in films of metal or semiconductor nanoclusters in dielectric matrices with nonlinear optical (NLO) or photoluminescence (PL) properties. Gold nanocluster thin films consisting of metal clusters 5-30 nm in size embedded in a Nb2O5 or a SiO2 oxide matrix were deposited by ion beam assisted deposition by co-evaporation of Au and Nb or Si with O2+ ion bombardment. Semiconductor nanocluster films have been prepared by IBAD as well. Silicon-rich silica films were deposited by coevaporation of silica and silicon with and without simultaneous ion bombardment. PL attributable to defects in SiO2 was observed at about 550 nm. After annealing, the PL peak shifts to 750 nm and increases in intensity, indicating the formation of Si nanoclusters. Transmission electron microscopy (TEM) images of annealed IBAD films show a dense distribution of mostly spherically shaped crystalline Si nanoclusters, about 1-4 nm in diameter, in a featureless amorphous SiO2 matrix. TEM images of films prepared without ion assist showed many less crystalline Si clusters, that were more irregularly shaped, within 0.1 micrometers amorphous silica grains. Passivation of the films with hydrogen removes the defect PL peak and enhances the peak due to nanoclusters. We have also prepared Ge nanoclusters in silica films with and without IBAD.
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