Synthesis of nanoparticles by reactive laser vaporization: silicon nanocrystals in polymers and properties of gallium and tungsten oxides

In this paper, we present three different examples of nanocrystals prepared by the pulsed laser vaporization–controlled condensation LVCC.technique. First, we present some new results on the photoluminescence PL.properties of the Si nanocrystals. One of the main goals of this work is to compare the results of the PL from the solid surface-oxidized particles with those from the incorporated particles in polymer films. We also present evidence for a novel photoreduction of the white WO3nanoparticles into the blue W2O5 following the irradiation of the particles with the second harmonic of the Nd:YAG laser at 532 nm. Finally, we report the observation of efficient blue PL from Ga oxide nanoparticles. These examples demonstrate the potential use of nanoparticles in the design of optical and photonic devices. q1998 Elsevier Science B.V.