FABRICATION OF PBS NANOPARTICLES EMBEDDED IN SILICA-GEL BY REVERSE MICELLES AND SOL-GEL ROUTES

PbS doped-silica gels showing a visible absorption onset were prepared by the sol gel method. PbS nanoparticles with strong quantum-confinem ent effect were obtained from sodium sulfide and lead nitrate by the r everse micelle method. Chemical parameters such as the water/surfactan t and the [Pb2+]/[S2-] ratios play a very important role in the PbS pa rticle size and in their absorption threshold. The PbS nanoparticles w ere dispersed in a hydrolyzed solution of TEOS and converted to homoge neous gels after heating. The absorption threshold of PbS doped-gel is blue shifted compared to the one of the as-prepared PbS particles. Th e non-linear optical properties of the PbS nanoparticle solution were measured by degenerate four-wave mixing and the chi((3)) value was est imated to be 1.95 10(-11) esu.