Nanostructuration of polysilane-SiQDs composite by pulsed electrical discharges in water

Pulsed electrical discharges in water were used for nanostructuration of the polysilane-silicon quantum dots (SiQDs) composite dispersed in a cellulose acetate matrix. For this purpose, the polysilane-SiQDs composite was synthesized by chain scission of a poly[diphenyl-co-methyl(H)] oligomer in the presence of molten sodium and catalytic amounts of methyl(H) dichlorosilane. The resulting solid was utilized to prepare free standing thin films using the cellulose acetate matrix as support. Samples of these films were exposed to nanosecond pulsed electrical discharges in water. Through this approach, chemo-mechanical nanostructuration of specific silicon-based structures occurred by removing the excess of polysilane and by oxidative action. Fluorescence measurements of the plasma treated samples showed a higher intensity compared to the untreated ones. The elemental composition and the morphology of the film surface were investigated by TEM, XPS, UHR-SEM and AFM analysis. Such a technique represents a new approach toward a selective processing of the polysilane-SiQDs composite to obtain patterns with different optoelectronic properties on various supports.