Plasmonic Stamps Fabricated by Gold Dewetting on PDMS for Catalyzing Hydrosilylation on Silicon Surfaces

In this work plasmonic stamps are harnessed to drive surface chemistry on silicon. The plasmonic stamps were prepared by sputtering gold films on PDMS, followed by thermal annealing to dewet the gold and form gold nanoparticles. By changing the film thickness of the sputtered gold, the approximate size and shape of these gold nanoparticles can be changed, leading to a shift of the optical absorbance maximum of the plasmonic stamp, from 535 nm to 625 nm. Applying the plasmonic stamp to a Si(111)-H surface using 1-dodecene as the ink, illumination with green light results in covalent attachment of 1-dodecyl groups to the surface. Of the dewetted gold films on PDMS used to make the plasmonic stamps, the thinnest three (5.0, 7.0, 9.2 nm) resulted in the most effective plasmonic stamps for hydrosilylation. The thicker stamps had lower efficacy due to the increased fraction of non-spherical particles, which have lower-energy localized surface plasmon resonances (LSPRs) that are not excited by green light. Since...