Nanomaterials for directed energy transfer [report]

Michael B. Sinclair, Julie A. Last, Andrea Lynn Slade, Thomas A. Westrich, Darryl Yoshio Sasaki, Jerrold Anthony Floro, Steven Craig Seel
2005 unpublished
An extremely desirable functionality for nanostructured materials is the ability to efficiently activate or interrogate structures within a nanoscale device using optical energy. However, given the packing densities obtainable with nanofabrication, direct focusing of incident optical energy onto individual nanostructures is impractical. One approach to developing such functionality involves the use of "energy transfer". Energy transfer is the process by which excitation energy resulting from
more » ... y resulting from absorption of photons can become delocalized and move from the site where the photon was absorbed. Energy transfer is often associated with organized arrays, or networks, of polarizable structures. In the current context, energy transfer networks can loosely be thought of as "lenses" that "focus" optical energy onto a desired site. The research program described in this report investigated several approaches toward the fabrication of both organic and inorganic energy transfer networks. For the production of metallic nanoparticle chains and arrays which are expected to act as "plasmonic" waveguides, we investigated strain-induced self assembly of metal particles on insulating substrates. We found that up to 6 monolayers of Ag on MgO(001) produced self-assembled island structures, but that thicker films with larger island sizes no longer produced monomodal distributions or periodic ordering. Growth of metallic nanoparticles on templated MgO substrates was also investigated. In a separate endeavor, ultrathin amorphous Si and Ge films composed of nanoscale holes and islands on oxidized Si were discovered to exhibit anomalously low reflectivity over the visible spectrum. For a number of distinct material systems, the low reflectivity regime coincided with
doi:10.2172/882541 fatcat:fbedhigknzexba7hgdwluxacqe