Self-assembled growth on flexible alumina and nanoporous silicon templates

Abstract

Several nanoscale arrays of metallic, semiconductor, and organic carbon compounds (carbon nanopearls) have been fabricated on nanoporous flexible alumina and silicon templates based on a new self-assembly growth mode. They were obtained using pulsed laser deposition, thermal evaporation, e-beam evaporation, or RF magnetron sputtering. The different moieties that were observed include nanodomes and nanodots (gold, nickel, cobalt, and aluminum nitride), nanonecklaces (carbon nanopearl), and nanopinetrees (gold) self assembled on flexible alumina templates. A nanoneedle array was also self assembled by e-beam evaporation of nickel on silicon substrates that were rendered nanoporous by the use of a porous alumina mask. The physical processes underpinning the new self assembly growth mode have been studied based on extensive characterization of the templates prior to and after deposition of the various metallic, semiconductor, and organic compounds. These include atomic force microscopy (AFM), X-ray diffraction (XRD) analysis, Raman spectroscopy and field emission-scanning electron microscopy (FE-SEM). Some of the arrays have been tested as potential candidates for new cold cathode arrays for vacuum electronic applications using the scanning electron field emission microscopy (SAFEM) technique.