Selective-Area Deposition of Indium and Its Plasmonic Properties.

We present an effective process sequence for the deposition of indium nanostructures using molecular beam epitaxy (MBE) on a silicon substrate. Using a template structure composed of inverted pyramids and V-grooves, we deposit indium nanostructures with various dimensions. Spatially resolved cathodoluminescence spectroscopy (CL) using an electron-beam energy of 30 keV electrons shows a localized surface plasmon (LSP) resonance in spherical particles with a peak wavelength at 300 nm and a full width at half-maximum of 70 nm for the smallest particles (diameter of 85 nm), showing high optical quality of the grown indium. V-groove template structures create indium nanowires for which CL spectroscopy reveals efficient propagation of surface plasmon polaritons (SPPs), and angle-resolved CL on the periodic inverted pyramids reveals optical lattice resonances arising from the array's periodicity. The high optical quality of these nanostructures enables further applications of plasmonic nanostructures in the ultraviolet (UV) spectral range.