Self-organized metal nanocolumns and nanowires produced by sequential Pulsed Laser Deposition

2021 Spring Meeting of the European Materials Research Society (E-MRS) to be held as a VIRTUAL Conference from May 31st to June 3rd, 2021.
Metal-dielectric nanostructures containing metal nanoparticles (NPs) present exciting optical properties, which make them ideal candidates for the development of nanoscale electronic and optical devices, due to the possibility of generating large electromagnetic field enhancement via Surface Plasmon Resonance (SPR). However, most practical applications require a fine control of the NP morphology and orientation. Sequential pulsed laser deposition (PLD) is a versatile technique which provides an excellent control over the amount of deposited metal, as well as reduced NP size dispersion. However, the Volmer-Weber nucleation and growth mode of metal NPs on a dielectric surface, along with surface processes, such as sputtering or sub-surface implantation associated to the presence of energetic ions in the laser generated plasma, hinder the production of NPs with well- defined symmetry. In this work, we show how these shortcomings can be tackled by exploiting the pulsed character of the PLD, appropriately designing the deposition sequence and geometry, and combining it with rippled substrates to produce oriented and elongated NPs along the direction of growth (nanocolumns, NCls) or parallel to the substrate plane (nanowires, NWs) with small diameters (D¿ 3 nm, D¿ 12 nm, respectively) and large aspect ratios (¿20 for NCls, ¿50 for Nos), that lead to a clear polarization dependence of the localized SPR modes. NUM. ADD