Tailoring spectral position and width of field enhancement by focused ion-beam patterning of plasmonic nanoparticles

We propose to use ion-beam patterning of plasmonic nanoparticles made by standard electron beam lithography, plasmonic metal deposition, and lift-off sequence. With this approach new three-dimensional (3D) tailoring of nanoparticles becomes possible: cut through the particle and into the substrate, cut-through at an angle, trim or bore nanoparticles or substrate. Here, we numerically simulate the expected optical properties of such 3D patterned nanoparticles. We show a particular case when spectrally broad extinction band can be created with a strong light field enhancement on a Si substrate.Nanoparticles with a 10-20 nm nano-gap cut by ion-beam at the chosen location and to the required depth into the substrate. Scanning electron microscopy (SEM) image of the fabricated Au-nanoparticles.(© 2010 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim)Free three-dimensional (3D) patterning of plasmonic nanoparticles by ion beam lithography can be used to control the light-field enhancement and its spectral position. This direct-write approach does not require resist and 3D tailoring of nanoparticles becomes possible by cut-through at arbitrary angle, boring nanoparticles and substrate. Authors show numerically that optical properties of such 3D patterned gold nanoparticles on silicon substrate are prospective for use in solar cells.

We propose to use ion-beam patterning of plasmonic nanoparticles made by standard electron beam lithography, plasmonic metal deposition, and lift-off sequence. With this approach new three-dimensional (3D) tailoring of nanoparticles becomes possible: cut through the particle and into the substrate, cut-through at an angle, trim or bore nanoparticles or substrate. Here, we numerically simulate the expected optical properties of such 3D patterned nanoparticles. We show a particular case when spectrally broad extinction band can be created with a strong light field enhancement on a Si substrate. [GRAPHICS] Nanoparticles with a 10-20 nm nano-gap cut by ion-beam at the chosen location and to the required depth into the substrate. Scanning electron microscopy (SEM) image of the fabricated Au-nanoparticles. (C) 2010 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim