Block-copolymer (BCP) self-assembling provides a unique tool for realizing large-area ordered metamaterials, with desired optical properties. The benefits of using BCPs as templates for metamaterials come from two main aspects: first, BCPs show a rich range of available nano-morphologies, whose domains can be conveniently tuned in size, shape and periodicity, by changing molecular parameters; second, the chemical properties of the block polymers can lead to the selective inclusion of functionalized nanoparticles (NPs) of different materials in specific nanodomains, generating periodic arrays of NPs according to the geometry of the BCP acting as template. This approach allows finely modulating the optical properties of NPs and can be used as an intriguing and versatile tool to build useful devices for Optics & Photonics applications, with significant benefits for both fundamental and applied investigations. In this work, we investigate nanostructured thin films of polystyrene-block-poly(methyl methacrylate) BCP (PS-PMMA), characterized by an hexagonal array of PS cylinders in the PMMA matrix. The PS cylindrical domain are selectively filled by functionalized metallic (Au, Ag) NPs. The optical properties of such nano-structures are strongly affected by localized surface plasmons (LSPs) in the NPs, arising from the collective resonances of conduction electrons in the metal at a characteristic spectral range, usually in the visible range. LSPs induce high field enhancement (FE), with respect to an incident light, in proximity of the NP surface, and in particular in the gap between two close NPs (hot-spot). Moreover, LSPs increase the intensity of absorption and scattering of light by the NPs in their range of resonance.
We formulated a hydrodynamic model in order to describe the dynamical behavior of the π- electrons in single carbon nanotube shells of arbitrary chirality, either metallic or semiconducting, below terahertz frequencies, as long as only intraband transitions of the π- electrons are allowed. The hydrodynamic equations were derived in a self-consistent way from the semiclassical Boltzmann equation. The electron fluid was taken to comprise many electron species, each characterized by a different effective mass, which takes into account the interaction with the nanotube ion lattice. A linear transport model for the π- electrons was derived from the hydrodynamic equations. A transmission line model was eventually formulated to describe the propagation of an electric signal along a single-wall carbon nanotube of arbitrary chirality. The transport model formulated can be also used for analyzing electromagnetic propagation in complex structures composed of single carbon-nanotube shells with different chirality, such as bundles of single wall carbon nanotubes and multi-wall carbon nanotubes, provided that the tunneling between adjacent shells may be disregarded.
Access to the requested content is limited to institutions that have purchased or subscribe to SPIE eBooks.
You are receiving this notice because your organization may not have SPIE eBooks access.*
*Shibboleth/Open Athens users─please
sign in
to access your institution's subscriptions.
To obtain this item, you may purchase the complete book in print or electronic format on
SPIE.org.
INSTITUTIONAL Select your institution to access the SPIE Digital Library.
PERSONAL Sign in with your SPIE account to access your personal subscriptions or to use specific features such as save to my library, sign up for alerts, save searches, etc.