Authors: C. Tallet, J. Vieaud, O. Merchiers, P.C. Sivasankaran, F. Nallet, A. Aradian, V. Ponsinet
Affilation: Centre de Recherche Paul Pascal, France
Pages: 618 - 619
Keywords: block copolymer, gold nanoparticle, nanocomposite, optical property
Bottom-up approaches, and among them nanochemistry and self-assembly, have recently appeared as promising tools for the fabrication of plasmonic nanostructured materials. We study nanocomposites of polymers and gold nanoparticles presenting plasmonic resonance at a visible wavelength, and aim at understanding the relation between the nature, density and spatial organization of the gold nanoparticles and the optical properties of the nanocomposite materials. Two types of nanocomposites are designed and fabricated. Disordered nanocomposites are obtained by randomly dispersing 15nm gold spheres in polymer thin films on silicon wafers. Ordered nanocomposites are obtained by incorporating 6nm gold nanoparticles in the layered domains of ordered block copolymer lamellar phases, both in bulk and thin films. Volume fraction of gold is varied from 1 to 30% and film thickness from a few nanometers to 300 nm. X-ray small-angle scattering and reflectivity, electron and atomic force microscopies are used to get a detailed structural description of the nanostructured composites. The optical properties of the nanocomposites are studied using spectrophotometry and spectroscopic ellipsometry. The refractive index results are confronted to effective medium models, which allows assessing the presence of plasmonic coupling between nanoresonators and relating them to their structural organization.