Plasmonic electric near-field enhancement in self-organized gold nanoparticles in macroscopic arrays

• Published in: Applied physics. B, Lasers and optics Lasers and optics, 2016-06, Vol.122 (6), p.1-9, Article 155
• Main Authors: Mondes, V., Antonsson, E., Plenge, J., Raschpichler, C., Halfpap, I., Menski, A., Graf, C., Kling, M. F., Rühl, E.
• Format: Article
• Language: English
• Subjects: Arrays; Coupling; Engineering; Finite difference method; Gold; Lasers; Nanoparticles; Nanospheres; Nanostructure; Optical Devices; Optics; Photonics; Physical Chemistry; Physics; Physics and Astronomy; Plasmonics; Quantum Optics; Ultrafast Nanooptics
• ISSN: 0946-2171; 1432-0649
• DOI: 10.1007/s00340-016-6412-1

When plasmonic nanoparticles are incorporated into nanostructures and they are exposed to external optical fields, plasmonic coupling causes electric near-field enhancement which is significantly larger than that of isolated nanoparticles. We report on the plasmonic coupling in arrays of gold nanospheres (20 ± 3 and 50 ± 4 nm) prepared by colloidal chemistry and self-organization. This yields field enhancement in arrays with areas of several mm 2 and provides an alternative approach to lithographic methods for preparation of nanostructures for plasmonic applications. Gold nanospheres are surface-functionalized by organic ligands, which define the interparticle distance in the array upon self-organization of the nanoparticles. The experiments are accompanied by finite-difference time-domain simulations, which quantify the dependence of the field enhancement on the interparticle distance.