Shape tailoring of hexagonally ordered triangular gold nanoparticles with nanosecond-pulsed laser light

• Published in: Applied surface science Vol. 255; no. 24; pp. 9822 - 9825
• Main Authors: Morarescu, Rodica, Sánchez, David Blázquez, Borg, Nils, Vartanyan, Tigran A., Träger, Frank, Hubenthal, Frank
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 30-09-2009
• Subjects: Gold nanoparticles; Hexagonal ordered array; Nanosphere lithography; ns-Pulsed laser light; 61.46.+w; 52.38.Bv; 78.67.Hc; Gold nanoparticles; Hexagonal ordered array; ns-Pulsed laser light; 42.79.Vb; Nanosphere lithography
• ISSN: 0169-4332; 1873-5584
• DOI: 10.1016/j.apsusc.2009.04.098

In this contribution recent results on selective and precise tailoring of triangular gold nanoparticles (NPs) using ns-pulsed laser light are presented. The NPs were prepared by nanosphere lithography and subsequently tailored with ns-pulsed laser light using different fluences and wavelengths. The method is based on the size and shape dependent localized surface plasmon polariton resonance (SPR) of the NPs. We will demonstrate that the gap size between triangular NPs can be tuned from approximately
102
±
14
nm to
122
±
11
nm, due to a shape change of the NP from triangular to oblate. These morphological changes are accompanied by a significant shift of the surface plasmon resonance from
λ
SPR
=
730
nm to
λ
SPR
=
680
nm. Most importantly if the laser wavelength is chosen such that the dipolar SPR is excited, the hexagonal order of the NPs remains intact after irradiation, in contrast to excitation via the quadrupole SPR or within the interband transition. A tuneable gap size and the conservation of the hexagonal order of the NP array is the precondition for applications, where the NPs should serve as anchor points, e.g. for functional molecular nanowires, which can be used to utilize molecular devices.