Dresden 2009 – wissenschaftliches Programm

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SYSO: Symposium Self-organizing Surfaces and Interfaces

SYSO 3: Self-Organizing Surfaces and Interfaces - Posters

SYSO 3.21: Poster

Mittwoch, 25. März 2009, 17:30–19:30, P3

Infrared studies of Pb nanowires on silicon vicinal surfaces — •Chung Hoang, Robert Lovrincic, Markus Klevenz, Frank Neubrech, and Annemarie Pucci — Kirchhoff-Institut für Physik der Universität Heidelberg, Im Neuenheimer Feld 227, 69120 Heidelberg

By means of polarized infrared (IR) spectroscopy we investigate the optical response of self-assembled lead nanowires growing on silicon vicinal surfaces. Under IR excitation polarized parallel to the long wire axis we see a shift of a resonance frequency to lower wave numbers when the nanowires are growing in length, meanwhile there is no significant change observed with perpendicular excitation. The different behaviour of the nanowires under polarized IR electrical field reveals surface plasmon excitation and resonant enhancement of the local field. This field enhancement is known to be localized at the tip-ends of the nanowires and it can be exploited, for example, via an optical nanoantenna concept. As the formation of lead nanowires is defined from the very beginning stage of the nucleation process and is related to the anisotropy of terrace and corner-rounding diffusion, we use Si(335) and Si(557) vicinal substrates with and without gold decoration as one-dimensional templates for producing various arrays of parallel nanowires for comparison. Our result demonstrates that the stability of the vicinal surfaces and also corner-rounding diffusion play key roles in the formation of the nanowires. The influence of the substrate temperature on the development and resonance frequencies of the nanowires is also studied.