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DS: Dünne Schichten
DS 21: Laser and plasma processes
DS 21.1: Vortrag
Donnerstag, 30. März 2006, 16:30–16:45, GER 37
Laser-induced formation and characterization of periodic nanostructures in polymer thin films with embedded metal particles — •Katrin Löschner1, Marcel Dyrba2, Andreas Kiesow1, Gerhard Seifert2, and Andreas Heilmann1 — 1Fraunhofer Institute for Mechanics of Materials, Heideallee 19, 06120 Halle — 2Martin Luther University Halle-Wittenberg, Department of Physics, Hoher Weg 8, 06120 Halle
The nanostructural properties of metal particle containing plasma polymer films can be modified by the irradiation with linearly polarized, femtosecond laser pulses. The interaction of the metal nanoparticles with the oriented, intense electric field leads to the formation of line-like, periodically arranged nanoparticle structures in the laser-treated area. These structural modifications are characterized by longish regions with obvious changes in particle size and shape distribution which alternate with regions without apparent particle changes. The optical properties of such nanocomposite materials are mainly determined by the size, shape, and spatial arrangement of the particles. Therefore, the generation of anisotropic structure changes results in dichroitic properties of the irradiated area. The periodical structural changes were generated by systematic variation of laser irradiation parameters (also at varying the film properties, i.e., thickness, matrix material). As result a phenomenological model of the occurring physical processes is suggested. For the characterization of the structural changes transmission and scanning electron microscopy were applied. Optical modelling is used as a helpful tool for explanation of the resulting optical properties.