Regensburg 2010 – wissenschaftliches Programm

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MM: Fachverband Metall- und Materialphysik

MM 26: Poster Session

MM 26.36: Poster

Dienstag, 23. März 2010, 14:45–16:30, Poster C

Adjusting the Size of Nanochannels in Silicon and Silicon Oxide Samples — •René Berwanger and Rolf Pelster — FR 7.2 - Experimentalphysik, Universität des Saarlandes, D-66123 Saarbrücken, Germany

We have prepared free-standing porous silicon layers by electrochemical etching of heavily p-doped silicon wafers. Pore size and porosity are analysed via nitrogen isotherms. With increasing etching time the thickness of the samples, the average pore radius and the porosity increase (r = 3 nm - 7 nm). Completely oxidized and transparent samples are obtained by heat treatment. This procedure does not affect the average pore radius although the total sample volume increases. Such a decrease of porosity can be explained with a simple model. These samples where used for measurements on confined n-alcohols. For some short-chain alcohols, which crystallize under normal condition, the confinement induces a glass transition.