Dresden 2009 – wissenschaftliches Programm

Bereiche | Tage | Auswahl | Suche | Downloads | Hilfe

O: Fachverband Oberflächenphysik

O 27: Poster Session I (Methods: Scanning probe techniques; Methods: Atomic and electronic structure; Methods: Molecular simulations and statistical mechanics; Oxides and Insulators: Clean surfaces; Oxides and Insulators: Adsorption; Oxides and Insulators: Epitaxy and growth; Semiconductor substrates: Clean surfaces; Semiconductor substrates: Epitaxy and growth; Semiconductor substrates: Adsorption; Nano- optics of metallic and semiconducting nanostructures; Electronic structure; Methods: Electronic structure theory; Methods: other (experimental); Methods: other (theory); Solutions on surfaces; Epitaxial Graphene; Surface oder interface magnetism; Phase transitions; Time-resolved spectroscopies)

O 27.55: Poster

Dienstag, 24. März 2009, 18:30–21:00, P2

Metal induced faceting of Si (112) — •Tobias Nabbefeld, Christian Wiethoff, Frank-Joachim Meyer zu Heringdorf, and Michael Horn-von Hoegen — Department of Physics and Center for Nanointegration Duisburg-Essen (CeNIDE), University of Duisburg-Essen, 47057 Duisburg

In vapour-liquid-solid growth of Si-nanowires intense faceting of (112)-sidewalls is observed when Au is used as catalyst [1,2]. Other catalyst metals commonly used for the growth of nanowires are Ag and Al. We studied the faceting of Si (112) samples, prepared in ultra-high-vacuum by molecular-beam-epitaxy, in-situ by spot-profile-analysing low-energy-electron-diffraction (SPA-LEED). The SPA-LEED shows facet orientations with high accuracy. Several morphologic phases depending on Ag or Al coverage and temperature were found, and orientations of facets as well as the average step heights, the terrace widths and roughness were identified. The temperature dependence of the faceting process is analysed for temperatures between 380°C and 740°C. This temperature range covers the temperatures of vapour-liquid-solid-growth mechanism and of vapor-solid-solid-growth mechanism for Al-catalysed Si-nanowires [3]. The results of these experiments will help to optimize the properties of nanowires, which are influenced by surface structures.

[1] F.M. Ross et al., Phys. Ref. Lett. 95, 146104, 2005

[2] C. Wiethoff et al., Nano Lett. 8, 3065, 2008

[3] Y. Wang et al., Nature Nanotech. 1, 186, 2006