Formation, deposition and examination of size selected metal clusters on semiconductor surfaces: An experimental setup

摘要

An instrument designed to investigate the chemical behavior of size selected metal clusters on semiconductor surfaces is described. The clusters are formed using laser vaporization, mass selected in a magnetic mass analyzer and deposited on TiO2 substrates under UHV conditions with impact energies ranging from <= 1 to >100 eV/atom. Intensities of mass selected Au-n(+) and Ag-n(+) clusters range from 0.03 to 3 nA. Intensity, beam focusing and deposition energy are discussed. Once deposited on the surface, the clusters are investigated using scanning tunneling microscopy (STM) and/or temperature programmed desorption (TPD). Examples are presented showing STM images of Au-5 deposited on a clean rutile titania surface and of the TPD of propene from TiO2. (C) 2006 Elsevier B.V. All rights reserved.