Berlin 2008 – wissenschaftliches Programm

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O: Fachverband Oberflächenphysik

O 69: Symposium: Size-Selected Clusters at Surfaces III

O 69.4: Vortrag

Donnerstag, 28. Februar 2008, 14:45–15:00, MA 042

Electrospray Ion Beam Deposition of Nonvolatile Molecules and Nanoparticles in High- and Ultrahigh Vacuum — •Stephan Rauschenbach, Thomas Weitz, Alicia Forment, Jens Boettcher, Giovanni Costantini, Nicola Malinowski, and Klaus Kern — Max-Planck-Institute for Solid State Research, Stuttgart, Germany

Electrospray Ionization is a soft ionization technique with which nonvolatile molecules or nanoparticles from a solution can be transferred into the gas phase. Based on this technique we developed a novel vacuum deposition apparatus, which is capable to transfer these ions into high- or ultrahigh vacuum, mass select them and deposited them on a surface [S.Rauschenbach et. al., Small 4 (2006)]. Destruction free deposition (soft landing) can be achieved, since the kinetic energy of the ions can be controlled. An UHV-STM/AFM is connected to the system for in-situ analysis.

The capability to deposit the large organic molecules, clusters and nanoparticles is demonstrated with a variety of systems. Soft landing of molecules is proven by fluorescence spectroscopy and TOF-SIMS identification of deposited dye molecules. Au-nanoparticles (5 - 20 nm) and carbon nanotubes deposited from ion beams were found intact on the surface identified by atomic force microscopy (AFM). CdS nanorods (30 nm diameter) and V₂O₅ nanowires (5 nm diameter) observed in AFM after deposition are identified by TOF-SIMS. Estimations of the charge state and the mass-to-charge-ratio show that the nanoparticle ion beams mainly consist of very highly charged particles.