| AVS 64th International Symposium & Exhibition | |
| Thin Films Division | Friday Sessions |
| Session TF-FrM |
| Session: | Self-assembled Monolayers and Organic/Inorganic Interface Engineering |
| Presenter: | Wolf-Dietrich Zabka, Department of Physics, University of Zürich, Switzerland |
| Authors: | W.-D. Zabka, Department of Physics, University of Zürich, Switzerland D. Leuenberger, Department of Physics, University of Zürich, Switzerland G. Mette, University of Zürich, Switzerland C. Monney, University of Zürich, Switzerland M. Mosberger, University of Zürich, Switzerland B. Probst-Rüd, University of Zürich, Switzerland R. Alberto, University of Zürich, Switzerland J. Osterwalder, University of Zürich, Switzerland |
| Correspondent: | Click to Email |
Ultrathin (ut) oxide films with a thickness of few atomic layers are often used as model systems for oxide surfaces and their interaction with adatoms, particles and molecules. In particular, epitaxial ut-alumina films grown on NiAl alloys have been used to study a wide range of phenomena under UHV-conditions [1,2]. However, their instability under ambient conditions limits the possibilities for application [3,4].
We developed a new wet chemistry setup directly attached to an existing ultra-high vacuum system that enables us to deposit self-assembled monolayers (SAM) from highly purified solvents onto substrates prepared under UHV conditions without exposure to air. The setup, the procedure for SAM-deposition and the characterization of residual contamination detected with X-ray photoelectron spectroscopy (XPS) will be described. Rhenium photosensitizers functionalized with carboxyl groups (Re(CO)3(NCS)bipycarb) are attached onto ut-alumina films. XPS measurements indicate that the resulting structure is stable in air. First results from time-resolved photoemission spectroscopy suggest that by altering the oxide thickness, a variation of the lifetime of excited electrons can be achieved. Both, the substrate stabilization and the control of hot electron lifetimes offer new prospects for the application of such ultrathin oxide films involving charge transfer and related mechanisms.
[1] N. Nilius, Surf. Sci. Rep. 64, 595 (2009).
[2] U. Diebold, S. C. Li, and M. Schmid, Annu. Rev. Phys. Chem. 61, 129 (2010).
[3] A. Shavorskiy, K. Müller, J. T. Newberg, D. E. Starr, and H. Bluhm, J. Phys. Chem. C 118, 29340 (2014).
[4] J. Evertsson, F. Bertram, F. Zhang, L. Rullik, L. R. Merte, M. Shipilin, M. Soldemo, S. Ahmadie, N. Vinogradov, F. Carlà, J. Weissenrieder, M. Göthelid, J. Pan, A. Mikkelsen, J.-O. Nilsson, and E. Lundgren, Appl. Surf. Sci. 349, 826 (2015).