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O: Fachverband Oberflächenphysik

O 106: Poster Session VIII: Poster to Mini-Symposium: Electrified solid-liquid interfaces III

O 106.6: Poster

Thursday, March 4, 2021, 13:30–15:30, P

In-situ optical detection of charge distributions at electrified solid-liquid interfaces — •Christoph Cobet, Saul Vazquez-Miranda, Luis Rosillo-Orozco, and Kurt Hingerl — Johannes Kepler University, Altenbergerstr 69, 4040, Linz, Austria

Polarization optical methods like Spectroscopic Ellipsometry are used by us to determine the distribution of charges, i.e. electrons and ions, and their potential dependent variation in the uppermost atomic layers of a working electrode as well as in the inner Helmholtz plane above. Our focus lad initially on planar surfaces with regular atomic structure to discriminate the different contributions to the optical response. On the one hand, the aforementioned optical probes are extremely sensitive to electronic surface/interface changes even in the presence of sub-monolayer changes. On the other hand, exactly this advantage often makes it problematic to extract quantitative information. But we will show that valuable additional information is accessible which is in parts complimentary to results of conventional methods such as impedance spectroscopy, EC-STM or novel XPS approaches. This will be demonstrated for single crystalline metal (Cu) as well as metal-oxide (ZnO) surfaces; both drosophila-like examples of catalytic surfaces where the optical resonances of Drude electrons, of electrons in surface states and of electronic states in the electrostatic as well as strain field at electrified solid-liquid interfaces contribute to the measured signal. [1] S. Vazquez-Miranda, et.al.: J. Phys. Chem. C 124, 5204 and 25403 (2020); [2] M.-H. Chien, et.al.: J. Phys. Chem. C 122, 8984 (2018), [3] G. Barati, et.al.: Langmuir 30, 14486 (2014)