Berlin 2018 – wissenschaftliches Programm
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O: Fachverband Oberflächenphysik
O 8: Solid-liquid interfaces: Structure, Spectroscopy I
O 8.5: Vortrag
Montag, 12. März 2018, 11:30–11:45, MA 144
Ab initio description of semiconductor-water interfaces at finite electrode potential — •Lei Yang1, Fang Niu1, Stefanie Tecklenburg1, Simantini Nayak1, Andreas Erbe1, Francois Gygi2, Giulia Galli3, and Stefan Wippermann1 — 1MPI Eisenforschung — 2UC Davis — 3U Chicago
Despite the importance of understanding the structural and bonding properties of solid-liquid interfaces for a wide range of (photo-)electrochemical applications, there are presently no experimental techniques available to directly probe the microscopic structure of solid-liquid interfaces. To develop robust strategies to interpret experiments and validate theory, we carried out attenuated total internal reflection (ATR-IR) spectroscopy measurements and ab initio molecular dynamics (AIMD) simulations of the vibrational properties of interfaces between liquid water and well-controlled prototypical semiconductor substrates. We show the Ge(100)/H2O interface to feature a reversible potential-dependent surface phase transition from a hydrophilic to a hydrophobic surface. The Si(100)/H2O interface is proposed as a model system for corrosion and oxidation processes. We performed ab initio time-resolved spectroscopy, providing a molecular-level explanation for the difference between the vibrational properties of the H2O molecules on surfaces with different hydrophobicities on the basis of hydrogen bonding. Funding from DOE-BES Grant No. DE-SS0008939, Deutsche Forschungsgemeinschaft (RESOLV, EXC 1069) and BMBF NanoMatFutur Grant No. 13N12972 is gratefully acknowledged.