1. Institute of Physical Chemistry, University of Zurich, Winterthurerstrasse 190, 8057 Zurich, Switzerland
2. Institute of Physical Chemistry, ETH Zurich, Wolfgang-Pauli Strasse 10, 8093 Zurich, Switzerland
3. Electron Microscopy Center of the ETH Zurich (EMEZ), Schafmattstrasse 18, 8093 Zurich, Switzerland