1. Institute for Integrative Nanosciences, Institute for Solid State and Materials Research Dresden, Leibniz IFW Dresden, 01069 Dresden, Germany.
2. Material Systems for Nanoelectronics, Chemnitz University of Technology, 09107 Chemnitz, Germany.
3. Research Center for Materials, Architectures and Integration of Nanomembranes (MAIN), TU Chemnitz, Rosenbergstraße 6, 09126 Chemnitz, Germany.
4. Nanophysics, Faculty of Physics, TU Dresden, 01062 Dresden, Germany.