1. Semiconductor Physics, Institute of Physics, Chemnitz University of Technology, Chemnitz, Germany
2. Center for Materials, Architectures, and Integration of Nanomembranes (MAIN), Chemnitz University of Technology, Chemnitz, Germany
3. Department of Electrical and Systems Engineering, University of Pennsylvania, Philadelphia, PA, USA
4. Center for Microtechnologies, Chemnitz University of Technology, Chemnitz, Germany
5. Institute of Physics, Montanuniversität Leoben, Leoben, Austria
6. Fraunhofer Institute for Electronic Nano Systems, Chemnitz, Germany