1. SIX
Research Centre, Brno University of Technology, 10 Technická, 60190 Brno, Czech Republic
2. Institute
of Physics of Material, Academy of Sciences of Czech Republic, 22 Zizkova, 61662 Brno, Czech Republic
3. Instituto
de Microelectrónica de Barcelona, Consejo Superior de Investigaciones Científica, Campus UAB, 08193 Bellaterra-Barcelona, Spain
4. Department
of Chemistry, University College London, 20 Gordon Street, London WC1H0AJ, U.K.
5. Institute
of Physical Engineering, Central European Institute of Technology, Brno University of Technology, 2896/2 Technická, 61669 Brno, Czech Republic