1. Department of Inorganic Chemistry, University of Chemistry and Technology Prague, Technicka 5, 166 28, Prague 6, Czech Republic
2. Institute of Electrical and Microengineering, École Polytechnique Fédérale de Lausanne (EPFL), CH-1015 Lausanne, Switzerland
3. Institute of Materials Science and Engineering, École Polytechnique Fédérale de Lausanne (EPFL), CH-1015 Lausanne, Switzerland
4. Institute of Physics of the Czech Academy of Sciences, v.v.i., Cukrovarnická 10, 162 00, Prague 6, Czech Republic
5. Institute of Microelectronics, TU Wien, Gußhausstraße 27−29, 1040 Vienna, Austria
6. Institute of Applied Physics, TU Wien, Wiedner Hauptstraße 8−10, 1040 Vienna, Austria