1. Measurement and Sensor Technology, Chemnitz University of Technology, Reichenhainer Str. 70, 09126 Chemnitz, Germany
2. Semiconductor Physics, Chemnitz University of Technology, Reichenhainer Str. 70, 09126 Chemnitz, Germany
3. Analysis of Solid Surfaces, Chemnitz University of Technology, Reichenhainer Str. 70, 09126 Chemnitz, Germany
4. Faculty of Physical Chemistry, University of Belgrade, Studentski trg 12-16, 11158 Belgrade, Serbia