1. National Research University of Electronic Technology “MIET,” Bld. 1, Shokin Square, 124498 Moscow, Russia
2. Faculty of Physics, Vilnius University, Sauletekio av. 9/3 817, LT-10222 Vilnius, Lithuania
3. Institute of Physics, National Academy of Sciences of Ukraine, 46, pr. Nauky, 03028 Kyiv, Ukraine
4. Faculty of Physics, Taras Shevchenko National University of Kyiv, 4, pr. Akademika Hlushkova, 03022 Kyiv, Ukraine
5. Institute for Material Science and Center for Nanointegration Duisburg-Essen (CENIDE), University of Duisburg-Essen, Universitätsstraße 15, 45141 Essen, Germany