1. V. Lashkaryov Institute of Semiconductor Physics, National Academy of Sciences of Ukraine, 41 Nauky Avenue, 03028 Kyiv, Ukraine
2. Educational Scientific Institute of High Technologies, Taras Shevchenko National University of Kyiv, 4-g Hlushkova Avenue, 03022 Kyiv, Ukraine
3. Institute of Physics, National Academy of Sciences of Ukraine, 46 Nauky Avenue, 03028 Kyiv, Ukraine