1. V. Lashkariov Institute of Semiconductor Physics, National Academy of Sciences of Ukraine, pr. Nauky 41, 03028 Kyiv, Ukraine
2. Radiophysical Faculty, Taras Shevchenko Kyiv National University, pr. Akademika Hlushkova 4g, 03022 Kyiv, Ukraine
3. Institute of Physics, National Academy of Sciences of Ukraine, pr. Nauky 46, 03028 Kyiv, Ukraine
4. Bogolyubov Institute for Theoretical Physics, National Academy of Sciences of Ukraine, 14-b Metrolohichna str., 03680 Kyiv, Ukraine