1. Institute of Physics
2. Kazimierz Wielki University in Bydgoszcz
3. 85090 Bydgoszcz
4. Poland
5. Department of Electronics
6. Ivan Franko National University of Lviv
7. 79017 Lviv
8. Ukraine
9. SSI Institute for Single Crystals
10. National Academy of Sciences of Ukraine
11. 61178 Kharkiv
12. Polish Academy of Sciences
13. 02-668 Warsaw