1. Institute of Chemical Physics, University of Latvia, Raina Blvd. 19, LV-1586 Riga, Latvia
2. Nano RAY-T, Instituta str. 1, Ulbroka, LV-2130, Stopinu Parish, Latvia
3. Materials Research Center, 03680, St. Ak. Krzhizhanovskogo, 3 Kyiv, Ukraine
4. Institute of Physics, University of Tartu, W. Ostwaldi 1, 50411, Tartu, Estonia
5. Faculty of Chemistry, University of Latvia, Raina Blvd. 19, LV-1586 Riga, Latvia