1. Department of Physical Chemistry, Faculty of Chemical Technology, University of Pardubice, Studentska 573, 532 10Pardubice, Czech Republic
2. Center of Materials and Nanotechnologies (CEMNAT), Faculty of Chemical Technology, University of Pardubice, Nam. Cs Legii 565, 530 02Pardubice, Czech Republic
3. Department of Physical Electronics, Herzen State Pedagogical University of Russia, 48 Moika Emb., St. Petersburg191186, Russia