1. Division of Physics of Dielectrics and Semiconductors, Ioffe Institute, St. Petersburg, Russia;
2. Division of Solid State Physics, Ioffe Institute, St. Petersburg, Russia;
3. Laboratory of Polymer Sorbents and Carriers for Biotechnology, Institute of Macromolecular Compounds, St. Petersburg, Russia;
4. Institute of Physics, Nanotechnology and Telecommunications, Peter the Great St. Petersburg Polytechnic University, St. Petersburg, Russia