1. Helmholtz-Zentrum Berlin für Materialien und Energie, Hahn-Meitner-Platz 1, Berlin 14109, Germany
2. Institute of Microelectronics Technology and High-Purity Materials, Russian Academy of Sciences, Academician Ossipyan Str. 6, Chernogolovka 142432, Russian Federation
3. Institute of Solid State Physics, Russian Academy of Sciences, Academician Ossipyan Str. 2, Chernogolovka 142432, Russian Federation