1. Department of Materials Science and Engineering, Korea University, Anamro 145, Seoul 02841, South Korea
2. National University of Science and Technology MISiS, Leninsky Ave., Moscow 194017, Russia
3. Soft-Epi, Inc., Opo-ro 240, Gwangju-si,
Gyeonggi-do 464-892, South Korea
4. Ioffe Physico-Technical Institute, 26
Polytekhnicheskaya Str., St. Petersburg 194021, Russia
5. Submicron Heterostructures for Microelectronics Research and Engineering Center, St. Petersburg 194021, Russia
6. Technological Institute for Superhard and Novel Carbon Materials, 7 Centralnaya St., Troitsk, Moscow 142190,
Russia
7. University of Florida, Gainesville, Florida
32611, USA