1. Ioffe Physico‐Technical Institute, Polytekhnicheskaya 26, 194021 St. Petersburg, Russia
2. Ioffe Physico‐Technical Institute, Russian Academy of Sciences, Scientific Engineering Center for Microelectronics, Polytekhnicheskaya 26, 194021 St. Petersburg, Russia
3. Svetlana‐Optoelektronika, Engelsa 27, 194156 St. Petersburg, Russia