1. V. Lashkaryov Institute of Semiconductors Physics, National Academy of Sciences of Ukraine, 41 Nauky av., Kyiv 03028, Ukraine
2. Taras Shevchenko National University of Kyiv, 64 Volodymyrs’ka st., Kyiv 01601, Ukraine
3. Semiconductor Physics, Chemnitz University of Technology, Chemnitz 09107, Germany
4. Center for Materials, Architectures and Integration of Nanomembranes (MAIN), Chemnitz University of Technology, Chemnitz 09107, Germany
5. L.V. Pysarzhevsky Institute of Physical Chemistry, National Academy of Sciences of Ukraine, 31 Nauky av., Kyiv 03028, Ukraine
6. Forschungszentrum Jülich GmbH, Helmholtz-Institut Erlangen Nürnberg für Erneuerbare Energien (HI ERN), Immerwahrstr. 2, Erlangen 91058, Germany