1. Forschungszentrum Jülich GmbH, Helmholtz-Institut Erlangen Nürnberg für Erneuerbare Energien (HI ERN), Immerwahrstr. 2, 91058 Erlangen, Germany
2. L.V. Pysarzhevsky Institute of Physical Chemistry, National Academy of Sciences of Ukraine, Kyiv 03028, Ukraine
3. Physical Chemistry, TU Dresden, 01062 Dresden, Germany
4. Semiconductor Physics, Chemnitz University of Technology, 09107 Chemnitz, Germany
5. V. Lashkaryov Institute of Semiconductor Physics, National Academy of Sciences of Ukraine, Kyiv 03028, Ukraine
6. Taras Shevchenko National University of Kyiv, 01601 Kyiv, Ukraine