1. Polytechnic University of Bucharest (PUB), Romania) Academy of Romanian Scientists,Faculty of Applied Sciences,Department of Physics,Bucharest,Romania
2. University of Oslo (UiO),Center for Materials Science and Nanotechnology,Department of Physics,Oslo,Norway
3. Polytechnic University of Bucharest (PUB),Faculty of Applied Sciences,Department of Physics,Romania
4. Institute for Energy Technology (IFE),Kjeller,Norway
5. National Institute of Research and Development for Optoelectronics (INOE-2000),Bucharest-Magurele,Romania