1. School of Physics and Astronomy, University of Southampton, Southampton, SO17 1BJ, United Kingdom
2. CNRS UMR 8181, Unité de Catalyse et de Chimie du Solide - UCCS, UArtois, Faculté des Sciences Jean Perrin, SP18, F-62307 Lens Cedex, France
3. Institute of Applied Physics, Military University of Technology, Warsaw, Poland
4. Institute of Microelectronics and Optoelectronics, Warsaw University of Technology, Warsaw, Poland
5. Institute of Optoelectronics, Military University of Technology, Warsaw, Poland