1. Laboratory for Photonics and Interfaces, Institute of Chemical Sciences and Engineering, Swiss Federal Institute of Technology; CH-1015 Lausanne Switzerland
2. Center of Nanotechnology, Department of Physics; Faculty of Science, King Abdulaziz University; Jeddah 21589 Saudi Arabia
3. Center of Nanotechnology, Department of Aeronautical Engineering; King Abdulaziz University; Jeddah 21589 Saudi Arabia
4. Center of Nanotechnology; King Abdulaziz University; Jeddah 21589 Saudi Arabia