1. King Abdullah Institute for Nanotechnology, King Saud University, Riyadh 11321, Saudi Arabia
2. Chemistry Department, Faculty of Science, King Saud University, Riyadh 11321, Saudi Arabia
3. Central Lab, College of Science, King Saud University, Riyadh 11321, Saudi Arabia
4. Physics Department, Faculty of Science, King Saud University, Riyadh 11321, Saudi Arabia
5. Department of Chemical Engineering, King Saud University, Riyadh 11421, Saudi Arabia
6. Department of Physics, University of Dammam, P.O. Box 1982, Dammam 31441, Saudi Arabia