1. Department of Chemistry, Quaid-i-Azam University, Islamabad 45320, Pakistan
2. Nanoscience and Technology Department, National Centre for Physics, QAU Campus, Shahdra Valley Road, Islamabad 45320, Pakistan
3. Department of Physics, College of Science, Princess Nourah Bint Abdulrahman University, P. O. Box 84428, Riyadh 11681, Saudi Arabia
4. Nanostructured Materials, Department of Physics, Chemistry and Biology (IFM), Linköping University, SE-581 83 Linköping, Sweden
5. Department of Physics and Applied Mathematics, Pakistan Institute of Engineering and Applied Sciences (PIEAS), Islamabad, 45650, Pakistan