1. Department of Physics, Center of Excellent for Advanced Materials Research, Faculty of Science, King Khalid University, P.O. Box 9004, Abha, Saudi Arabia
2. Nano-Science & Semiconductor Labs., Physics Department, Faculty of Education, Ain Shams University Roxy, Cairo, Egypt
3. Thin Film Laboratory, Department of Physics, Faculty of Education, Ain Shams University, Roxy, Cairo, Egypt