1. High National College of Technology, Department of Energy and Environment, University of Maroua, P.O. Box 814, Maroua814, Cameroon
2. Materials Science Laboratory, Department of Physics, Faculty of Science, University of Maroua, P.O. Box 814, Maroua814, Cameroon
3. Department of Physics and Astronomy, College of Science, King Saud University, Riyadh11451, Saudi Arabia