1. Department of Physics University of Engineering and Technology Lahore 54890 Pakistan
2. USPCAS-E National University of Science and Technology (NUST) H-12 Islamabad 44000 Pakistan
3. Laser and Optronics Center University of Engineering and Technology Lahore 54890 Pakistan
4. Department of Physics University of the Punjab Lahore 54590 Pakistan
5. Laboratary of Lumininescence Analysis and Moleculae Sensing Ministry of Education, School of Materials and Energy Southwest University Chongqing 400715 P. R. China