1. Department of Physics , Career Point University , Hamirpur , HP , India
2. Department of Physics , Guru Nanak Dev University , Amritsar , Punjab , India
3. Department of Chemistry , Career Point University , Hamirpur , HP , India
4. Department of Physics , University of the West Indies , Trinidad , West Indies
5. School of Physics and Materials Science , Shoolini University of Biotechnology & Management Sciences , Bajhol , Solan 173212 , HP , India