1. Department of Physics, R.D. Govt. Arts College, Tamilnadu, Sivaganga - 630561, India
2. Department of Material Science, School of Chemistry, Madurai Kamaraj University, Tamilnadu Madurai-625 021, India
3. Department of Physics/Centre for Materials Science and Nanotechnology, University of Oslo, P.O Box 1048 Blindern, NO-0316 Oslo, Norway
4. Department of Materials Science & Engineering, Michigan Technological University, USA
5. Department of Solar Energy, Institute for Energy Technology, P.O. Box 40, NO-2027 Kjeller, Norway
6. Department of Electrical & Computer Engineering, Michigan Technological University, USA