1. Department of Physics, Tezpur University (Central University), Tezpur 784028, India
2. Centre of Biomedical Research, SGPGIMS Campus, Lucknow 226014, India
3. Department of Molecular Biology and Biotechnology, Tezpur University (Central University), Tezpur 784028, India
4. Department of Electrical Engineering, IIT Bombay, Mumbai 400076, India
5. UGC-DAE Consortium for Scientific Research, Bhabha Atomic Research Centre, Mumbai Centre, R-5 Shed, Mumbai 400085, India
6. Solid State Physics Division, Bhabha Atomic Research Centre, Mumbai 400085, India