1. Department of Applied Chemistry, Cochin University of Science and Technology, Kochi, Kerala, India
2. Department of Physics, Cochin University of Science and Technology, Kochi, Kerala, India
3. Centre for Advanced Materials, Cochin University of Science and Technology, Kochi, Kerala, India
4. School of Physics, Trinity College Dublin, Dublin, Ireland
5. School of Chemistry and Advanced Materials and Bioengineering Research Centre (AMBER), Trinity College Dublin, Dublin, Ireland
6. Inter University Centre for Nanomaterials and Devices, Cochin University of Science and Technology, Kochi, Kerala, India