1. Department of Physics, Government College for Women (Affiliated to University of Kerala), Thiruvananthapuram, Kerala 695014, India
2. Research Centre for Nanomaterials and Energy Technology (RCNMET), School of Engineering and Technology, Sunway University, No. 5 Jalan University, Bandar Sunway, 47500 Selangor Darul Ehsan, Malaysia
3. School of Engineering and Technology, Sunway University, No. 5 Jalan University, Bandar Sunway, 47500 Selangor Darul Ehsan, Malaysia