1. School of Electronics Engineering, Vellore Institute of Technology, Vellore, India
2. Department of Materials and Mineral Resources Engineering, National Taipei University of Technology, Taipei, Taiwan
3. Department of Physics, School of Advanced Sciences, Vellore Institute of Technology, Vellore, India
4. Centre for Nanotechnology Research, Vellore Institute of Technology, Vellore, India
5. Department of Mechatronic Engineering, National Taiwan Normal University, Taipei, Taiwan