1. Department of Physics, Indian Institute of Technology Patna, Bihta Campus, Patna-801106, India
2. Department of Electronics and Communication Engineering, Indian Institute of Technology Roorkee, Roorkee-247667, India
3. Institute and Undergraduate Program of Electro-Optical Engineering, National Taiwan Normal University, Taipei 11677, Taiwan
4. Micro/Nano Device Inspection and Research Center, National Taiwan Normal University, Taipei 106, Taiwan
5. Global Innovation Centre for Advanced Nanomaterials, The University of Newcastle, University Drive, Newcastle-2308, NSW, Australia