1. Department of Physics, Jadavpur University, Kolkata-700032, India
2. Department of Physics, Jogamaya Devi College, Kolkata-700026, India
3. Shenzhen Key Laboratory of Advanced Functional Carbon Materials Research and Comprehensive Application, Shenzhen Key Laboratory of Flexible Printed Electronics Technology, and School of Science, Harbin Institute of Technology, Shenzhen 518055, China