1. Phenikaa University Nano Institute (PHENA), Phenikaa University, Hanoi 12116, Vietnam
2. Institute of Physics at Ho Chi Minh City, Vietnam Academy of Science and Technology (VAST), Ho Chi Minh 70000, Vietnam
3. Department of Physics, Tien Giang University, My Tho City, Tien Giang Province, Vietnam
4. Faculty of Materials Science and Engineering, Phenikaa University, Hanoi 12116, Vietnam