1. School of Materials Science and Engineering, Shanghai University, Baoshan District, Shanghai 200444, China
2. Key Laboratory of Graphene Technologies and Applications of Zhejiang Province & Division of Functional Materials and Nano Devices, Ningbo Institute of Materials Technology and Engineering, Chinese Academy of Sciences, Ningbo 315201, People’s Republic of China
3. Department of Physics, Government College University Faisalabad, Allama Iqbal Road, 38000 Faisalabad, Pakistan
4. Department of Physics, National Sun Yat-Sen University, Kaohsiung 80424, Taiwan