1. Faculty of Applied Science, Ho Chi Minh City University of Technology and Education, 01 Vo Van Ngan Street, Ho Chi Minh City 700000, Vietnam
2. Department of Materials Science and Engineering, National Yang Ming Chiao Tung University, 1001, Daxue Road, East District, Hsinchu 300093, Taiwan
3. Department of Physics, National Sun Yat-sen University, Kaohsiung 80424, Taiwan
4. Faculty of Fundamental Sciences, University of Architecture Ho Chi Minh City, 196 Pasteur St., Dist. 3, Ho Chi Minh City 700000, Vietnam
5. Faculty of electrical and electronics engineering, Ho Chi Minh City University of Technology and Education, 01 Vo Van Ngan Street, Ho Chi Minh City 700000, Vietnam
6. EEE Department, University of Sheffield, Sheffield S10 2TN, UK