1. Department of Solid State Physics, University of Science, Vietnam National University-Ho Chi Minh City (VNU-HCM), 227 Nguyen Van Cu, Ward 4, District 5, Ho Chi Minh City, Vietnam
2. NTT Hi-Tech Institute, Nguyen Tat Thanh University, 298-300 A Nguyen Tat Thanh Street, Ho Chi Minh City, Vietnam
3. LED Agri-Bio Fusion Technology Research Center, Chonbuk National University, Jeonju 561-853, Republic of Korea