1. Department of Chemistry, Faculty of Natural Sciences, Quy Nhon University, 170 An Duong Vuong, Quy Nhon 590000, Vietnam
2. Department of Physics, Faculty of Natural Sciences, Quy Nhon University, 170 An Duong Vuong, Quy Nhon 590000, Vietnam
3. Division of Molecular Imaging and Photonics, Department of Chemistry, KU Leuven, Celestijnenlaan 200F, Leuven B-3001, Belgium