1. Jiangsu Key Laboratory of Organic Electronics & Information Displays and Institute of Advanced Materials (IAM), Nanjing University of Posts and Telecommunications, Nanjing 210046, People's Republic of China
2. Inorganic Chemistry Department, Faculty of Chemistry, University of Bucharest, Dumbrava Rosie 23, Bucharest 020462, Romania
3. Department of Physics, “A. I. Cuza” University, Iasi 700506, Romania