1. Department of Physics, University of Salerno, 84084 Fisciano, Italy
2. Centre NANO_MATES, University of Salerno, 84084 Fisciano, Italy
3. Department of Information and Electrical Engineering and Applied Mathematics, University of Salerno, 84084 Fisciano, Italy
4. Narrando Srl, Via Arcangelo Rotunno 43, 84134 Salerno, Italy
5. Research Institute for Nuclear Problems Belarusian State University, 220030 Minsk, Belarus
6. Department of Physics and Mathematics, University of Eastern Finland, 80101 Joensuu, Finland
7. State Key Lab of Polymer Material Engineering, Sichuan University, Chengdu 610065, China
8. Department of Industrial Engineering, University of Salerno, 84084 Fisciano, Italy