[1] Univ Salento, Natl Nanotechnol Lab, CNR, Ist Nanosci, Via Arnesano, I-73100 Lecce, Italy
[2] Univ Salento, Dipartimento Ingn Innovaz, I-73100 Lecce, Italy
[3] Brindisi Res Ctr, Tech Unit Mat Technol, ENEA, I-72100 Brindisi, Italy
[4] Ist Italiano Tecnol, I-16163 Genoa, Italy