1. Materials Science Department, University of Patras, 26504 Patras, Greece
2. LumiLab, Department of Solid State Sciences, Ghent University, Krijgslaan 281-S1, 9000 Ghent, Belgium
3. TEI of Western Greece, Department of Mechanical Engineering, M. Alexandrou 1, Patras, Greece
4. Laboratory of High-Tech Materials, School of Engineering, University of Patras, 26504 Patras, Greece