1. Institute of Microelectronics, NCSR Demokritos, Terma Patriarchou Grigoriou, 15310
Aghia Paraskevi, Greece
2. Department of Physics, University of Patras, 26500 Patras, Greece
3. Department
of Chemical Engineering, University of Patras, 26500 Patras, Greece
4. Department of Electronics, Technological and Educational Institute of Pireaus,
12244 Aegaleo, Greece