1. Department
of Physics, Adnan Menderes University, Aydın 09010, Turkey
2. Department
of Electrical and Electronic Engineering, Adnan Menderes University, 09100 Aydın, Turkey
3. Nanotechnology
Application and Research Center, Adnan Menderes University, Aydın 09010, Turkey
4. Department
of Physics, Bilkent University, Ankara 06800, Turkey