1. NANOTAM-Nanotechnology Research CenterBilkent University 06800 Ankara Turkey
2. Department of Electrical and Electronics EngineeringBilkent University 06800 Ankara Turkey
3. Department of PhysicsBilkent University 06800 Ankara Turkey
4. UNAM-Institute of Materials Science and NanotechnologyBilkent University 06800 Ankara Turkey