1. Nanotechnology Research Center (NANOTAM), Bilkent University, Ankara 06800, Turkey
2. Department of Electrical and Electronics Engineering, Bilkent University, Ankara 06800, Turkey
3. Department of Electrical Engineering and Computer Science, University of Michigan, Ann Arbor, Michigan 48109, United States
4. National Nanotechnology Research Center (UNAM), Bilkent University, Ankara 06800, Turkey
5. Department of Chemistry, Bilkent University, Ankara 06800, Turkey
6. Department of Physics, Bilkent University, Ankara 06800, Turkey