1. Department of Electrical and Electronics Engineering; UNAM - National Nanotechnology Research Center; Bilkent University; Ankara 06800 Turkey
2. UNAM - National Nanotechnology Research Center; Institute of Materials Science and Nanotechnology; Bilkent University; Ankara 06800 Turkey
3. Department of Electrical and Electronics Engineering; UNAM - National Nanotechnology Research Center; Institute of Materials Science and Nanotechnology; Bilkent University; Ankara 06800 Turkey