1. UNAM-National Nanotechnology Research Center; Bilkent University; Ankara 06800 Turkey
2. Institute of Materials Science and Nanotechnology; Bilkent University; Ankara 06800 Turkey
3. Department of Energy Engineering; Faculty of Engineering; Ankara University; Ankara 06830 Turkey
4. NANOTAM- Nanotechnology Research Center; Bilkent University; Ankara 06800 Turkey
5. Department of Electrical and Electronics Engineering; Bilkent University; Ankara 06800 Turkey
6. Department of Physics; Bilkent University; Ankara 06800 Turkey
7. Department of Chemistry; Bilkent University; Ankara 06800 Turkey