1. Bilkent University UNAM – Institute of Materials Science and Nanotechnology, Ankara, 06800, Turkey
2. Department of Physics, Bilkent University, Ankara 06800, Turkey
3. Department of Materials Science and Engineering, Korea Advanced Institute of Science and Technology (KAIST), Daejeon 34141, Republic of Korea
4. Graduate School of Semiconductor Materials and Devices Engineering, Ulsan National Institute of Science and Technology (UNIST), Ulsan 44919, Republic of Korea