1. Department of Electrical‐Electronics Engineering Department of Engineering Sciences and Department of Nanotechnology Engineering Abdullah Gül University Kayseri 38080 Turkey
2. Departments of Physics, Electrical‐Electronics Engineering and UNAM‐Institute of Materials Science and Nanotechnology Bilkent University Ankara 06800 Turkey
3. Physical Chemistry Technische Universität Dresden Zellescher Weg 19 01069 Dresden Germany
4. LUMINOUS! Center of Excellence for Semiconductor Lighting and Displays School of Electrical and Electronic Engineering School of Mathematical and Physical Sciences School of Materials Science and Engineering Nanyang Technological University Nanyang Avenue Singapore 639798 Singapore