1. Department of Electrical and Electronics Engineering and Department of Physics; UNAM - Institute of Materials Science and Nanotechnology; Bilkent University; Ankara 06800 Turkey
2. Department of Materials Science and Nanotechnology and Department of Electrical-Electronics Engineering; Abdullah Gül University; Kayseri TR-38080 Turkey
3. Department of Chemistry and Applied Biosciences; ETH Zürich Zürich CH-8093 Switzerland
4. Empa-Swiss Federal Laboratories for Material Science and Technology; Dübendorf CH-8600 Switzerland
5. Luminous! Center of Excellence for Semiconductor Lighting and Displays; School of Electrical and Electronic Engineering; School of Physical and Mathematical Sciences; School of Materials Science and Nanotechnology; Nanyang Technological University; Singapore 639798 Singapore