1. The Center for Solar Energy Research and Applications (GÜNAM) Çankaya 06800 Ankara Turkey
2. Micro and Nanotechnology DepartmentMiddle East Technical University Çankaya 06800 Ankara Turkey
3. Department of Electrical and Electronics EngineeringAnkara Yıldırım Beyazıt University Keçiören 06010 Ankara Turkey
4. Instituto de Ciencia MolecularUniversidad de Valencia C/Cat. J. Beltran 2 46980 Paterna Spain
5. Department of Electrical and Electronics EngineeringMiddle East Technical University Çankaya 06800 Ankara Turkey