Affiliation: | a Head of Solar Energy Factory, Arab International Optronics Co., El-Salam City, Cairo 11491, Egypt b Semiconductor Lab., Physics Department, Faculty of Education, Ain Shams University, Roxy, Cairo, Egypt c Semimagnetic Semiconductors Lab., Institute of Physics, Polish Academy of Sciences, Al. Lotnikow, 32/46, 02-668 Warszawa, Poland |