Mohamed CHEGAAR is a professor at the department of physics, faculty of sciences, Ferhat Abbas Setif-1 University-Setif. He graduated from Constantine University in 1987 in energetics physics. He completed his “magister” entitled: ‘Effect of non-uniform illumination on photovoltaic generators’ from Tlemcen University in 1991.  He fulfilled an MA (Licence) of English; dissertation entitled: ‘Emergence of radicalism in Colonial America’ from Setif University (UFC) in 1997. He completed his PhD degree (Doctorat d’état), entitled “Extracting solar cells parameters and estimating the atmospheric effects on their performance”, from Ferhat Abbas-Setif-1 University in 2002. Many of these research works have been achieved thanks to great helpful people and multiple short stays in Perpignan University, France; Institute of Physical Electronics (IPE), Stuttgart, Germany; Center for Solar Energy and Hydrogen Research Baden-Württemberg (ZSW), Stuttgart, Germany and Lorraine University, Metz, France. He has been teaching physics since 1987. His fields of interest are renewable energies and materials modeling. He has been the head of the solar energy (photovoltaics and solar radiation) team in the Optoelectronic and Components Laboratory (LOC) since 2000 and the head of the laboratory in the period 2016-2019. He has authored or co-authored numerous scientific papers and participated in many international conferences (see google scholar “M. Chegaar”). He supervised different, “magister” and PhD theses. He was requested to review several research papers to electronics letters journal, Applied Energy journal, Agricultural and Forest Meteorology journal, International Journal of Photoenergy, Renewable Energy journal and Chinese optics letters.