Department of Physics;
University of Sargodha;
Sargodha 40100;
Pakistan;
Department of Energy&Power Engineering;
Tsinghua-BP Clean Energy Center;
Tsinghua University;
Beijing 100084;
People’s Republic of China;
National Institute of Lasers and Optronics(NILOP);
Nilore;
Islamabad 45650;
Pakistan;
National Center for Physics;
Quaid-i-Azam University Campus;
Islamabad 45320;
Pakistan;