[1] COMSATS Univ Islamabad, Dept Phys, Lahore Campus,Def Rd Raiwind, Lahore 54000, Pakistan
[2] Mohammad Nawaz Sharif Univ Engn & Technol, Dept Phys, Multan 60000, Pakistan
[3] Southeast Univ, Sch Energy & Environm, 2 Si Pai Lou, Nanjing 210096, Peoples R China
[4] King Saud Univ, King Abdullah Inst Nanotechnol, POB 2455, Riyadh 11458, Saudi Arabia
[5] King Saud Univ, Dept Phys & Astron, Coll Sci, POB 2455, Riyadh 11451, Saudi Arabia
[6] COMSATS Univ Islamabad, Micro Mm Wave Lab M2L, Dept Phys, Lahore Campus,Def Rd Raiwind, Lahore 54000, Pakistan