[1] NUST, SNS, Dept Phys, PCSL, Islamabad 44000, Pakistan
[2] Shenzhen Univ, Coll Phys & Energy, Shenzhen Key Lab Adv Thin Films & Applicat, Shenzhen 518060, Guangdong, Peoples R China
[3] Shenzhen Univ, Coll Optoelect Engn, Minist Educ & Guangdong Prov, Key Lab Optoelect Devices & Syst, Shenzhen 518060, Guangdong, Peoples R China
[4] UAEU, Dept Chem & Petr Engn, Al Ain 15551, U Arab Emirates
[5] Univ Texas Austin, Microelect Res Ctr, Austin, TX 78758 USA