[1] Univ Elect Sci & Technol, Sch Phys, Chengdu 611731, Sichuan, Peoples R China
[2] Univ Elect Sci & Technol, State Key Lab Elect Thin Films & Integrated Devic, Chengdu 611731, Sichuan, Peoples R China
[3] Sukkur IBA Univ, Dept Elect Engn, Sukkur 65200, Pakistan
[4] Harbin Inst Technol, Ctr Composite Mat & Struct, Harbin 150001, Heilongjiang, Peoples R China