[1] Hubei Univ Automot Technol, Sch Sci, Shiyan 442002, Peoples R China
[2] Huazhong Univ Sci & Technol HUST, Ctr Nanoscale Characterizat & Devices CNCD, Sch Phys, Wuhan Natl Lab Optoelect WNLO, Wuhan 430074, Peoples R China
[3] Guilin Univ Technol, Coll Mat Sci & Engn, Guangxi Key Lab Opt & Elect Mat & Devices, Guilin 541004, Peoples R China