[1] Hebei Normal Univ, Coll Phys, Shijiazhuang 050024, Peoples R China
[2] Hebei Normal Univ, Hebei Adv Thin Films Lab, Shijiazhuang 050024, Peoples R China
[3] Hebei Univ Sci & Technol, Sch Sci, Shijiazhuang 050018, Peoples R China
[4] Hebei Univ Sci & Technol, Hebei Key Lab Photoelect Control Surface & Interfa, Shijiazhuang 050018, Peoples R China
[5] Shijiazhuang Univ, Dept Phys, Shijiazhuang 050035, Peoples R China