1. Anhui Province Key Laboratory for Control and Applications of Optoelectronic Information Materials, Department of Physics, Anhui Normal University, Wuhu, Anhui 241000, P. R. China
2. School of Electrical and Mechanical Engineering, Henan Key Laboratory of Research for Central Plains Ancient Ceramics, Pingdingshan University, Pingdingshan, Henan, 467000, P. R. China