1. Institute of Novel Semiconductors, State Key Laboratory of Crystal Materials, Shandong University, Jinan, 250100, P.R. China
2. National Center for International Joint Research of Electronic Materials and Systems, School of Information Engineering, Zhengzhou University, Zhengzhou, Henan 450052, P. R. China
3. Key Laboratory of Processing and Testing Technology of Glass, & Functional Ceramics of Shandong Province, School of Materials Science and Engineering, Qilu University of Technology (Shandong Academy of Sciences), Jinan 250353, P. R. China