1. Guangxi Key Laboratory of Information Materials, School of Materials Science and Engineering, Guilin University of Electronic Technology, Guilin 541004, P.R. China
2. Engineering Research Center of Electronic Information Materials and Devices, Ministry of Education, Guilin University of Electronic Technology, Guilin 541004, P.R. China
3. Institute for Clean Energy and Advanced Materials, School of Materials and Energy, Chongqing Key Laboratory for Advanced Materials and Technologies of Clean Energy, Southwest University, Chongqing 400715, P.R. China
4. Center for Advanced Thin Films and Devices, School of Materials and Energy, Southwest University, Chongqing 400715, P.R. China
5. Department of Chemistry, Physics and Atmospheric Sciences, Jackson State University, Jackson, Mississippi 39217, United States