1. Shenzhen Engineering Laboratory of Phosphorene and OptoelectronicsInternational Collaborative Laboratory of 2D Materials for Optoelectronics Science and Technology of Ministry of EducationCollege of Physics and Optoelectronic EngineeringShenzhen University Shenzhen 518060 China
2. School of Materials Science and EngineeringNational Institute for Advanced MaterialsNankai University Tongyan Road 38 Tianjin 300350 P. R. China
3. Department of Electronic EngineeringXiamen University Xiamen 361005 P. R. China