1. The Institute for Advanced Studies Wuhan University Wuhan 430072 China
2. Frontier Institute of Science and Technology Xi'an Jiaotong University Xi'an 710054 China
3. School of Physics State Key Laboratory of Crystal Materials Shandong University Jinan Shandong 250100 P. R. China
4. Department of Physics and Organic and Carbon Electronics Laboratories (ORaCEL) North Carolina State University Raleigh NC 27695 USA
5. Institute of Polymer Optoelectronic Materials and Devices State Key Laboratory of Luminescent Materials and Devices South China University of Technology Guangzhou 510640 China
6. Key Laboratory of Materials Processing and Mold Ministry of Education Zhengzhou University Zhengzhou 450002 China