1. Key Laboratory of Yunnan Provincial Higher Education Institutions for Organic Optoelectronic Materials and Devices, Kunming University, Kunming 650091, People’s Republic of China
2. School of Physics and Technology, Kunming University, Kunming 650091, People’s Republic of China
3. UCL Department of Physics and Astronomy and London Centre for Nanotechnology, University College London, Gower Street, London WC1E 6BT, United Kingdom
4. School of Materials and Energy, Yunnan University, Kunming 650091, People’s Republic of China
5. School of Physics and Astronomy, Yunnan University, Kunming 650091, People’s Republic of China
6. Yunnan Ocean Organic Optoelectronic Technology Ltd., Kunming 650214, People’s Republic of China