1. Department of Applied Chemistry and Institute of Molecular Science, National Chiao Tung University, Hsinchu 30010, Taiwan
2. Henan Key Laboratory of Photovoltaic Materials, Henan University, Kaifeng 475004, People’s Republic of China
3. Center for Condensed Matter Sciences, National Taiwan University, Taipei 106, Taiwan
4. Center for Emergent Functional Matter Science, National Chiao Tung University, Hsinchu 30010, Taiwan