1. MOE
Key Laboratory of Organic OptoElectronics and Molecular Engineering,
Department of Chemistry, Tsinghua University, Beijing 100084, P. R. China
2. Key
Laboratory of Organic Solids, Beijing National Laboratory for Molecular
Science (BNLMS), Institute of Chemistry, Chinese Academy of Science, Beijing 100190, P. R. China
3. Collaborative
Innovation Center of Chemistry for Energy Materials, Xiamen University, Xiamen 351005, P. R. China