1. Department of Materials Science and Engineering, University of California, Los Angeles, California 90095, United States
2. Beijing National Laboratory for Molecular Sciences, CAS Key Laboratory of Organic Solids, Institute of Chemistry, Chinese Academy of Sciences, Beijing 100190, China
3. Department of Materials Science and Engineering, Monash University, Wellington Road, Clayton, Victoria 3800, Australia
4. Advanced Light Source, Lawrence Berkeley National Laboratory, Berkeley, California 94720, United States