1. Department of Materials Science and Engineering; University of California; Berkeley CA 94720 USA
2. ANTARES Beamline; Synchrotron SOLEIL; Université Paris-Saclay; L'Orme des Merisiers; Saint Aubin-BP 48 91192 Gif sur Yvette Cedex France
3. Department of Physics; University of California; Berkeley CA 94720 USA
4. Materials Sciences Division; Lawrence Berkeley National Laboratory; Berkeley CA 94720 USA
5. Institute of Physics and University of Chinese Academy of Sciences; Chinese Academy of Sciences; Beijing 100190 China
6. Key Laboratory of Organic Solids; Institute of Chemistry; Chinese Academy of Sciences; Beijing 100190 China
7. Department of Materials Science and Engineering; Stanford University; Stanford CA 94305 USA
8. State Key Laboratory of Superlattices and Microstructures; Institute of Semiconductors; Chinese Academy of Sciences; Beijing 100083 China
9. School of Physics and Electronics; Hunan Key Laboratory for Super-microstructure and Ultrafast Process; Central South University; Changsha 410083 China