1. Beijing Institute of Nanoenergy and Nanosystems; Chinese Academy of Sciences; National Center for Nanoscience and Technology (NCNST); Beijing 100083 China
2. Institute of Semiconductors; University of Chinese Academy of Sciences; Beijing 100083 China
3. Research Center for Bioengineering and Sensing Technology; Beijing Key Laboratory for Bioengineering and Sensing Technology; School of Chemistry and Biological Engineering; University of Science and Technology Beijing; Beijing 100083 China
4. Center for Green Innovation; School of Mathematics and Physics; University of Science and Technology Beijing; Beijing 100083 China
5. School of Material Science and Engineering; Georgia Institute of Technology; Atlanta GA 30332-0245 USA