Zhejiang-California Nanosystems Institute, Zhejiang University, Hangzhou, China.|Zhejiang-California Nanosystems Institute, Zhejiang University, Hangzhou, China.|Zhejiang-California Nanosystems Institute, Zhejiang University, Hangzhou, China.|Zhejiang-California Nanosystems Institute, Zhejiang University, Hangzhou, China.|Zhejiang-California Nanosystems Institute, Zhejiang University, Hangzhou, China.|Zhejiang-California Nanosystems Institute, Zhejiang University, Hangzhou, China.|Zhejiang-California Nanosystems Institute, Zhejiang University, Hangzhou, China.|Zhejiang-California Nanosystems Institute, Zhejiang University, Hangzhou, China.