1. Collaborative
Innovation Center for Optoelectronic Semiconductors and Efficient
Devices, Department of Physics/Pen-Tung Sah Institute of Micro-Nano
Science and Technology, Xiamen University, Xiamen, Fujian, 361005 China
2. Department
of Mechanical Engineering, University of California, Berkeley, California 94720, United States
3. State
Key Lab of Physical Chemistry of Solid Surfaces, and Department of
Chemistry, College of Chemistry and Chemical Engineering, Xiamen University, Xiamen, 361005 China
4. State
Key Laboratory for Manufacturing Systems Engineering Xi’an Jiaotong University, Xi’an, Shaanxi, 710049 P.R. China