1. Key Laboratory for Thin Film and Micro Fabrication of the Ministry of Education, School of Sensing Science and Engineering, School of Electronic Information and Electrical Engineering, Shanghai Jiao Tong University, Shanghai 200240, China
2. National Engineering Research Center for Nanotechnology, 28 East Jiangchuan RD, Shanghai, 200241, China
3. Kunming Metallurgical Research Institute Co. LTD, Kunming 650031, China