Jinhua Hong1, Zhixin Hu2, Matt Probert3 , Kun Li4 , Danhui Lv1 , Xinan Yang5 , Lin Gu5 , Nannan Mao6,7, Qingliang Feng6 , Liming Xie6 , Jin Zhang7 , Dianzhong Wu8 , Zhiyong Zhang8 , Chuanhong Jin1, *, Wei Ji2, *, Xixiang Zhang4 , Jun Yuan3,*, Ze Zhang1
1 State Key Laboratory of Silicon Materials, Key Laboratory of Advanced Materials and Applications for Batteries of Zhejiang Province, School of Materials Science and Engineering, Zhejiang University, Hangzhou, Zhejiang 310027, China.
2 Beijing Key Laboratory of Optoelectronic Functional Materials & Micro-Nano Devices, Department of Physics, Renmin University of China, Beijing 100872, China
3 Department of Physics, University of York, Heslington, York, YO10 5DD, United Kingdom
4 Advanced Nanofabrication, Imaging and Characterization Core Lab, King Abdullah University of Science and Technology (KAUST), Thuwal 239955, Kingdom of Saudi Arabia
5 Instituteof Physics, Chinese Academy of Sciences, c/o Collaborative Innovation Center of Quantum Matter, Beijing 100190, China
6 CAS Key Laboratory of Standardization and Measurement for Nanotechnology, National Center for Nanoscience and Technology, Beijing 100190, China
7 Center for Nanochemistry, Beijing National Laboratory for Molecular Sciences, Key Laboratory for the Physics and Chemistry of Nanodevices, State Key Laboratory for Structural Chemistry of Unstable and Stable Species, College of Chemistry and Molecular Engineering, Peking University, Beijing 100871, China
8 Key Laboratory for the Physics and Chemistry of Nanodevices and Department of Electronics, Peking University, Beijing 100871, China
DOI:10.1038/ncomms7293 Publication Date: 19 Feb 2015
Defects usually play an important role in tailoring various properties of two-dimensional materials. Defects in two-dimensional monolayer molybdenum disulphide may be responsible for large variation of electric and optical properties. Here we present a comprehensive joint experiment-theory investigation of point defects in monolayer molybdenum disulphide prepared by mechanical exfoliation, physical and chemical vapour deposition. Defect species are systematically identified and their concentrations determined by aberration-corrected scanning transmission electron microscopy and also studied by ab-initio calculation. Defect density up to 3.5×1013 cm-2 is found and the dominant category of defects changes from sulfur vacancy in mechanical exfoliation and chemical vapour deposition samples to molybdenum antisite in physical vapour deposition samples. Influence of defects on electronic structure and charge-carrier mobility are predicted by calculation and observed by electric transport measurement. In light of these results, the growth of ultra-high quality monolayer molybdenum disulphide appears a primary task for the community pursuing high-performance electronic devices.