title: Periodic Modulation of the Doping Level in Striped MoS₂ Superstructures.
abstract: Although the recently discovered monolayer transition metal dichalcogenides exhibit novel electronic and optical properties, fundamental physical issues such as the quasiparticle bandgap tunability and the substrate effects remain undefined. Herein, we present the report of a quasi-one-dimensional periodically striped superstructure for monolayer MoS2 on Au(100). The formation of the unique striped superstructure is found to be mainly modulated by the symmetry difference between MoS2 and Au(100) and their lattice mismatch. More intriguingly, we find that the monolayer MoS2 is heavily n-doped on the Au(100) facet with a bandgap of 1.3 eV, and the Fermi level is upshifted by ∼0.10 eV on the ridge (∼0.2 eV below the conduction band) in contrast to the valley regions (∼0.3 eV below the conduction band) of the striped patterns after high-temperature sample annealing process. This tunable doping effect is considered to be caused by the different defect densities over the ridge/valley regions of the superstructure. Additionally, an obvious bandgap reduction is observed in the vicinity of the domain boundary for monolayer MoS2 on Au(100). This work should therefore inspire intensive explorations of adlayer-substrate interactions, the defects, and their effects on band-structure engineering of monolayer MoS2.
authors.affiliation: Department of Materials Science and Engineering, College of Engineering and ‡Center for Nanochemistry (CNC), Beijing National Laboratory for Molecular Sciences, College of Chemistry and Molecular Engineering, Peking University , Beijing 100871, People's Republic of China.
authors.forename: Xiebo
authors.initials: X
authors.lastname: Zhou
authors.affiliation: Department of Materials Science and Engineering, College of Engineering and ‡Center for Nanochemistry (CNC), Beijing National Laboratory for Molecular Sciences, College of Chemistry and Molecular Engineering, Peking University , Beijing 100871, People's Republic of China.
authors.forename: Jianping
authors.initials: J
authors.lastname: Shi
authors.affiliation: Department of Materials Science and Engineering, College of Engineering and ‡Center for Nanochemistry (CNC), Beijing National Laboratory for Molecular Sciences, College of Chemistry and Molecular Engineering, Peking University , Beijing 100871, People's Republic of China.
authors.forename: Yue
authors.initials: Y
authors.lastname: Qi
authors.affiliation: Department of Materials Science and Engineering, College of Engineering and ‡Center for Nanochemistry (CNC), Beijing National Laboratory for Molecular Sciences, College of Chemistry and Molecular Engineering, Peking University , Beijing 100871, People's Republic of China.
authors.forename: Mengxi
authors.initials: M
authors.lastname: Liu
authors.affiliation: Department of Materials Science and Engineering, College of Engineering and ‡Center for Nanochemistry (CNC), Beijing National Laboratory for Molecular Sciences, College of Chemistry and Molecular Engineering, Peking University , Beijing 100871, People's Republic of China.
authors.forename: Donglin
authors.initials: D
authors.lastname: Ma
authors.affiliation: Department of Materials Science and Engineering, College of Engineering and ‡Center for Nanochemistry (CNC), Beijing National Laboratory for Molecular Sciences, College of Chemistry and Molecular Engineering, Peking University , Beijing 100871, People's Republic of China.
authors.forename: Yu
authors.initials: Y
authors.lastname: Zhang
authors.affiliation: Department of Materials Science and Engineering, College of Engineering and ‡Center for Nanochemistry (CNC), Beijing National Laboratory for Molecular Sciences, College of Chemistry and Molecular Engineering, Peking University , Beijing 100871, People's Republic of China.
authors.forename: Qingqing
authors.initials: Q
authors.lastname: Ji
authors.affiliation: Department of Materials Science and Engineering, College of Engineering and ‡Center for Nanochemistry (CNC), Beijing National Laboratory for Molecular Sciences, College of Chemistry and Molecular Engineering, Peking University , Beijing 100871, People's Republic of China.
authors.forename: Zhepeng
authors.initials: Z
authors.lastname: Zhang
authors.affiliation: Department of Materials Science and Engineering, College of Engineering and ‡Center for Nanochemistry (CNC), Beijing National Laboratory for Molecular Sciences, College of Chemistry and Molecular Engineering, Peking University , Beijing 100871, People's Republic of China.
authors.forename: Cong
authors.initials: C
authors.lastname: Li
authors.affiliation: Department of Materials Science and Engineering, College of Engineering and ‡Center for Nanochemistry (CNC), Beijing National Laboratory for Molecular Sciences, College of Chemistry and Molecular Engineering, Peking University , Beijing 100871, People's Republic of China.
authors.forename: Zhongfan
authors.initials: Z
authors.lastname: Liu
authors.affiliation: Department of Materials Science and Engineering, College of Engineering and ‡Center for Nanochemistry (CNC), Beijing National Laboratory for Molecular Sciences, College of Chemistry and Molecular Engineering, Peking University , Beijing 100871, People's Republic of China.
authors.forename: Yanfeng
authors.initials: Y
authors.lastname: Zhang
keywords: Au(100); atomic structure; doping level; molybdenum disulfide; scanning tunneling microscope/spectroscopy