title: Line and Point Defects in MoSe2 Bilayer Studied by Scanning Tunneling Microscopy and Spectroscopy.
abstract: Bilayer (BL) MoSe2 films grown by molecular-beam epitaxy (MBE) are studied by scanning tunneling microscopy and spectroscopy (STM/S). Similar to monolayer (ML) films, networks of inversion domain boundary (DB) defects are observed both in the top and bottom layers of BL MoSe2, and often they are seen spatially correlated such that one is on top of the other. There are also isolated ones in the bottom layer without companion in the top-layer and are detected by STM/S through quantum tunneling of the defect states through the barrier of the MoSe2 ML. Comparing the DB states in BL MoSe2 with that of ML film reveals some common features as well as differences. Quantum confinement of the defect states is indicated. Point defects in BL MoSe2 are also observed by STM/S, where ionization of the donor defect by the tip-induced electric field is evidenced. These results are of great fundamental interests as well as practical relevance of devices made of MoSe2 ultrathin layers.
authors.affiliation: †Physics Department, The University of Hong Kong, Pokfulam Road, Hong Kong, China.
authors.forename: Hongjun
authors.initials: H
authors.lastname: Liu
authors.affiliation: †Physics Department, The University of Hong Kong, Pokfulam Road, Hong Kong, China.|‡Key Laboratory of Artificial Structures and Quantum Control (Ministry of Education), Department of Physics and Astronomy, Shanghai Jiaotong University, 800 Dongchuan Road, Shanghai 200240, China.|§Collaborative Innovation Center of Advanced Microstructures, Department of Physics and Astronomy, Shanghai Jiao Tong University, Shanghai 200240, P. R. China.
authors.forename: Hao
authors.initials: H
authors.lastname: Zheng
authors.affiliation: ‡Key Laboratory of Artificial Structures and Quantum Control (Ministry of Education), Department of Physics and Astronomy, Shanghai Jiaotong University, 800 Dongchuan Road, Shanghai 200240, China.
authors.forename: Fang
authors.initials: F
authors.lastname: Yang
authors.affiliation: †Physics Department, The University of Hong Kong, Pokfulam Road, Hong Kong, China.
authors.forename: Lu
authors.initials: L
authors.lastname: Jiao
authors.affiliation: †Physics Department, The University of Hong Kong, Pokfulam Road, Hong Kong, China.
authors.forename: Jinglei
authors.initials: J
authors.lastname: Chen
authors.affiliation: †Physics Department, The University of Hong Kong, Pokfulam Road, Hong Kong, China.
authors.forename: Wingkin
authors.initials: W
authors.lastname: Ho
authors.affiliation: ‡Key Laboratory of Artificial Structures and Quantum Control (Ministry of Education), Department of Physics and Astronomy, Shanghai Jiaotong University, 800 Dongchuan Road, Shanghai 200240, China.|§Collaborative Innovation Center of Advanced Microstructures, Department of Physics and Astronomy, Shanghai Jiao Tong University, Shanghai 200240, P. R. China.
authors.forename: Chunlei
authors.initials: C
authors.lastname: Gao
authors.affiliation: ‡Key Laboratory of Artificial Structures and Quantum Control (Ministry of Education), Department of Physics and Astronomy, Shanghai Jiaotong University, 800 Dongchuan Road, Shanghai 200240, China.|§Collaborative Innovation Center of Advanced Microstructures, Department of Physics and Astronomy, Shanghai Jiao Tong University, Shanghai 200240, P. R. China.
authors.forename: Jinfeng
authors.initials: J
authors.lastname: Jia
authors.affiliation: †Physics Department, The University of Hong Kong, Pokfulam Road, Hong Kong, China.
authors.forename: Maohai
authors.initials: M
authors.lastname: Xie
keywords: 2D materials; MBE; MoSe2 bilayer; STM/S; defects