Line and Point Defects in MoSe2 Bilayer Studied by Scanning Tunneling Microscopy and Spectroscopy

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• 作者：Hongjun Liu ; Hao Zheng ; Fang Yang ; Lu Jiao ; Jinglei Chen ; Wingkin Ho ; Chunlei Gao ; Jinfeng Jia ; Maohai Xie
• 刊名：ACS Nano
• 出版年：2015
• 出版时间：June 23, 2015
• 年：2015
• 卷：9
• 期：6
• 页码：6619-6625
• 全文大小：451K
• ISSN：1936-086X

文摘

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.