title: Visualizing band offsets and edge states in bilayer-monolayer transition metal dichalcogenides lateral heterojunction.
abstract: Semiconductor heterostructures are fundamental building blocks for many important device applications. The emergence of two-dimensional semiconductors opens up a new realm for creating heterostructures. As the bandgaps of transition metal dichalcogenides thin films have sensitive layer dependence, it is natural to create lateral heterojunctions (HJs) using the same materials with different thicknesses. Here we show the real space image of electronic structures across the bilayer-monolayer interface in MoSe2 and WSe2, using scanning tunnelling microscopy and spectroscopy. Most bilayer-monolayer HJs are found to have a zig-zag-orientated interface, and the band alignment of such atomically sharp HJs is of type-I with a well-defined interface mode that acts as a narrower-gap quantum wire. The ability to utilize such commonly existing thickness terraces as lateral HJs is a crucial addition to the tool set for device applications based on atomically thin transition metal dichalcogenides, with the advantage of easy and flexible implementation.
authors.affiliation: Department of Physics, University of Texas at Austin, Austin, Texas 78712, USA.
authors.forename: Chendong
authors.initials: C
authors.lastname: Zhang
authors.affiliation: Department of Physics, University of Texas at Austin, Austin, Texas 78712, USA.
authors.forename: Yuxuan
authors.initials: Y
authors.lastname: Chen
authors.affiliation: Department of Physics, University of Texas at Austin, Austin, Texas 78712, USA.|Physical Sciences and Engineering Division, King Abdullah University of Science and Technology, Thuwal 23955-6900, Kingdom of Saudi Arabia.
authors.forename: Jing-Kai
authors.initials: JK
authors.lastname: Huang
authors.affiliation: Department of Physics and Center of Theoretical and Computational Physics, University of Hong Kong, Hong Kong, China.|Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China.
authors.forename: Xianxin
authors.initials: X
authors.lastname: Wu
authors.affiliation: Physical Sciences and Engineering Division, King Abdullah University of Science and Technology, Thuwal 23955-6900, Kingdom of Saudi Arabia.
authors.forename: Lain-Jong
authors.initials: LJ
authors.lastname: Li
authors.affiliation: Department of Physics and Center of Theoretical and Computational Physics, University of Hong Kong, Hong Kong, China.
authors.forename: Wang
authors.initials: W
authors.lastname: Yao
authors.affiliation: IBM Research Division, T.J. Watson Research Center, Yorktown Heights, New York 10598, USA.
authors.forename: Jerry
authors.initials: J
authors.lastname: Tersoff
authors.affiliation: Department of Physics, University of Texas at Austin, Austin, Texas 78712, USA.
authors.forename: Chih-Kang
authors.initials: CK
authors.lastname: Shih