title: Interlayer couplings, Moiré patterns, and 2D electronic superlattices in MoS2/WSe2hetero-bilayers.
abstract: By using direct growth, we create a rotationally aligned MoS2/WSe2hetero-bilayer as a designer van der Waals heterostructure. With rotational alignment, the lattice mismatch leads to a periodic variation of atomic registry between individual van der Waals layers, exhibiting a Moiré pattern with a well-defined periodicity. By combining scanning tunneling microscopy/spectroscopy, transmission electron microscopy, and first-principles calculations, we investigate interlayer coupling as a function of atomic registry. We quantitatively determine the influence of interlayer coupling on the electronic structure of the hetero-bilayer at different critical points. We show that the direct gap semiconductor concept is retained in the bilayer although the valence and conduction band edges are located at different layers. We further show that the local bandgap is periodically modulated in theX-Ydirection with an amplitude of ~0.15 eV, leading to the formation of a two-dimensional electronic superlattice.
authors.affiliation: Department of Physics, University of Texas at Austin, Austin, TX 78712, USA.
authors.forename: Chendong
authors.initials: C
authors.lastname: Zhang
authors.affiliation: Institute of Atomic and Molecular Sciences, Academia Sinica, P.O. Box 23-166, Taipei 10617, Taiwan.
authors.forename: Chih-Piao
authors.initials: CP
authors.lastname: Chuu
authors.affiliation: State Key Laboratory of Silicon Materials and School of Materials Science and Engineering, Zhejiang University, Hangzhou, Zhejiang 310027, People's Republic of China.
authors.forename: Xibiao
authors.initials: X
authors.lastname: Ren
authors.affiliation: Physical Science and Engineering Division, King Abdullah University of Science and Technology, Thuwal 23955-6900, Kingdom of Saudi Arabia.; Research Center for Applied Sciences, Academia Sinica, Taipei 10617, Taiwan.
authors.forename: Ming-Yang
authors.initials: MY
authors.lastname: Li
authors.affiliation: Physical Science and Engineering Division, King Abdullah University of Science and Technology, Thuwal 23955-6900, Kingdom of Saudi Arabia.; Research Center for Applied Sciences, Academia Sinica, Taipei 10617, Taiwan.
authors.forename: Lain-Jong
authors.initials: LJ
authors.lastname: Li
authors.affiliation: State Key Laboratory of Silicon Materials and School of Materials Science and Engineering, Zhejiang University, Hangzhou, Zhejiang 310027, People's Republic of China.
authors.forename: Chuanhong
authors.initials: C
authors.lastname: Jin
authors.affiliation: Institute of Atomic and Molecular Sciences, Academia Sinica, P.O. Box 23-166, Taipei 10617, Taiwan.; School of Physics, Georgia Institute of Technology, Atlanta, GA 30332, USA.; Department of Physics, National Taiwan University, Taipei 10617, Taiwan.
authors.forename: Mei-Yin
authors.initials: MY
authors.lastname: Chou
authors.affiliation: Department of Physics, University of Texas at Austin, Austin, TX 78712, USA.
authors.forename: Chih-Kang
authors.initials: CK
authors.lastname: Shih
keywords: 2D electronic super-lattices; Moire Pattern; Transition metal dichacogenides; interlayer coupling; van der Waals heterostructures