DataVXAPL MaterialsPaper
journal article·2022-03-01Open access

Direct STM measurements of R-type and H-type twisted MoSe2/WSe2

Rachel Nieken, Anna Roche, Fateme Mahdikhanysarvejahany, Takashi Taniguchi, Kenji Watanabe, Michael R. Koehler, David G. Mandrus, John Schaibley, Brian J. LeRoy

APL Materials· Volume 10· Issue 3
Publisher pageOpen full text
Source abstract

Abstract

When semiconducting transition metal dichalcogenide heterostructures are stacked, the twist angle and lattice mismatch lead to a periodic moiré potential. As the angle between the layers changes, so do the electronic properties. As the angle approaches 0° or 60°, interesting characteristics and properties, such as modulations in the band edges, flat bands, and confinement, are predicted to occur. Here, we report scanning tunneling microscopy and spectroscopy measurements on the bandgaps and band modulations in MoSe2/WSe2 heterostructures with near 0° rotation (R-type) and near 60° rotation (H-type). We find a modulation of the bandgap for both stacking configurations with a larger modulation for R-type than for H-type as predicted by theory. Furthermore, local density of states images show that electrons are localized differently at the valence band and conduction band edges.
Source: crossref · Quality: baseline

Research context

OpenAlex topics: 2D Materials and Applications · Chalcogenide Semiconductor Thin Films · Graphene research and applications

SciVX discovery tags are terminology-based. OpenAlex topics are source-provided classifications.

Affiliations

Department of Physics, University of Arizona 1 , Tucson, Arizona 85721, USA

International Center for Materials Nanoarchitectonics, National Institute for Materials Science 2 , 1-1 Namiki, Tsukuba 305-0044, Japan

Research Center for Functional Materials, National Institute for Materials Science 3 , 1-1 Namiki, Tsukuba 305-0044, Japan

JIAM Diffraction Facility, Joint Institute for Advanced Materials, University of Tennessee 4 , Knoxville, Tennessee 37920, USA

Department of Materials Science and Engineering, University of Tennessee 5 , Knoxville, Tennessee 37996, USA

Materials Science and Technology Division, Oak Ridge National Laboratory 6 , Oak Ridge, Tennessee 37831, USA

Department of Physics and Astronomy, University of Tennessee 7 , Knoxville, Tennessee 37996, USA

Funding

Army Research Office · National Science Foundation · Gordon and Betty Moore Foundation · Ministry of Education, Culture, Sports, Science and Technology · Japan Society for the Promotion of Science

References (31)

Show source-provided references
1. Quantum-confined electronic states arising from the moiré pattern of MoS2–WSe2 heterobilayers10.1021/acs.nanolett.7b05125 ↗
2. Emergence of superlattice Dirac points in graphene on hexagonal boron nitride10.1038/nphys2272 ↗
3. Tunable moiré bands and strong correlations in small-twist-angle bilayer graphene10.1073/pnas.1620140114 ↗
4. Atomic and electronic reconstruction at the van der Waals interface in twisted bilayer graphene10.1038/s41563-019-0346-z ↗
5. Electronic correlations in twisted bilayer graphene near the magic angle10.1038/s41567-019-0606-5 ↗
6. Maximized electron interactions at the magic angle in twisted bilayer graphene10.1038/s41586-019-1431-9 ↗
7. Unconventional superconductivity in magic-angle graphene superlattices10.1038/nature26160 ↗
8. Correlated insulator behaviour at half-filling in magic-angle graphene superlattices10.1038/nature26154 ↗
9. Probing the wave functions of correlated states in magic angle graphene10.1103/physrevresearch.2.033181 ↗
10. Superconductors, orbital magnets and correlated states in magic-angle bilayer graphene10.1038/s41586-019-1695-0 ↗
11. Correlated electronic phases in twisted bilayer transition metal dichalcogenides10.1038/s41563-020-0708-6 ↗
12. Signatures of moiré-trapped valley excitons in MoSe2/WSe2 heterobilayers10.1038/s41586-019-0957-1 ↗
13. Evidence for moiré excitons in van der Waals heterostructures10.1038/s41586-019-0975-z ↗
14. Diffusivity reveals three distinct phases of interlayer excitons in MoSe2/WSe2 heterobilayers10.1103/physrevlett.126.106804 ↗
15. Mott and generalized Wigner crystal states in WSe2/WS2 moiré superlattices10.1038/s41586-020-2092-4 ↗
16. Evidence of high-temperature exciton condensation in two-dimensional atomic double layers10.1038/s41586-019-1591-7 ↗
17. Theory of optical absorption by interlayer excitons in transition metal dichalcogenide heterobilayers10.1103/physrevb.97.035306 ↗
18. Interlayer excitons in MoSe2/WSe2 heterostructures from first principles10.1103/physrevb.97.165306 ↗
19. Interlayer couplings, moiré patterns, and 2D electronic superlattices in MoS2/WSe2 hetero-bilayers10.1126/sciadv.1601459 ↗
20. Flat bands in twisted bilayer transition metal dichalcogenides10.1038/s41567-020-0958-x ↗
21. Imaging moiré flat bands in 3D reconstructed WSe2/WS2 superlattices10.1038/s41563-021-00923-6 ↗
22. Twist angle-dependent atomic reconstruction and moiré patterns in transition metal dichalcogenide heterostructures10.1021/acsnano.0c00088 ↗
23. Atomic reconstruction in twisted bilayers of transition metal dichalcogenides10.1038/s41565-020-0682-9 ↗
24. Hubbard model physics in transition metal dichalcogenide moiré bands10.1103/PhysRevLett.121.026402 ↗
25. Maximally localized wannier orbitals and the extended hubbard model for twisted bilayer graphene10.1103/physrevx.8.031087 ↗
26. Symmetry, maximally localized wannier states, and a low-energy model for twisted bilayer graphene narrow bands10.1103/physrevx.8.031088 ↗
27. Deep moiré potentials in twisted transition metal dichalcogenide bilayers10.1038/s41567-021-01174-7 ↗
28. Moiré excitons: From programmable quantum emitter arrays to spin-orbit–coupled artificial lattices10.1126/sciadv.1701696 ↗
29. Flat bands and mechanical deformation effects in the moiré superlattice of MoS2-WSe2 heterobilayers10.1021/acsnano.0c03414 ↗
30. Two-dimensional atomic crystals10.1073/pnas.0502848102 ↗
31. Second harmonic generation from artificially stacked transition metal dichalcogenide twisted bilayers10.1021/nn500228r ↗