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Title: High density of (pseudo) periodic twin-grain boundaries in molecular beam epitaxy-grown van der Waals heterostructure: MoTe{sub 2}/MoS{sub 2}

Abstract

Growth of transition metal dichalcogenide heterostructures by molecular beam epitaxy (MBE) promises synthesis of artificial van der Waals materials with controllable layer compositions and separations. Here, we show that MBE growth of 2H-MoTe{sub 2} monolayers on MoS{sub 2} substrates results in a high density of mirror-twins within the films. The grain boundaries are tellurium deficient, suggesting that Te-deficiency during growth causes their formation. Scanning tunneling microscopy and spectroscopy reveal that the grain boundaries arrange in a pseudo periodic “wagon wheel” pattern with only ∼2.6 nm repetition length. Defect states from these domain boundaries fill the band gap and thus give the monolayer an almost metallic property. The band gap states pin the Fermi-level in MoTe{sub 2} and thus determine the band-alignment in the MoTe{sub 2}/MoS{sub 2} interface.

Authors:
; ; ;  [1]
  1. Department of Physics, University of South Florida, Tampa, Florida 33620 (United States)
Publication Date:
OSTI Identifier:
22591703
Resource Type:
Journal Article
Journal Name:
Applied Physics Letters
Additional Journal Information:
Journal Volume: 108; Journal Issue: 19; Other Information: (c) 2016 Author(s); Country of input: International Atomic Energy Agency (IAEA); Journal ID: ISSN 0003-6951
Country of Publication:
United States
Language:
English
Subject:
75 CONDENSED MATTER PHYSICS, SUPERCONDUCTIVITY AND SUPERFLUIDITY; 71 CLASSICAL AND QUANTUM MECHANICS, GENERAL PHYSICS; DENSITY; FERMI LEVEL; GRAIN BOUNDARIES; MOLECULAR BEAM EPITAXY; MOLECULAR BEAMS; MOLYBDENUM SULFIDES; MOLYBDENUM TELLURIDES; PERIODICITY; SCANNING TUNNELING MICROSCOPY; SILICON OXIDES; SPECTROSCOPY; SUBSTRATES; TELLURIUM; TRANSITION ELEMENTS; TUNNEL EFFECT; VAN DER WAALS FORCES

Citation Formats

Diaz, Horacio Coy, Ma, Yujing, Chaghi, Redhouane, and Batzill, Matthias. High density of (pseudo) periodic twin-grain boundaries in molecular beam epitaxy-grown van der Waals heterostructure: MoTe{sub 2}/MoS{sub 2}. United States: N. p., 2016. Web. doi:10.1063/1.4949559.
Diaz, Horacio Coy, Ma, Yujing, Chaghi, Redhouane, & Batzill, Matthias. High density of (pseudo) periodic twin-grain boundaries in molecular beam epitaxy-grown van der Waals heterostructure: MoTe{sub 2}/MoS{sub 2}. United States. https://doi.org/10.1063/1.4949559
Diaz, Horacio Coy, Ma, Yujing, Chaghi, Redhouane, and Batzill, Matthias. 2016. "High density of (pseudo) periodic twin-grain boundaries in molecular beam epitaxy-grown van der Waals heterostructure: MoTe{sub 2}/MoS{sub 2}". United States. https://doi.org/10.1063/1.4949559.
@article{osti_22591703,
title = {High density of (pseudo) periodic twin-grain boundaries in molecular beam epitaxy-grown van der Waals heterostructure: MoTe{sub 2}/MoS{sub 2}},
author = {Diaz, Horacio Coy and Ma, Yujing and Chaghi, Redhouane and Batzill, Matthias},
abstractNote = {Growth of transition metal dichalcogenide heterostructures by molecular beam epitaxy (MBE) promises synthesis of artificial van der Waals materials with controllable layer compositions and separations. Here, we show that MBE growth of 2H-MoTe{sub 2} monolayers on MoS{sub 2} substrates results in a high density of mirror-twins within the films. The grain boundaries are tellurium deficient, suggesting that Te-deficiency during growth causes their formation. Scanning tunneling microscopy and spectroscopy reveal that the grain boundaries arrange in a pseudo periodic “wagon wheel” pattern with only ∼2.6 nm repetition length. Defect states from these domain boundaries fill the band gap and thus give the monolayer an almost metallic property. The band gap states pin the Fermi-level in MoTe{sub 2} and thus determine the band-alignment in the MoTe{sub 2}/MoS{sub 2} interface.},
doi = {10.1063/1.4949559},
url = {https://www.osti.gov/biblio/22591703}, journal = {Applied Physics Letters},
issn = {0003-6951},
number = 19,
volume = 108,
place = {United States},
year = {Mon May 09 00:00:00 EDT 2016},
month = {Mon May 09 00:00:00 EDT 2016}
}