Visualizing Grain Statistics in MOCVD WSe2through Four-Dimensional Scanning Transmission Electron Microscopy

Alejandra Londoño-Calderon; Rohan Dhall; Colin Ophus; Matthew Schneider; Yongqiang Wang; Enkeleda Dervishi; Hee Seong Kang; Chul Ho Lee; Jinkyoung Yoo; Michael T. Pettes

doi:10.1021/acs.nanolett.1c04315

Visualizing Grain Statistics in MOCVD WSe₂through Four-Dimensional Scanning Transmission Electron Microscopy

Alejandra Londoño-Calderon, Rohan Dhall, Colin Ophus, Matthew Schneider, Yongqiang Wang, Enkeleda Dervishi, Hee Seong Kang, Chul Ho Lee, Jinkyoung Yoo, Michael T. Pettes

KU-KIST Graduate School of Converging Science and Technology

Research output: Contribution to journal › Article › peer-review

3 Citations (Scopus)

Abstract

Using four-dimensional scanning transmission electron microscopy, we demonstrate a method to visualize grains and grain boundaries in WSe₂grown by metal organic chemical vapor deposition (MOCVD) directly onto silicon dioxide. Despite the chemical purity and uniform thickness and texture of the MOCVD-grown WSe₂, we observe a high density of small grains that corresponds with the overall selenium deficiency we measure through ion beam analysis. Moreover, reconstruction of grain information permits the creation of orientation maps that demonstrate the nucleation mechanism for new layers-Triangular domains with the same orientation as the layer underneath induces a tensile strain increasing the lattice parameter at these sites.

Original language	English
Pages (from-to)	2578-2585
Number of pages	8
Journal	Nano Letters
Volume	22
Issue number	6
DOIs	https://doi.org/10.1021/acs.nanolett.1c04315
Publication status	Published - 2022 Mar 23

Bibliographical note

Funding Information:
This work was supported by the Laboratory Directed Research and Development program of Los Alamos National Laboratory under project numbers 20190516ECR, 20210036DR, 20220485MFR, and 20210782ER, and the National Security Education Center under project numbers IMS RR19PETT, IMS RR21PETT, and ISTI IP2104MP. Work at the Molecular Foundry was supported by the Office of Science, Office of Basic Energy Sciences, of the U.S. Department of Energy under Contract no. DE-AC02-05CH11231. C.O. acknowledges additional support from the Department of Energy Early Career Research Award program. C.-H.L. acknowledges support from the National Research Foundation (NRF) of Korea (2020M3D1A1110548) and the KU-KIST School Project. This work was performed in part at the Center for Integrated Nanotechnologies, an Office of Science User Facility operated for the U.S. Department of Energy (DOE) Office of Science. Los Alamos National Laboratory, an affirmative action equal opportunity employer, is managed by Triad National Security, LLC for the U.S. Department of Energy’s NNSA, under contract 89233218CNA000001.

Publisher Copyright:
© 2022 American Chemical Society. All rights reserved.

Keywords

2D materials
4D-STEM
MOCVD
grain boundaries
orientation
strain

ASJC Scopus subject areas

Bioengineering
Chemistry(all)
Materials Science(all)
Condensed Matter Physics
Mechanical Engineering

Access to Document

10.1021/acs.nanolett.1c04315

Cite this

@article{886986f29b41482e996216a2e31ca56e,

title = "Visualizing Grain Statistics in MOCVD WSe2through Four-Dimensional Scanning Transmission Electron Microscopy",

abstract = "Using four-dimensional scanning transmission electron microscopy, we demonstrate a method to visualize grains and grain boundaries in WSe2grown by metal organic chemical vapor deposition (MOCVD) directly onto silicon dioxide. Despite the chemical purity and uniform thickness and texture of the MOCVD-grown WSe2, we observe a high density of small grains that corresponds with the overall selenium deficiency we measure through ion beam analysis. Moreover, reconstruction of grain information permits the creation of orientation maps that demonstrate the nucleation mechanism for new layers-Triangular domains with the same orientation as the layer underneath induces a tensile strain increasing the lattice parameter at these sites.",

keywords = "2D materials, 4D-STEM, MOCVD, grain boundaries, orientation, strain",

author = "Alejandra Londo{\~n}o-Calderon and Rohan Dhall and Colin Ophus and Matthew Schneider and Yongqiang Wang and Enkeleda Dervishi and Kang, {Hee Seong} and Lee, {Chul Ho} and Jinkyoung Yoo and Pettes, {Michael T.}",

note = "Funding Information: This work was supported by the Laboratory Directed Research and Development program of Los Alamos National Laboratory under project numbers 20190516ECR, 20210036DR, 20220485MFR, and 20210782ER, and the National Security Education Center under project numbers IMS RR19PETT, IMS RR21PETT, and ISTI IP2104MP. Work at the Molecular Foundry was supported by the Office of Science, Office of Basic Energy Sciences, of the U.S. Department of Energy under Contract no. DE-AC02-05CH11231. C.O. acknowledges additional support from the Department of Energy Early Career Research Award program. C.-H.L. acknowledges support from the National Research Foundation (NRF) of Korea (2020M3D1A1110548) and the KU-KIST School Project. This work was performed in part at the Center for Integrated Nanotechnologies, an Office of Science User Facility operated for the U.S. Department of Energy (DOE) Office of Science. Los Alamos National Laboratory, an affirmative action equal opportunity employer, is managed by Triad National Security, LLC for the U.S. Department of Energy{\textquoteright}s NNSA, under contract 89233218CNA000001. Publisher Copyright: {\textcopyright} 2022 American Chemical Society. All rights reserved.",

year = "2022",

month = mar,

day = "23",

doi = "10.1021/acs.nanolett.1c04315",

language = "English",

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pages = "2578--2585",

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T1 - Visualizing Grain Statistics in MOCVD WSe2through Four-Dimensional Scanning Transmission Electron Microscopy

AU - Londoño-Calderon, Alejandra

AU - Dhall, Rohan

AU - Ophus, Colin

AU - Schneider, Matthew

AU - Wang, Yongqiang

AU - Dervishi, Enkeleda

AU - Kang, Hee Seong

AU - Lee, Chul Ho

AU - Yoo, Jinkyoung

AU - Pettes, Michael T.

N1 - Funding Information: This work was supported by the Laboratory Directed Research and Development program of Los Alamos National Laboratory under project numbers 20190516ECR, 20210036DR, 20220485MFR, and 20210782ER, and the National Security Education Center under project numbers IMS RR19PETT, IMS RR21PETT, and ISTI IP2104MP. Work at the Molecular Foundry was supported by the Office of Science, Office of Basic Energy Sciences, of the U.S. Department of Energy under Contract no. DE-AC02-05CH11231. C.O. acknowledges additional support from the Department of Energy Early Career Research Award program. C.-H.L. acknowledges support from the National Research Foundation (NRF) of Korea (2020M3D1A1110548) and the KU-KIST School Project. This work was performed in part at the Center for Integrated Nanotechnologies, an Office of Science User Facility operated for the U.S. Department of Energy (DOE) Office of Science. Los Alamos National Laboratory, an affirmative action equal opportunity employer, is managed by Triad National Security, LLC for the U.S. Department of Energy’s NNSA, under contract 89233218CNA000001. Publisher Copyright: © 2022 American Chemical Society. All rights reserved.

PY - 2022/3/23

Y1 - 2022/3/23

N2 - Using four-dimensional scanning transmission electron microscopy, we demonstrate a method to visualize grains and grain boundaries in WSe2grown by metal organic chemical vapor deposition (MOCVD) directly onto silicon dioxide. Despite the chemical purity and uniform thickness and texture of the MOCVD-grown WSe2, we observe a high density of small grains that corresponds with the overall selenium deficiency we measure through ion beam analysis. Moreover, reconstruction of grain information permits the creation of orientation maps that demonstrate the nucleation mechanism for new layers-Triangular domains with the same orientation as the layer underneath induces a tensile strain increasing the lattice parameter at these sites.

AB - Using four-dimensional scanning transmission electron microscopy, we demonstrate a method to visualize grains and grain boundaries in WSe2grown by metal organic chemical vapor deposition (MOCVD) directly onto silicon dioxide. Despite the chemical purity and uniform thickness and texture of the MOCVD-grown WSe2, we observe a high density of small grains that corresponds with the overall selenium deficiency we measure through ion beam analysis. Moreover, reconstruction of grain information permits the creation of orientation maps that demonstrate the nucleation mechanism for new layers-Triangular domains with the same orientation as the layer underneath induces a tensile strain increasing the lattice parameter at these sites.

KW - 2D materials

KW - 4D-STEM

KW - MOCVD

KW - grain boundaries

KW - orientation

KW - strain

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JF - Nano Letters

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