# Unveiling Twist Domains in Monolayer MoS<sub>2</sub> through 4D‐STEM and Unsupervised Machine Learning

https://mdr.nims.go.jp/datasets/0a00adee-2414-4314-86ee-f56c7f3a8847

## File

- [Small Methods - 2025 - Kimoto - Unveiling Twist Domains in Monolayer MoS2 through 4D‐STEM and Unsupervised Machine Learning.pdf](https://mdr.nims.go.jp/filesets/55474abe-e117-4e8a-8c92-376f6054181f/download) ([Detail](https://mdr.nims.go.jp/filesets/55474abe-e117-4e8a-8c92-376f6054181f.md))
- [smtd70040-sup-0001-suppmat .docx](https://mdr.nims.go.jp/filesets/4bfeeeee-63ed-439c-a6c0-3393209ed137/download) ([Detail](https://mdr.nims.go.jp/filesets/4bfeeeee-63ed-439c-a6c0-3393209ed137.md))

## Id

0a00adee-2414-4314-86ee-f56c7f3a8847

## Local identifier



## Visibility

open_to_public

## State

published

## Created at

2025-08-26T03:09:44.011690Z

## Updated at

2025-08-27T03:30:17.764112Z

## Published at

2025-08-26T23:19:15.135636Z

## Doi



## First published url

https://doi.org/10.1002/smtd.202501065

## Date published

2025-08-06

## Recorded date published

2025-9

## Resource type

journal_article

## Manuscript type

vor

## Collection



## Title

- title: Unveiling Twist Domains in Monolayer MoS<sub>2</sub> through 4D‐STEM and
    Unsupervised Machine Learning
  title_type: original
  lang: en

## Description

- description: 'Dichalcogenides, such as molybdenum disulfide (MoS₂), are being studied
    extensively due to their two-dimensional feature and various material properties.
    Although crystal structures are critical for applications, conventional atomic
    structure analyses have limited field of view. In this study, the crystal domains
    of monolayer MoS2 synthesized by metal-organic chemical vapor deposition (MOCVD)
    are analyzed using 4D scanning transmission electron microscopy (STEM) and unsupervised
    machine learning. Twist domains (±11°) are identified through the nonnegative
    matrix factorization (NMF) and hierarchical clustering of numerous (>22k) diffraction
    patterns from a wide field of view. Preprocessing for detecting noncentrosymmetry
    effectively visualizes the polarities of distinct MoS2 domains by highlighting
    the violation of Friedel’s law in diffraction physics. Analyses reveal that the
    specimen deposited on Al2O3 (0001) at 850 °C consists of domains measuring approximately
    100 nm in size and featuring many mirror-twin boundaries. The findings provide
    valuable insights into optimizing the MOCVD process and elucidating crystal growth
    mechanisms. '
  description_type: abstract
  lang: und

## Creator

- name: Koji Kimoto
  role: author
  orcid: https://orcid.org/0000-0002-3927-0492
- name: Ovidiu Cretu
  role: author
  orcid: https://orcid.org/0000-0002-1822-8172
- name: Koji Harano
  role: author
  orcid: https://orcid.org/0000-0001-6800-8023
- name: Fumihiko Uesugi
  role: author
  orcid: https://orcid.org/0000-0003-3346-4218
- name: Jun Kikkawa
  role: author
  orcid: https://orcid.org/0000-0003-0659-1844
- name: Kohei Aso
  role: author
  orcid: https://orcid.org/0000-0001-6935-7655
- name: Yoshifumi Oshima
  role: author
  orcid: https://orcid.org/0000-0003-1898-0142
- name: Takashi Matsumoto
  role: author
  orcid: https://orcid.org/0009-0007-7418-6724
- name: Yoshiki Sakuma
  role: author
  orcid: https://orcid.org/0000-0001-6804-7217

## Contact agent



## Publisher

organization: Wiley

## Managing organization



## Keyword

- subject: 4D-STEM
  schema: not_defined
- subject: dichalcogenide
  schema: not_defined
- subject: metal–organic chemical vapor deposition
  schema: not_defined
- subject: MoS2,
  schema: not_defined
- subject: scanning transmission electron microscopy
  schema: not_defined
- subject: unsupervised machine learning
  schema: not_defined

## Rights

- identifier: https://creativecommons.org/licenses/by/4.0/

## Other identifier(s)



## Data origin

- data_origin_type: other

## Embargo



## Journal

- title: Small Methods
  issn: '23669608'
  article_number: e01065

## Conference



## Related item



## Funding

- identifier: JP22H05145
  funder_name: 日本学術振興会
  description: 学術変革領域研究(A)超セラミックスの高度構造解析
- identifier: JP20H02624
  funder_name: 日本学術振興会
  description: ソフトマテリアル解析を可能とする電子計数型透過電子顕微鏡法の要素技術開発
- identifier: JP23H04874
  funder_name: 日本学術振興会
  description: メゾヒエラルキーの映像分子科学
- identifier: JP24K08253
  funder_name: 日本学術振興会
  description: Development of an intelligent dose-reducing imaging method for the
    transmission electron microscope
- identifier: JP17H03241
  funder_name: 日本学術振興会
  description: ＭＯＣＶＤ法による遷移金属ダイカルコゲナイドの成長技術開発とフォトニクス機能探索
- identifier: JPMJCR24A3
  funder_name: JST
  description: ウエハースケールvdWエピタキシーの確立と 2D-CMOS集積化のためのプロセス技術の構築

## Instrument



## Instrument operator



## Instrument managing organization



## Measurement method



## Specimen



## Chemical composition



## Structure for specimen



## Structural feature for specimen



## Specific property for specimen



## Process for specimen treatment



## Computational method



## Energy level/transition state



## Software



## Custom property



## Fileset

- id: 55474abe-e117-4e8a-8c92-376f6054181f
  filename: Small Methods - 2025 - Kimoto - Unveiling Twist Domains in Monolayer MoS2
    through 4D‐STEM and Unsupervised Machine Learning.pdf
  content_type: application/pdf
  size: 1823474
  md5: e00720dc619e02e31c9aaf56072712d9
- id: 4bfeeeee-63ed-439c-a6c0-3393209ed137
  filename: smtd70040-sup-0001-suppmat .docx
  content_type: application/vnd.openxmlformats-officedocument.wordprocessingml.document
  size: 1096895
  md5: c42dd014ad8fd80d1ac9c6e890184560

## Thumbnail

fileset_id: 55474abe-e117-4e8a-8c92-376f6054181f
filename: Small Methods - 2025 - Kimoto - Unveiling Twist Domains in Monolayer MoS2
  through 4D‐STEM and Unsupervised Machine Learning.pdf