Local phase transition at crack edges of Mo1−xWxTe2 polymorphs

Ha Heun Lee, Eunji Lim, Seohui Kang, Yonas Assefa Eshete, Dongyeun Won, Yongjoon Lee, Ju yeong Jeong, Heejun Yang, Ching Yu Chiang, Suyeon Cho

Research output: Contribution to journalArticlepeer-review

3 Scopus citations

Abstract

The phase engineering of two-dimensional (2D) materials has attracted considerable attention in recent years, but nanometer-scale samples and experimental techniques have limited the rigorous study of the local phase engineering of 2D atomic crystals. Here, we report on a nanometer-scale probe of phase evolution in the Mo1−xWxTe2 alloys, which exhibit a structural transition between the semiconducting 2H phase and the metallic 1T′ phase. We found that many crack edges are created by the accumulated tungsten atoms, resulting in poor crystallinity in the 2H-Mo1−xWxTe2 flakes at the vicinity of phase transition with a tungsten content, x = 0.08. With mild laser irradiation of the 2H-Mo1−xWxTe2 flakes, the 2H phase region near a crack edge was easily converted to the 1T′ phase, while other areas apart from the crack edge region retained their 2H phase under the same laser treatment. Our study clarifies the role of locally accumulated atoms and crystallinity for the phase engineering of 2D materials, which opens the way to various applications based on heterophase structures, ranging from energy conversion and storage to optoelectronic devices.

Original languageEnglish
Article number153503
JournalApplied Surface Science
Volume596
DOIs
StatePublished - 15 Sep 2022

Bibliographical note

Funding Information:
This work was support by Basic Science Research Program through the National Research Foundation of Korea (NRF) funded by the Ministry of Science, ICT and Future Planning under Grant No. NRF-2020R1A2C2003377, NRF-2020K1A3A7A09080370, NRF-2021M3H4A1A03054856 and NRF-2018M3D1A1058793.

Publisher Copyright:
© 2022 Elsevier B.V.

Keywords

  • Kelvin probe force microscopy (KPFM)
  • Nano X-ray fluorescence
  • Phase transition
  • Transition-metal dichalcogenide alloy
  • X-ray nanodiffraction

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