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Observing phase transformation in CVD-grown MoS2via atomic resolution TEM
Kuo-Lun Tai1, Guan-Min Huang1, Chun-Wei Huang1
1Department of Materials Science and Engineering, National Chiao Tung University, Hsinchu 300, Taiwan. wwwu@mail.nctu.edu.tw.
Chemical Communications (Cambridge, England)
|August 18, 2018
Summary
Electron irradiation enabled observation of phase transformation in molybdenum disulfide (MoS2). A novel pathway between 2H and 1T phases via higher energy states was identified.
Area of Science:
- Materials Science
- Nanotechnology
- Solid-State Physics
Background:
- Molybdenum disulfide (MoS2) is a layered material with distinct phases (2H and 1T) exhibiting different electronic properties.
- Understanding phase transformations is crucial for tailoring MoS2 for electronic and catalytic applications.
Purpose of the Study:
- To investigate the phase transformation mechanism in chemical vapor deposition (CVD)-grown MoS2.
- To explore the role of electron irradiation in inducing and observing these transformations.
- To identify new pathways between the 2H and 1T phases.
Main Methods:
- In situ transmission electron microscopy (TEM) was employed to observe dynamic processes.
- Controlled electron irradiation was used to induce and study the phase transformation.
- Analysis focused on electron dose and exposure time parameters.
Main Results:
- Direct observation of phase transformation in CVD-grown MoS2 under electron irradiation.
- Identification of a novel transformation pathway involving higher energy states (TS1/TS2) between the 2H and 1T phases.
- Demonstration of controlled phase switching using electron microscopy.
Conclusions:
- Electron irradiation provides a viable method for studying phase transitions in MoS2.
- The proposed TS1/TS2 pathway offers new insights into the fundamental mechanisms of MoS2 phase transformation.
- This work contributes to the development of strategies for phase engineering in 2D materials.
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