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Synthesis and Performance Characterizations of Transition Metal Single Atom Catalyst for Electrochemical CO2 Reduction
Published on: April 10, 2018
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Orientation-dependent optical characterization of atomically thin transition metal ditellurides.
Anh Tuan Hoang1, Sachin M Shinde, Ajit K Katiyar
1School of Electrical and Electronic Engineering, Yonsei University, 50 Yonsei-ro, Seodaemun-gu, Seoul 03722, Republic of Korea. ahnj@yonsei.ac.kr.
Nanoscale
|November 20, 2018
Summary
Researchers developed a method to distinguish between metallic 1T' and semiconducting 2H molybdenum ditelluride (MoTe2) phases. This technique uses polarized light microscopy and Raman spectroscopy for reliable identification in manufacturing.
Area of Science:
- Materials Science
- Condensed Matter Physics
- Nanotechnology
Background:
- Molybdenum ditelluride (MoTe2) exhibits tunable properties between metallic 1T' and semiconducting 2H phases.
- Controllable synthesis and phase identification of MoTe2 are crucial for its applications.
Purpose of the Study:
- To semi-controllably synthesize 1T' and 2H MoTe2 crystals.
- To investigate the grain-orientation dependency of these phases.
- To establish a reliable method for MoTe2 phase identification.
Main Methods:
- Atmospheric pressure chemical vapor deposition (APCVD) for crystal synthesis.
- Polarization-sensitive optical microscopy.
- Raman scattering spectroscopy.
- Second-harmonic generation (SHG) microspectroscopy.
Main Results:
- 1T'-MoTe2 showed anisotropic optical absorption due to its quasi-1D zigzag chains, enabling clear visualization of lattice domains.
- 2H-MoTe2 grains did not show discernible differences under polarized light.
- The combined techniques effectively visualized and identified lattice orientations.
Conclusions:
- The developed microscopy techniques offer a non-destructive and accessible method for identifying MoTe2 lattice orientation.
- This approach is suitable for quality control in industrial-scale MoTe2 manufacturing.
- The findings facilitate the controlled production of MoTe2 for diverse applications.
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