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Anisotropy and thermal properties in GeTe semiconductor by Raman analysis
Shuai Yang1, Fengrui Sui1, Yucheng Liu1
1Key Laboratory of Polar Materials and Devices (MOE), Department of Electronics, East China Normal University, Shanghai 200241, China. fyyue@ee.ecnu.edu.cn.
Nanoscale
|August 4, 2023
Summary
This study reveals the in-plane optical anisotropy of Germanium Telluride (GeTe) using Raman spectroscopy. The findings are key for developing advanced optoelectronic and thermoelectric devices.
Area of Science:
- Materials Science
- Condensed Matter Physics
- Solid State Chemistry
Background:
- Low-symmetric Germanium Telluride (GeTe) exhibits promising optical and thermal properties.
- In-plane optical anisotropy is critical for GeTe's use in optoelectronic and thermoelectric applications, yet remains under-explored.
Purpose of the Study:
- To investigate the in-plane optical anisotropic properties of GeTe.
- To establish a method for analyzing light-matter interactions in low-symmetry layered materials.
Main Methods:
- Polarization-resolved Raman spectroscopy was employed to study GeTe.
- First-principles calculations complemented experimental findings.
- Transmission electron microscopy identified armchair and zigzag crystal directions.
Main Results:
- GeTe exhibits strong in-plane anisotropic Raman intensity for two main vibrational modes.
- A mode at ~88.1 cm⁻¹ can determine crystal orientation.
- A mode at ~124.6 cm⁻¹ detects temperature-dependent phase transitions.
Conclusions:
- The study provides a general approach to investigate optical anisotropy in low-symmetry layered materials.
- Findings benefit the design of optoelectronic, anisotropic thermoelectric, and phase-transition memory devices using GeTe.
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