Helicity-resolved Raman scattering of MoS₂ bulk crystal

Area of Science:

• Condensed Matter Physics
• Materials Science
• Spectroscopy

Background:

• Helicity-resolved Raman spectroscopy (HRRS) is crucial for differentiating Raman modes in 2D layered materials based on phonon symmetry.
• Understanding phonon behavior is key to characterizing material properties.

Purpose of the Study:

• To systematically investigate the phonon helicity selection of basal and edge planes in bulk molybdenum disulfide (MoS2) using HRRS.
• To elucidate the influence of crystal structure symmetry on phonon helicity in MoS2.

Main Methods:

• Systematic investigation using Helicity-resolved Raman spectroscopy (HRRS).
• Theoretical calculations to confirm experimental findings on phonon helicity selection.

Main Results:

• Crystal structure symmetry alters the helicity selection of E1g, E¹_2g, and A1g modes in the edge plane of MoS2.
• Basal plane E¹_2g and A1g modes show perfect helicity exchange.
• Helicity selection for E¹_2g and A1g modes in the edge plane is weakened or eliminated.

Conclusions:

• The study provides a detailed understanding of phonon helicity selection in MoS2.
• Findings offer valuable references for analyzing 2D layered materials using HRRS.