Anisotropic Optical And Vibrational Properties Of GeS

Abstract

The optical response of bulk germanium sulfide (GeS) is investigated systematically using different polarization-resolved experimental techniques, such as photoluminescence (PL), reflectance contrast (RC), and Raman scattering (RS). It is shown that while the low-temperature ($T$=5 K) optical band-gap absorption is governed by a single resonance related to the neutral exciton, the corresponding emission is dominated by the disorder/impurity- and/or phonon-assisted recombination processes. Both the RC and PL spectra are found to be linearly polarized along the armchair direction. The low and room ($T$=300 K) temperature RS spectra consist of six Raman peaks identified with the help of Density Fuctional Theory (DFT) calculations: A${}_{\text{g}}^1$, A${}_{\text{g}}^2$, A${}_{\text{g}}^3$, A${}_{\text{g}}^4$, B${}_{\text{1g}}^1$, and B${}_{\text{1g}}^2$, which polarization properties are studied under four different excitation energies. We found that the polarization orientations of the A${}_{\text{g}}^2$ and A${}_{\text{g}}^4$ modes under specific excitation energy can be useful tools to determine the GeS crystallographic directions: armchair and zigzag.

7 pages, 7 figures

References in corpus (7)

• High Electron Mobility, Quantum Hall Effect and Anomalous Optical Response in Atomically Thin InSe
• Optical response of monolayer, few-layer and bulk tungsten disulfide
• Excitonic valley effects in monolayer WS${}_2$ under high magnetic fields
• Complete determination of crystallographic orientation of ReX2 (X=S, Se) by polarized Raman spectroscopy
• Optical phonons of SnSe(1-x)Sx layered semiconductor alloys
• The optical signature of few-layer ReSe${}_2$
• Revealing the nature of excitons in liquid exfoliated monolayer WS2

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• Optical properties of orthorhombic germanium sulfide: Unveiling the Anisotropic Nature of Wannier Exciton
• Raman scattering fingerprints of the charge density wave state in one-dimensional NbTe${}_4$