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(Reference retrieved automatically from Web of Science through information on FAPESP grant and its corresponding number as mentioned in the publication by the authors.)

Edge phonons in layered orthorhombic GeS and GeSe monochalcogenides

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Author(s):
Ribeiro, H. B. [1] ; Ramos, S. L. L. M. [2] ; Seixas, L. [1] ; de Matos, C. J. S. [1] ; Pimenta, M. A. [3]
Total Authors: 5
Affiliation:
[1] Univ Prebiteriana Mackenzie, MackGraphe Graphene & Nanomat Res Ctr, BR-01302907 Sao Paulo - Brazil
[2] Univ Fed Minas Gerais, Ctr Tecnol Nanomat & Grafeno CTNano, BR-30161970 Belo Horizonte, MG - Brazil
[3] Univ Fed Minas Gerais, Dept Fis, BR-30123970 Belo Horizonte, MG - Brazil
Total Affiliations: 3
Document type: Journal article
Source: Physical Review B; v. 100, n. 9 SEP 3 2019.
Web of Science Citations: 0
Abstract

Germanium sulfide (GeS) and germanium selenide (GeSe) are layered orthorhombic crystals whose structure bears a strong resemblance with that of black phosphorus and, additionally, are expected to exhibit high piezoelectricity in the few layer domain. In this work, we investigate the Raman properties of exfoliated GeS and GeSe and show that their edges exhibit unusual polarized Raman features that were first observed in black phosphorus. The results include the activation in the spectra of otherwise not allowed modes at the edges of the sample, depending on the crystallographic direction of the edge and the polarization configuration used in the measurements. These features are attributed to atomic rearrangements at the crystal terminations, as well as their impact on phonon symmetries, similar to the case of black phosphorus. Our conclusions are further corroborated by using density functional theory and suggest that edge rearrangements, which will have an impact on the mechanical, electronic, and chemical properties of devices, is a general phenomenon of orthorhombic layered structures. (AU)

FAPESP's process: 15/11779-4 - Plasmonic and nonlinear effects in graphene coupled to optical waveguides
Grantee:Christiano José Santiago de Matos
Support type: Research Projects - Thematic Grants
FAPESP's process: 12/50259-8 - Graphene: photonics and opto-electronics: UPM-NUS collaboration
Grantee:Antonio Helio de Castro Neto
Support type: Research Projects - SPEC Program
FAPESP's process: 17/20100-0 - Spectroscopy of excitonic and many body effects in two-dimensional materials
Grantee:Henrique Bücker Ribeiro
Support type: Scholarships in Brazil - Post-Doctorate
FAPESP's process: 18/04926-9 - Spectroscopy of excitonic and many-body effects in two-dimensional materials
Grantee:Henrique Bücker Ribeiro
Support type: Scholarships abroad - Research Internship - Post-doctor