Use este identificador para citar o ir al link de este elemento: http://hdl.handle.net/1843/55452
Tipo: Artigo de Periódico
Título: Multiple excitations and temperature study of the disorder-induced Raman bands in MoS2
Autor(es): Rafael Nunes Gontijo
Tianyi Zhang
Kazunori Fujisawa
Ana Laura Elias
Marcos Assunção Pimenta
Ariete Righi
Mauricio Terrones
Cristiano Fantini Leite
Resumen: Raman spectroscopy has been extensively used to probe disorder in graphene and other carbon-related materials, and disorder-induced (DI) Raman bands are prominent even for low defect densities. The DI bands in MoS2 have been studied in the last years, but a multiple excitation study using laser excitation energies near the excitonic energies was still lacking. In this work, we investigate the low-frequency defect-induced Raman bands in MoS2 coming from the acoustic phonon branches near the Brillouin zone edge using samples produced by mechanical exfoliation and chemical vapor deposition, recorded with different laser excitation energies close to the resonance with the excitonic transitions, and measured at different temperatures, from 100 K to 400 K. Our results show that the defect-induced Raman processes are affected by both excitation energy and temperature. We find that the temperature of measurement affects the linear dependence between the intensities of the DI peaks and the defect concentration. In particular, we observed that the ratio of intensities of the DI longitudinal acoustic (LA) and transversal acoustic (TA) modes with respect to the first-order E′ mode is about the same for the two different samples when results are corrected by the defect density. We show in this work that the largest intensity of the DI peaks occurs for laser energies in the resonance with the excitonic transitions. Finally, we introduce a general expression that provides the parameters for the quantification of defects in MoS2 samples based on the intensity of the DI Raman bands, measured at different laser energies across the excitonic transitions.
Asunto: Metais de transição
Análise espectral
Fonons
Teoria dos excitons
Idioma: eng
País: Brasil
Editor: Universidade Federal de Minas Gerais
Sigla da Institución: UFMG
Departamento: ICX - DEPARTAMENTO DE FÍSICA
Tipo de acceso: Acesso Restrito
Identificador DOI: https://doi.org/10.1088/2053-1583/ac0170
URI: http://hdl.handle.net/1843/55452
Fecha del documento: 2021
metadata.dc.url.externa: https://iopscience.iop.org/article/10.1088/2053-1583/ac0170
metadata.dc.relation.ispartof: 2D Materials
Aparece en las colecciones:Artigo de Periódico

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