Use este identificador para citar o ir al link de este elemento: http://hdl.handle.net/1843/44980
Tipo: Artigo de Periódico
Título: Temperature-dependent phonon dynamics and anharmonicity of suspended and supported few-layer gallium sulfide
Autor(es): Francisco Diasis Vieira de Araújo
Antonio Gomes de Souza Filho
Rafael Silva Alencar
Bartolomeu Cruz Viana Neto
Victor Viana Oliveira
Andreij de Carvalho Gadelha
Thais C. V. Carvalho
Thales Fernando Damasceno Fernandes
Francisco Wellery Nunes Silva
Raphael Longuinhos Monteiro Lobato
Jenaina Ribeiro Soares
Ado Jorio de Vasconcelos
Resumen: Phonons play a fundamental role in the electronic and thermal transport of 2D materials which is crucial for device applications. In this work, we investigate the temperature-dependence of A11g and A2 1g Raman modes of suspended and supported mechanically exfoliated few-layer gallium sulfide (GaS), accessing their relevant thermodynamic Grüneisen parameters and anharmonicity. The Raman frequencies of these two phonons soften with increasing temperature with different θ = ∂ω/∂T temperature coefficients. The first-order temperature coefficients θ of A21g mode is ∼ -0.016 cm-1/K, independent of the number of layers and the support. In contrast, the θ of A1 1g mode is smaller for two-layer GaS and constant for thicker samples (∼ -0.006 2 cm-1 K-1). Furthermore, for two-layer GaS, the θ value is ∼ -0.004 4 cm-1 K-1 for the supported sample, while it is even smaller for the suspended one (∼ -0.002 9 cm-1K-1). The higher θ value for supported and thicker samples was attributed to the increase in phonon anharmonicity induced by the substrate surface roughness and Umklapp phonon scattering. Our results shed new light on the influence of the substrate and number of layers on the thermal properties of few-layer GaS, which are fundamental for developing atomically-thin GaS electronic devices.
Asunto: Sulfetos
Gálio
Espectroscopia de Raman
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/10.1088/1361-6528/abb107
URI: http://hdl.handle.net/1843/44980
Fecha del documento: 21-sep-2020
metadata.dc.url.externa: https://iopscience.iop.org/article/10.1088/1361-6528/abb107
metadata.dc.relation.ispartof: Nanotechnology
Aparece en las colecciones:Artigo de Periódico

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