Anisotropic thermal conductivity of crystalline layered SnSe2

The degree of thermal anisotropy affects critically key device-relevant properties of layered two-dimensional materials. Here, we systematically study the in-plane and cross-plane thermal conductivity of crystalline SnSe2 films of varying thickness (16-190 nm) and uncover a thickness-independent the...

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Detalhes bibliográficos
Autores: Xiao, Peng|||0000-0002-4711-2566, Chávez Ángel, Emigdio|||0000-0002-9783-0806, Chaitoglou, Stefanos, Sledzinska, Marianna|||0000-0001-8592-1121, Dimoulas, Athanasios|||0000-0003-3199-1356, Sotomayor Torres, Clivia M.|||0000-0001-9986-2716, Sachat, Alexandros el|||0000-0003-3798-9724
Formato: artículo
Fecha de publicación:2021
País:España
Recursos:Universitat Autònoma de Barcelona
Repositorio:Dipòsit Digital de Documents de la UAB
Idioma:inglés
OAI Identifier:oai:ddd.uab.cat:268431
Acesso em linha:https://ddd.uab.cat/record/268431
https://dx.doi.org/urn:doi:10.1021/acs.nanolett.1c03018
Access Level:acceso abierto
Palavra-chave:Phonon transport
Mean free path
SnSe2
Thermal conductivity anisotropy
Frequency-domain thermoreflectance
Raman thermometry
Descrição
Resumo:The degree of thermal anisotropy affects critically key device-relevant properties of layered two-dimensional materials. Here, we systematically study the in-plane and cross-plane thermal conductivity of crystalline SnSe2 films of varying thickness (16-190 nm) and uncover a thickness-independent thermal conductivity anisotropy ratio of about ∼8.4. Experimental data obtained using Raman thermometry and frequency domain thermoreflectance showed that the in-plane and cross-plane thermal conductivities monotonically decrease by a factor of 2.5 with decreasing film thickness compared to the bulk values. Moreover, we find that the temperature-dependence of the in-plane component gradually decreases as the film becomes thinner, and in the range from 300 to 473 K it drops by more than a factor of 2. Using the mean free path reconstruction method, we found that phonons with MFP ranging from ∼1 to 53 and from 1 to 30 nm contribute to 50% of the total in-plane and cross-plane thermal conductivity, respectively.