TY - JOUR
T1 - Measurement of Lateral and Interfacial Thermal Conductivity of Single- and Bilayer MoS2 and MoSe2 Using Refined Optothermal Raman Technique
AU - Zhang, Xian
AU - Sun, Dezheng
AU - Li, Yilei
AU - Lee, Gwan Hyoung
AU - Cui, Xu
AU - Chenet, Daniel
AU - You, Yumeng
AU - Heinz, Tony F.
AU - Hone, James C.
N1 - Publisher Copyright:
© 2015 American Chemical Society.
PY - 2015/11/25
Y1 - 2015/11/25
N2 - Atomically thin materials such as graphene and semiconducting transition metal dichalcogenides (TMDCs) have attracted extensive interest in recent years, motivating investigation into multiple properties. In this work, we demonstrate a refined version of the optothermal Raman technique1,2 to measure the thermal transport properties of two TMDC materials, MoS2 and MoSe2, in single-layer (1L) and bilayer (2L) forms. This new version incorporates two crucial improvements over previous implementations. First, we utilize more direct measurements of the optical absorption of the suspended samples under study and find values 40% lower than previously assumed. Second, by comparing the response of fully supported and suspended samples using different laser spot sizes, we are able to independently measure the interfacial thermal conductance to the substrate and the lateral thermal conductivity of the supported and suspended materials. The approach is validated by examining the response of a suspended film illuminated in different radial positions. For 1L MoS2 and MoSe2, the roomerature thermal conductivities are 84 ± 17 and 59 ± 18 W/(m·K), respectively. For 2L MoS2 and MoSe2, we obtain values of 77 ± 25 W and 42 ± 13 W/(m·K). Crucially, the interfacial thermal conductance is found to be of order 0.1-1 MW/m2 K, substantially smaller than previously assumed, a finding that has important implications for design and modeling of electronic devices.
AB - Atomically thin materials such as graphene and semiconducting transition metal dichalcogenides (TMDCs) have attracted extensive interest in recent years, motivating investigation into multiple properties. In this work, we demonstrate a refined version of the optothermal Raman technique1,2 to measure the thermal transport properties of two TMDC materials, MoS2 and MoSe2, in single-layer (1L) and bilayer (2L) forms. This new version incorporates two crucial improvements over previous implementations. First, we utilize more direct measurements of the optical absorption of the suspended samples under study and find values 40% lower than previously assumed. Second, by comparing the response of fully supported and suspended samples using different laser spot sizes, we are able to independently measure the interfacial thermal conductance to the substrate and the lateral thermal conductivity of the supported and suspended materials. The approach is validated by examining the response of a suspended film illuminated in different radial positions. For 1L MoS2 and MoSe2, the roomerature thermal conductivities are 84 ± 17 and 59 ± 18 W/(m·K), respectively. For 2L MoS2 and MoSe2, we obtain values of 77 ± 25 W and 42 ± 13 W/(m·K). Crucially, the interfacial thermal conductance is found to be of order 0.1-1 MW/m2 K, substantially smaller than previously assumed, a finding that has important implications for design and modeling of electronic devices.
KW - Raman
KW - molybdenum diselenide
KW - molybdenum disulfide
KW - thermal conductivity
KW - thermal interface conductance
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U2 - 10.1021/acsami.5b08580
DO - 10.1021/acsami.5b08580
M3 - Article
AN - SCOPUS:84948678550
SN - 1944-8244
VL - 7
SP - 25923
EP - 25929
JO - ACS Applied Materials and Interfaces
JF - ACS Applied Materials and Interfaces
IS - 46
ER -