Measurement of Lateral and Interfacial Thermal Conductivity of Single- and Bilayer MoS2 and MoSe2 Using Refined Optothermal Raman Technique

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• 作者：Xian Zhang ; Dezheng Sun ; Yilei Li ; Gwan-Hyoung Lee ; Xu Cui ; Daniel Chenet ; Yumeng You ; Tony F. Heinz ; James C. Hone
• 刊名：ACS Applied Materials & Interfaces
• 出版年：2015
• 出版时间：November 25, 2015
• 年：2015
• 卷：7
• 期：46
• 页码：25923-25929
• 全文大小：422K
• ISSN：1944-8252

文摘

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 鈭?0% 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 room-temperature thermal conductivities are 84 卤 17 and 59 卤 18 W/(m路K), respectively. For 2L MoS₂ and MoSe₂, we obtain values of 77 卤 25 W and 42 卤 13 W/(m路K). Crucially, the interfacial thermal conductance is found to be of order 0.1鈥? MW/m² K, substantially smaller than previously assumed, a finding that has important implications for design and modeling of electronic devices.