Measurement of interfacial thermal conductance of few-layer MoS2 supported on different substrates using Raman spectroscopy

Abstract

Atomically thin molybdenum disulfide (MoS2) has attracted significant research interest due to its unique properties, e.g., large on/off ratio, moderate bandgap, and ultralow standby power dissipation, which offer the potential for advanced devices. Interfacial thermal transport significantly affects the heat removal abilities of the devices, thus influencing the thermal stability of the devices. In this work, high thermal conductivity material graphene is used as a supporting substrate for MoS2 to improve heat dissipation in devices based on MoS2. Combining temperature- and laser power-dependent Raman spectroscopy studies, interfacial thermal conductance (g) of five-layer MoS2 supported on SiO2/Si and three-layer graphene substrates are obtained, which are 1.73 ± 0.07 MW m−2 K−1 and 2.56 ± 0.08 MW m−2 K−1, respectively. It is found that a 47.9% increase of g for MoS2 was supported by graphene. Using the high thermal conductivity material graphene as a supporting substrate for MoS2, therefore, opens up another channel for conducting heat, and this dramatically increases the thermal stability of the devices based on MoS2. Our results shed light on experimentally probing interfacial thermal conductance between MoS2 flakes and different supported substrates.

Extremely anisotropic van der Waals thermal conductors

“…To obtain κ TMD from G 1 , we perform TDTR on various N-layer TMD films, then perform a linear fit on the effective thermal resistance (R TDTR , equal to 1/G 1 ) versus N data points; the slope of the linear fit is inversely proportional to the thermal conductivity, whereas the y intercept yields the total interfacial thermal resistances (R 0 ) of the top and bottom interfaces. In Extended Data Table 1, our R 0 values match the values reported in literature 22,27,53 . We note that, although R 0 changes depending on the chemical nature of the metal-TMD interface, the slope of the R TDTR -N plot (which is used to extract κ ⊥ ) remains constant, despite the use of different transducer metals, as illustrated in Extended Data Fig.…”

Significant Reduction of Interfacial Thermal Resistance and Phonon Scattering in Graphene/Polyimide Thermally Conductive Composite Films for Thermal Management

“…This is because as the laser power increases, the temperature at the interfaces of rGO (or NH 2 -rGO) and the PI matrix rises sharply, and the degree of phonon scattering at the interfaces increases sharply, causing the phonon tangential mode vibration to weaken. Next, according to Equation (1) [35], the change trend of Raman peak positions of C-N-C groups in 15 wt% rGO/PI and 15 wt% NH 2 -rGO/PI thermally conductive composite films is linearly fitted with laser power. The fitting results are shown in Figure 3(d).…”

“…It is acknowledged that Raman spectroscopy can reflect the vibration and rotation of molecules and can reflect the phonon vibration mode, which can be used to characterize the thermal conduction and the degree of phonon scattering at the interfaces [33,34]. Yue et al [35] used Raman spectroscopy to study the thermal conduction property of the interfaces between molybdenum disulfide (MoS 2 ) and silica (SiO 2 ) as well as that between MoS 2 and graphene, respectively, finding that the thermal conduction property of the interfaces between MoS 2 and graphene was significantly better than MoS 2 /SiO 2 , because graphene obtains higher λ than SiO 2 , and the heat at the interfaces can be transferred more efficiently. Qiu et al [36] modified gold (Au) nanoparticles on the surfaces of CNTs by chemical vapor deposition (CVD) and used Raman spectroscopy to study the thermal conduction property of the interfaces between CNTs before and after modification.…”

High-performance, self-powered flexible MoS2 photodetectors with asymmetric van der Waals gaps

“…37 The E 1 2g and A 1g peaks originate from the in-plane opposing motions of molybdenum and sulfur atoms and the out-of-plane relative motions of sulfur atoms, respectively. 38 The Raman spectrum indicates that the fabricated MoS 2 flake has a good crystal quality.…”