No abstract

Thermal properties can substantially affect the operation of various electronics and optoelectronics devices based on two-dimensional materials. In this work, we describe our investigation of temperature-dependent thermal conductivity and interfacial thermal conductance of molybdenum disulfide monolayers supported on SiO2/Si substrates, using Raman spectroscopy. We observed that the calculated thermal conductivity (κ) and interfacial thermal conductance (g) decreased with increasing temperature from 62.2 W m(-1) K(-1) and 1.94 MW m(-2) K(-1) at 300 K to 7.45 W m(-1) K(-1) and 1.25 MW m(-2) K(-1) at 450 K, respectively.

Transition metal dichalcogenides (TMDCs) are attractive for variety of nanoscale electronics and optoelectronics devices due to their unique properties. Despite growing progress in the research field of TMDCs, many of their properties are still unknown. In this letter, we report measurements of Raman spectra of rhenium diselenide (ReSe2) and tin diselenide (SnSe2) layered semiconductor nanosheets as a function of temperature (70–400 K). We analyze the temperature dependence of the positions of eight ReSe2 modes and SnSe2 A1g mode. All observed Raman mode shifts exhibit nonlinear temperature dependence at low temperatures which is explained by optical phonon decay process into two or three acoustics phonons. The first order temperature coefficients (χ), determined for high temperatures, of rhenium diselenide Raman modes are in the range between −0.0033 and −0.0118 cm−1/K, whereas χ of tin diselenide A1g mode was −0.0129 cm−1/K. Our findings are useful for further analysis of phonon and thermal properties of these dichalcogenide layered semiconductors.

We report Raman spectra measurements on a MoS2 monolayer supported on SiO2 as a function of temperature. Unlike in previous studies, the positions of the two main Raman modes, 2 1 and 1 exhibited nonlinear temperature dependence. Temperature dependence of phonon shifts and widths is explained by optical phonon decay process into two acoustic phonons. Based on Raman measurements local temperature change under laser heating power at different global temperatures is derived. Obtained results contribute to our understanding of the thermal properties of twodimensional atomic crystals and can help to solve the problem of heat dissipation, which is crucial for use in the next generation of nanoelectronic devices.

We present the results of Raman measurements of few-layer black phosphorus in a temperature range between 4 and 400 K. The BP Raman mode positions, widths, and intensity ratios exhibit apparent nonlinear temperature dependences, which we attributed to the phenomenon of optical phonon decay into two or three acoustic phonons. These results pave the way for a deeper understanding of the phonon and thermal properties of black phosphorus.