Measuring the Thermal Conductivity of Semiconductors and Semimetals Using Raman Spectroscopy*

We present a measurement of the thermal conductivity for Bi₂Se₃ and Te and semimetals at room temperature by using Raman scattering spectroscopy on a clean prepared sample on a SiO₂ substrate. Aluminum is deposited on either side of the flake and is used as a heat sink at room temperature. Using a He/Ne laser (633 nm), we measure the Raman shift of the sample as a function of laser power between 0.1mW and 1mW. The linear red shift of Raman modes due to heating of the sample provides a measure of the temperature of the sample around the incident laser area. We calculate the thermal conductivity of the sample by solving a simplified one dimensional heat diffusion equation, ignoring the heat conduction to the ambient air and substrate. Our results for Bi₂Se₃ suggest a value of 4 W/mK for the thermal conductivity, comparable to the measurements of others; using the same technique we plan make measurements of several Weyl semimetals (eg/ WTe₂ and NbIrTe₄).