Separating Lattice and Electronic Thermal Conductivity Contributions in Bi$_{2}$Se$_{3}$ and Bi$_{2}$Te$_{3}$ Single Crystals

Nanostructured materials are an effective approach in reducing lattice thermal conductivity and improving overall thermoelectric efficiency. A challenge for experimental measurements of thermal conductivity is separating the contributions from both carriers and phonons. Building on the work of K. Lukas et al., Phys. Rev. B 85, 205410 (2012),$^{\, }$we report measurements of thermal and electrical conductivity of single crystal thermoelectrics: Bi$_{2}$Se$_{3}$ and Bi$_{2}$Te$_{3}$ in a transverse magnetic field up to 9 Tesla. Our experiments provide a separation of the lattice/electronic components and make possible a better theoretical model of the lattice portion of the thermal conductivity in materials.