induced by electron-phonon scattering: A first principles study

Multi-valley structure is known as one of the favorable band structures for enhancing thermoelectric efficiency. N-type TiS₂, also has electronic structure with multi-valley character, and its power factor is relatively high: ~40 μW/cmK² at room temperature. In previous experimental studies, the electrical resistivity of TiS₂ has been found to exhibit strong temperature dependence of ~T². One of the previous studies indicated that inter-valley scattering among conduction band valleys may be related to the peculiar temperature dependence of the electrical resistivity [1].
In the present study, we perform DFT calculations and calculate the electronic transport properties by considering the electron-phonon scattering effect using the EPW code [2]. As a target material in this study, we consider not TiS₂, but instead its analogous compound ZrS₂. One of the results suggests that inter-valley scattering has a larger contribution to electrical resistivity than intra-valley scattering. In this presentation, we will discuss the role of the inter-valley scattering played in the electronic transport properties of ZrS₂.

[1] P. C. Klipstein et al., J. Phys. C: Solid State Phys. 14, 4067 (1981).
[2] S. Ponce, E. R. Margine and F. Giustino, Phys. Rev. B 97, 121201 (2018).