Abstract
Combining the effect of layer mixing, mass mismatch, and intrinsic defects, we have investigated the origin of very low phonon conductivity in thermoelectric (TE) : S, Se, Te) compounds. Based on the first-principles anharmonic, lattice dynamics calculations, we use the single-mode relaxation time approximation of the linearized phonon Boltzmann equation, which shows good agreement with experiments. Here, we found that the most important parameter for low is the interlayer interaction between the BiO and layers. By analyzing the phonon linewidth distribution, which indicates the phonon scattering rate, we propose that the interlayer interactions play a critical role on suppressing , i.e., the heterolayered crystal controls these interlayer interactions, achieving low and optimal TE properties.
- Received 29 April 2016
- Revised 10 August 2016
DOI:https://doi.org/10.1103/PhysRevB.94.115203
©2016 American Physical Society