Abstract
Lattice thermal conductivity (κ) is one of the most important thermoelectric parameters in determining the energy conversion efficiency of thermoelectric materials. However, thermal conductivity calculations are time-consuming in solving the Boltzmann transport equation or performing the molecular dynamic simulations. This paper reviews the first-principles Debye–Callaway approach, in which the Debye–Callaway model input parameters (i.e., the Debye temperature Θ, the phonon velocity v and the Grüneisen parameter γ) can be directly determined from the first-principles calculations of the vibrational properties of compounds within the quasiharmonic approximation. The first-principles Debye–Callaway approach for three experimentally well studied compounds (i.e., Cu3SbSe4, Cu3SbSe3 and SnSe) was proposed. The theoretically calculated κ using the approach is in agreement with the experimental value. Soft acoustic modes with low Θ and v but large γ have an effect on the determination of low lattice thermal conductivity thermoelectric materials. The first-principles Debye–Callaway approach has been proved as an effective tool to calculate κ without the experimental inputs. The results calculated by this approach can be used to predict the performance of low lattice thermal conductivity compounds.
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