Electronic Properties of Thermoelectric PbSe2 Compound by Density Functional Theory Method

Based on the first-principles calculation and the quasi-harmonic Debye model, the electronic and thermodynamic properties of CuCl2-type PbSe2 compound of a promising thermoelectric (TE) material are studied. According to the analysis of the density of states (DOS) and the Mulliken electron population, it is found that the PbSe2 compound possesses weak metallic characterization, where the covalent bonding exists in PbSe2 compound and the ionic bonding exists between Pb and Se atoms. Besides, the Debye temperature decreases with increasing temperature at certain pressures, and it shows the increasing tendency under the elevated pressure at certain temperatures. The Grüneisen parameter increases with increasing temperature at the given pressures, and it also decreases with increasing pressure at the given temperatures. The density functional theory (DFT) is used to obtain the parameters of the Debye temperature, the Grüneisen constant and thermal expansion coefficient, which are about 319.76 K, 2.42, and 8.41×10-5K-1 at 0 GPa, which provides useful parameters and contributes to explore new potential TE materials in future.