Chalcogenide perovskite materials have received extensive attention in the field of thermoelectrics (TEs) due to their inherent large Seebeck coefficient and ultra-low thermal conductivity. Herein, we demonstrate that the orthorhombic CaZrS3 perovskite is a promising TE material by using first-principles calculations combined with the semiclassical Boltzmann transport theory. The anisotropic property has been observed clearly on the electronic properties and TE performances of CaZrS3 along a, b, and c directions. The orthorhombic CaZrS3 shows excellent thermal stability, which leads to superior performance of electric and thermal conductivities simultaneously; thus it possesses outstanding power factor and ultra-low thermal conductivity and yields impressive ZT values of n-4.06 and p-2.62. This study provides a guideline for chemical doping and provides inspiration for the promotion of related experimental investigations.

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Thermoelectric (TE) technology, which can convert scrap heat into electricity, has attracted considerable attention. However, broader applications of TE are hindered by lacking high-performance thermoelectric materials, which can be effectively progressed by regulating the carrier concentration. In this work, a series of PbSe(NaCl)x (x = 3, 3.5, 4, 4.5) samples were synthesized through the NaCl salt-assisted approach with Na+ and Cl− doped into their lattice. Both theoretical and experimental results demonstrate that manipulating the carrier concentration by adjusting the content of NaCl is conducive to upgrading the electrical transport properties of the materials. The carrier concentration elevated from 2.71 × 1019 cm−3 to 4.16 × 1019 cm−3, and the materials demonstrated a maximum power factor of 2.9 × 10−3 W m−1 K−2. Combined with an ultralow lattice thermal conductivity of 0.7 W m−1 K−1, a high thermoelectric figure of merit (ZT) with 1.26 at 690 K was attained in PbSe(NaCl)4.5. This study provides a guideline for chemical doping to improve the thermoelectric properties of PbSe further and promote its applications.