Synergistically optimizing interdependent thermoelectric parameters of n-type PbSe through introducing a small amount of Zn

In this work, we found that the interdependent thermoelectric parameters of n-type PbSe can be synergistically optimized through introducing a small amount of Zn. A record high power factor of 26.2 μW cm−1K−2 was achieved in PbZn0.01Se at 523 K, which is ascribed to the outstanding roles of Zn. We found that small Zn atoms first occupy Pb vacancies, which not only increases the carrier concentration but also improves the carrier mobility. When the content of Zn exceeds a certain level, the small Zn atoms will form interstitials and nanoprecipitates, which can enormously decrease the lattice thermal conductivity but slightly scatter carriers, thus maintaining a high carrier mobility. Combination of significantly enhanced power factor and remarkedly reduced lattice thermal conductivity contributes to a high thermoelectric performance. A maximum ZT ∼1.5 at 873 K and a high average ZT ∼0.84 are achieved in PbZn0.01Se, which are superior to those of the most reported n-type PbSe systems. This work provides a strategy to synergistically optimize interdependent thermoelectric parameters through introducing small metallic atoms. A maximum ZT ∼ 1.5 at 873 K and a high average ZT ∼ 0.84 are achieved in n-type PbSe by synergistically optimizing interdependent thermoelectric parameters. The carrier concentration and mobility can be improved and the lattice thermal conductivity can be decreased through introducing a small amount of Zn. Our results indicate that the thermoelectric performance of lead chalcogenides can be enhanced through introducing small amount of metallic atoms. [Display omitted] •Because the radius between Cu (1.28 Å) and Zn (1.37 Å) atoms is very similar, it is worthy of investigating whether Zn can produce the similar work as Cu.•Different from the dynamic doping behavior of Cu, Zn atoms first occupy Pb vacancies, which not only increases the carrier concentration but also improves the hall carrier mobility.•When the content of Zn exceeds a certain level, the small Zn atoms will form interstitials and nanoprecipitates, which can enormously decrease the lattice thermal conductivity.•A maximum ZT ∼1.5 at 873 K and a high average ZT ∼0.84 are achieved in PbZn0.01Se, which are superior to those of most reported n-type PbSe systems.