Cost‐Effective Symmetric PbSe‐Based Device for Thermoelectric Cooling

Abstract Thermoelectric cooling technology has broad applications but is limited by the high cost of tellurium (Te) in commercially available Bi 2 Te 3 ‐based thermoelectric materials. Herein, a cost‐effective symmetric PbSe‐based device constructed from 7 pairs of Pb 0.988 Cu 0.002 Se (p‐type) and Pb 1.02 Cu 0.002 Se (n‐type) is presented, which demonstrates impressive cooling temperature difference (Δ T C ) of 32.8 and 41.0 K with the hot side maintained at 303 and 343 K, respectively. This low‐cost symmetric PbSe‐based device exhibits superior cost‐effectiveness (Δ T /cost) for near‐room‐temperature thermoelectric cooling compared to other Bi 2 Te 3 ‐based devices. Its high cooling performance primarily stems from an advanced carrier and phonon transport properties in p‐type Pb 0.988 Cu 0.002 Se. Specifically, Pb vacancy and Cu substitution in Pb 0.988 Cu 0.002 Se act as strong p‐type dopants that effectively optimize carrier density, resulting in a maximum power factor of 28.69 µW cm −1 K −2 at room temperature. Moreover, the mobile Cu atoms within the lattice significantly impede phonon propagation, leading to a low room‐temperature lattice thermal conductivity of 1.10 W m −1 K −1 . Finally, the room‐temperature figure of merit ( ZT ) and average ZT value in p‐type Pb 0.988 Cu 0.002 Se can reach 0.6 and 0.68 at 300–573 K, surpassing previous p‐type PbSe‐based polycrystals. This work emphasizes the significant potential of a cost‐effective PbSe compound for near‐room‐temperature cooling applications.