Advancing N‐Type PbSe as Promising Candidates for Thermoelectric Cooling and Power Generation

ABSTRACT PbSe crystals exhibit significant potential for development in thermoelectric cooling and power generation applications due to their high‐ranged thermoelectric performance. Herein, we achieve lattice plainification in n‐type PbSe crystals through Ge doping and additional Ge incorporation, leading to a ZT value of 0.7 at room temperature in n‐type Pb 0.993 Ge 0.007 Se+0.0015Ge crystals. The 7‐pair thermoelectric cooling device constructed by n‐type Pb 0.993 Ge 0.007 Se+0.0015Ge crystals and p‐type Bi 2 Te 3 alloys attains a peak temperature difference of 66.3 K with the hot‐side temperature of 343 K. Furthermore, the introduction of interstitial Cu enables a broad‐temperature‐range enhancement of thermoelectric performance. A high average ZT value of 1.07 can be obtained in Pb 0.993 Ge 0.007 Se+0.0015Ge+0.0012Cu crystal across the 303–673 K, as well as a single‐leg device exhibits a peak power generation efficiency of 8.7% under the temperature gradient of 423 K. This study elucidates the great potential of n‐type PbSe crystals in both thermoelectric cooling and power generation, thereby significantly advancing the practical implementation of this cost‐effective thermoelectric material.