Grid-plainification enables medium-temperature PbSe thermoelectrics to cool better than Bi<sub>2</sub>Te<sub>3</sub>.

Qin, Yongxin; Qin, Bingchao; Hong, Tao; Zhang, Xiao; Wang, Dongyang; Liu, Dongrui; Wang, Zi-Yuan; Su, Lizhong et al. · Science · 2024

basic_science · Level V

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Abstract

Thermoelectric cooling technology has important applications for processes such as precise temperature control in intelligent electronics. The bismuth telluride (Bi<sub>2</sub>Te<sub>3</sub>)-based coolers currently in use are limited by the scarcity of Te and less-than-ideal cooling capability. We demonstrate how removing lattice vacancies through a grid-design strategy switched PbSe from being useful as a medium-temperature power generator to a thermoelectric cooler. At room temperature, the seven-pair device based on n-type PbSe and p-type SnSe produced a maximum cooling temperature difference of ~73 kelvin, with a single-leg power generation efficiency approaching 11.2%. We attribute our results to a power factor of >52 microwatts per centimeter per square kelvin, which was achieved by boosting carrier mobility. Our demonstration suggests a path for commercial applications of thermoelectric cooling based on Earth-abundant Te-free selenide-based compounds.