Ultralow chromium doping enables all-PbSe thermoelectric cooling

Thermoelectric cooling is pivotal for solid-state thermal management, yet large-scale deployment is hindered by the scarcity and cost of tellurium in commercial bismuth telluride devices. We developed a tellurium-free thermoelectric cooler based on all lead selenide (PbSe), in which an ultralow-dopant chromium (Cr) grid allows the engineering of defects and donors to optimize carrier transport to match the performance of the n-type and p-type legs. We fabricated high-performance n-type (PbSe + 0.005Cr) and p-type (PbSe + 0.001Cr) crystals with synergistically matched properties. The device exhibits exceptional performance with lower power consumption and higher cooling capacity, achieving a cooling density of approximately 6 watts per square centimeter, a peak coefficient of performance of approximately 21, and a maximum temperature difference of approximately 53 kelvin at a 363-kelvin hot-side temperature. These findings establish PbSe as a highly effective, sustainable alternative for large-scale cooling applications.