The rising demand for cooling, including refrigeration and air conditioning, poses environmental and economic challenges. Conventional cooling systems used in homes, vehicles, industries, and data centers are based on vapor-compression cycles utilizing coolants that are a major source of greenhouse gas emissions. The International Energy Agency reported that air conditioning was responsible for almost 20% of the electricity use in buildings globally, with some studies estimating up to 30%-40% usage. Distributed thermoelectric (TE) cooling o↵ers a viable solution, but it requires discovery and development of low-temperature TE materials. In addition to cooling, lowtemperature TE materials have applications in powering Internet of Things devices , including low-power Arctic data sensors. Historically, narrow-gap semiconductors and semimetals have been found to exhibit good low-temperature TE performance. Bi 2 Te 3 (band gap: 0.14 eV) is the state-ofthe-art TE material in the near-room temperature range (300-350 K). The recent demonstration of semi-metallic Mg 3 Bi 2 -based materials with a peak zT of 0.9 at 350 K has renewed interest in low-temperature TE materials discovery. Other narrow-gap semiconductors and semimetals such as CsBi 4 Te 6 , 15 Bi 1 x Sb x , Cd 3 As 2 , and ZrTe 5 18 have also been studied for TE applications at or below room temperature. However, the coe cient of performance of current TE cooling devices (10% 20% of the Carnot limit) is poor compared to vapor compression technology (50% of the Carnot limit under ideal conditions). Since the coe cient of performance increases with the TE figure of merit zT , it is important to search for new TE materials with high zT .