Grid-plainification enables medium-temperature PbSe thermoelectrics to cool better than Bi ₂ Te ₃

Abstract

Thermoelectric cooling technology has important applications for processes such as precise temperature control in intelligent electronics. The bismuth telluride (Bi 2 Te 3 )–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.

Mg-Defect Compensation to Realize High Performance at Room Temperature in Mg3Bi2-Based Thermoelectric Single Crystals

“…(a) Temperature dependence of zT of Mg 3.1 Li y Bi 1.49 Sb 0.5 Te 0.01 ( y = 0, 0.001, 0.002, 0.003, 0.004) single crystals throughout the temperature range of 300–573 K. (b) zT values compared with other reported advanced thermoelectric materials at 300 K. ,− …”

“…For an optimized composition of Mg 3.1 Li 0.003 Bi 1.49 Sb 0.5 Te 0.01 at 300 K, the carrier concentration increased from 1.45 × 10 19 to 3.18 × 10 19 cm –3 compared to the Li-free one, whereas the thermal conductivity was reduced from 1.644 to 1.141 W m –1 K –1 . As a result, a record-high zT value of 1.05 was achieved at room temperature, suggesting competitive cooling applications compared to other state-of-art thermoelectric materials. ,− …”

Atomic-Resolution Interfacial Reaction Mechanism between Bi2Te3-Based Alloys and Ni Electrodes

“…Thermoelectric (TE) materials are important energy materials that can realize direct conversion between thermal energy and electrical energy. − Practically, p-type TE materials and n-type TE materials are assembled to build TE devices that generate electricity under a thermal gradient and provide heating or cooling under an electrical field. − For TE devices, it is important to find compatible electrode materials with low electrical resistivity, high thermal stability, and excellent connectivity with TE materials. − As TE devices are constantly under thermal gradient and electrical field, the microstructural evolution at the electrode/TE interface plays an important role in the TE device service performance. − Interdiffusion between the electrode and the TE material can degrade the TEM performance by forming new interfacial phases, breaking TE structural integrity, reducing interfacial electrical conductivity, causing mechanical failure, and so on. Therefore, it is critical to understand the interface structure evolution at atomic resolution under prolonged thermal annealing or electrical field, to design better TE/electrode interface …”

Valence Bands Convergence in p-Type CoSb3 through Electronegative Fluorine Filling

“…For example, Xie et al [8] developed a screening strategy for thermoelectric interface materials based on phase diagram prediction calculated by density functional theory, which combines room-temperature resistivity and melting point criteria to discover more complex interface candidates. Qin et al [9] proposed the gridplainification strategy, which grew the crystal by physical vapor deposition and added additional Pb to fill the lattice vacancies, greatly weakening the scattering of lattice defects on the carriers and significantly improving the carrier mobility.…”