Foreign Research on Bismuth Telluride Thermoelectric Materials

For decades, the ribbon-melted Bi2Te3-based alloy has been the most widely used thermoelectric material, with its optimal working regime close to room temperature. However, the rich waste heat in the mid-temperature range poses challenges. How and to what extent can the service temperature of Bi2Te3-based alloys be raised to a medium-temperature system? We report on a collaborative optimization program for indium doping and thermal deformation, combining intrinsic point defect engineering, banded structure engineering, and multiscale microstructure. Indium doping regulates inherent point defects and widens the band gap, thereby suppressing harmful bipolar effects in medium-temperature systems; In addition, thermal deformation treatment makes multiscale microstructures conducive to phonon scattering, similar to donor effects that help optimize carrier concentration. Therefore, the peak value of zT reached~1.4 at 500K, and between 400 and 600K, the average zTav of Bi0.3Sb1.625In0.075Te3 was~1.3. These results demonstrate the efficacy of multiple synergies and can also be used to optimize other thermoelectric materials. A popular material that converts heat into electrical energy can now operate at high temperatures associated with industrial machinery. Bismuth telluride is a thermoelectric alloy that works at room temperature and can be used for refrigeration and power generation. Still, it generates much waste heat in the so-called intermediate temperature range of 100-300 degrees Celsius. Zhu Tiejun of Zhejiang University and his colleagues doped bismuth telluride with indium atoms to balance excess, thermally activated charge carriers that typically turn into substances when the alloy is heated to intermediate temperatures. During the manufacturing process, the thermal deformation of the alloy introduces missing atomic defects and microcrystalline particles, which interact with dopants to scatter thermal transmission acoustic waves and optimize carrier concentration. Thermoelectric and X-ray tests have shown that doped alloys have higher operating temperatures and better mechanical properties. We report a collaborative optimization program that combines point defect engineering, band structure engineering, and multiscale microstructure in p-type (Bi, Sb) 2Te3 thermoelectric materials through indium doping and thermal deformation. As a result, Bi0.3Sb1.625In0.075Te3 reached a peak value of zT~1.4 at 500K and got the most advanced average zTav~1.3 between 400-600K. These results demonstrate the efficacy of multiple synergistic effects and can also be used to optimize other thermoelectric materials. If you are looking for high quality, high purity and cost-effective bismuth telluride, or if you require the latest price of bismuth telluride, please feel free to email contact mis-asia.

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