Niobium-doped bismuth-antimony-system low-temperature thermoelectric material and preparation method thereof

Abstract

Niobium-doped bismuth-antimony low-temperature thermoelectric material and its preparation method. Its composition formula is Bi85Sb15-xNbx, where x is any value between 0 and 15. Its preparation method is to chemically mix Bi, Sb and Nb powder , produced by mechanical alloying and ultra-high pressure process; this material has excellent thermoelectric properties near 200K. The material has high mechanical strength, good thermoelectric potential and conductivity, and has high quality at low temperatures; the material The material performance is stable, the manufacturing process is simple, the cost is low, and it is easy to promote and apply.

Description

Technical field [0001] The invention relates to a Nb-doped Bi-Sb series low-temperature thermoelectric material and a preparation method thereof, and belongs to the field of semiconductor thermoelectric materials for thermoelectric coolers. Background technique [0002] Rapid economic growth has made energy and environmental issues the most serious challenge facing mankind in the new century. The development of environmentally friendly clean energy technologies is an important foundation for maintaining the sustainable development of the national economy and social production. The main areas of semiconductor thermoelectric materials include: thermoelectric power generation devices, Peltier refrigeration devices and temperature sensors. The figure of merit Z is usually used to describe the efficiency of thermoelectric cooling, Z=α2σ / λ, α is the thermoelectric coefficient, σ is the electrical conductivity of the material, and λ is the thermal conductivity of the material. Combined...

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Problems solved by technology

[0005] At 80 K, its figure of merit can reach 6.5×10 -3 K -1 . Both Bi and Sb are semi-metallic materials with the same rhombohedral crystal structure and similar lattice doping numbers. The physical properties of Bi-Sb alloys are related to the content of Sb. At 01-x Sb x The alloy behaves as a semi-metal, it is an n-type semiconductor at 0.070.22. However, the preparation cycle of single crystal is long, the machining performance is relatively poor, and the cost is high, which is not conducive to large-scale industrial production

It can be seen that there is a lack of a thermoelectric material with high mechanical strength and good performance in the low temperature range in the prior art

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