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

Abstract

The invention discloses a niobium-doped bismuth-antimony-system low-temperature thermoelectric material and a preparation method thereof. The formula is Bi85Sb15-xNbx. In the formula, x is any number between 0 and 15. The preparation method comprises the following steps of: mixing Bi powder, Sb powder and Nb powder according to the chemical proportion, and adopting mechanical alloying and ultrahigh pressure processes to prepare the niobium-doped bismuth-antimony-system low-temperature thermoelectric material; and the niobium-doped bismuth-antimony-system low-temperature thermoelectric material has excellent thermoelectric performance near 200K. In the niobium-doped bismuth-antimony-system low-temperature thermoelectric material, the mechanical strength is high, the thermoelectrical potential and the electrical conductivity are good, the quality is higher under low temperature, the performance is stable, the manufacturing process is simpler and more convenient, the cost is low and the promotion and the application are easy.

Description

technical field [0001] The invention relates to a Nb-doped Bi-Sb series low-temperature thermoelectric material and a preparation method thereof, belonging 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 challenges faced by mankind in the new century. The development of environmentally friendly and clean energy technologies is an important basis for maintaining the sustainable and rapid development of national economy and social production. The main areas of semiconductor thermoelectric materials include: thermoelectric power generation devices, Peltier refrigeration devices and temperature sensors. Usually, the figure of merit Z is used to describe the efficiency of thermoelectric refrigeration, Z=α2σ / λ, α is the thermoelectric coefficient, σ is the electrical conductivity of the material, and λ is the thermal conductivity of the m...

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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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