Directional growth method of bismuth telluride thermoelectric material

Abstract

The invention relates to the field of semiconductors. A directional growth method of a bismuth telluride thermoelectric material comprises the following steps: step 1, preparing the bismuth telluride thermoelectric material to be zone-melted, and sealing the bismuth telluride thermoelectric material in a heat-resistant pipe which is a quartz tube or a heat-resistant glass tube; secondly, the heat-resisting pipe fitting is placed in a vacuum cavity, a vertically-arranged rotary supporting shaft is installed in the vacuum cavity, the heat-resisting pipe fitting is vertically installed at the top of the rotary supporting shaft, and a water cooling channel is formed in the rotary supporting shaft; and step 3, preparing the Bi2Te3 crystal by using a zone melting method. According to the utility model, the uniformity of radial heating of the crystal material is improved, the crystal heat conduction direction in the crystallization process is controlled, the temperature gradient in the growth direction is increased, the thermoelectric performance of the crystal material is improved, and the problem of corner cracking or corner incompleteness of a thermoelectric element caused by inclination of a growth interface is effectively prevented.

Description

technical field [0001] The invention relates to the field of semiconductors, in particular to a Bi 2 Te 3 Method for directional growth of polycrystalline thermoelectric materials. Background technique [0002] Thermoelectric materials are the key materials for thermoelectric cooling or power generation devices. Bi2Te3-based thermoelectric materials (that is, bismuth telluride thermoelectric materials) are still the best commercial materials around room temperature so far. coefficient ZT, where (α: the seebeck coefficient of the material, σ: the electrical conductivity of the material; κ: the thermal conductivity of the material); due to Bi 2 Te 3 The crystal structure, the arrangement of atoms and the type of interatomic bonds determine its anisotropic characteristics, and it has the largest performance figure of merit in the direction parallel to the basal plane (00l). The difference in its thermoelectric properties: [0003] Conductivity: σ / / / σ ⊥ ≈4~10 [0004...

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Problems solved by technology

[0010] The patent with publication number CN1488572A adopts the method of powder sintering, which cannot obtain crystals with a certain degree of orientation, and the thermoelectric performance is limited

[0011] The patent with the publication number CN101403139A adopts the method of direct hot pressing of blocks after zone melting. Although it avoids the loss of material orientation caused by powder pressing in the previous method, the processing capacity is limited by equipment, and the efficiency is low and difficult to realize. Low-cost mass production

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