JP4665391B2 - THERMOELECTRIC SEMICONDUCTOR MATERIAL, THERMOELECTRIC SEMICONDUCTOR ELEMENT BY THE THERMOELECTRIC SEMICONDUCTOR MATERIAL, THERMOELECTRIC MODULE USING THE THERMOELECTRIC SEMICONDUCTOR ELEMENT, AND METHOD FOR PRODUCING THEM - Google Patents

Description

  The present invention relates to a thermoelectric semiconductor element applied to thermoelectric power generation and the like, a thermoelectric semiconductor material used for manufacturing the thermoelectric semiconductor element, a thermoelectric module using the thermoelectric semiconductor element, and a manufacturing method thereof.

  The devices that perform thermoelectric cooling, thermoelectric heating, and thermoelectric power generation using the thermoelectric characteristics of the thermoelectric semiconductor are all configured as a basic structure, as shown in FIG. A plurality of thermoelectric modules 1 formed by joining N-type thermoelectric semiconductor elements 3 via metal electrodes 4 to form PN element pairs are connected in series.

One type of thermoelectric semiconductor for forming the thermoelectric semiconductor elements 2 and 3 as described above is one or two elements selected from bismuth (Bi) and antimony (Sb), which are 5B groups, and 6B group. There is a thermoelectric semiconductor using a composite compound composed of one or two elements selected from certain tellurium (Te) and selenium (Se), which mainly includes the number of atoms of Group 5B (Bi and Sb), The composition is a composition in which the ratio of the number of atoms of the group 6B (Te and Se) is about 2: 3, that is, an alloy of a (Bi—Sb) ₂ (Te—Se) ₃ composition.

An alloy having a (Bi-Sb) ₂ (Te-Se) _3- based composition as a thermoelectric semiconductor material as described above has a hexagonal structure, and due to this crystal structure, It has thermal anisotropy and acts on electricity or heat in the C-axis direction by acting electricity or heat along the <110> direction of the crystal structure, that is, the direction of the C plane of the hexagonal crystal structure. It is known that better thermoelectric performance can be obtained as compared with the case where the above is performed.

In general, the thermoelectric performance of a material used for manufacturing a thermoelectric semiconductor is evaluated by a figure of merit Z expressed by the following equation.
Z = α ² · σ / κ = α ² / (ρ · κ)
In the above, α: Seebeck coefficient, σ: electrical conductivity, κ: thermal conductivity, and ρ: specific resistance.

  Therefore, in order to improve the thermoelectric performance (performance index: Z) of the thermoelectric semiconductor material, the absolute value of the Seebeck coefficient (α) or the value of electrical conductivity (σ) is increased, or the thermal conductivity ( It can be seen that (κ) should be reduced.

Therefore, as one of the methods for improving the thermoelectric performance of the thermoelectric semiconductor material, Bi and Sb, Te and Se in the raw material composition of the (Bi—Sb) ₂ (Te—Se) ₃ series thermoelectric semiconductor are used. The ratio of the Seebeck coefficient (α) or the electrical conductivity (σ) can be changed by changing the ratio, changing the composition of the thermoelectric semiconductor material by changing the kind of dopant added, the amount of addition, etc. Conventionally, it has been widely practiced to increase the value of or to reduce the thermal conductivity (κ).

  By the way, when thermoelectric cooling, thermoelectric heating, or thermoelectric power generation is performed using the thermoelectric module 1, the P-type and N-type thermoelectric semiconductor elements 2 and 3 are energized or in the direction in which heat flows. A temperature gradient is formed along. However, even if the thermoelectric semiconductor material has a uniform composition, the thermoelectric performance changes depending on the temperature, and even if the composition is set so as to exhibit high thermoelectric performance in a certain temperature range, the thermoelectric material having a different composition can be used under temperature conditions other than that temperature range. Thermoelectric performance may be lower than that of semiconductor materials.

  Therefore, the P-type thermoelectric semiconductor element 2 and the N-type thermoelectric semiconductor element 3 which are the constituent elements of the thermoelectric module 1 are each moved in the direction in which the temperature gradient occurs on the heat radiation side (high temperature side) and the cooling side (low temperature side). By forming a layer of a plurality of thermoelectric semiconductor materials having different compositions so as to exhibit excellent thermoelectric performance at a plurality of temperature ranges formed side by side in the direction, so as to be a so-called functionally gradient material, the high temperature side Conventionally, it has been proposed to exhibit good thermoelectric performance on the low temperature side (see, for example, Patent Document 1).

  The thermoelectric module 1 based on such an idea, as shown in FIG. 24 schematically shows an example thereof, when manufacturing the P-type thermoelectric semiconductor element 2, first, a P having a composition exhibiting excellent thermoelectric performance in the high temperature region. -Type thermoelectric semiconductor raw material alloy and P-type thermoelectric semiconductor alloy raw material with a composition showing excellent thermoelectric performance in the low-temperature region are individually made into molten alloys, and then each directionally solidified material is formed by rapid solidification Let Next, the unidirectionally solidified material of each composition is laminated as it is or in a crushed state so that the solidified material of each composition forms a layer having a required thickness. By uniaxially pressing from the stacking direction of the unidirectional solidified material, a layer 2H having a composition exhibiting excellent thermoelectric performance in the high temperature region and a layer 2L having a composition exhibiting excellent thermoelectric performance in the low temperature region are laminated. A P-type thermoelectric semiconductor element 2 having the following structure is manufactured.

  Further, when the N-type thermoelectric semiconductor element 3 is manufactured, as in the case of manufacturing the P-type thermoelectric semiconductor element, first, a raw material alloy of the N-type thermoelectric semiconductor having a composition exhibiting excellent thermoelectric performance in the high temperature side region. Then, the N-type thermoelectric semiconductor alloy raw material having a composition exhibiting excellent thermoelectric performance in the low temperature region is individually made into a molten alloy, and then a unidirectional solidified material is formed by rapid solidification. Next, the unidirectionally solidified material of each composition is laminated as it is or in a crushed state so that the solidified material of each composition forms a layer having a required thickness. By uniaxially pressing from the laminating direction of the unidirectional solidified material, a layer 3H having a composition exhibiting excellent thermoelectric performance in the high temperature region and a layer 3L having a composition exhibiting excellent thermoelectric performance in the low temperature region are laminated. An N-type thermoelectric semiconductor element 3 having the following structure is manufactured.

  After that, the P-type thermoelectric semiconductor element 2 and the N-type thermoelectric semiconductor element 3 each having the layers 2H and 2L or 3H and 3L having compositions having different temperature suitability are respectively provided with temperature suitability on the high temperature side and the low temperature side, respectively. Arranged so that 2H and 3H and 2L and 3L are aligned, the P-type and N-type thermoelectric semiconductor elements 2 and 3 are joined via the metal electrode 4 to form a PN element pair.

  Further, as another method for improving the thermoelectric performance (performance index: Z) of the thermoelectric semiconductor material, by increasing the orientation of crystal grains in the thermoelectric semiconductor material having the above hexagonal crystal structure, It is also conceivable to reduce the resistance (ρ).

  In view of this, when manufacturing a thermoelectric semiconductor material having a uniform composition in the previous application (Japanese Patent Application No. 2003-130618), the applicants of the present patent application, first, a raw material as a required thermoelectric semiconductor composition. After melting the alloy, the molten alloy is brought into contact with the surface of the cooling member and cooled (slowly cooled) to form a plate-like thermoelectric semiconductor material, and then the thermoelectric semiconductor material is laminated almost into a layer and solidified. Forming a molded body, and then constraining the molded body to be deformed in one of the two axial directions intersecting in a plane substantially perpendicular to the main lamination direction of the thermoelectric semiconductor material. The thermoelectric semiconductor material is formed by pressing from the other axial direction and applying a shearing force in a uniaxial direction substantially parallel to the main laminating direction of the thermoelectric semiconductor material.

  This is because, by bringing a molten alloy of a raw material alloy of the thermoelectric semiconductor material into contact with the surface of the cooling member, a thermoelectric semiconductor material that is oriented so that the C-plane of the hexagonal crystal structure extends substantially parallel to the plate thickness direction is obtained. The thermoelectric semiconductor material is laminated in a substantially layered manner in the plate thickness direction and solidified and molded, so that the extending direction of the C-plane of the crystal grains is held in the lamination direction in the formed body. Further, the molded body is plastically deformed by pressing so as to apply a shearing force in a uniaxial direction substantially parallel to the main lamination direction of the thermoelectric semiconductor, which substantially coincides with the extending direction of the C-plane of the crystal grains, The crystal grains are flattened in the direction in which the shearing force acts, thereby breaking the laminated interface between the thermoelectric semiconductor materials laminated and solidified substantially in the plate thickness direction, and further, the C plane of the crystal grains The direction in which the crystal extends is kept aligned with the direction in which the shearing force is applied during the plastic deformation, and at the same time the C-axis direction of the crystal grains is oriented substantially parallel to the pressing direction for plastic deformation. . Therefore, since the obtained thermoelectric semiconductor material is in a state in which the C-plane extending direction and the C-axis direction of the hexagonal crystal structure are aligned in the structure, the orientation of the crystal structure can be improved. High thermoelectric performance can be obtained by setting so that current and heat are applied in the direction in which the C-plane extends.

  By the way, when performing thermoelectric power generation, the thermoelectric module may be as thick as about 10 mm. Therefore, each of the P-type and N-type thermoelectric semiconductor elements constituting the thermoelectric module is relatively large. Become. In thermoelectric power generation, the temperature difference may be very large, with the low temperature side of the thermoelectric module near room temperature and the high temperature side of about 200 to 300 ° C.

When the thermoelectric semiconductor material is applied to thermoelectric power generation, the magnitude of the electromotive force that can be extracted can be evaluated by the power factor P represented by the following formula using the Seebeck coefficient (α) and the electrical conductivity (σ). Are known.
P = α ² × σ
For this reason, in order to enlarge the said power factor (P), it turns out that what is necessary is just to enlarge the absolute value of Seebeck coefficient ((alpha)) or to increase electrical conductivity.

JP 2003-92432 A

  However, the thermoelectric semiconductor element in which the thermoelectric semiconductor layers having compositions having different temperature suitability are provided along the direction in which the temperature gradient acts as described in the above-mentioned Patent Document 1 has temperature suitability on the high temperature side and the low temperature side, respectively. The unidirectionally solidified material of the thermoelectric semiconductor raw material alloy having the composition is laminated so as to form layers, and then uniaxially pressed in the laminating direction and sintered, so the uniaxial pressure is applied in the laminating direction. Sometimes, there is a problem that the crystal orientation of the laminated interface portion of the laminated solidified material is disturbed, and the crystal grains formed in the unidirectional solidified material are crystal grains of the hexagonal structure by unidirectional solidification. Even if the C-plane extending direction is aligned, there is a problem that the orientation of the C-axis is not aligned and is random, so that the crystal orientation cannot be made very high. Furthermore, since the thermoelectric semiconductor layers having different compositions are formed in the direction in which the temperature gradient acts, the thermoelectric semiconductor layers having different compositions, that is, at the laminated interface where the unidirectional solidified materials having different compositions overlap with each other, For example, if the electrical conductivity differs between thermoelectric semiconductor materials of different compositions due to different compositions, there is a concern that electrical conduction may be hindered at the laminated interface between the thermoelectric semiconductor layers of the different compositions. The

  Furthermore, in the above-described Patent Document 1, only the figure of merit (Z) is considered for the evaluation of thermoelectric performance of thermoelectric semiconductors having different compositions, and the performance evaluation of thermoelectric semiconductors applied to thermoelectric power generation is considered. There is no description regarding the power factor P more effective.

  Therefore, the present invention can improve the thermoelectric performance of the entire element even if a large temperature gradient acts from the low temperature side to the high temperature side as in the case of performing thermoelectric power generation, and in the direction in which the temperature gradient acts. A thermoelectric semiconductor element capable of improving the crystal orientation along the direction, and further preventing the formation of a laminated interface in the direction in which the temperature gradient acts to prevent electric conduction from being disturbed, and the thermoelectric semiconductor It is intended to provide a thermoelectric semiconductor material used for manufacturing an element, a thermoelectric module using the thermoelectric semiconductor element, and a manufacturing method thereof.

In order to solve the above problems, the present invention provides a Seebeck coefficient as a parameter for evaluating thermoelectric performance in different temperature ranges in a temperature range from a low temperature side to a high temperature side for a plurality of thermoelectric semiconductor materials having different compositions. The composition of thermoelectric semiconductors that can exhibit superior thermoelectric performance compared to the thermoelectric performance that can exhibit the composition of each of the above different thermoelectric semiconductors on the low temperature side Compare the thermoelectric performance that can exhibit the composition of each of the different thermoelectric semiconductors, and select the thermoelectric semiconductor composition that can exhibit excellent thermoelectric performance, or the thermoelectric performance that can exhibit the composition of each different thermoelectric semiconductor on the low temperature side. Comparing the composition of thermoelectric semiconductors that can exhibit superior thermoelectric performance in comparison with the thermoelectric performance that can exhibit the composition of each of the above different thermoelectric semiconductors on the high temperature side The composition of a thermoelectric semiconductor capable of exhibiting excellent thermoelectric performance by comparing the composition of the thermoelectric semiconductor capable of exhibiting the thermoelectric performance and the thermoelectric performance capable of exhibiting the composition of each of the different thermoelectric semiconductors in the temperature range from the low temperature side to the high temperature side. and selecting, the selection was different thermoelectric semiconductor material compositions from the low temperature side and stacked filled solidifying and molding a layer in the order of the high temperature side and the molded body, the molded article, the product of different thermoelectric semiconductor material having the composition and pressed from perpendicular uniaxial in the layer direction and plastically deformed such that different thermoelectric semiconductor shear on a flat line uniaxial direction to the product layer direction of the material of the composition is applied, along the stacking direction of the thermoelectric semiconductor material The crystal grain in the structure of the thermoelectric semiconductor material has a hexagonal C-plane extending in the tilt direction of the composition, and the C-axis direction is also aligned to enhance crystal orientation. What is being done It is a thermoelectric semiconductor material is.

In addition, thermoelectric semiconductor materials made by melting and solidifying the thermoelectric semiconductor raw material alloy into foils , plates, or pulverized products of these thermoelectric semiconductor materials with different compositions can be cooled at low temperatures. The composition of each of the different thermoelectric semiconductors on the low temperature side based on the thermoelectric performance data on the change with temperature obtained with the Seebeck coefficient as a parameter for evaluating the thermoelectric performance in different temperature ranges within the temperature range from the high temperature side to the high temperature side Thermoelectric semiconductors that can exhibit superior thermoelectric performance by comparing the composition of thermoelectric semiconductors that can exhibit superior thermoelectric performance by comparing the thermoelectric performance that can be exhibited by the thermoelectric performance that can exhibit the composition of each of the above different thermoelectric semiconductors on the high temperature side Of thermoelectric semiconductors that can exhibit excellent thermoelectric performance by comparing the thermoelectric performance that can exhibit the composition of each of the different thermoelectric semiconductors on the low temperature side. The composition of the thermoelectric semiconductor that can exhibit excellent thermoelectric performance by comparing the thermoelectric performance that can be exhibited by the composition of each of the above different thermoelectric semiconductors on the high temperature side, and each of the above differences in the temperature range from the low temperature side to the high temperature side Compare the thermoelectric performance that can exhibit the composition of the thermoelectric semiconductor, select and prepare the thermoelectric semiconductor composition that can exhibit excellent thermoelectric performance , and prepare the thermoelectric semiconductor materials of the prepared multiple compositions in order from the low temperature side to the high temperature side and solidifying and molding by laminating in layers to form a molded body, then, the molded article, one of the two axial directions to intersect at a straight intersects plane to the product layer the direction of different thermoelectric semiconductor material having the composition and pressed from the other axial deformation in the axial direction at constrained state by the action of shear forces on the flat line uniaxial direction to the product layer direction of the thermoelectric semiconductor material by plastically deforming, the thermoelectric semiconductor material Inclination of composition along the stacking direction The crystal grains in the structure of the thermoelectric semiconductor material have a C-plane of the hexagonal structure extending in the tilt direction of the composition, and the C-axis direction is also aligned to enhance crystal orientation. It is set as the manufacturing method of the thermoelectric semiconductor material which becomes .

Further, a thermoelectric semiconductor material and a method for manufacturing the thermoelectric semiconductor material in which the parameters for evaluating the thermoelectric performance in the above are any of Seebeck coefficient, electrical conductivity, power factor, and performance index.

  Similarly, the thermoelectric semiconductor material is a plate-like thermoelectric semiconductor material formed by melting a raw material alloy having a plurality of thermoelectric semiconductor compositions individually and then slowly cooling them, and a manufacturing method thereof.

  Furthermore, when the molten alloy of the raw material alloy is brought into contact with the surface of the cooling member to form a plate-shaped thermoelectric semiconductor material, a speed at which 90% or more of the thickness of the formed plate-shaped thermoelectric semiconductor material is not rapidly cooled. The method for producing a thermoelectric semiconductor material in which the molten alloy is cooled and solidified.

Further, in the above, the thermoelectric semiconductor material of a plurality of compositions, both (Bi-Sb) thermoelectric semiconductor material and a manufacturing method thereof that alter the Ingredient based on the composition of ₂ Te ₃ system and having composition comprising And

Similarly, in the above, the thermoelectric semiconductor material having a composition in which the required components are changed based on the Bi ₂ (Te-Se) ₃ -based composition are used as the thermoelectric semiconductor materials having a plurality of compositions. The method.

  Furthermore, as described above, the composition has a continuous gradient composition without causing a lamination interface, and the direction in which the C-plane of the hexagonal crystal structure extends is aligned with the gradient direction of the composition, and also the C-axis direction is aligned. A thermoelectric semiconductor material with good crystal orientation and high thermoelectric performance is joined to the electrode at both ends in the uniaxial direction where a shearing force is applied when the molded body is plastically deformed to form the thermoelectric semiconductor material. The thermoelectric semiconductor element is cut out so as to be able to be made.

  Further, the thermoelectric semiconductor material as described above is cut and processed so that both ends in the uniaxial direction to which a shearing force is applied when the molded body is plastically deformed to form the thermoelectric semiconductor material can be joined to the electrode. A method of manufacturing a thermoelectric semiconductor element for forming a semiconductor element is provided.

  Furthermore, in the above, a thermoelectric semiconductor element and a method of manufacturing the thermoelectric semiconductor element are obtained by cutting the uniaxial direction one end side and the other end side where shearing force is applied at the time of composition deformation processing of the molded body of the thermoelectric semiconductor material.

Further, the crystal grains in the structure of the thermoelectric semiconductor have a continuous gradient composition without causing the laminated interface as described above, and the C plane of the hexagonal structure extends in the gradient direction of the composition, P-type and N-type thermoelectric semiconductor materials that are aligned in the axial direction and have improved crystal orientation , and from the P-type and N-type thermoelectric semiconductor materials, plastic deformation of the molded body is performed. sometimes a uniaxial direction both end portions of the Eject and switching power sale by can be bonded with electrode processing and P-type obtained by forming each the N-type each thermoelectric semiconductor elements of the action of shear forces, the at respective thermoelectric a semiconductor element Based on the thermoelectric performance data about the change with respect to the temperature obtained with the Seebeck coefficient as a parameter for evaluating the thermoelectric performance, the thermoelectric semiconductor compositions that can exhibit excellent thermoelectric performance on the low temperature side, and the high temperature excellent on the side Align electric performance thermoelectric semiconductor composition which can exhibit distribution by side with each other, respectively, and a uniaxial direction by applying a pressing force at the time of plastic deformation of the shaped body, co uniaxially that shear force by the pressing pressure to thereby arranged in a straight direction orthogonal includes a PN element pair constituted by forming a structure with the P-type and N-type PN element pair formed by formed by bonding via the electrodes of each thermoelectric semiconductor elements A thermoelectric module having the above configuration.

Also, P-type and N-type thermoelectric semiconductor elements are prepared as the thermoelectric semiconductor elements as described above, and the P-type and N-type thermoelectric semiconductor elements are replaced with the P-type and N-type thermoelectric semiconductor elements. Based on the thermoelectric performance data about the change with respect to the temperature obtained by the Seebeck coefficient as a parameter for evaluating the thermoelectric performance in each thermoelectric semiconductor element, the composition of the thermoelectric semiconductor that can exhibit excellent thermoelectric performance on the low temperature side Uniaxial directions in which the arranged sides and the arranged sides of the thermoelectric semiconductor composition capable of exhibiting excellent thermoelectric performance on the high temperature side are aligned, and a pressing force is applied during plastic deformation processing of the molded body. , as well as arranged in a straight direction orthogonal to the co uniaxially which has a shearing force by pressing pressure, thermoelectric forming a PN element pairs are joined via the electrodes of each thermoelectric semiconductor elements of the P-type and N-type Mod The method of production.

According to the present invention, the following excellent effects are exhibited.
(1) About the change with respect to the temperature obtained by the Seebeck coefficient as a parameter for evaluating the thermoelectric performance in different temperature ranges in the temperature range from the low temperature side to the high temperature side for a plurality of thermoelectric semiconductor materials having different compositions Based on the thermoelectric performance data, the composition of the thermoelectric semiconductor that can exhibit superior thermoelectric performance by comparing the thermoelectric performance that can exhibit the composition of each different thermoelectric semiconductor on the low temperature side, and the composition of each thermoelectric semiconductor that differs on the high temperature side Compare the thermoelectric performance that can be exhibited, select the composition of the thermoelectric semiconductor that can exhibit excellent thermoelectric performance, or compare the thermoelectric performance that can exhibit the composition of each of the above different thermoelectric semiconductors on the low temperature side and demonstrate excellent thermoelectric performance Thermoelectric semiconductor that can exhibit excellent thermoelectric performance by comparing the composition of thermoelectric semiconductor that can be produced and the thermoelectric performance that can be exhibited by the different thermoelectric semiconductor compositions on the high temperature side The composition of the thermoelectric semiconductor that can exhibit excellent thermoelectric performance is selected by comparing the composition of the thermoelectric performance that can exhibit the composition of each of the different thermoelectric semiconductors in the temperature range from the low temperature side to the high temperature side, and the selection was laminated filled solidified molded in layers and molded body in the order of the high-temperature side different thermoelectric semiconductor material from a low temperature side of the composition, a molded article, the uniaxial direction perpendicular to the product layer the direction of different thermoelectric semiconductor material having the composition and more pressed plastically deformed differently thermoelectric semiconductor shear on a flat line uniaxial direction to the product layer direction of the material of the composition is applied, the slope of the composition is provided along the stacking direction of the thermoelectric semiconductor material The crystal grains in the structure of the thermoelectric semiconductor material have their crystal orientation improved by extending the C-plane of the hexagonal structure in the direction of inclination of the composition and further aligning the C-axis direction. a thermoelectric semiconductor material are Is because, when forming the molded body can be the molding body, providing a gradient in composition along the direction laminated thermoelectric semiconductor material of a plurality of compositions. Further, the molded body is further pressed and plastically deformed so that a shearing force acts in a uniaxial direction parallel to the stacking direction of the thermoelectric semiconductor materials having the plurality of compositions. The interface region between the semiconductor materials can be eliminated. Therefore, a thermoelectric semiconductor material having a continuous gradient composition of the plurality of compositions can be obtained without generating a laminated interface. Further, the composition deformation process allows the crystal grains in the structure to have the hexagonal structure C-plane extending in the direction of inclination of the composition, and the C-axis direction can be evenly aligned. It can be very expensive. For this purpose, the direction in which the current or heat acts is set in the inclination direction of the composition, and the thermoelectric performance of the thermoelectric semiconductor materials having a plurality of compositions used to incline the composition during the action of the current or heat. The thermoelectric performance can be improved by generating a temperature gradient so that the parameters to be evaluated correspond to temperature ranges where the parameters are dominant.
(2) Accordingly, a plurality of thermoelectric semiconductor materials having different compositions from the thermoelectric semiconductor materials obtained by melting and solidifying a thermoelectric semiconductor raw material alloy into a foil shape, a plate shape, or a pulverized product thereof. On the basis of the thermoelectric performance data on the change with respect to the temperature obtained with the Seebeck coefficient as a parameter for evaluating the thermoelectric performance in different temperature ranges in the temperature range from the low temperature side to the high temperature side, Comparing the thermoelectric performance that can exhibit excellent thermoelectric performance by comparing the thermoelectric performance that can exhibit the composition of the semiconductor, and excellent thermoelectric performance by comparing the thermoelectric performance that can exhibit the composition of each of the different thermoelectric semiconductors on the high temperature side The composition of thermoelectric semiconductors that can be used can be selected, or excellent thermoelectric performance can be demonstrated by comparing the thermoelectric performance that can be exhibited by the different thermoelectric semiconductor compositions on the low temperature side. Comparing the composition of the thermoelectric semiconductor and the thermoelectric performance capable of exhibiting the above different thermoelectric semiconductor compositions on the high temperature side, the composition of the thermoelectric semiconductor capable of exhibiting excellent thermoelectric performance, and the temperature range from the low temperature side to the high temperature side Compare the thermoelectric performance that can be exhibited by the different thermoelectric semiconductor compositions, select and prepare the thermoelectric semiconductor composition that can exhibit excellent thermoelectric performance , and prepare the thermoelectric semiconductor materials of the prepared multiple compositions from the low temperature side to the high temperature and solidifying and molding by laminating in layers in this order on the side to form a molded body, then, the molded article, biaxial direction intersecting with the straight intersects plane to the product layer the direction of different thermoelectric semiconductor material having the composition among the modifications to the one axial direction at constrained state by pressing than other axial cause a shearing force to the flat line uniaxial direction to the product layer direction of the thermoelectric semiconductor material by plastically deforming, the In the stacking direction of thermoelectric semiconductor materials The crystal grain in the structure of the thermoelectric semiconductor material has a hexagonal C-plane extending in the tilt direction of the composition, and the C-axis direction is also aligned to provide crystal orientation. A thermoelectric semiconductor material manufacturing method for forming a thermoelectric semiconductor material that has been enhanced has the above-described tilted composition and a high thermoelectric power by applying current or heat in the tilt direction of the composition. It is possible to obtain a thermoelectric semiconductor material capable of exhibiting performance and having no risk of impeding electrical conduction in the gradient direction of the composition.
(3) Further, in place of the Seebeck coefficient as a parameter for evaluating the thermoelectric performance in the electrical conductivity, power factor, by either of the performance index, the thermoelectric semiconductor current or heat to composition gradient direction acts When a temperature gradient occurs in the composition gradient direction with respect to the material, the corresponding parameters can be excellent over the entire composition gradient direction, so that the thermoelectric performance of the thermoelectric semiconductor material can be improved. it can.
(4) Furthermore, by making the thermoelectric semiconductor material into a plate-like thermoelectric semiconductor material formed by melting the raw material alloys having a plurality of thermoelectric semiconductor compositions individually and then slowly cooling them, a plurality of compositional compositions are obtained. As the thermoelectric semiconductor material, the crystal grains in the structure extend in the plate thickness direction, and the direction in which the C-plane of the hexagonal crystal structure of the crystal grains extends can be aligned. For this reason, the orientation of the C-plane of the crystal grains can be increased even in a molded body formed by laminating the above thermoelectric semiconductor materials, and C in the thermoelectric semiconductor material produced from the molded body. Since the orientation of the surface can be further improved, the thermoelectric performance can be further improved.
(5) Furthermore, when the plate-shaped thermoelectric semiconductor material is formed by bringing the molten alloy of the raw material alloy into contact with the surface of the cooling member, 90% or more of the thickness of the formed plate-shaped thermoelectric semiconductor material is rapidly cooled. If the molten alloy is cooled and solidified at a rate that does not become a problem, the orientation of the thermoelectric semiconductor material can be further improved, and therefore the thermoelectric performance of the manufactured thermoelectric semiconductor material can be further improved. .
(6) In the above, the thermoelectric semiconductor material of a plurality of compositions, either by the (Bi-Sb) of ₂ Te ₃ system composition comprising by changing the Ingredient based on the composition as, as described above It is possible to obtain a P-type thermoelectric semiconductor material having a continuous gradient composition and having high thermoelectric performance without generating a laminated interface.
(7) On the other hand, in the above, the thermoelectric semiconductor material of a plurality of compositions, either by those of Bi 2 _(Te-Se) the composition of the ₃ system by changing the Ingredient based comprising composition, above Thus, an N-type thermoelectric semiconductor material having a continuous gradient composition and high thermoelectric performance can be obtained without causing such a laminated interface.
(8) As described above , the crystal grains in the structure of the thermoelectric semiconductor material have a continuous gradient composition without causing a laminated interface, and the C-plane of the hexagonal structure extends in the gradient direction of the composition. , A thermoelectric semiconductor material in which the C-axis direction is aligned and the crystal orientation is enhanced , and both end portions in the uniaxial direction on which shearing force acts during plastic deformation processing of the molded body in the thermoelectric semiconductor material with Eject and switching power sale by can be bonded with the electrodes processed comprising thermoelectric semiconductor elements, with the current and heat is applied to the flat row in the extending direction of C face of the crystal grains is the above composition gradient direction, are inclined By forming a temperature gradient according to the temperature characteristics of the composition, the entire thermoelectric semiconductor element can have high thermoelectric performance.
(9) Therefore, the thermoelectric semiconductor material as described above is cut out so that both ends in the uniaxial direction to which a shearing force is applied when the molded body is plastically deformed to form the thermoelectric semiconductor material can be joined to the electrode. and by a method for manufacturing a thermoelectric semiconductor elements forming a thermoelectric semiconductor element, is allowed to act on the flat row in the extending direction of C face of the crystal grains having a composition gradient direction current and heat, the composition obtained by gradient temperature By forming a temperature gradient according to the characteristics, a thermoelectric semiconductor element capable of exhibiting high thermoelectric performance throughout can be obtained.
(10) In the above, if the cross-sectional area of the one end side and the other end side in the uniaxial direction in which the shearing force acts during the composition deformation processing of the molded body in the thermoelectric semiconductor material is cut out and processed, the difference in cross-sectional area Accordingly, the electric conductivity in one end side and the other end side of the thermoelectric semiconductor element manufactured by inclining the composition can be adjusted because the uniaxial energization resistance in which a shearing force acts during plastic processing of the molded body can be adjusted. Are different from each other, the cross-sectional area is set so as to be inversely proportional to the magnitude of the electric conductivity, whereby the electric resistance from one end side to the other end side can be made uniform over the entire thermoelectric semiconductor element.
(11) The crystal grains in the structure of the thermoelectric semiconductor have a continuous gradient composition without causing the laminated interface as described above, and the C-plane of the hexagonal structure extends in the gradient direction of the composition. P-type and N-type thermoelectric semiconductor materials that are aligned in the axial direction and have improved crystal orientation , and from the P-type and N-type thermoelectric semiconductor materials, plastic deformation of the molded body is performed. sometimes a uniaxial direction both end portions of the Eject and switching power sale by can be bonded with electrode processing and P-type obtained by forming each the N-type each thermoelectric semiconductor elements of the action of shear forces, the at respective thermoelectric a semiconductor element Based on the thermoelectric performance data about the change with respect to the temperature obtained with the Seebeck coefficient as a parameter for evaluating the thermoelectric performance, the thermoelectric semiconductor compositions that can exhibit excellent thermoelectric performance on the low temperature side, and the high temperature excellent on the side Align electric performance thermoelectric semiconductor composition which can exhibit distribution by side with each other, respectively, and a uniaxial direction by applying a pressing force at the time of plastic deformation of the shaped body, co uniaxially that shear force by the pressing pressure while arranged in a straight direction orthogonal to, when a thermoelectric module having a configuration with the P-type and N-type each thermoelectric semiconductor elements PN element pair formed by formed by bonding via the electrode of the P-type In addition, an electrode attached to the low temperature side of the thermoelectric semiconductor element of each of the N-type thermoelectric semiconductor elements is attached to the low temperature side, and an electrode attached to the high temperature side of each of the thermoelectric semiconductor elements is attached to the temperature appropriate side. By applying current or heat to the module so as to be on the high temperature side, it can be made a thermoelectric module with high thermoelectric performance, and further, the elongation of the metal electrode that occurs with temperature change during use, Since the stress due to the contraction can be applied to the P-type and N-type thermoelectric semiconductor elements in the direction parallel to the C-plane of the hexagonal crystal structure of each crystal grain, the metal electrode expands and contracts. Even if it is deformed, it is possible to prevent the occurrence of crystal delamination in the structure of each thermoelectric semiconductor element, and to improve the strength and durability of the thermoelectric module.
(12) Therefore, P-type and N-type thermoelectric semiconductor elements are prepared as the thermoelectric semiconductor elements as described above, and the P-type and N-type thermoelectric semiconductor elements are connected to the thermoelectric semiconductor elements in the thermoelectric semiconductor elements. Based on the data obtained with the parameters that evaluate performance, the thermoelectric semiconductor compositions that can exhibit excellent thermoelectric performance on the low temperature side, and the thermoelectric semiconductor that can exhibit excellent thermoelectric performance on the high temperature side align the composition distribution by side with each other, respectively, and a uniaxial direction by applying a pressing force at the time of plastic deformation of the shaped body, side by side in a straight direction orthogonal to the co uniaxially which has a shearing force by pressing pressure The thermoelectric module has a good thermoelectric performance as well as durability and strength by arranging the P-type and N-type thermoelectric semiconductor elements through electrodes and forming a PN element pair. High It can be obtained thermoelectric modules that are.

  The best mode for carrying out the present invention will be described below with reference to the drawings.

  FIG. 1 to FIG. 9 show an embodiment of a method for producing a thermoelectric semiconductor material according to the present invention. As shown in the flow in FIG. Prepare raw material alloys of thermoelectric semiconductors having a plurality of compositions, each of which has excellent values related to thermoelectric performance in different temperature ranges in the temperature range from the low temperature side to the high temperature side, and the raw material alloys of the respective compositions Are melted to form molten alloys, and then each molten alloy is slowly cooled (slowly cooled) at a speed at which 90% or more of the thickness of the thermoelectric semiconductor material to be formed is not rapidly cooled by a cooling method described later. Then, a thin plate-like foil (annealed foil) that is solidified to become a thermoelectric semiconductor material is separately manufactured for each of the above compositions. Next, in the mold, the slow cooling foils as thermoelectric semiconductor materials for each of the above-mentioned components that are separately manufactured are laminated in parallel in the thickness direction so that they are arranged in the order of the temperature at which excellent thermoelectric performance can be exhibited. Fill. Next, the thermoelectric semiconductor material filled in the mold is solidified and molded under the required pressing conditions described later, and the thermoelectric semiconductor material is distributed according to the distribution in the stacking direction of the plurality of thermoelectric semiconductor materials having different temperature suitability. A molded body having a gradient composition related to temperature appropriateness in the stacking direction of the semiconductor material is formed. Thereafter, the molded body is plastically deformed by applying a load so that a shear stress is applied in a uniaxial direction substantially parallel to the lamination direction of the thermoelectric semiconductor material, thereby producing a thermoelectric semiconductor material.

Specifically, a method for producing an N-type thermoelectric semiconductor material will be described. First, a thermoelectric module is assumed to be used when a thermoelectric semiconductor element produced from the thermoelectric semiconductor material is used, for example, when performing thermoelectric power generation. In the case where the temperature range assumed to act on the thermoelectric semiconductor element is from about room temperature to about 300 ° C., the stoichiometric composition of the N-type thermoelectric semiconductor that is Bi ₂ (Te-Se) ₃ in advance is basically used. The N-type thermoelectric semiconductor material formed with various compositions in which the component ratio of each element is changed or the kind and addition amount of the dopant is changed, in a temperature range from around room temperature to around 300 ° C. Various parameters related to thermoelectric performance, such as power factor (P), Seebeck coefficient (α), and electrical conductivity (σ), are collected and collected. Based on the obtained data, the composition of an N-type thermoelectric semiconductor that can exhibit excellent thermoelectric performance on the low temperature side near room temperature, and the composition of the N-type thermoelectric semiconductor that can exhibit excellent thermoelectric performance on the high temperature side near 300 ° C. Furthermore, the composition of an N-type thermoelectric semiconductor capable of exhibiting excellent thermoelectric performance in a temperature range from room temperature to 300 ° C. is selected as necessary.

  That is, for example, Bi: 40 atomic%, Te: 51 atoms based on the stoichiometric composition (composition A) of an N-type thermoelectric semiconductor of Bi: 40 atomic%, Te: 54 atomic%, Se: 6 atomic% %, Se: 9 atomic%, composition with increased Se concentration (composition B), Bi: 40 atomic%, Te: 48 atomic%, Se: 12 atomic%, composition with further increased Se concentration (composition C) A composition (composition D) obtained by adding 3 atomic% of sulfur (S) as a dopant to the composition A, and a non-stoichiometric composition by adding Te in a weight ratio with respect to the composition A in an excess of 0.05%. Regarding the five types of compositions (composition E), the change in Seebeck coefficient (α) as shown in FIG. 2 with respect to temperature, the change in electrical conductivity (σ) as shown in FIG. 3 with respect to temperature, and Power factor as shown in FIG. -Assume that data on change in temperature of (P) is obtained. In this case, as an example of a parameter for evaluating the thermoelectric performance, when paying attention to the temperature suitability of the Seebeck coefficient (α) shown in FIG. 2, the absolute value of the Seebeck coefficient (α) at the low temperature side near room temperature. Is selected as a material composition of a thermoelectric semiconductor suitable for the low temperature side, while a composition C whose absolute value of the Seebeck coefficient (α) increases on the high temperature side near 300 ° C. is suitable for the high temperature side. The material composition is selected in advance. As is clear from FIG. 2, the compositions A, D, and E all have an absolute Seebeck coefficient (α) higher than that of the composition B and the composition C in the intermediate temperature range from room temperature to 300 ° C. The value never takes a large value. Therefore, in such a case, it is not necessary to select a composition having temperature suitability in the intermediate temperature range.

  When selecting the material composition of the above thermoelectric semiconductor, we focused on the Seebeck coefficient (α) as a parameter for evaluating the thermoelectric performance of the thermoelectric semiconductor material because the electrical conductivity was adjusted by adjusting the type of dopant and its addition amount. (Σ) can be increased relatively easily, but similarly, the Seebeck coefficient (α) is difficult to change even if the dopant type and amount added are adjusted, so the thermoelectric performance of the thermoelectric semiconductor is more than the electrical conductivity. This is because it is considered to have a greater influence.

  Next, as the component adjustment step I, the alloy of the thermoelectric semiconductor material alloy having the composition B and the thermoelectric semiconductor material alloy having the composition C are separately charged.

  Next, as a slow cooling foil manufacturing process II, as shown in FIG. 5, a metal mixture of raw material alloys is reduced into a reducing gas atmosphere and an inert gas atmosphere for each of the compositions B and C separately charged in the component preparation process I. Alternatively, after being put in a quartz melting crucible 6 installed in a container 5 that can maintain a low oxygen concentration atmosphere such as a vacuum, the molten alloy 8 is melted by heating with a heating coil 7, The molten alloy 8 is supplied to the surface of a rotating roll 9 such as a water-cooled roll as a cooling member to be solidified. As a result, the raw material alloys of the composition B and the composition C are thin plate-like as shown in FIG. The slow cooling foils as the thermoelectric semiconductor materials 10b and 10c are manufactured separately. At this time, by adjusting the peripheral speed of the rotating roll 9 as appropriate, for example, by setting it to 5 m / second or less, the molten alloy 8 is solidified on the surface of the rotating roll 9 so that the thermoelectric semiconductor material 10b having the composition B and the composition C is obtained. When each of the 10c is formed, 90% or more of the thickness of the formed thermoelectric semiconductor material 10b, 10c is prevented from being rapidly cooled. In the thermoelectric semiconductor materials 10b and 10c, the lower case alphabets attached to the reference numerals are the compositions indicated by the corresponding upper case alphabets of the thermoelectric semiconductor materials 10b and 10c, that is, the compositions B and C, respectively. It shows that it has the composition shown. The same applies to the following embodiments.

  Thereby, the molten alloy 8 of the raw material alloy of the composition B and the composition C is supplied onto the rotating roll 9 and gradually cooled, whereby the molten alloy 8 is moved from the contact surface side with the rotating roll 9 toward the outer periphery of the roll. Thus, as shown in FIG. 6, most of the extending direction of the hexagonal crystal structure C surface of the crystal grains 11 is aligned in the plate thickness direction (the direction indicated by the arrow t in the figure). Then, a thick slow cooling foil as the thermoelectric semiconductor materials 10b and 10c is formed.

  In FIG. 6, the crystal grains 11 in the structure of the thermoelectric semiconductor materials 10 b and 10 c are schematically shown as hexagons. The hexagons indicate the actual crystal lattice of the hexagonal crystal structure of the crystal grains 11. For convenience of explanation, the direction of the C-plane of the hexagonal crystal structure of the crystal grain 11 is schematically shown by the hexagonal face, and the direction in which the crystal grain 11 is flattened by the flattening direction of the hexagon. That is, the orientation of the crystal grains 11 is schematically shown. The same applies to the following figures.

Further, the thermoelectric semiconductor materials 10b and 10c of the composition B and the composition C manufactured in the slow cooling foil manufacturing process II have small particle diameters mixed before being sent to the solidification molding process III described below. The powder may be removed in advance by sieving.

Thereafter, as the solidification molding step III, the above slow cooling foil production step II is performed in a reducing gas atmosphere, an inert gas atmosphere, or a container (not shown) capable of maintaining a low oxygen concentration atmosphere such as a vacuum of 10 Pa or less. The thermoelectric semiconductor material 10b annealed foil of composition B and the annealed foil of thermoelectric semiconductor material 10c of composition C, which are separately manufactured in the above, are annealed at one end in the stacking direction. While only the foil is present, only the slow cooling foil of the thermoelectric semiconductor material 10c having the composition C is present at the other end portion in the stacking direction, and the composition B is formed from the one end side toward the other end side in the intermediate portion in the stacking direction. A mixture of the gradually cooled foils of the thermoelectric semiconductor materials 10b and 10c, in which the mixing ratio of the two is gradually changed so that the ratio of the thermoelectric semiconductor material 10b gradually decreases and the ratio of the thermoelectric semiconductor material 10c having the composition C gradually increases, is obtained. Arranged In the so that, in the not-shown mold is filled to stacked in the thickness direction (direction of arrow t) substantially parallel.

  Specifically, the height dimension to be filled by laminating the slow cooling foil in the mold is divided into a plurality of layers, for example, five layers, and the composition B is formed in the first layer which is the lowest layer. Only the thermoelectric semiconductor material 10b is filled, and then the second layer is filled with a slow cooling foil obtained by mixing the thermoelectric semiconductor material 10b and the thermoelectric semiconductor material 10c having the composition C in a ratio of 3: 1, The third layer and the fourth layer are filled with slow cooling foils obtained by mixing the thermoelectric semiconductor material 10b and the thermoelectric semiconductor material 10c with a mixing ratio of 2 to 2, and 1 to 3, respectively. The fifth layer, which is the upper layer, is filled with only the slow cooling foil of the thermoelectric semiconductor material 10c having the composition C.

  Thereafter, the slow cooling foils of the thermoelectric semiconductor materials 10b and 10c filled in the mold are sintered and pressed to be integrally solidified and molded into a desired shape, for example, FIG. ), A rectangular parallelepiped shaped body 12 having a required width dimension corresponding to the width between the restraining members 15 in the plastic working device 13 used in the plastic deformation step IV described later is manufactured.

  Thereby, the molded body 12 has the composition B at one end in the stacking direction of the thermoelectric semiconductor material, the composition C at the other end, and the composition B from the one end side toward the other end. The material has a composition that is inclined so that the composition gradually changes to composition C. FIG. 7B schematically shows a laminated structure of slow cooling foils as the thermoelectric semiconductor materials 10b and 10c, which is the basic structure of the structure of the molded body 12, and FIG. 7 (b) is an enlarged view of a part of the laminated structure of the thermoelectric semiconductor materials 10b and 10c.

  As the reaction conditions at the time of the sintering, while applying a required pressure, for example, a pressure of 14.7 MPa or more, a temperature condition of 500 ° C. or lower, preferably 420 ° C. or higher and 450 ° C. or lower is applied. Thus, the sintering is performed at the temperature for a short time, for example, for about 5 seconds to 5 minutes. The lower limit of the temperature condition range during the sintering is 380 ° C. or higher. This is because when the sintering temperature is less than 380 ° C., the density of the molded body 12 does not increase.

  Furthermore, at the time of the above-mentioned sintering, the sintering object can be made to reach the required sintering temperature condition almost uniformly throughout the whole without causing the temperature distribution to be uneven in the sintering object. It is preferable to perform multistage heating. Here, the multi-stage heating means that the temperature of the sintering object is raised to the required sintering temperature condition using a required heating source (not shown) at least once during the required period, for example, 10 seconds or longer. The heating stop period or the temperature rising rate lowering period can be temporarily stopped by temporarily stopping heating by the heating source or changing the heating rate by the heating source so as to temporarily slow the temperature rising rate of the object to be sintered. The temperature of the entire sintered object is made uniform by utilizing the heat conduction of the sintered object itself, and the entire temperature is made uniform at the temperature in the middle of the temperature rise in this way. In this method, the object is further heated to raise the temperature of the object to be sintered to the above sintering temperature condition, which is the final temperature. Therefore, by making the temperature of the object to be sintered uniform in the middle, even if the heating location by the heating source is uneven, it is possible to suppress uneven distribution of the temperature distribution when the sintering temperature is reached. As a heating device (heating furnace) used for sintering in this case, a normal hot press, energizing hot press, pulse energizing hot press, or the like may be used. Further, the heating stop period and the temperature increase rate decrease period are not limited to 10 seconds or more, and may be arbitrarily set according to the heating capacity of the heating source, the size of the sintering object, and the like. .

The slow cooling foils as the thermoelectric semiconductor materials 10b and 10c of the composition B and the composition C formed in the slow cooling foil manufacturing process II have a large thickness, and when they are laminated as they are, the bulk increases and there are gaps in the laminate. Although there are many, the thermoelectric semiconductor materials 10b, 10c in the solidification molding process III
When the layers are stacked and then sintered under pressure, the atoms of the thermoelectric semiconductor materials 10b and 10c move so as to fill the gaps between the thermoelectric semiconductor materials 10b and 10c. The thermoelectric semiconductor materials 10b and 10c are plastically deformed so that the gaps between the materials 10b and 10c are filled, and the interfaces of the thermoelectric semiconductor materials 10b and 10c that are in contact with the plastic deformation are joined. At this time, with the deformation of the thermoelectric semiconductor materials 10b and 10c, the orientation of the C-plane of the crystal grains 11 aligned so as to be substantially aligned in the plate thickness direction of the thermoelectric semiconductor materials 10b and 10c is somewhat disturbed. As shown in FIG. 3B, the orientation of the crystal grains 11 within the slow cooling foils of the thermoelectric semiconductor materials 10b and 10c constituting the molded body 12 is such that the thermoelectric semiconductor materials 10b and 10c shown in FIG. In this case, the orientation is substantially the same as in the case of (in the direction of arrow t).

  Further, since the molded body 12 is formed by solidifying and molding the slow cooling foils as the thermoelectric semiconductor materials 10b and 10c which are thick in parallel to the plate thickness direction, the thermoelectric semiconductor materials 10a and 10b are Can be easily reduced, and the density of the formed body 12 is improved to about 99% or more compared to the density when a composite compound semiconductor having the same composition is formed into an ideal crystal structure. It becomes possible to make it.

Thereafter, as a plastic deformation step IV, a low oxygen concentration such as a reducing gas atmosphere, an inert gas atmosphere, or a vacuum, for example, an oxygen partial pressure of 0.2 Pa or less can be maintained so as to prevent oxidation of each material. In a sealed container (not shown), as shown in FIGS. 8 (a), (b), and (c), a pair of plate-like restraining members 15 each having a substantially parallel facing surface portion are provided at the left and right positions on the base 14. Requirement corresponding to the dimension in the width direction of the molded body 12 (the dimension in one of the two axial directions intersecting in a plane orthogonal to the main stacking direction of the thermoelectric semiconductor materials 10b and 10c constituting the molded body 12). The punch 16 is disposed so as to be slidable in the vertical direction inside the left and right restraining members 15 while standing upright. The punch 16 can be lowered while applying a load from an upper position of the left and right restraining members 15 to a lower position inside each restraining member 15 by an elevator drive device (not shown). Furthermore, a plastic working device 13 having a heating device (not shown) is prepared at required positions of the base 14, the restraining member 15, and the punch 16, and the punch 16 is moved as shown in FIG. In a state where the restraint member 15 is pulled up to the upper position, the molded body 12 formed in the solidification molding step III is formed at the center inside the restraint members 15. The stacking direction of the materials 10b and 10c (the direction of the arrow t which is the same as the thickness direction of the thermoelectric semiconductor materials 10b and 10c) is arranged parallel to the left and right restraining members 15, and both side surfaces in the width direction of the molded body 12 are It arrange | positions so that the inner surface of the said right and left restraint member 15 may be contacted. Next, in a state where the molded body 12 is heated to a temperature condition of 470 ° C. or less, preferably 450 ° C. or less by a heating device, the punch 16 is moved by an elevating drive device as shown by a two-dot chain line in FIG. And a pressing force of a required load is applied to the molded body 12 from above. Thus, the compact 12 is plastically deformed so as to extend in a uniaxial direction parallel to the stacking direction of the thermoelectric semiconductor materials 10b and 10c, and a rectangular parallelepiped thermoelectric semiconductor material 17 is obtained as shown in FIG. Try to manufacture.

  When the pressing force applied by the punch 16 is applied to the molded body 12 from above by the plastic working device 13, the molded body 12 is restrained by deformation in the width direction by the right and left restraining members 15. Only deformation in the direction parallel to the member 15, that is, the thermoelectric semiconductor materials 10 b and 10 c in the stacking direction (arrow t direction) in the molded body 12 is allowed, and therefore, shear force acts in a uniaxial direction parallel to the stacking direction. Be made. Thereby, the slow cooling foils of the thermoelectric semiconductor materials 10b and 10c of the composition B and the composition C constituting the molded body 12 before the plastic deformation are destroyed and the adjacent ones are integrated with each other. In addition, the shearing force acts on the crystal grains 11 that are oriented so that the C plane of the hexagonal crystal structure extends in a direction parallel to the plate thickness direction of the thermoelectric semiconductor materials 10b and 10c in the molded body 12. The cleaved surface is oriented so as to be perpendicular to the pressing direction while being plastically deformed flat in the direction to be pressed. Therefore, in the structure of the thermoelectric semiconductor material 17 formed after plastic deformation of the molded body 12 as shown in FIG. 9 (a), each crystal grain is schematically shown in FIG. 9 (b). 11, the C-plane of the hexagonal crystal structure is deformed so as to extend in parallel to the extending direction of the molded body 12, that is, the stacking direction (the arrow t direction) of the thermoelectric semiconductor materials 10b and 10c in the molded body 12 before deformation. At the same time, most of the crystal grains 11 are oriented so that their C-axis directions are aligned with the pressing direction (the direction indicated by the arrow p in the figure) during the plastic working. Note that the hexagonal shape in FIG. 9B only indicates the orientation of the crystal grains 11 and does not reflect the actual size of the crystal grains 11. Furthermore, as described above, since the slow cooling foils as the thermoelectric semiconductor materials 10b and 10c are destroyed and the adjacent ones are integrated, in the thermoelectric semiconductor material 17 to be formed, the composition B The slow cooling foil as the thermoelectric semiconductor material 10b and the slow cooling foil as the thermoelectric semiconductor material 10c of the composition C are integrated with each other. For this reason, the thermoelectric semiconductor material 17 has a direction in which the thermoelectric semiconductor materials 10b and 10c are laminated. It is assumed that the composition continuously changes from the composition B to the composition C from one end side to the other end side (t direction in the figure).

  In the plastic working device 13, since a large outward stress is applied to the left and right restraining members 15 during plastic deformation of the molded body 12, as shown in FIG. As a configuration in which a series of position fixing rings 15a is provided so as to surround the outer peripheral side of the member 15, stress acting on the left and right restraining members 15 may be received by the position fixing ring 15a.

  As described above, the N-type thermoelectric semiconductor material 17 of the present invention is obtained by slowly cooling and solidifying the molten alloy 8 of the raw material alloy having the composition B and the composition C by using the rotating roll 9 individually. The thermoelectric semiconductor materials 10b and 10c of the composition B and the composition C each having a structure in which the crystal orientation is improved by orienting in the plate thickness direction and having a length substantially extending over the entire length in the plate thickness direction. The thermoelectric semiconductor materials 10b and 10c are stacked and pressure-sintered while gradually changing the abundance ratio from 100% to 0% to 0% to 100% while maintaining the crystal orientation. Formed body 12 is formed. Further, the molded body 12 has a structure in which the molded body 12 is expanded only in a uniaxial direction substantially parallel to the plate thickness direction of the thermoelectric semiconductor materials 10b and 10c, which is the stacking direction of the thermoelectric semiconductor materials 10b and 10c. The composition of one end portion of the thermoelectric semiconductor material 17 is a region where the absolute value of the Seebeck coefficient is large near room temperature with the composition B, and the composition of the other end portion is the composition C and the absolute value of the Seebeck coefficient is near 300 ° C. The intermediate region can be a gradient composition that continuously changes from composition B to composition C from one end side to the other end side. Therefore, the thermoelectric semiconductor material 17 is heated from one end side to the other end side of the thermoelectric semiconductor material 17 so that one end thereof is kept at a temperature around room temperature and the other end is exposed to a high temperature around 300 ° C. When a temperature gradient is formed from near to 300 ° C., the thermoelectric semiconductor material 17 can obtain a Seebeck coefficient having a large absolute value from one end side to the other end side. Further, when the thermoelectric semiconductor material 17 is manufactured, the molded body 12 is plastically deformed in the stacking direction of the thermoelectric semiconductor materials 10b and 10c at the time of manufacturing the molded body 12, thereby causing recombination at the same time as the destruction of the stacked interface. Therefore, the composition change from the composition B to the composition C can be performed continuously. Therefore, like the conventional thermoelectric semiconductor material made into a functionally graded material as described in Patent Document 1, it is possible to eliminate the inhibition of electrical conduction that has occurred between layers having different compositions.

  Further, since the thermoelectric semiconductor material 17 can substantially align the crystal grains 11 in the hexagonal C-plane extending direction and the C-axis direction, the thermoelectric semiconductor material 17 extends in the C-plane of each of the crystal grains 11. The electric resistance (ρ) can be reduced by setting the direction, that is, the direction in which the current or heat acts in the same direction as the direction in which the composition is continuously inclined from the composition B to the composition C.

  FIG. 10 shows another embodiment of the method for manufacturing a thermoelectric semiconductor material of the present invention. In the plastic deformation step IV in the same procedure for manufacturing a thermoelectric semiconductor material as in the above-described embodiment, a molded body is formed. The uniaxial shearing force action that causes the plastic deformation itself to be performed when pressing 12 to apply a shearing force in a uniaxial direction parallel to the laminating direction of the slow cooling foils of the thermoelectric semiconductor materials 10b and 10c to plastic deformation to a required shape. During the process IV-1, for example, at a low deformation rate, the composition deformation may be performed in a plurality of times by performing one or more omnidirectional hydrostatic pressure processes IV-2. . Here, the omnidirectional hydrostatic pressure step IV-2 is a state in which, during plastic deformation of the molded body 12, the molded body 12 in the middle of the deformation is brought into contact with a surface in the deformation direction to restrain temporary deformation for a certain period of time. A process that continues to apply pressure.

Note that the omnidirectional hydrostatic pressure step IV-2 may be performed twice or more as shown in FIGS. 11 (a), (b), and (c). Preparing a plurality of plastic working devices 13a in which the intervals between the front and rear directions are narrowed and using them in order from the narrowest spacing between the restraining members 18 in the front-rear direction, and lowering the punch 16a in the same manner as described above, thereby solidifying and forming the step. III
A pressing force is applied to the molded product 12 formed from above to apply a shearing force in a uniaxial direction substantially parallel to the stacking direction of the thermoelectric semiconductor material 10 so that the amount of deformation from the initial state sequentially increases. After the plastic deformation, the omnidirectional hydrostatic pressure is applied in a state where the deformation is restrained by the front and rear restraining members 18, and finally, the plastic working device 13 without the front and rear restraining members 18 is expanded in the front-rear direction. What is necessary is just to make it plastically deform.

  In this case, the molded body 12 in the middle of plastic deformation can be densified by performing the omnidirectional hydrostatic pressure process IV-2 on the molded body 12 in the middle of plastic deformation in the uniaxial shear force action step IV-1. In addition, it is possible to prevent the molded body 12 that is finally plastically deformed by the plastic working device 13 from being buckled, and the front and rear restraining members 18 are provided at both ends in the front-rear direction, which are front ends in the plastic deformation direction. Since the shape of both the front and rear ends of the molded body 12 can be adjusted in the middle of plastic deformation, the deformation speed of the molded body 12 to be deformed can be made uniform. Therefore, the uniformity of the structure of the thermoelectric semiconductor material 17 can be improved. Further, when the omnidirectional hydrostatic pressure step IV-2 is performed, the front and rear ends of the molded body 12 abut against the front and rear restraining members 18, so that the C-plane orientation of the crystal grains 11 is obtained at both the front and rear ends of the molded body 12. However, the plastic working device 13 finally applies a shearing force in a uniaxial direction substantially parallel to the lamination direction of the thermoelectric semiconductor material 10 constituting the molded body 12 without restricting the front-rear direction. However, since the thermoelectric semiconductor material 17 to be produced can be substantially aligned in the C-plane direction and the C-axis direction of the crystal grains 11 at both ends in the front-rear direction.

  Next, as a method for manufacturing a thermoelectric semiconductor element of the present invention, an N-type thermoelectric semiconductor element 3a using the N-type thermoelectric semiconductor material 17 manufactured in the embodiment shown in FIGS. The case of manufacturing will be described.

  In this case, one end of the N-type thermoelectric semiconductor material 17 is a region of composition B having temperature suitability on the low temperature side so that a large Seebeck coefficient having a large absolute value can be obtained near room temperature, and the other end is 300 ° C. A region of composition C having temperature suitability on the high temperature side where a large Seebeck coefficient having a large absolute value can be obtained in the vicinity, and the composition continuously changes from composition B to composition C from one end side to the other end side in the intermediate portion. As a functionally gradient material, the direction in which the C plane of the hexagonal crystal structure of the crystal grains 11 extends is aligned along the tilt direction of the composition, and the direction of the C axis is also aligned with the pressing direction during composition deformation processing. It is as. Therefore, as shown in FIGS. 12A and 12B, the hexagonal structure of the crystal grains 11 in the direction of the composition and in the direction of the composition in consideration of the direction of the inclination of the composition and the orientation of the crystal grains 11 with a good orientation. The N-type thermoelectric semiconductor element 3a is formed by cutting so that the current and heat flow directions can be set in the direction in which the C-plane extends.

  Specifically, as shown in FIG. 9B, the N-type thermoelectric semiconductor material 17 is such that the direction of composition gradient and the direction in which the C-plane of the hexagonal crystal structure of each crystal grain extends is the compact 12. Along the extending direction at the time of plastic deformation (arrow t direction), and the C axis of the hexagonal crystal structure of each crystal grain is substantially aligned with the pressing direction at the time of plastic deformation (arrow p direction) Therefore, as shown in FIG. 12 (a), both end surfaces in the composition gradient direction are treated with a conductive material to form a conductive material-treated surface 19 for electrode bonding, and then the thermoelectric semiconductor material 17 is replaced with the thermoelectric semiconductor. A plane perpendicular to the pressing direction (arrow p direction) of the molded body 12 at the time of manufacturing the material 17 and two axes of the pressing direction (arrow p direction) and the extending direction at the time of manufacturing the thermoelectric semiconductor material 17 (arrow t direction). Cut along the specified surface and cut into a rectangular parallelepiped shape as shown in FIG. Diced) to produce a N-type thermoelectric semiconductor element 3a by.

  Thereby, as shown in FIG. 12B, the N-type thermoelectric semiconductor element 3a is oriented in the direction of the conductive material processing surface 19 (the same direction as the extending direction during the manufacture of the thermoelectric semiconductor material 17 indicated by the arrow t in the figure). Along the composition B to the composition C, the C-plane of the hexagonal crystal structure of the crystal grains 11 extends in the same direction, and the C-axis of the crystal grains 11 is connected to the conductive material treated surface 20. The crystal structure is aligned in the pressing direction (arrow p direction in the figure) at the time of manufacturing the thermoelectric semiconductor material 17 out of the two perpendicular axes.

  Therefore, when a temperature gradient from near room temperature to near 300 ° C. is formed from one end side to the other end side, a Seebeck coefficient having a large absolute value can be obtained at a location corresponding to the formed temperature gradient. An element having an inclined composition can be obtained. Furthermore, the C-plane direction of the hexagonal crystal structure can be aligned along the inclination direction of the above composition, and a texture structure including crystal grains 11 with a well-oriented orientation in the C-axis direction is obtained. it can. Thereby, the one end part which becomes the composition B is kept near room temperature, and the other end part which becomes the composition C is heated to a high temperature around 300 ° C., and the hexagonal structure of the crystal grains is in the gradient direction of the composition. By applying a heat flow in the direction along the C-plane, it is possible to obtain an N-type thermoelectric semiconductor element 3a with good thermoelectric performance (high thermoelectric conversion efficiency) capable of performing thermoelectric power generation as a whole.

In the above description, when the N-type thermoelectric semiconductor element 3a is cut out from the N-type thermoelectric semiconductor material 17, cutting is performed on a plane perpendicular to the direction in which the composition is inclined, that is, the direction in which the uniaxial shear force is applied. Therefore, when plastic forming of the molded body 12 is performed in the plastic deformation step IV for manufacturing the N-type thermoelectric semiconductor material 17, the uniaxial shear force of the thermoelectric semiconductor material 17 obtained after the plastic processing is applied and extended. The dimension in the direction may be made to substantially match the dimension desired in the direction in which the final desired heat flow of the N-type thermoelectric semiconductor element 3a acts. Therefore, the thickness to be stacked (filled) when the thermoelectric semiconductor materials 10b and 10c are stacked so as to be stacked in the mold used for manufacturing the molded body 12 in the solidification molding process III is the same as that in the plastic deformation process IV. Thus, the molded body 12 may be determined by calculating back from the deformation amount to be plastically deformed in the main lamination direction of the thermoelectric semiconductor materials 10b and 10c. (The same applies to a P-type thermoelectric semiconductor element 2a described later.)
Next, FIGS. 13 (a), (b), and (c) show other embodiments of the method of manufacturing a thermoelectric semiconductor element of the present invention. As shown in FIGS. In the case where the N-type thermoelectric semiconductor element 3a is manufactured using the N-type thermoelectric semiconductor material 17 manufactured in the embodiment shown in 1 to 9 (A) and (B), the N-type thermoelectric semiconductor material 17 is used. Even if there is a difference in electrical conductivity (σ) due to the difference in composition between the thermoelectric semiconductor material 10b having the composition B and the thermoelectric semiconductor material 10c having the composition C selected for manufacturing the N The electric resistance in the direction along the direction in which the composition is inclined from the composition B to the composition C in the type thermoelectric semiconductor element 3a can be made uniform over the entire element.

  That is, in order to make the electrical resistance constant, the product in the energization direction depends on the value of the electrical conductivity (σ) so that the product of the electrical conductivity (σ) and the cross-sectional area in the energization direction of the element is constant. What is necessary is just to set a cross-sectional area. Specifically, the N-type thermoelectric semiconductor element 3a having a composition that inclines from the composition B to the composition C from one end side to the other end side, the one end side, which is a temperature condition assumed to be used, at room temperature. When the temperature condition is in the vicinity and the other end side is in the vicinity of 300 ° C., the electrical conductivity on one end side and the other end side in the N-type thermoelectric semiconductor element 3a has the composition B shown in FIG. The value of the electric conductivity when the thermoelectric semiconductor material is set to a temperature condition near room temperature and the electric conductivity when the thermoelectric semiconductor material having the composition C shown in FIG. As is apparent from the values, the electric conductivity on one end under the temperature condition near the normal temperature is larger than the electric conductivity on the other end under the temperature condition near 300 ° C. Therefore, in consideration of the difference in electrical conductivity between the one end side and the other end side, the cross-sectional area on the one end side that becomes the composition B is smaller than the cross-sectional area on the other end side that becomes the composition C. From the thermoelectric semiconductor material 17 as shown in FIGS. 9 (a) and 9 (b), FIG. 13 (a) is parallel to a plane perpendicular to the pressing direction (arrow p direction) of the molded body 12 when the thermoelectric semiconductor material 17 is manufactured. It cuts out in the trapezoid shape as shown, or the biaxial of the pressing direction (arrow p direction) of the molded object 12 at the time of manufacture of the thermoelectric semiconductor material 17 and the extending direction (arrow t direction) at the time of manufacture of the thermoelectric semiconductor material 17 N-type thermoelectric semiconductor element 3a by cutting out into a trapezoidal shape as shown in FIG. 13 (b) parallel to the plane defined in FIG. 13 or by cutting out into a truncated pyramid shape as shown in FIG. 13 (c). Are formed.

  13 (a), (b), and (c), the same components as those shown in FIGS. 9 (a) and (b) are denoted by the same reference numerals.

Next, a case where a P-type thermoelectric semiconductor material is manufactured will be described. In this case, first, in the same manner as the method for manufacturing the N-type thermoelectric semiconductor material, a temperature range that is assumed to act when the thermoelectric semiconductor element to be manufactured is used, for example, each thermoelectric module of the thermoelectric module when performing thermoelectric power generation. When the temperature range assumed to act on the semiconductor element is from about room temperature to about 300 ° C., based on the stoichiometric composition of the N-type thermoelectric semiconductor that is (Bi—Sb) ₂ Te ₃ in advance, Various thermoelectric performance materials in the temperature range from around room temperature to around 300 ° C. with respect to thermoelectric semiconductor materials formed with various compositions in which the component ratio of each element is changed or the kind and addition amount of the dopant are changed. Parameters such as power factor (P), Seebeck coefficient (α), and electrical conductivity (σ) are collected, and based on the collected data, Composition of P-type thermoelectric semiconductor capable of exhibiting excellent thermoelectric performance on the low temperature side near the temperature, composition of P-type thermoelectric semiconductor capable of exhibiting excellent thermoelectric performance on the high temperature side near 300 ° C., and if necessary A composition of a P-type thermoelectric semiconductor that can exhibit excellent thermoelectric performance in an intermediate temperature range from room temperature to 300 ° C. is selected.

  That is, for example, the stoichiometric composition (composition F) of a P-type thermoelectric semiconductor of Bi: 10 atomic%, Sb: 30 atomic%, Te: 60 atomic%, Bi: 9 atomic%, Sb: 31 atomic%, 3: a composition in which the Sb concentration was increased with Te: 60 atomic% (composition G), Bi: 8 atomic%, Sb: 32 base paper%, and a composition in which the Sb concentration was further increased with Te: 60 atomic% (composition H). For each type of composition, change in Seebeck coefficient (α) with respect to temperature as shown in FIG. 14, change in electrical conductivity (σ) with respect to temperature as shown in FIG. 15, and power factor (P) as shown in FIG. Suppose data about changes with temperature is obtained. In this case, as a parameter for evaluating the thermoelectric performance, for example, when attention is paid to the temperature suitability of the Seebeck coefficient (α) shown in FIG. 14, the absolute value of the Seebeck coefficient (α) on the low temperature side near room temperature. Is selected as the material composition of the thermoelectric semiconductor suitable for the low temperature side, while the composition H that increases the absolute value of the Seebeck coefficient (α) on the high temperature side near 300 ° C. is suitable for the high temperature side. In addition, the composition G having a larger absolute value of the Seebeck coefficient (α) than the composition F and the composition H in the substantially intermediate temperature range between normal temperature and 300 ° C. is selected as the intermediate temperature. A composition having temperature suitability in the region is selected.

  Next, as the component adjustment step I, the alloy of the thermoelectric semiconductor material alloy having the composition F, the thermoelectric semiconductor material alloy having the composition G, and the thermoelectric semiconductor material alloy having the composition H are separately charged.

  Next, as in the case of manufacturing the N-type thermoelectric semiconductor material 17, the composition F and the composition mixed in the component adjustment step I using the apparatus shown in FIG. For each metal mixture of the raw material alloys of G and composition H, a rotating roll 9 in which the molten alloy is melted in a melting crucible 6 to form a molten alloy 8 and then the molten alloy is rotated at a low peripheral speed of 5 m / sec or less. The thin plate-like thermoelectric semiconductor materials 10f, 10g, and 10h (gradual cooling foils) similar to the thermoelectric semiconductor materials 10b and 10c shown in FIG. To manufacture. Here, the peripheral speed of the rotating roll 9 is set to 5 m / second or less, as in the case of forming the N-type thermoelectric semiconductor materials 10b and 10c, the thickness of the gradually cooled foil to be generated is increased, This is to make it possible to obtain thermoelectric semiconductor materials 10f, 10g, and 10h having good crystal orientation and large crystal grains 11 extending over almost the entire length in the plate thickness direction.

Accordingly, the thermoelectric semiconductor materials 10f, 10g, and 10h having the composition F, the composition G, and the composition H, which are the material compositions of the P-type thermoelectric semiconductor, are all the same as the N-type thermoelectric semiconductor materials 10b and 10c described above. Further, when cooled on the rotary roll 9, it is solidified while the crystal orientation is aligned in the plate thickness direction, so that the crystal grains 11 are substantially in the plate thickness direction as shown in FIG. It is in the state extended long so that the dimension of thickness may be reached. The thermoelectric semiconductor materials 10f, 10g, and 10h may be sieved in advance to remove the powder before the solidification molding step III described later.

Next, as the solidification molding process III, the composition F manufactured separately in the slow cooling foil manufacturing process II.
P-type thermoelectric semiconductor materials 10f, 10g, and 10h of each of the composition G and composition H, and only the slow-cooling foil of the thermoelectric semiconductor material 10f of the composition F is present at one end in the stacking direction, Only the slow cooling foil of the thermoelectric semiconductor material 10g having the composition G is present in the central portion in the stacking direction, and only the slow cooling foil of the thermoelectric semiconductor 10h having the composition H is present in the other end in the stacking direction. In the region from one end to the center, the ratio of the slow cooling foil of the thermoelectric semiconductor 10f having the composition F is gradually decreased, and at the same time, the mixing ratio of the two is so that the ratio of the slow cooling foil of the thermoelectric semiconductor 10g having the composition G is gradually increased. Is gradually changed, and in the region from the central portion to the other end in the stacking direction, the rate of the gradually cooled foil of the thermoelectric semiconductor material 10g having the composition G is gradually decreased and the thermoelectric semiconductor 10h having the composition H is gradually decreased. The proportion of cold foil gradually increases To such as mixing ratio of both is gradually changed, in a mold (not shown), Xu Hiyahaku of the thermoelectric semiconductor material 10f and 10g and 10h, substantially parallel to stacked in a thickness direction.

  Specifically, the height dimension to be stacked and filled with the slow cooling foil in the mold is divided into, for example, five layers, and the first layer which is the lowest layer is formed of the thermoelectric semiconductor material 10f having the composition F. Filled only with slow cooling foil, and then in the second layer, the slow cooling foil of composition F of thermoelectric semiconductor material 10f and the slow cooling foil of thermoelectric semiconductor material 10g of composition G were mixed one-on-one. The foil is filled, and the third layer is filled only with a slow cooling foil of 10 g of the thermoelectric semiconductor material of composition G, and the fourth layer of the slow cooling foil of the thermoelectric semiconductor material 10 g of composition G and the composition H. Fill the 5th layer, which is a one-to-one mixture with the thermoelectric semiconductor material 10h, and fill only the slow cooling foil of the thermoelectric semiconductor material 10h of composition H in the fifth layer which is the uppermost layer. That's fine.

  Next, the thermoelectric semiconductor materials 10f, 10g, 10h filled in the mold are subjected to the same pressure conditions, temperature conditions, and multistage heating method as in the production of the molded body 12 having the N-type composition. By using and sintering, the laminated thermoelectric semiconductor materials 10f, 10g, and 10h are solidified while being plastically processed so as to be in contact with each other by filling the gaps between the thermoelectric semiconductor materials 10f, 10g, and 10h, As shown in FIGS. 17 (a), (b), and (c), a rectangular parallelepiped shaped body 12 similar to that shown in FIGS. 7 (a), (b), and (c) is manufactured.

  As a result, the gaps between the P-type thermoelectric semiconductor materials 10f, 10g, and 10h are reduced, and the density of the formed body 12 is the same when the composite compound semiconductor having the same composition has an ideal crystal structure. The density can be improved to about 99% or more as compared with the density.

  Thereafter, as the plastic deformation step IV, as in the case of manufacturing the N-type thermoelectric semiconductor material 17, the above-described forming is performed by the plastic working device 13 as shown in FIGS. 8 (a), (b), (c), and (d). The body 12 is plastically deformed so as to be expanded only in a uniaxial direction substantially parallel to the lamination direction of the thermoelectric semiconductor materials 10f, 10g, and 10h in a state heated to 500 ° C. or less, preferably 350 ° C. or less. P-shaped thermoelectric semiconductor material 17 is manufactured.

  As a result, the shearing force is applied only in the stacking direction of the thermoelectric semiconductor materials 10f, 10g, and 10h, as shown in FIGS. 18 (a) and (b). Similarly, the crystal grains 11 oriented in the thickness direction of the thermoelectric semiconductor materials 10f, 10g, and 10h inside the compact 12 are cleaved while being flatly plastically deformed in the uniaxial direction where the shearing force acts. The plane is oriented so as to be substantially perpendicular to the pressing direction, and the C-plane of the hexagonal crystal structure of each crystal grain 11 is deformed so as to extend in the extending direction (the direction of the arrow t in FIGS. 18A and 18B). P-type thermoelectric semiconductor material 17 is formed in a state in which the C-axis of most crystal grains 11 is oriented in the compression direction at the time of plastic deformation (the direction of arrow p in FIGS. 18A and 18B). Further, during the plastic deformation, the slow cooling foils laminated with the thermoelectric semiconductor materials 10f, 10g, and 10h are laminated together because the laminated interface is destroyed and the adjacent ones are integrated with each other. The thermoelectric semiconductor material 17 of the mold was provided with a composition that continuously changed from composition F to composition H from one end side to the other end side in the laminating direction of the slow cooling foil, that is, a gradient composition. It is supposed to be.

  Therefore, also in the P-type thermoelectric semiconductor material 17, one end side in the stacking direction of the thermoelectric semiconductor materials 10 f, 10 g, and 10 h is defined as a region in which the absolute value of the Seebeck coefficient increases near room temperature as a region composed of the composition F. The central portion in the stacking direction can be a region in which the absolute value of the Seebeck coefficient is large at an intermediate temperature between room temperature and 300 ° C. as the region made of the composition G, and the other end side in the stacking direction is The region composed of the composition H can be a region where the absolute value of the Seebeck coefficient becomes large at around 300 ° C. Further, the region from one end side to the intermediate portion and from the intermediate portion to the other end side is composed of the composition F to the composition. It can be set as the area | region where a composition changes continuously, without having a lamination | stacking interface from G and the composition G to the composition H, respectively.

  Therefore, the P-type thermoelectric semiconductor material 17 is exposed to a high temperature around 300 ° C. while one end in the stacking direction of the thermoelectric semiconductor material is kept at a temperature near room temperature and the other end is exposed to a high temperature around 300 ° C. When a temperature gradient from near normal temperature to near 300 ° C. is generated from one end side of the material 17 to the other end side, a Seebeck coefficient having a large absolute value is obtained over the entire range from one end side to the other end side of the thermoelectric semiconductor material. It can be obtained.

  Further, the molded body 12 is plastically deformed in the stacking direction of the thermoelectric semiconductor materials 10f, 10g, and 10h at the time of manufacturing the molded body 12 at the time of manufacturing the thermoelectric semiconductor material 17, thereby causing recombination at the same time as the destruction of the stacked interface. Since the interface region can be eliminated, the composition can be continuously changed from the composition F to the composition H through the composition G. Therefore, similarly to the N-type thermoelectric semiconductor material 17, it is possible to eliminate the possibility that electric conduction is inhibited between layers having different compositions.

  Further, the P-type thermoelectric semiconductor material 17 has a direction in which the C plane of the hexagonal crystal structure of each crystal grain 11 extends along the stacking direction of the thermoelectric semiconductor materials, that is, the direction in which the gradient of the composition is formed. In addition, since the C-axis direction can be substantially aligned, the electric resistance (specific resistance: ρ) is set by setting the direction in which the current and heat act so as to generate a temperature gradient in the gradient direction of the composition. Can be reduced.

  When the P-type thermoelectric semiconductor material 17 is manufactured, the omnidirectional hydrostatic pressure step IV-2 in the plastic deformation step IV shown in FIG. 10 may be performed.

  Next, the case where the P-type thermoelectric semiconductor element 2a is manufactured using the P-type thermoelectric semiconductor material 17 manufactured by the above method will be described.

  In this case, also in the P-type thermoelectric semiconductor material 17, as shown in FIGS. 18A and 18B, as in the N-type thermoelectric semiconductor material 17 shown in FIGS. A gradient of composition is provided from one end side to the other end side in the stacking direction of the thermoelectric semiconductor materials 10f, 10g, and 10h when the semiconductor material 17 is manufactured, and a temperature gradient from near normal temperature to near 300 ° C. from one end side to the other end side. As a result, the absolute value of the Seebeck coefficient is increased over the entire structure, and the C-plane of the hexagonal crystal structure of most of the crystal grains 11 over the entire structure is in the plastic deformation state of the compact 12. Extending in the inclination direction of the composition in the same direction as the spreading direction (direction of arrow t in FIGS. 18A and 18B), and the C-axis is the pressing direction during the plastic deformation (FIGS. 18A and 18B). In the direction of arrow p in FIG. Thus, the P-type thermoelectric semiconductor material 17 is first shown in FIG. 19A, similarly to the method for manufacturing the N-type thermoelectric semiconductor element 3a shown in FIGS. Thus, the conductive material treatment is performed on both end faces in the extending direction (arrow t direction) at the time of plastic deformation of the molded body 12 to form a conductive material treatment surface 19, and then the P-type thermoelectric semiconductor material 17 is Cutting is performed by a plane defined by two axes, that is, a plane perpendicular to the pressing direction of the molded body 12 when the thermoelectric semiconductor material 17 is manufactured and the extending direction (arrow t direction) when the thermoelectric semiconductor material 17 is manufactured. By cutting out, a rectangular parallelepiped P-type thermoelectric semiconductor element 2a similar to the N-type thermoelectric semiconductor element 3a shown in FIG. 12B is manufactured as shown in FIG.

  As a result, the P-type thermoelectric semiconductor element 2a is formed from the composition F in the direction of the pair of opposing surfaces (conductive material-treated surface 19) where the conductive material treatment has been performed, like the N-type thermoelectric semiconductor element 3a described above. The composition has a composition that continuously slopes to composition H via composition G, the C-plane of the hexagonal crystal structure of crystal grains 11 extends long in the same direction, and the C-axis of crystal grains 11 is perpendicular to the conductive material-treated surface 19. Among the two biaxial directions, the crystal structure is aligned in the pressing direction (arrow p direction) when the thermoelectric semiconductor material 17 is manufactured.

  Therefore, also in the P-type thermoelectric semiconductor element 2a, as in the N-type thermoelectric semiconductor element 3a of the present invention described above, from one end side that is the composition F to the other end side that is the composition H, from around normal temperature to around 300 ° C. When the temperature gradient is formed, an element having a gradient composition can be obtained so that a Seebeck coefficient having a large absolute value can be obtained at a location corresponding to the formed temperature gradient. Furthermore, the C-plane direction of the hexagonal crystal structure can be aligned along the inclination direction of the above composition, and a texture structure including crystal grains 11 with a well-oriented orientation in the C-axis direction is obtained. it can. Thereby, the one end part that becomes the composition F is held at around room temperature, and the other end part that becomes the composition H is heated to a high temperature around 300 ° C., so that the hexagonal structure of the crystal grains is in the tilt direction of the composition. By causing the heat flow to act in the direction along the C-plane, it is possible to obtain a P-type thermoelectric semiconductor element 2a with good thermoelectric performance (high thermoelectric conversion efficiency) that can efficiently perform thermoelectric power generation as a whole.

  When the P-type thermoelectric semiconductor element 2a is cut out from the P-type thermoelectric semiconductor material 17, the thermoelectric semiconductor materials of the composition F, the composition G, and the composition H are electrically conductive with each other due to the difference in composition. When the rates are different, the relationship between the electrical conductivity of each composition shown in FIG. 15 and the temperature condition is taken into account, and the trapezoidal shape, as shown in FIGS. 13 (a), (b), and (c), Alternatively, the P-type thermoelectric semiconductor element 2a is formed by cutting into a truncated pyramid shape so that the electrical resistance of the entire element along the direction in which the above-described composition that is the energization direction is inclined is made uniform. Good.

  Furthermore, as still another embodiment of the present invention, a thermoelectric module using the P-type and N-type thermoelectric semiconductor elements 2a and 3a manufactured by the method of the present invention and a manufacturing method thereof will be described.

  FIG. 20 shows the thermoelectric module 1a of the present invention. When forming a PN element pair as in the conventional thermoelectric module 1 shown in FIG. 23, the P-type manufactured by the manufacturing method of the present invention is used. The thermoelectric semiconductor element 2a and the N-type thermoelectric semiconductor element 3a are provided with a temperature suitability on the low temperature side by providing an inclination to each composition (the composition F side in the P-type thermoelectric semiconductor element 2a and the N-type thermoelectric semiconductor element) 3a) at the ends and the ends on the high temperature side (the composition H side in the P-type thermoelectric semiconductor element 2a and the composition C side in the N-type thermoelectric semiconductor element 3a). They are aligned on the same side and arranged side by side in the direction in which the C plane of the hexagonal crystal structure of the crystal grains 11 in the tilt direction of the composition extends and in the direction perpendicular to the C-axis direction. That. Further, by inclining the composition in each of the thermoelectric semiconductor elements 2a and 3a, the conductive material processing surfaces 19 formed at the end portion on the side having temperature suitability on the low temperature side are connected to each other via the metal electrode 4a on the low temperature side. In addition to bonding, the conductive material treated surfaces formed at the end portions having temperature suitability on the high temperature side are bonded via the metal electrode 4b on the high temperature side.

  As a result, in the thermoelectric module 1a of the present invention, the low-temperature side metal electrode 4a is held near room temperature, and the high-temperature side metal electrode 4b is exposed to a high temperature around 300 ° C. The thermoelectric semiconductor elements 2a and 3a have a large Seebeck coefficient with a large absolute value as a whole by generating a temperature gradient from near room temperature to about 300 ° C. in the composition inclination direction with respect to the semiconductor elements 2a and 3a. It can be set as the element which can do. For this reason, it becomes possible to perform thermoelectric power generation efficiently by applying the above temperature condition. Further, in both the P-type thermoelectric semiconductor element 2a and the N-type thermoelectric semiconductor element 3a, the extending direction of the C plane of the crystal grain 11 is the same as the inclination direction of the composition, that is, the opposing metal electrodes 4a and 4b. Since the electric current and the heat are applied in between, and the C-axis direction is substantially aligned, the thermoelectric module 1a with good thermoelectric performance can be obtained.

  When thermoelectric cooling, thermoelectric heating, thermoelectric power generation or the like is performed using the thermoelectric module 1a, the metal electrodes 4a and 4b expand and contract with temperature change, so that the metal electrodes 4a or 4b are joined together. The adjacent P-type and N-type heat transfer semiconductor elements 2a and 3a are subjected to stress in the approaching and separating directions. In the thermoelectric module 1a of the present invention, the PN element pair is When forming, adjacent thermoelectric semiconductor elements 2a and 3a joined by one metal electrode 4a or 4b are arranged in the same plane in the C-plane direction of crystal grains 11 as shown in FIG. Therefore, the stress accompanying the expansion and contraction of the metal electrode 4a or 4b can be applied to each crystal grain 11 only in the direction parallel to the C plane. Therefore, even if the stress is applied, the possibility of delamination of the hexagonal crystal grains 11 in the structure of the thermoelectric semiconductor elements 2a and 3a can be prevented. Therefore, the thermoelectric semiconductor elements 2a and 3a can be prevented. Can be prevented from being cleaved, and the strength and durability of the thermoelectric module 1a can be improved. That is, as shown in FIG. 21 as a comparative example, the P-type and N-type thermoelectric semiconductor elements 2 a and 3 a are arranged side by side in the C-axis direction of the hexagonal crystal structure of the crystal grains 11. When the elements 2a and 3a are joined via the metal electrode 4 to form a PN element pair, the stress due to the expansion and contraction deformation caused by the temperature change of the metal electrode 4 is caused by the stress generated in each of the heat transfer semiconductor elements 2a and 3a. In contrast, it acts along the C-axis direction of the crystal grains 11. Therefore, since it acts to peel off the hexagonal crystal structure of the crystal grains 11, in this case, it is considered that the thermoelectric semiconductor elements 2a and 3a are easily damaged by cleavage. In the thermoelectric module 1a of the present invention, occurrence of such damage can be prevented.

In addition, this invention is not limited only to the said embodiment, The process conditions at the time of solidification shaping | molding (sintering) of the thermoelectric semiconductor raw material 10 in the solidification shaping | molding process III of the manufacturing method of a thermoelectric semiconductor material are 380 degreeC. Above 500 ° C., preferably 420 ° C. to 450 ° C. for 5 seconds to 5 minutes, but it is possible to sinter at 400 ° C. or less over time, and press, rolling It is also possible to form the molded body 12 by applying plastic deformation by extrusion. The plastic working device 13 used in the plastic deformation step IV has a structure in which the punch 16 can be moved up and down inside the left and right restraining members 15, and the molded body 12 is placed at the center inside the left and right restraining members 15. Arranged and pressed the molded body 12 from above with a punch 16 so that the molded body 12 is expanded to both front and rear sides in a uniaxial direction parallel to the lamination direction of the thermoelectric semiconductor material 10. However, as shown in FIGS. 22 (a) and 22 (b), the plastic working device 13 is deformed (expanded) in the front-rear direction of the molded body 12 at a position on one end side between the left and right restraining members 15 on the base 14. When the molded body 12 is plastically deformed, the molded body 12 is first brought into contact with the left and right restraint members 15 and the restraint member 15b. Then, as shown by a two-dot chain line in FIG. 22 (a), the molded body 12 is pressed from above by the punch 16 so that the molded body 12 is only in one direction on the anti-restraining member 15b side. You may make it extend. The plastic working device 13a used in the omnidirectional hydrostatic pressure process IV-2 shown in FIGS. 11 (a), 11 (b) and 11 (c) is arranged on the outer peripheral side of the restraining member 15 in the left-right direction and the restraining member 18 in the front-rear direction. A position fixing ring 15a similar to that shown in (d) may be provided so as to receive an outwardly acting stress on the restraining members 15 and 18 when the molded body 12 is plastically deformed. When the omnidirectional hydrostatic pressure step IV-2 is performed twice or more, instead of preparing a plurality of plastic working devices 13a having different intervals between the front and rear direction restraining members 18, the front and rear direction restraining members 18 are provided. You may make it use the plastic processing apparatus 13a of the form which can be adjusted to arbitrary intervals.

The composition of the thermoelectric semiconductor raw material alloy was selected based on the temperature characteristics of the Seebeck coefficient of the thermoelectric semiconductor material in both cases of P-type and N-type, but the electrical conductivity (σ) and power factor The composition may be determined based on the temperature characteristics of other parameters related to thermoelectric performance such as (P) and figure of merit (Z). The N-type thermoelectric semiconductor material 17 is shown as a composition in which two compositions of a low-temperature side composition B and a high-temperature side composition C are continuously inclined, and the P-type thermoelectric semiconductor material 17 is composed from the low-temperature side to the high-temperature side. The three different compositions of F, composition G, and composition H have been shown as being continuously graded, but it relates to the temperature range expected to act on the thermoelectric semiconductor element of the thermoelectric module to be manufactured and the desired thermoelectric performance. Depending on the temperature characteristics of the parameters, the number of compositions to be inclined from the low temperature side to the high temperature side may be arbitrarily set.
In addition, the composition gradient may be changed by changing the concentration or addition amount of any component other than Se or Sb, and three or more composition changes are performed from the low temperature side to the high temperature side. When trying to make it change, you may make it change the density | concentration and addition amount of a different component by the case where it changes from one composition to another composition, and the case where it changes from this another composition to another composition. The temperature gradient assumed to act on the thermoelectric semiconductor element of the thermoelectric module to be manufactured has been described as being from around room temperature to around 300 ° C., but the temperature on the low temperature side and the high temperature side depends on the purpose and place of use of the thermoelectric module. Each may be set arbitrarily. In the embodiment shown in FIGS. 13A, 13B, and 13C, the thermoelectric semiconductor element 3a has a cross-sectional area on the composition B side having temperature suitability on the low temperature side, and on the composition C side having temperature suitability on the high temperature side. Although shown as a trapezoidal or pyramidal trapezoidal shape that is smaller than the area, the electrical conductivity when a portion of the composition having temperature suitability on the high temperature side is placed under high temperature conditions has temperature suitability on the low temperature side In the case where the electrical conductivity becomes higher when the portion of the composition is placed under a low temperature condition, the cross-sectional area of the portion having the temperature suitability on the high temperature side is the composition having the temperature suitability on the low temperature side. You may cut out so that it may become narrower than the cross-sectional area of a part. The thermoelectric semiconductor element of the present invention, the thermoelectric semiconductor material used for manufacturing the thermoelectric semiconductor, and the thermoelectric module using the thermoelectric semiconductor element can be applied to thermoelectric cooling and thermoelectric heating in addition to thermoelectric power generation, Of course, various changes can be made without departing from the scope of the present invention.

It is a figure which shows the flow in one Embodiment of the manufacturing method of the thermoelectric-semiconductor material of this invention. It is a figure which shows the correlation with respect to the temperature change of Seebeck coefficient about the material of the N-type thermoelectric semiconductor of a several different composition. It is a figure which shows the correlation with respect to the temperature change of an electrical conductivity about the material of the N type thermoelectric semiconductor of a several different composition. It is a figure which shows the correlation with respect to the temperature change of the power factor about the material of the N type thermoelectric semiconductor of a several different composition. It is a figure which shows the outline | summary of the apparatus used at the slow cooling foil manufacturing process of FIG. It is a schematic perspective view which shows the thermoelectric semiconductor raw material formed in the slow cooling foil manufacturing process of FIG. FIGS. 1A and 1B show a molded body formed from an N-type thermoelectric semiconductor material in the solidification molding step of FIG. 1. FIG. 1A is a schematic perspective view, and FIG. 1B is a perspective view schematically showing a laminated structure of thermoelectric semiconductor materials. (C) is an expansion perspective view which cuts and shows a part of (b). FIG. 2 shows a plastic working apparatus used in the plastic deformation step of FIG. 1, (A) is a schematic cut side view showing an initial state of the molded body before plastic deformation, and (B) is a view in the AA direction of (A). Fig. (C) is a schematic cut side view showing a state in which a thermoelectric semiconductor material is formed by plastic deformation of a molded body. (D) is a diagram corresponding to (b) showing a type having a position fixing ring. It is. FIGS. 2A and 2B show an N-type thermoelectric semiconductor material formed in the plastic deformation step of FIG. 1. FIG. 1A is a schematic perspective view, and FIG. 2B is a perspective view schematically showing crystal grain orientation. It is a figure which shows the flow in other form of implementation of the manufacturing method of the thermoelectric-semiconductor material of this invention. FIG. 11 shows a plastic working apparatus used for the implementation of the omnidirectional hydrostatic pressure step of FIG. 10, (A) is a schematic cut side view showing an initial state before plastic deformation of the molded body, and (B) is B- of (A). B direction arrow directional view, (c) is a schematic cut side view showing a state in which omnidirectional hydrostatic pressure is applied to a molded body that has been plastically deformed in a required amount. The procedure of the manufacturing method of the thermoelectric semiconductor element of this invention is shown, (A) is the state which performed the electrically conductive material process to the N-type thermoelectric semiconductor material, (B) is cut out from the thermoelectric semiconductor material of (A). It is a schematic perspective view which shows each N type thermoelectric semiconductor element. (A), (B), and (C) are schematic perspective views showing an N-type thermoelectric semiconductor element cut out from a thermoelectric semiconductor material as another embodiment of the method for manufacturing a thermoelectric semiconductor element of the present invention. It is a figure which shows the correlation with respect to the temperature change of a Seebeck coefficient about the material of the P-type thermoelectric semiconductor of a several different composition. It is a figure which shows the correlation with respect to the temperature change of electrical conductivity about the material of the P-type thermoelectric semiconductor of a several different composition. It is a figure which shows the correlation with respect to the temperature change of a power factor about the material of the P-type thermoelectric semiconductor of several different composition. FIG. 1 shows a molded body formed from a P-type thermoelectric semiconductor material in the solidification molding step of FIG. 1, (A) is a schematic perspective view, and (B) is a perspective view schematically showing a laminated structure of thermoelectric semiconductor materials. (C) is an expansion perspective view which cuts and shows a part of (b). FIGS. 2A and 2B show a P-type thermoelectric semiconductor material formed in the plastic deformation step of FIG. 1. FIG. 1A is a schematic perspective view, and FIG. 2B is a perspective view schematically showing crystal grain orientation. The procedure of the manufacturing method of the thermoelectric semiconductor element of the present invention is shown. (A) shows a state where a P-type thermoelectric semiconductor material is treated with a conductive material, and (B) is cut out from the thermoelectric semiconductor material of (A). It is a schematic perspective view which shows each P type thermoelectric semiconductor element. It is a schematic perspective view which shows one Embodiment of the thermoelectric module of this invention. It is a schematic perspective view which shows the comparative example of the thermoelectric module of FIG. The other example of the plastic working apparatus used at the plastic deformation process of FIG. 1 is shown, (A) is a schematic cut | disconnection side view, (B) is a CC direction arrow directional view of (A). It is a perspective view which shows the outline of an example of a thermoelectric module. It is a schematic side view which shows an example of the thermoelectric module using the thermoelectric semiconductor element formed by laminating | stacking the thermoelectric semiconductor material of a different composition proposed conventionally.

Explanation of symbols

I Component preparation process
II Slow cooling foil manufacturing process
III Solidification process
IV Composition deformation process 1, 1a Thermoelectric module 2, 2a P-type thermoelectric semiconductor element 3, 3a N-type thermoelectric semiconductor element 4 Metal electrode 4a Low-temperature side metal electrode (electrode)
4b High-temperature side metal electrode (electrode)
8 Molten alloy 9 Rotating roll (cooling member)
10b, 10c, 10f, 10g, 10h Thermoelectric semiconductor material 12 Molded body 17 Thermoelectric semiconductor material

Claims (43)

For thermoelectric semiconductor materials with different compositions, the thermoelectric performance of the change to temperature obtained with the Seebeck coefficient as a parameter for evaluating thermoelectric performance in different temperature ranges in the temperature range from the low temperature side to the high temperature side. Based on the data, the thermoelectric semiconductor composition that can exhibit superior thermoelectric performance by comparing the thermoelectric performance that can exhibit the different thermoelectric semiconductor compositions on the low temperature side, and the thermoelectric that can exhibit the different thermoelectric semiconductor compositions on the high temperature side. Select a thermoelectric semiconductor composition that can exhibit superior thermoelectric performance by comparing performance, or thermoelectric semiconductor that can exhibit superior thermoelectric performance by comparing the thermoelectric performance that can exhibit the different thermoelectric semiconductor compositions on the low temperature side Of thermoelectric semiconductors that can exhibit excellent thermoelectric performance by comparing the thermoelectric performance that can be exhibited by the different thermoelectric semiconductor compositions on the high temperature side And comparing the thermoelectric performance that can exhibit the composition of each of the different thermoelectric semiconductors in the temperature range from the low temperature side to the high temperature side, and selecting the composition of the thermoelectric semiconductor that can exhibit excellent thermoelectric performance, the selected composition different thermoelectric semiconductor material and a layer stacked filled into solidified molding in the order of the high temperature side from the low temperature side and the molded body, the molded article, pressed from the uniaxial direction perpendicular to the product layer the direction of different thermoelectric semiconductor material having the composition of and plastically deformed so as shearing force is applied to the flat line uniaxial direction to the product layer the direction of different thermoelectric semiconductor material having the above composition, the gradient of composition along the stacking direction of the thermoelectric semiconductor material is provided, the The crystal grains in the structure of the thermoelectric semiconductor material have a hexagonal C-plane extending in the tilt direction of the composition, and the C-axis direction is also aligned to enhance crystal orientation. Thermoelectric semiconductor characterized by Material. The thermoelectric semiconductor material according to claim 1 , wherein a parameter for evaluating the thermoelectric performance is changed to an electric conductivity instead of the Seebeck coefficient . The thermoelectric semiconductor material according to claim 1 , wherein a parameter for evaluating the thermoelectric performance is changed to a power factor in place of the Seebeck coefficient . The thermoelectric semiconductor material according to claim 1 , wherein a parameter for evaluating the thermoelectric performance is used as a figure of merit instead of the Seebeck coefficient . The thermoelectric semiconductor material according to claim 1, 2, 3, or 4 , wherein the thermoelectric semiconductor material is a plate-shaped thermoelectric semiconductor material formed by melting a raw material alloy having a plurality of thermoelectric semiconductor compositions individually and then slowly cooling it. Semiconductor material. The thermoelectric semiconductor material of a plurality of compositions, both _(Bi-Sb) 2 Te ₃ system claims a composition were of compositions comprising varying the Ingredient based on 1, 2, 3, 4 or 5, wherein Thermoelectric semiconductor material. The thermoelectric semiconductor material of a plurality of compositions, both _Bi 2 _{(Te-Se) 3} based claim 1, 2, 3 compositions were of compositions comprising varying the Ingredient based on the, 4 or 5, wherein Thermoelectric semiconductor material. For thermoelectric semiconductor materials with different compositions, the thermoelectric performance of the change to temperature obtained with the Seebeck coefficient as a parameter for evaluating thermoelectric performance in different temperature ranges in the temperature range from the low temperature side to the high temperature side. Based on the data, the thermoelectric semiconductor composition that can exhibit superior thermoelectric performance by comparing the thermoelectric performance that can exhibit the different thermoelectric semiconductor compositions on the low temperature side, and the thermoelectric that can exhibit the different thermoelectric semiconductor compositions on the high temperature side. Select a thermoelectric semiconductor composition that can exhibit superior thermoelectric performance by comparing performance, or thermoelectric semiconductor that can exhibit superior thermoelectric performance by comparing the thermoelectric performance that can exhibit the different thermoelectric semiconductor compositions on the low temperature side Of thermoelectric semiconductors that can exhibit excellent thermoelectric performance by comparing the thermoelectric performance that can be exhibited by the different thermoelectric semiconductor compositions on the high temperature side And comparing the thermoelectric performance that can exhibit the composition of each of the different thermoelectric semiconductors in the temperature range from the low temperature side to the high temperature side, and selecting the composition of the thermoelectric semiconductor that can exhibit excellent thermoelectric performance, the selected composition different thermoelectric semiconductor material and a layer stacked filled into solidified molding in the order of the high temperature side from the low temperature side and the molded body, the molded article, pressed from the uniaxial direction perpendicular to the product layer the direction of different thermoelectric semiconductor material having the composition of and plastically deformed so as shearing force is applied to the flat line uniaxial direction to the product layer the direction of different thermoelectric semiconductor material having the above composition, the gradient of composition along the stacking direction of the thermoelectric semiconductor material is provided, the The thermoelectric semiconductor material has a crystal grain in which the C-plane of the hexagonal crystal structure extends in the tilt direction of the composition and the C-axis direction is aligned to enhance crystal orientation. As a semiconductor material, the heat Thermoelectric semiconductor elements, characterized in that by uniaxially opposite end portions of the Eject and switching power sale by can be bonded with electrode processing to the action of shear forces during plastic deformation of the shaped body in the semiconductor material. The thermoelectric semiconductor element according to claim 8, which is cut out by making the cross-sectional areas of one end side and the other end side in a uniaxial direction on which a shearing force acts during the composition deformation processing of the molded body in the thermoelectric semiconductor material differ. The thermoelectric semiconductor element according to claim 8 or 9, wherein a parameter for evaluating the thermoelectric performance is changed to an electric conductivity instead of the Seebeck coefficient . The thermoelectric semiconductor element according to claim 8 or 9 , wherein a parameter for evaluating the thermoelectric performance is changed to a power factor in place of the Seebeck coefficient . The thermoelectric semiconductor element according to claim 8 or 9 , wherein a parameter for evaluating the thermoelectric performance is a performance index instead of the Seebeck coefficient . The thermoelectric semiconductor material is a plate-shaped thermoelectric semiconductor material formed by melting a raw material alloy having a composition of a plurality of thermoelectric semiconductors individually and then slowly cooling the material alloy, 13, 10, 11, or 12. Thermoelectric semiconductor element. The thermoelectric semiconductor material of a plurality of compositions, both _(Bi-Sb) claims a composition of 2 Te ₃ system were of compositions comprising varying the Ingredient based 8,9,10,11,12 or 13. The thermoelectric semiconductor element according to 13 . The thermoelectric semiconductor material of a plurality of compositions, both _Bi 2 _(Te-Se) claims a composition of ₃ systems were of compositions comprising varying the Ingredient based 8,9,10,11,12 or 13. The thermoelectric semiconductor element according to 13 . About the change with respect to the temperature obtained by the Seebeck coefficient as a parameter for evaluating the thermoelectric performance in different temperature ranges in the temperature range from the low temperature side to the high temperature side for materials of a plurality of P-type thermoelectric semiconductors with different compositions Based on the thermoelectric performance data, the composition of the P-type thermoelectric semiconductor capable of exhibiting superior thermoelectric performance by comparing the thermoelectric performance capable of exhibiting the composition of each thermoelectric semiconductor of different P-type on the low temperature side, and the above P on the high temperature side. Compare the thermoelectric performance that can be exhibited by the composition of each thermoelectric semiconductor of different types, and select the composition of the P-type thermoelectric semiconductor that can exhibit excellent thermoelectric performance, or the composition of each of the thermoelectric semiconductors of different P-type on the low temperature side Compared to the thermoelectric performance that can be exhibited, the composition of P-type thermoelectric semiconductor that can exhibit excellent thermoelectric performance, and the thermoelectric performance that can exhibit the composition of each thermoelectric semiconductor different from the P-type on the high temperature side Compare the composition of P-type thermoelectric semiconductors that can exhibit superior thermoelectric performance and thermoelectric performance that can exhibit the composition of each P-type thermoelectric semiconductor different in the temperature range from the low temperature side to the high temperature side. Different temperature ranges in the temperature range from the low temperature side to the high temperature side for a plurality of N type thermoelectric semiconductor materials that have selected the composition of P-type thermoelectric semiconductors that can exhibit excellent thermoelectric performance. Based on the thermoelectric performance data on the change with temperature obtained by the Seebeck coefficient as a parameter for evaluating thermoelectric performance in the thermoelectric performance, the thermoelectric performance that can exhibit the composition of each thermoelectric semiconductor of different N type on the low temperature side is superior The composition of an N-type thermoelectric semiconductor capable of exhibiting excellent thermoelectric performance and the thermoelectric performance capable of exhibiting the composition of each thermoelectric semiconductor different from the above N-type on the high temperature side are compared. The composition of the N-type thermoelectric semiconductor that can exhibit excellent thermoelectric performance by comparing the thermoelectric performance that can exhibit the composition of each thermoelectric semiconductor different from the N-type on the low temperature side, The composition of the N-type thermoelectric semiconductor capable of exhibiting excellent thermoelectric performance by comparing the thermoelectric performance capable of exhibiting the composition of each thermoelectric semiconductor different in N-type on the side, and the above in the temperature region from the low temperature side to the high temperature side Comparing the thermoelectric performance that can exhibit the composition of each thermoelectric semiconductor having different N-type, selecting the composition of the N-type thermoelectric semiconductor that can exhibit excellent thermoelectric performance, each of the P-type and N-type having different selected compositions The thermoelectric semiconductor material is layered and packed in layers from the low temperature side to the high temperature side and solidified to form separate molded bodies. Each molded body having the composition of the P-type and N-type thermoelectric semiconductors has the above composition. product layers of different thermoelectric semiconductor material Direction and then pressed from the uniaxial direction perpendicular plastically deformed as a shear force is applied to the flat line uniaxial direction to the product layer the direction of different thermoelectric semiconductor material having the above composition, in the stacking direction of the respective thermoelectric semiconductor material The crystal grain in the structure of the thermoelectric semiconductor extends along the C-plane of the hexagonal structure in the tilt direction of the composition, and the C-axis direction is also aligned to enhance the crystal orientation. Both P-type and N-type thermoelectric semiconductor materials, and both end portions in the uniaxial direction on which shearing force acts during plastic deformation processing of the molded body from the P-type and N-type thermoelectric semiconductor materials in Seebeck coefficient of the Eject and switching power sale by can be bonded with the electrodes processed obtained by forming each P-type and N-type each thermoelectric semiconductor elements, as a parameter for evaluating the thermoelectric performance at respective thermoelectric a semiconductor element Changes to the obtained temperature Based on the data of thermoelectric performance for, distribution by side each other thermoelectric semiconductor composition excellent thermoelectric performance can be exhibited at a low temperature side, and were distribution of the thermoelectric semiconductor composition which can exhibit excellent thermoelectric properties at high temperature side align the side between each and the uniaxial direction by applying a pressing force at the time of plastic deformation of the shaped body, as well as arranged in a straight direction orthogonal to the co uniaxially that shear force by the pressing pressure, the P A thermoelectric module comprising a PN element pair formed by joining a thermoelectric semiconductor element of a type and an N type through electrodes. The thermoelectric module according to claim 16 , wherein a parameter for evaluating the thermoelectric performance is changed to an electric conductivity instead of the Seebeck coefficient . The thermoelectric module according to claim 16 , wherein a parameter for evaluating the thermoelectric performance is changed to a power factor instead of the Seebeck coefficient . The thermoelectric module according to claim 16 , wherein a parameter for evaluating the thermoelectric performance is changed to a performance index instead of the Seebeck coefficient . 20. The thermoelectric semiconductor material according to claim 16, 17, 18 or 19, wherein the thermoelectric semiconductor material is a plate-shaped thermoelectric semiconductor material formed by melting a raw material alloy having a plurality of thermoelectric semiconductor compositions individually and then slowly cooling it. module. Thermoelectric semiconductor raw material alloys are melted and solidified into foils , plates, or pulverized products of thermoelectric semiconductor materials with different compositions from the low temperature side. Based on the thermoelectric performance data on changes to temperature obtained with the Seebeck coefficient as a parameter for evaluating thermoelectric performance in different temperature ranges up to the high temperature side, the composition of each of the different thermoelectric semiconductors on the low temperature side is demonstrated. The composition of a thermoelectric semiconductor capable of exhibiting excellent thermoelectric performance by comparing the thermoelectric performance capable of exhibiting excellent thermoelectric performance by comparing the thermoelectric performance capable of exhibiting the above-mentioned different thermoelectric semiconductor compositions on the high temperature side Or a composition of a thermoelectric semiconductor that can exhibit excellent thermoelectric performance by comparing the thermoelectric performance that can exhibit the composition of each of the different thermoelectric semiconductors on the low temperature side Compare the thermoelectric performance that can exhibit the different thermoelectric semiconductor compositions on the high temperature side, and the thermoelectric semiconductor composition that can exhibit excellent thermoelectric performance, and the different thermoelectric semiconductors in the temperature range from the low temperature side to the high temperature side. Compare the thermoelectric performance that can be exhibited by selecting the composition of the thermoelectric semiconductor that can exhibit excellent thermoelectric performance , prepare the thermoelectric semiconductor material of the prepared multiple compositions in layers from the low temperature side to the high temperature side are stacked solidified molded to form a molded body, then, the molded article, one of the axial direction in the biaxial direction intersecting with the straight intersects plane to the product layer the direction of different thermoelectric semiconductor material having the composition and pressed from the other axial direction on the state of restraining the deformation of the by the action of shear forces on the flat line uniaxial direction to the product layer direction of the thermoelectric semiconductor material to plastic deformation working, the lamination of the thermoelectric semiconductor material The composition gradient along the direction The crystal grains in the structure of the thermoelectric semiconductor material have a C-plane of the hexagonal structure extending in the inclination direction of the composition, and the C-axis direction is also aligned to enhance the crystal orientation. A method of manufacturing a thermoelectric semiconductor material, comprising forming the thermoelectric semiconductor material. The method for producing a thermoelectric semiconductor material according to claim 21 , wherein a parameter for evaluating the thermoelectric performance is changed to an electric conductivity instead of the Seebeck coefficient . The method for producing a thermoelectric semiconductor material according to claim 21 , wherein a parameter for evaluating the thermoelectric performance is changed to a power factor in place of the Seebeck coefficient . The method for producing a thermoelectric semiconductor material according to claim 21 , wherein a parameter for evaluating the thermoelectric performance is replaced with a Seebeck coefficient and a performance index is used. The thermoelectric semiconductor material of a plurality of compositions, thermoelectric of both _(Bi-Sb) is varied with Ingredient based on the composition of 2 Te ₃ system and having composition comprising according to claim 21, 22, 23 or 24, wherein Manufacturing method of semiconductor material. The thermoelectric semiconductor material of a plurality of compositions, thermoelectric of both _Bi 2 _(Te-Se) the composition of the ₃ system by changing the Ingredient based on the intended composition comprising according to claim 21, 22, 23 or 24, wherein Manufacturing method of semiconductor material. Claims: As a thermoelectric semiconductor material, a plate-like thermoelectric semiconductor material formed by melting a raw material alloy having a plurality of thermoelectric semiconductor compositions individually and then bringing the molten alloy into contact with the surface of a cooling member and gradually cooling it is used. Item 27. A method for producing a thermoelectric semiconductor material according to Item 21, 22, 23, 24, 25, or 26 . When the molten alloy of the raw material alloy is brought into contact with the surface of the cooling member to form a plate-like thermoelectric semiconductor material, the above-mentioned melting is performed at a speed at which 90% or more of the thickness of the formed plate-like thermoelectric semiconductor material is not rapidly cooled. 28. The method for producing a thermoelectric semiconductor material according to claim 27, wherein the alloy is cooled and solidified. Thermoelectric semiconductor raw material alloys are melted and solidified into foils , plates, or pulverized products of thermoelectric semiconductor materials with different compositions from the low temperature side. Based on the thermoelectric performance data on changes to temperature obtained with the Seebeck coefficient as a parameter for evaluating thermoelectric performance in different temperature ranges up to the high temperature side, the composition of each of the different thermoelectric semiconductors on the low temperature side is demonstrated. The composition of a thermoelectric semiconductor capable of exhibiting excellent thermoelectric performance by comparing the thermoelectric performance capable of exhibiting excellent thermoelectric performance by comparing the thermoelectric performance capable of exhibiting the above-mentioned different thermoelectric semiconductor compositions on the high temperature side Or a composition of a thermoelectric semiconductor that can exhibit excellent thermoelectric performance by comparing the thermoelectric performance that can exhibit the composition of each of the different thermoelectric semiconductors on the low temperature side Compare the thermoelectric performance that can exhibit the different thermoelectric semiconductor compositions on the high temperature side, and the thermoelectric semiconductor composition that can exhibit excellent thermoelectric performance, and the different thermoelectric semiconductors in the temperature range from the low temperature side to the high temperature side. Compare the thermoelectric performance that can be exhibited by selecting the composition of the thermoelectric semiconductor that can exhibit excellent thermoelectric performance , prepare the thermoelectric semiconductor material of the prepared multiple compositions in layers from the low temperature side to the high temperature side are stacked solidified molded to form a molded body, then, the molded article, one of the axial direction in the biaxial direction intersecting with the straight intersects plane to the product layer the direction of different thermoelectric semiconductor material having the composition and pressed from the other axial direction on the state of restraining the deformation of the by the action of shear forces on the flat line uniaxial direction to the product layer direction of the thermoelectric semiconductor material to plastic deformation working, the lamination of the thermoelectric semiconductor material The composition gradient along the direction The crystal grains in the structure of the thermoelectric semiconductor material have a C-plane of the hexagonal structure extending in the inclination direction of the composition, and the C-axis direction is also aligned to enhance the crystal orientation. going on to form a thermoelectric semiconductor material, thereafter, the thermoelectric semiconductor material, and both end portions of the Eject and switching power sale by can be bonded with electrode processing uniaxial direction acting shear forces during plastic deformation of the shaped body A method of manufacturing a thermoelectric semiconductor element, comprising forming a thermoelectric semiconductor element. When the thermoelectric semiconductor element is cut out from the thermoelectric semiconductor material, the cross-sectional areas on one end side and the other end side in the uniaxial direction where the shearing force acts during the composition deformation processing of the molded body in the thermoelectric semiconductor element to be formed are made different. Item 30. A method for producing a thermoelectric semiconductor element according to Item 29 . The method for producing a thermoelectric semiconductor element according to claim 29 or 30 , wherein a parameter for evaluating the thermoelectric performance is changed to an electric conductivity instead of the Seebeck coefficient . The method for producing a thermoelectric semiconductor element according to claim 29 or 30 , wherein a parameter for evaluating the thermoelectric performance is replaced with a Seebeck coefficient to be a power factor. 31. The method of manufacturing a thermoelectric semiconductor element according to claim 29 or 30 , wherein a parameter for evaluating the thermoelectric performance is a performance index instead of the Seebeck coefficient . The thermoelectric semiconductor material of a plurality of compositions, both _(Bi-Sb) 2 Te ₃ system according to claim 29, 30, 31, 32 or 33, wherein group by changing the components in the composition and that of the composition comprising the A method for manufacturing a thermoelectric semiconductor element. The thermoelectric semiconductor material of a plurality of compositions, both _Bi 2 _(Te-Se) the composition of the ₃ system by changing the Ingredient based on the intended composition comprising according to claim 29, 30, 31, 32 or 33, wherein Manufacturing method of the thermoelectric semiconductor element. Claims: As a thermoelectric semiconductor material, a plate-like thermoelectric semiconductor material formed by melting a raw material alloy having a plurality of thermoelectric semiconductor compositions individually and then bringing the molten alloy into contact with the surface of a cooling member and gradually cooling it is used. Item 36. A method for manufacturing a thermoelectric semiconductor element according to Item 29, 30, 31, 32, 33, 34, or 35 . When the molten alloy of the raw material alloy is brought into contact with the surface of the cooling member to form a plate-like thermoelectric semiconductor material, the above-mentioned melting is performed at a speed at which 90% or more of the thickness of the formed plate-like thermoelectric semiconductor material is not rapidly cooled. The method of manufacturing a thermoelectric semiconductor element according to claim 36, wherein the alloy is cooled and solidified. Thermoelectric semiconductor raw material alloy is melted and solidified into a foil shape, a plate shape, or a thermoelectric semiconductor material formed into a pulverized product of a plurality of P type thermoelectric semiconductor materials with different compositions, Based on the thermoelectric performance data about the change with respect to the temperature obtained with the Seebeck coefficient as a parameter for evaluating the thermoelectric performance in different temperature ranges in the temperature range from the low temperature side to the high temperature side, each of the different P-types on the low temperature side Compare the thermoelectric performance that can be demonstrated by comparing the thermoelectric performance that can be demonstrated by the composition of the thermoelectric semiconductor, and the thermoelectric performance that can be demonstrated by the composition of each thermoelectric semiconductor that is different from the above P type on the high temperature side. The composition of the P-type thermoelectric semiconductor capable of exhibiting excellent thermoelectric performance is selected, or the thermoelectric performance capable of exhibiting the composition of each thermoelectric semiconductor different from the P-type is compared on the low temperature side. The composition of the P-type thermoelectric semiconductor capable of exhibiting excellent thermoelectric performance by comparing the composition of the P-type thermoelectric semiconductor capable of exhibiting the electrical performance and the thermoelectric performance capable of exhibiting the composition of each thermoelectric semiconductor different from the P-type on the high temperature side Compare the thermoelectric performance that can exhibit the composition of each P-type different thermoelectric semiconductor in the temperature range from the low temperature side to the high temperature side, and select the composition of the P type thermoelectric semiconductor that can exhibit excellent thermoelectric performance. The change with respect to the temperature obtained by the Seebeck coefficient as a parameter for evaluating the thermoelectric performance in different temperature ranges in the temperature range from the low temperature side to the high temperature side for the materials of a plurality of N-type thermoelectric semiconductors having different compositions On the basis of the thermoelectric performance data about N-type thermoelectric semiconductors that can exhibit superior thermoelectric performance by comparing the thermoelectric performance that can exhibit the composition of each of the N-type different thermoelectric semiconductors on the low temperature side The composition of the N-type thermoelectric semiconductor capable of exhibiting excellent thermoelectric performance is selected by comparing the composition and the thermoelectric performance capable of exhibiting the composition of each thermoelectric semiconductor of different N-type on the high temperature side, or the above N on the low temperature side Comparing the thermoelectric performance that can exhibit the composition of each thermoelectric semiconductor of different types, the composition of the N-type thermoelectric semiconductor that can exhibit excellent thermoelectric performance, and the thermoelectric that can exhibit the composition of each thermoelectric semiconductor of different N type on the high temperature side Comparing the composition of N-type thermoelectric semiconductors that can demonstrate superior thermoelectric performance by comparing the performance, and the thermoelectric performance that can exhibit the composition of each N-type different thermoelectric semiconductor in the temperature range from the low temperature side to the high temperature side The composition of N-type thermoelectric semiconductor that can exhibit excellent thermoelectric performance is selected and prepared, and the thermoelectric semiconductor material for each of the plurality of compositions prepared for the P-type and N-type thermoelectric semiconductors is heated from the low temperature side to the high temperature. Layered in order of side And solidifying and molding by laminating to form a molded body, then the P-type and N-type each molded body having a thermoelectric semiconductor composition, straight interlinked planar to the product layer the direction of different thermoelectric semiconductor material having the composition the deformation of the one axial direction in the biaxial direction intersecting the inner at restrained state by pressing than other axial cause a shearing force to the flat line uniaxial direction to the product layer direction of the thermoelectric semiconductor material The composition of the thermoelectric semiconductor material is inclined along the stacking direction of the thermoelectric semiconductor material, and the crystal grains in the structure of the thermoelectric semiconductor material are aligned in the direction of inclination of the composition in the C plane of the hexagonal structure. The P-type and N-type thermoelectric semiconductor materials are formed in which the C-axis direction is aligned and the crystal orientation is enhanced , and then the P-type and N-type thermoelectric semiconductor materials are formed. Uniaxial direction in which a shearing force acts during plastic deformation of the molded body Both end portions and Eject and switching power sale by can be bonded to the electrode machining to form a P-type and N-type thermoelectric semiconductor elements, respectively, and thereafter, the P-type and N-type each thermoelectric semiconductor element, respective thermoelectric semiconductor elements Based on the thermoelectric performance data on the change to temperature obtained with the Seebeck coefficient as a parameter to evaluate the thermoelectric performance in the above , the sides of the thermoelectric semiconductor composition that can exhibit excellent thermoelectric performance on the low temperature side And the uniaxial direction in which the thermoelectric semiconductor compositions capable of exhibiting excellent thermoelectric performance on the high temperature side are aligned with each other, and a pressing force is applied during plastic deformation processing of the molded body, and shearing is caused by the pressing. while disposed co uniaxially an acting force are arranged in a straight direction orthogonal, thermoelectric, characterized in that to form a PN element pairs each thermoelectric semiconductor elements of the P-type and N-type bonding through the electrode Mo Manufacturing method of Yuru. 39. The method of manufacturing a thermoelectric module according to claim 38 , wherein a parameter for evaluating the thermoelectric performance is changed to an electric conductivity instead of the Seebeck coefficient . The method for manufacturing a thermoelectric module according to claim 38 , wherein a parameter for evaluating the thermoelectric performance is replaced with a Seebeck coefficient to be a power factor. The method for manufacturing a thermoelectric module according to claim 38 , wherein a parameter for evaluating the thermoelectric performance is replaced with a Seebeck coefficient and a performance index is used. Claims: As a thermoelectric semiconductor material, a plate-like thermoelectric semiconductor material formed by melting a raw material alloy having a plurality of thermoelectric semiconductor compositions individually and then bringing the molten alloy into contact with the surface of a cooling member and gradually cooling it is used. Item 42. A method for manufacturing a thermoelectric module according to Item 38, 39, 40 or 41 . When the molten alloy of the raw material alloy is brought into contact with the surface of the cooling member to form a plate-like thermoelectric semiconductor material, the above-mentioned melting is performed at a speed at which 90% or more of the thickness of the formed plate-like thermoelectric semiconductor material is not rapidly cooled. The method of manufacturing a thermoelectric module according to claim 42, wherein the alloy is cooled and solidified.

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