KR20190009470A - Composition of thermoelectric element - Google Patents

Abstract

According to one aspect of the present invention, a method of manufacturing a thermoelectric element is provided. The method includes: a step of preparing thermoelectric element powder; a step of injecting the thermoelectric element powder into a heating part; a step of sealing the heating part; a step of heating the heating part and melting the thermoelectric element powder to transform the thermoelectric element powder into a molten thermoelectric material; a step of heating the molten thermoelectric material by a zone melting method; and a step of growing the purified molten thermoelectric material based on a predetermined crystal. A thermoelectric element having a high thermoelectric performance index can be manufactured.

Description

[0001] The present invention relates to a thermoelectric element,

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method of manufacturing a thermoelectric element, and more particularly, to a method of manufacturing an ingot operated by a thermoelectric element.

A thermoelectric effect is a phenomenon in which a potential difference is generated between two contacts when two ends of two different metal conductors are connected to form a closed circuit and a temperature difference is applied to both ends. This thermoelectric phenomenon can be classified into the Hebeck effect of obtaining the electromotive force using the temperature difference between the both ends, the Peltier effect of cooling and heating by the electromotive force, and the Thomson effect of generating the electromotive force by the temperature difference of the conductor.

로 정의되는 열전 성능지수(ZT)값을 사용한다. 여기서

는 제백 계수이고,

는 전기 전도도이고,

는 열전도도이고,

는 온도이다. ZT값을 결정하는 주요 변수인 제백 계수와 전기 전도도는 어느 한쪽의 성능을 증가시키면 다른 한쪽이 감소하는 상반 관계를 나타내어, 캐리어 농도가 낮아져 열기전력이 증가하면 전기 전도도가 감소하는 특징을 가진다. The performance of these thermoelectric materials is commonly referred to as the dimensionless figure of merit,

(ZT) value, which is defined as " a " here

Is a whiteness coefficient,

Is the electrical conductivity,

Is a thermal conductivity,

Is the temperature. The ZT value is determined by increasing the performance of the whiteness coefficient and the electric conductivity, which are opposite to each other. The electric conductivity decreases when the carrier concentration decreases and the thermoelectric power increases.

A thermoelectric element having such a characteristic has a high reliability because it has a solid structure, can be used semi-permanently, can simultaneously provide heating and cooling, and has an advantage that temperature can be precisely controlled. However, conventional thermoelectric elements have a disadvantage in that the thermoelectric performance index (ZT), which indicates heat and electric conversion performance, is low.

An object of the present invention is to provide a thermoelectric device manufacturing method for manufacturing a thermoelectric device having a high thermoelectric performance index in order to solve the above problems.

It is to be understood that the present invention is not limited to the above-described embodiments and that various changes and modifications may be made without departing from the spirit and scope of the present invention as defined by the following claims .

According to one aspect of the present invention, there is provided a method of manufacturing a thermoelectric element, comprising: preparing a thermoelectric element powder; Injecting the thermoelectric element powder into a heating unit; Sealing the heating unit; Heating the heating unit to melt the thermoelectric element powder to transform the thermoelectric element powder into a thermoelectric body; Heating the thermoelectric melt by a zone melting method; And growing the purified thermo-melt on the basis of a predetermined crystal.

The thermoelectric element powder is composed of 70% by weight to 97% by weight of a first compound having a structure represented by the following formula (1), Bi-Sb-Te-Se, and 3% to 8% Wherein the Bi is from 2.14 parts by weight to 44.82 parts by weight, the Sb is from 13.23 parts by weight to 70.02 parts by weight, the Se is from 0.722 parts by weight to 22.62 parts by weight, and the Te is from 16.34 parts by weight to 77.22 parts by weight, A device manufacturing method can be provided. ≪ Formula 1 >

Further, the thermoelectric-element powder is composed of 91% by weight to 99% by weight of a Bi-Sb-Te-Se system as a second compound having a structure of the following formula 2 and 1% to 5% Wherein the Bi is from 22.71 to 74.78 parts by weight, the Sb is from 0.99 to 22.97 parts by weight, the Se is from 0.623 to 16.067 parts by weight, and the Te is from 18.78 to 69.02 parts by weight based on 100 parts by weight of the thermoplastic resin have. (2)

Also, the temperature for heating by the zone melting method is 873K.

Also, a method of manufacturing a thermoelectric device, wherein the rate of growing the purified thermoelectric melt on the basis of a predetermined crystal is 15 mm / h.

According to the thermoelectric-element composition of the present invention, it is possible to produce a thermoelectric element having a high ratio of conversion from electric energy to thermal energy.

The effects of the present invention are not limited to the above-mentioned effects, and the effects not mentioned can be clearly understood by those skilled in the art from the present specification and the accompanying drawings.

1 is a perspective view of a thermoelectric module according to an embodiment of the present invention;
2 is an enlarged view of a thermoelectric-element composition provided in a thermoelectric module according to an embodiment of the present invention.
3 is an enlarged view of a thermoelectric element composition provided in a thermoelectric module according to an embodiment of the present invention.
FIG. 4 is a graph showing the performance index of a thermoelectric device according to the melting temperature in an embodiment of the present invention. FIG.
5 is a graph of the performance index of a thermoelectric device according to a growth rate in an embodiment of the present invention.

Hereinafter, specific embodiments of the present invention will be described in detail with reference to the drawings. It will be apparent to those skilled in the art that various modifications and variations can be made in the present invention without departing from the spirit or scope of the inventive concept. Other embodiments falling within the scope of the inventive concept may readily be suggested, but are also considered to be within the scope of the present invention.

The same reference numerals are used to designate the same components in the same reference numerals in the drawings of the embodiments.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, a detailed description of known configurations or functions related to the present invention will be omitted when it is determined that the gist of the present invention may be blurred.

1 is a perspective view of a thermoelectric module according to an embodiment of the present invention.

1, the thermoelectric module includes an upper insulating portion 10, a lower insulating portion 20, an upper electrode portion 30, a lower electrode portion 40, a P-type thermoelectric material 50, an N-type thermoelectric material ( 60, and a lead electrode unit 70.

The upper insulation part 10 and the lower insulation part 20 may be non-conductive, which does not allow electricity or heat.

For example, the upper insulating portion 10 and the lower insulating portion 20 may be made of gallium arsenide (GaAs), sapphire, silicon, Pyrex, or a quartz substrate.

The upper electrode part 30 may be patterned in the upper insulating part 10.

In addition, the lower electrode part 40 may be patterned in the lower insulating part 20.

For example, the upper electrode unit 30 and the lower electrode unit 40 may be formed of aluminum, nickel, gold, titanium, or the like.

In addition, the upper electrode unit 30 and the lower electrode unit 40 may be variously modified at a level that is obvious to a person skilled in the art.

The upper electrode unit 30 and the lower electrode unit 40 may be patterned to the upper insulation unit 10 and the lower insulation unit 20 by any known patterning method.

For example, a lift-in semiconductor process, a deposition method, a photolithography process, or the like can be used.

The P-type thermoelectric material 50 may include a first compound having a structure of the following formula (1).

Further, the N-type thermoelectric material 60 may include a second combustible having a structure of the following formula (2).

The P-type thermoelectric material 50 and the N-type thermoelectric material may be disposed between the upper electrode unit 30 and the lower electrode unit 40 and may be in contact with each other.

The P-type thermoelectric material (50) and the N-type thermoelectric material (60) may be alternately arranged.

The lead electrode unit 70 may connect the upper electrode unit 30 and the lower electrode unit 40 to the outside of the thermoelectric module.

The P-type thermoelectric material and the N-type thermoelectric material may be formed by processing with an ingot (100).

Here, the ingot 100 can be manufactured by a single crystal growth technique by a zone melting method.

The single crystal growth technique by the zone melting method is a method of crystal growth of a material through local melting and cooling of a material due to movement of a heater or the like, and a single crystal ingot 100 of high purity can be produced through relatively simple facilities.

The single crystal ingot 100 manufactured by a single crystal growth technique can be manufactured into a single individual chip form through complicated post-processing such as slicing, coating, or dicing.

However, the present invention is not limited thereto, and a thermoelectric material can be manufactured in a different manner at a level that is obvious to a general engineer.

For example, the ingot 100 may be manufactured according to a powder sintering method, and then the ingot may be pulverized and sieved to obtain a thermoelectric material powder, and the thermoelectric material may be obtained through the sintering process.

However, in order to improve the efficiency of the thermoelectric performance index, it may be preferable to use the zone melting method.

로 표현되는 화학식 1의 구조를 갖는 제1 화합물을 포함할 수 있다.The P-type thermoelectric material produced by the above-

Lt; RTI ID = 0.0 > 1 < / RTI >

Here, a, b, c, and d may have a range of 0.1? A? 1.0, 1.0 b? 3.0, 1.0 c? 4.0, and 0.1 d? 1.0.

Also. The P-type thermoelectric material may further include a first additive for increasing the thermoelectric performance index.

Here, the first additive may be Te (Tellurium).

As a specific example, the content of the first additive may be 1 part by weight to 5 parts by weight based on 100 parts by weight of the first composition.

In the first composition, Bi (bismuth) is 2.14 parts by weight to 44.82 parts by weight, Sb (antimony) is 13.23 parts by weight to 70.02 parts by weight, Se (Selenium) is 0.722 weight parts To 22.62 parts by weight, and Te (Tellurium) may be from 16.34 parts by weight to 77.22 parts by weight.

However, it is preferable that a is 0.5, b is 1.5, c is 2.87, and d is 0.13.

That is, it is preferable that the first composition contains 15.746 parts by weight of Bi, 27.522 parts by weight of Bi, 55.185 parts by weight of Te, and 1.547 parts by weight of Se based on 100 parts by weight of the first composition.

The first additive Te may preferably be 3 parts by weight based on 100 parts by weight of the first composition.

로 표현되는 화학식 2의 구조를 갖는 제2 화합물을 포함할 수 있다.The N-type thermoelectric material produced by the above-

A second compound having a structure represented by the general formula (2).

Here, a, b, c and d may have a range of 1.0? A? 3.0, 0.1? B? 1.0, 1.5? C? 4.0 and 0.1? D? 1.0.

Also. The N-type thermoelectric material may further include a second additive for increasing the thermoelectric performance index.

(Antimony triiodide)를 포함할 수 있다. Here, the second additive is

(Antimony triiodide).

As a specific example, the content of the second additive may be 0.001 part by weight to 1 part by weight based on 100 parts by weight of the second composition.

Also, the second composition may contain 22.71 to 74.78 parts by weight of Bi, 0.99 to 22.97 parts by weight of Sb, 0.623 to 16.067 parts by weight of Se, and 18.78 to 69.02 parts by weight of Te, based on 100 parts by weight of the second composition. have.

However, it is preferable that a is 1.8, b is 0.2, c is 2.82, and d is 0.18.

That is, it is preferable that the second composition contains 48.565 parts by weight of Bi, 3.144 parts by weight of Bi, 46.456 parts by weight of Te, and 1.835 parts by weight of Se based on 100 parts by weight of the second composition.

은 제2 조성물의 100 중량부에 대해서 0.095 중량부인 것이 바람직할 수 있다. Further, the second additive

May be preferably 0.095 part by weight based on 100 parts by weight of the second composition.

FIG. 2 is an enlarged view of a thermoelectric module provided in a thermoelectric module according to an embodiment of the present invention, and FIG. 3 is an enlarged view of a thermoelectric module provided in a thermoelectric module according to an embodiment of the present invention.

내지 3

일 수 있다. The first additive has a particle size of 1

To 3

Lt; / RTI >

내지 8

일 수 있다. 3, the first additive has a particle diameter of 6

To 8

Lt; / RTI >

내지 3

일 수 있다. The second additive has a particle diameter of 1

To 3

Lt; / RTI >

내지 8

일 수 있다. 3, the second additive has a particle diameter of 6

To 8

Lt; / RTI >

The particle diameter of the first additive can be selected according to the content of the first additive.

For example, when the content of the first additive is small, the first additive having a relatively large particle size can be selected.

In addition, when the content of the first additive is large, the first additive having a relatively small particle size can be selected.

Similarly, the particle size of the second additive can be selected according to the content of the second additive.

For example, when the content of the second additive is small, the second additive having a relatively large particle size can be selected.

Further, when the content of the second additive is large, the second additive having a relatively small particle diameter can be selected.

In order to produce a thermoelectric material having a high performance index, it is preferable that the content of the first additive and the content of the second additive be inversely proportional to each other.

FIG. 4 is a graph illustrating the performance index of the thermoelectric device according to the melting temperature in an embodiment of the present invention. FIG.

There are many parameters for producing ingots by the zone melting method, but one of the main variables may be the melting tempera- ture.

The characteristics of the ingot produced according to the zone melting temperature are changed, and the performance index of the thermoelectric material may be changed accordingly.

Referring to FIG. 4, the highest thermoelectric performance index was observed when the zone melting temperature was 500 K, and when the temperature was increased, the thermoelectric performance index gradually increased and the zone melting temperature was 873 K.

Also, it was observed that the thermoelectric performance index sharply decreased as the zone melting temperature became larger than 873K.

Therefore, when a thermoelectric material is produced using the thermoelectric-element composition described above, it may be preferable that the zone-melting temperature is 873K.

FIG. 5 is a graph illustrating a performance index of a thermoelectric device according to a growth rate in an embodiment of the present invention. FIG.

There are many parameters for producing ingots by the zone melting method, but one of the main variables may be the growth rate.

The characteristics of the ingot produced according to the growth rate are changed, and the performance index of the thermoelectric material can be changed accordingly.

Referring to FIG. 4, it was observed that the thermoelectric performance index gradually increased as the growth rate was increased at a growth rate of 1 mm / h. This increase trend can continue until the growth rate reaches 5mm / h.

However, when the growth rate is further increased at 5 mm / h, it is observed that the thermoelectric performance index decreases gradually. This declining trend can continue until the growth rate reaches 8 mm / h.

It is observed that the thermoelectric performance index increases gradually when the growth rate is further increased at 8 mm / h. This increase can continue until the growth rate reaches 15 mm / h.

However, when the growth rate was further increased at 15 mm / h, the thermoelectric performance index was observed to decrease gradually.

Therefore, when a thermoelectric material is produced using the thermoelectric-element composition described above, it is preferable that the growth rate is 15 mm / h.

Based on such experimental data, it is possible to determine the variable value of the zone melting manufacturing method.

For example, the melting temperature may be 873 K, the zone melting temperature may be 873 K, the heat consumption rate may be 20 K / min, the holding time may be 2 h, and the growth rate may be 15 mm / h.

A thermoelectric device can be manufactured using the zone melting method and the thermoelectric conversion composition.

A method of manufacturing a thermoelectric element includes the steps of preparing a thermoelectric element powder, injecting the thermoelectric element powder into a heating part, sealing the heating part, heating the heating part to melt the thermoelectric element powder, Heating the thermoelectric body by heating in the zone melting method, and growing the purified thermoelectric body on the basis of a predetermined crystal.

Here, the heating portion may be made of a transparent tube providing a space therein.

However, the present invention is not limited thereto and can be variously modified at a level that is obvious to a general technician.

The melting temperature may be a temperature at which the thermoelectric element powder is heated in the heating section.

In other words, it may be a temperature at which the thermoelectric element powder is converted into a thermoelectric melt.

Here, it is preferable that the melting temperature and the zone melting temperature are the same.

If the melting temperature and the zone melting temperature are different, the bonding may be overlapped or separated among various materials constituting the thermoelectric element powder.

의 구조를 갖는 제1 화합물 70 중량% 내지 97 중량% 및 제1 첨가제 3% 내지 8%로 이루어질 수 있다. Here, the thermoelectric element powder

70% by weight to 97% by weight of the first compound having a structure of 3% to 8% by weight of the first additive.

The first compound may further contain 2.14 parts by weight to 44.82 parts by weight of Bi, 13.23 parts by weight to 70.02 parts by weight of Sb, 0.722 parts by weight to 22.62 parts by weight of Se, and 16.34 parts by weight of Te, based on 100 parts by weight of the first compound. Parts by weight to 77.22 parts by weight.

의 구조를 갖는 제2 화합물 91중량% 내지 99 중량% 및 제2 첨가제 1% 내지 5%로 이루어질 수 있다. Further, the thermoelectric element powder

91% by weight to 99% by weight of the second compound having a structure of 1% to 5% by weight of the second additive.

The second compound may be used in an amount of 22.71 to 74.78 parts by weight of Bi, 0.99 to 22.97 parts by weight of Sb, 0.623 to 16.067 parts by weight of Se, and 18.78 to 69.02 parts by weight of Te, based on 100 parts by weight of the second compound. have.

BRIEF DESCRIPTION OF THE DRAWINGS The accompanying drawings, which are included to provide a further understanding of the invention and are incorporated in and constitute a part of this specification, illustrate embodiments of the invention and, together with the description, serve to explain the principles of the invention.

While the present invention has been described with reference to exemplary embodiments, it is to be understood that the invention is not limited to the disclosed exemplary embodiments, but, on the contrary, It will be apparent to those skilled in the art that changes or modifications may fall within the scope of the appended claims.

10: upper insulating portion 20: lower insulating portion
30: upper electrode part 40: lower electrode part

Claims (5)

Preparing a thermoelectric element powder;
Injecting the thermoelectric element powder into a heating unit;
Sealing the heating unit;
Heating the heating unit to melt the thermoelectric element powder to transform the thermoelectric element powder into a thermoelectric body;
Heating the thermoelectric melt by a zone melting method;
And growing the purified thermo-melt on the basis of a predetermined crystal.
The method according to claim 1,
In the thermoelectric element powder,
70 to 97% by weight of a first compound having a structure represented by the following formula (1), Bi-Sb-Te-Se, and 3 to 8%
Bi is from 2.14 parts by weight to 44.82 parts by weight, Sb is from 13.23 parts by weight to 70.02 parts by weight, Se is from 0.722 parts by weight to 22.62 parts by weight, and Te is from 16.34 parts by weight to 77.22 parts by weight based on 100 parts by weight of the first compound Wherein the thermoelectric element is a thermoelectric element.
≪ Formula 1 >

The method according to claim 1,
In the thermoelectric element powder,
91% by weight to 99% by weight of Bi-Sb-Te-Se based on a second compound having a structure represented by the following formula (2) and 1% to 5%
Wherein the Bi is 22.71 to 74.78 parts by weight, Sb is 0.99 to 22.97 parts by weight, Se is from 0.623 to 16.067 parts by weight, and Te is from 18.78 to 69.02 parts by weight based on 100 parts by weight of the second compound. .
(2)

4. The method according to any one of claims 1 to 3,
Wherein the temperature for heating by the zone melting method is 873K.
5. The method of claim 4,
Wherein the rate of growth of the purified thermo-melt on the basis of a predetermined crystal is 15 mm / h.

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