KR20120105390A - Nanocomposite thermoelectric materials and their fabrication method - Google Patents

Abstract

PURPOSE: A nanocomposite thermoelectric materials and a manufacturing method thereof are provided to improve thermoelectric performance by maximizing phonon scattering due to an interface of a nano structure. CONSTITUTION: A nano structure is diffused into a thermoelectric material matrix. The thermoelectric material matrix includes bismuth and tellurium. The nano structure includes indium and selenium. The size of the nano structure is below 10μm. [Reference numerals] (AA) ∧ reduction - K reduction

Description

Nanocomposite thermoelectric material and its manufacturing method {NANOCOMPOSITE THERMOELECTRIC MATERIALS AND THEIR FABRICATION METHOD}

The present invention relates to a nanocomposite thermoelectric material and a method of manufacturing the same. More particularly, the present invention relates to a nanocomposite thermoelectric material manufactured by a simple process and a method of manufacturing the same.

The thermoelectric performance index (ZT) indicating the performance of the thermoelectric material is ZT = TS ² σ / κ; T = absolute temperature, S = thermoelectric constant, σ = electrical conductivity, and κ = thermal conductivity. In order to improve the thermoelectric performance index in the thermoelectric material, the electrical conductivity constituting the molecule and the thermal conductivity constituting the denominator may be independently controlled. However, the physically high thermal conductivity of the material has a high electrical conductivity, there is a limit to improve the thermal performance index value. This is well explained by the physically well-known Wiedemann-Franz law (κ = σLT; L = Lorentz constant), that is, the electrical conductivity is primarily proportional to the thermal conductivity. Therefore, the thermoelectric performance index value of the conventional lump-type thermoelectric material has a value of 1 or less.

Advances in nanostructured material technology in the 2000s have produced results that differ from the laws of conventional physical concepts. In other words, the superlattice structure manufactured by crossing heterogeneous thermoelectric materials of several nanometers cycle or the heterogeneous thermoelectric material of nano size is manufactured by inserting into the matrix in the form of heterogeneous quantum dots of several nanometers periodically during growth. It is reported that the thermoelectric performance index can be made larger than 1 by maximizing the scattering of phonons responsible for heat transfer and lowering the thermal conductivity. However, the above method is a top-down method takes a lot of time and money to manufacture the material. These approaches require very slow growth rates of several tens of nanometers per minute to form the same level of nanosized layers or quantum dots. Therefore, it takes a considerable amount of time to obtain the tens of μm thickness required for device fabrication, and the process is cumbersome.

Republic of Korea Patent Publication No. 10-2002-0042519

Kim Hyo-jung and 6 others, 'Thermoelectric properties of multi-layered Bi-Te / In-Se / Bi-Te thin film deposited by RF magnetron sputter, Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference, Vol.11, June 16, 2010. , p231

An object of one embodiment of the present invention is to provide a thermoelectric material exhibiting high thermoelectric performance.

It is an object of another embodiment of the present invention to provide a thermoelectric material that can be manufactured in a simple process.

It is an object of another embodiment of the present invention to provide a Bi-Te-based thermoelectric material that can be manufactured by a simple process.

It is an object of another embodiment of the present invention to provide a simple process for manufacturing a thermoelectric material.

Another object of one embodiment of the present invention, by maximizing phonon scattering is to significantly lower the thermal conductivity of the thermoelectric material.

Thermoelectric material according to an embodiment of the present invention, the thermoelectric material matrix including bismuth (Bi) and tellurium (Te); And a nanostructure comprising indium (In) and selenium (Se) dispersed in the matrix.

In another embodiment of the present invention, the thermoelectric material matrix may have a composition of (Bi _{1 -} aSb _a ) ₂ (Se _1-b Te _b ) ₃ , where a and b are 0 to 1 as molar ratios. It can have a value of.

In another embodiment of the present invention, the thermoelectric material may have a composition of Formula 1 or 2.

(Formula 1)

x {(Bi _{1 - a} Sb _a ) ₂ (Se _{1 - b} Te _b ) ₃ } + 1-x (In ₂ Se ₃ )

Wherein, as molar ratio, a, b is a number from 0 to 1 and x is 1> x> 0.85.

(Formula 2)

x {(Bi _{1 - a} Sb _a ) ₂ (Se _{1 - b} Te _b ) ₃ } + 1-x (In ₄ Se ₃ )

Wherein, as molar ratio, a, b is a number from 0 to 1 and x is 1> x> 0.85.

In another embodiment of the present invention, the nanostructure may have an average size of 10㎛ or less.

In another embodiment of the present invention, the thermoelectric material may have a thermoelectric performance index value ZT of 1 or more.

In another embodiment of the present invention, the thermoelectric material may be manufactured by a sputtering method, or a melting and cooling method.

In another embodiment of the present invention, the sputtering method, the sputtering target containing bismuth (Bi) and tellurium (Te) and the sputtering target containing indium (In) and selenium (Se) at the same time It may include doing.

In another embodiment of the present invention, the melting and cooling method, the step of melting the elements constituting the thermoelectric material matrix and the nanostructure; Quenching the melt obtained by the melting; And heat treating the quenched melt to form nanostructures.

Thermoelectric material according to an embodiment of the present invention, the thermoelectric material matrix; And a nanostructure dispersed in the matrix, wherein the thermoelectric material is manufactured by a sputtering method or a melting and cooling method.

In another embodiment of the present invention, the thermoelectric material matrix may include bismuth (Bi) and tellurium (Te).

In another embodiment of the present invention, the nanostructure may include indium (In) and selenium (Se).

In another embodiment of the present invention, the thermoelectric material is x {(Bi _{1 - a} Sb _a ) ₂ (Se _{1 -} bTe _b ) ₃ } + 1-x (In ₂ Se ₃ ) or x {(Bi _{1 - a} Sb _a ) ₂ (Se _{1 - b} Te _b ) ₃ } + 1-x (In ₄ Se ₃ ) (as molar ratio, a, b is a number from 0 to 1 and x is 1> x ≥ 0.85 It may have a composition of).

In another embodiment of the present invention, the thermoelectric material may have a thermoelectric performance index value ZT of 1 or more.

In another embodiment of the present invention, the thermoelectric material is manufactured by a sputtering method, the sputtering method, including the sputtering target for the thermoelectric material matrix and the sputtering target for the nanostructures at the same time Can be.

In another embodiment of the present invention, the thermoelectric material is manufactured by a melting and cooling method, the melting and cooling method, melting the elements constituting the thermoelectric material matrix and the nanostructure; Quenching the melt obtained by the melting; And heat treating the quenched melt to form nanostructures.

Method for manufacturing a thermoelectric material according to an embodiment of the present invention, a method for manufacturing a thermoelectric material, the thermoelectric material, a thermoelectric material matrix; And a nanostructure dispersed in the matrix, wherein the method may include sputtering a sputtering target for the thermoelectric matrix and a sputtering target for the nanostructure simultaneously.

In the manufacturing method according to another embodiment of the present invention, the thermoelectric material is x {(Bi _1-a Sb _a ) ₂ (Se _1-b Te _b ) ₃ } + 1-x (In ₂ Se ₃ ) Or x {(Bi _{1 - a} Sb _a ) ₂ (Se _{1 - b} Te _b ) ₃ } + 1-x (In ₄ Se ₃ ) (as molar ratio, a, b is a number from 0 to 1, x is 1 >x> 0.85).

In the manufacturing method according to another embodiment of the present invention, the thermoelectric material may have a thermoelectric performance index value ZT of 1 or more.

In a manufacturing method according to another embodiment of the present invention, the method comprises the steps of determining the sputtering power required to obtain the composition of the desired thermoelectric material; And sputtering at the determined sputtering power.

In the manufacturing method according to another embodiment of the present invention, the step of determining the sputtering power, the sputtering target of the thermoelectric material matrix and the sputtering target of the nanostructure is sputtered separately, and the resulting thickness of each film It may include measuring and comparing.

Method for manufacturing a thermoelectric material according to an embodiment of the present invention, a method for manufacturing a thermoelectric material, the thermoelectric material, a thermoelectric material matrix; And a nanostructure dispersed in the matrix, the method comprising: melting the thermoelectric matrix and the elements constituting the nanostructure together; Quenching the melt obtained by the melting; And heat treating the quenched melt to form nanostructures.

In the manufacturing method according to another embodiment of the present invention, the thermoelectric material is x {(Bi _1-a Sb _a ) ₂ (Se _1-b Te _b ) ₃ } + 1-x (In ₂ Se ₃ ) Or x {(Bi _{1 - a} Sb _a ) ₂ (Se _{1 - b} Te _b ) ₃ } + 1-x (In ₄ Se ₃ ) (as molar ratio, a, b is a number from 0 to 1, x is 1 >x> 0.85).

In the manufacturing method according to another embodiment of the present invention, the thermoelectric material may have a thermoelectric performance index value ZT of 1 or more.

In a manufacturing method according to another embodiment of the present invention, between the step of melting the element and the step of quenching the melt, maintaining the molten state for at least 10 hours to further mix each element It may include.

By using the present invention, a nanocomposite thermoelectric material can be easily obtained in a low cost process. In addition, using the present invention, a mass production process is possible and very economical. By using the present invention, not only a high-performance thermoelectric material in the form of a lump, but also a film-type thermoelectric material requiring a thickness of several tens of micrometers or more can be easily manufactured by a low cost process. In addition, the thermoelectric material of the composition according to an embodiment of the present invention is significantly lowered thermal conductivity by maximizing phonon scattering.

1 is an electron micrograph and a thermal conductivity reduction mechanism of a thermoelectric material of Bi ₂ Te ₃ and In-Se composition according to an embodiment of the present invention.
Figure 2 is a thermoelectric material according to an embodiment of the present invention, a graph showing a measurement result of the thermoelectric constant (Seebeck coefficient) according to the heat treatment of In ₂ Se ₃ added to the Bi ₂ Te ₃ matrix.
3 is an electron microscope image of a thermoelectric material according to an embodiment of the present invention, and is a photograph showing a result in which In ₂ Se ₃ particles are dispersed in a nano size in a thermoelectric material Bi ₂ Te ₃ matrix.
4 is a microstructure of a thermoelectric material including a Bi ₂ Te ₃ matrix and In-Se particles prepared by melting and cooling according to an embodiment of the present invention, and the Bi ₂ Te ₃ and In ₂ Se ₃ phases are finely formed. Scanning electron microscope image showing separated shapes.

Thermoelectric material according to an embodiment of the present invention may have a composition as follows.

≪ Formula 1 >

x {(Bi _{1 - a} Sb _a ) ₂ (Se _{1 - b} Te _b ) ₃ } + 1-x (In ₂ Se ₃ )

<Formula 2>

x {(Bi _{1 - a} Sb _a ) ₂ (Se _{1 - b} Te _b ) ₃ } + 1-x (In ₄ Se ₃ )

In the above formula, x, a, and b are molar ratios. It is possible to control the n and p conductivity of the thermoelectric material by adjusting a and b having values of 0 to 1. Here, the x composition is 1> x ≧ 0.85 in molar ratio. If x is 1, the composition of the common thermoelectric materials well known in the art is mutually solid so that phonon scattering maximization effect cannot be obtained. If x is less than 0.85, the thermoelectric properties are deteriorated due to excess of In-Se compound. There is this.

As used herein, the term "nano structure" refers to inclusions dispersed in a matrix, wherein the averaged size of all nano structures is in the nano range, that is, 1 μm or less. The average value of the sizes of the whole structures is preferably 500 nm or less, more preferably 100 nm or less. This range is for maximizing phonon scattering. The size of the inclusions dispersed in the matrix may be 10 μm or less. If the inclusions exceed 10 μm, the phonon scattering effect may be less.

As used herein, "size" means the average value of several measurable dimensions. If the nanostructures are spherical, they are not completely spherical, so different diameters measured in different directions will be different. In this case, the average value of the five diameters, including the maximum diameter and the minimum diameter, is defined herein as "size". In addition, when the nanostructure is a linear or triangular shape or more, a value obtained by averaging all dimensions such as horizontal, vertical, and diagonal is defined as "size".

As mentioned above, the "nanostructure" herein may be in the shape of a zero-dimensional point, a one-dimensional line, or a two-dimensional surface. Such nanostructures exist in a dispersed form in a thermoelectric material matrix.

1, 3 and 4 illustrate a thermoelectric material according to an embodiment of the present invention. 1 and 3, it can be seen that spherical nanostructures are dispersed in a matrix. The spherical dark colored part is the nanostructure of In-Se composition, and the light colored background part is the matrix of Bi-Te composition. In FIG. 4, it can be seen that linear nanostructures are dispersed in a matrix. The light colored linear portion is the nanostructure of In-Se composition and the gray background is the matrix of Bi-Te composition. 3, it can be seen that the crystal interface of Bi ₂ Te _{3 and} the crystal interface of In ₂ Se ₃ intersect with each other. This shows that the nanostructures are dispersed and precipitated in the matrix. The nanocomposite thermoelectric material has a low thermal conductivity due to phonon scattering due to the interface of the nanostructures, thereby improving the thermoelectric performance.

In the present specification, the "thermoelectric performance index (ZT)" means a value calculated by the following equation.

ZT = TS ² σ / κ; T = absolute temperature, S = thermoelectric constant, σ = electrical conductivity, κ = thermal conductivity

As shown in the above equation, the lower the thermal conductivity, the higher the thermal performance index.

The thermoelectric element may be composed of n-type and p-type thermoelectric materials. In particular, a n- type thermoelectric material in the vicinity of room temperature is Bi ₂ Te ₃ or Bi _{2 -} may be mentioned _{(1 b} Se _b Te) _3. Examples of the p-type thermoelectric material include Sb ₂ Te ₃ or (Bi _{1 - a} Sb _a ) ₂ Te ₃ .

The compound of In-Se exists in the form of InSe, In ₂ Se ₃ , In ₄ Se _3, and the like. This compound is a useful thermoelectric material in the room temperature and low temperature regions.

The method for producing a thermoelectric material according to the present invention is not particularly limited and any method may be used.

The thermoelectric material according to an embodiment of the present invention may be in the form of a film, or may be in the form of agglomerates.

In the case of the film form, a method of sputtering or thermal evaporation can be adopted. Two or more compounds, such as matrix compounds and nanostructure compounds, such as Bi-Te compounds and In-Se compounds, can be prepared into targets or mixtures of desired composition and the mixture can be sputtered or thermally deposited. Alternatively, two compounds may be prepared separately, and the thermoelectric material may be obtained by sputtering or simultaneously thermally depositing the two compounds.

For example, in more detail, for example, a chamber equipped with a Bi ₂ Te ₃ sputtering target and an In ₂ Se ₃ sputtering target is prepared and the substrate is mounted. As the substrate, various materials such as sapphire, Si, GaAs, glass, and a metal patterned on an insulating substrate may be used. First, the sputtering power suitable for the desired composition of Bi ₂ Te ₃ and In ₂ Se ₃ can be determined. For example, the compositions of the desired Bi ₂ Te ₃ and In ₂ Se ₃ are 90% Bi ₂ Te ₃ and 10% In ₂ Se ₃ If so, you should determine the sputtering power for it. There is a difference in the rate or amount of sputtering depending on the type of each compound. First, select a sputtering power that is expected to be suitable, and sputter the Bi ₂ Te ₃ sputtering target and the In ₂ Se ₃ sputtering target separately at that power. The thickness of each of the films Bi ₂ Te ₃ and In ₂ Se ₃ obtained as a result of sputtering is measured. Sputtering power can be determined from the thickness of the film measured in this way. For example, when the thicknesses of Bi ₂ Te ₃ and In ₂ Se ₃ deposited at a sputtering power of 20W of Ar atmosphere of 10 ⁻³ torr are ₂ μm and 200 nm per hour, respectively, Bi ₂ Te ₃ and In formed during simultaneous sputtering under the same conditions The composition of ₂ Se ₃ is 90% Bi ₂ Te ₃ and 10% In ₂ Se ₃ to be. Therefore, the sputtering conditions necessary to obtain a thermoelectric material of 90% Bi ₂ Te ₃ and 10% In ₂ Se ₃ composition, can be determined by the sputtering power of 20W of Ar atmosphere of 10 ^-3 torr.

Meanwhile, in the case of the film form, the metal precursor of the matrix, for example, Bi-Te, may be formed by simultaneously injecting the metal precursor of the nanostructure, such as In-Se metal precursor, onto the substrate. For example, a thermoelectric material in the form of a film may be manufactured by metal organic chemical vapor deposition (MOCVD) or the like.

In addition, in order to obtain a thermoelectric material in the form of a lump, the matrix compound and the nanostructure compound having a desired composition may be melted, quenched, and heat treated. Alternatively, the elements constituting the thermoelectric material may be melted and quenched, followed by heat treatment.

In the melting process, all the elements constituting the thermoelectric material may be melted in an amount according to the composition. Alternatively, the matrix compound and the nanostructure compound may be mixed and melted. The melting process is heated to a temperature above the highest melting point of the melting points of the materials to be melted. For _{example, 90% Bi 2 Te 3 -} 10% In 2 Se 3 In the case of a thermoelectric material, it may be heated to a temperature of 700 to 800 ℃. More preferably, it can be heated to a temperature of 730 to 770 ℃. The melting process may be heated in a vacuum sealed state.

After the melting step, it is preferable to maintain the elements for at least 10 hours so that the elements can be sufficiently mixed well.

The subsequent quenching step is not particularly limited, but a method of immersing in cooling water or liquid nitrogen may be employed.

After the quenching process, the nanostructure may be formed by heat treatment again. This heat treatment process is at least 10 ° C lower, or at least 20 ° C lower, or at least 30 ° C lower, or at least 40 ° C lower than the melting point of the lowest melting point of all the elements constituting the thermoelectric material. Heat treatment at temperatures or lower than 50 ° C. For _{example, 90% Bi 2 Te 3 -} 10% In 2 Se 3 In the case of a thermoelectric material, heat treatment may be performed at about 750 ° C. This heat treatment promotes the formation of nanostructures. The heat treatment time may be at least 1 day, at least 2 days, at least 3 days, at least 4 days, at least 5 days. Alternatively, the heat treatment time may be 24 hours to 4 days. Alternatively, the heat treatment time may be 2 days to 4 days. For _{example, 90% Bi 2 Te 3 -} 10% In 2 Se 3 In the case of a thermoelectric material, heat treatment may be performed for about 3 days. Only within the heat treatment time range may promote nanostructure formation while increasing process efficiency.

Hereinafter, the present invention will be described in detail with reference to examples, but these examples are only presented to more clearly understand the present invention, and are not intended to limit the scope of the present invention. It will be determined within the spirit of the claims.

Example  One

In this embodiment, Bi ₂ Te _{3 In 2} Se ₃ , which is a thermoelectric material in the form of a film, was manufactured by the method of simultaneous sputtering.

A chamber equipped with two Bi ₂ Te ₃ and In ₂ Se ₃ targets was prepared and mounted with a substrate. As the substrate, a silicon substrate was used. The desired compositions of Bi ₂ Te ₃ and In ₂ Se ₃ were 90% Bi ₂ Te ₃ and 10% In ₂ Se ₃ . In order to determine the sputtering power suitable for the composition, the thickness of each film formed according to the power when sputtering each material of Bi ₂ Te ₃ and In ₂ Se ₃ was measured. Among the various powers, the thicknesses of Bi ₂ Te ₃ and In ₂ Se ₃ deposited at 10 ^-3 torr Ar atmosphere at 20W sputtering power were ₂ μm and 200 nm per hour, respectively. The compositions of ₂ Te ₃ and In ₂ Se ₃ were 90% Bi ₂ Te ₃ and 10% In ₂ Se ₃ . Accordingly, the sputtering power was set to 20 W of 10 ⁻³ torr Ar atmosphere, and the materials of Bi ₂ Te ₃ and In ₂ Se ₃ were sputtered simultaneously to obtain a thermoelectric material.

1 is 90% Bi ₂ Te ₃ prepared from this example -10% In ₂ Se ₃ HAADF (High Angle Annular Dark Field) image. 1, it can be seen that the In ₂ Se ₃ nanostructures are dispersed in a bright Bi ₂ Te ₃ matrix.

Figure 2 is made of the composition of _{90% Bi 2 Te 3 - 10} % In 2 Se 3 And pure Bi ₂ Te ₃ The thermoelectric constant value of each thermoelectric material of the composition is shown according to the heat treatment temperature. As shown in Figure 2, it was confirmed that the thermoelectric constant value was increased by the addition of In-Se.

Figure 3 is manufactured in the above manner _{90% Bi 2 Te 3 - 10} % In 2 Se 3 Thermoelectric material HAADF (High Angle Annular Dark Field) electron microscope image is shown. The HAADF image shows the element information, and shows that the sputtered sample was precipitated with In ₂ Se ₃ dispersed in several nm size in the Bi ₂ Te ₃ parent composition. The nanocomposite thermoelectric material has a low thermal conductivity due to phonon scattering due to the nanomaterial interface, and therefore, an improvement in thermoelectric performance can be expected.

Example  2

In this embodiment, the nanocomposite thermoelectric material in the form of agglomerates was prepared. First, 90% Bi ₂ Te ₃ in a molar ratio - 10% In ₂ Se ₃ The elements constituting the thermoelectric material were weighed into a quartz tube and vacuum-sealed. The vacuum sealed quartz tube was placed in a furnace and heated to about 750 ° C. so that all materials could be melted. After that, each element was kept for 10 hours or more to be sufficiently mixed. The quartz tube was then quenched by immersing in liquid nitrogen. Then, it heat-processed for 3 days at the temperature of 520 degreeC.

Figure 4 shows a scanning electron microscope image of a sample prepared in this manner naturally formed into a nanostructure by phase separation. Such a thermoelectric material may improve the performance of the thermoelectric constant by forming heat treatment after the heat treatment process and powder manufacturing. In this process, the improvement of the characteristics of the thermoelectric material, such as the reduction of the thermal conductivity due to the maintenance of the existing nanostructures can be expected.

Claims (19)

As a nanocomposite thermoelectric material,
The nanocomposite thermoelectric material has a form in which nanostructures are dispersed in a thermoelectric material matrix;
The thermoelectric material matrix includes bismuth (Bi) and tellurium (Te),
The nanostructure includes indium (In) and selenium (Se),
The thermoelectric material is a nanocomposite thermoelectric material having a composition of the following formula (1) or (2).
(Formula 1)
x {(Bi _{1 - a} Sb _a ) ₂ (Se _{1 - b} Te _b ) ₃ } + 1-x (In ₂ Se ₃ )
Wherein, as molar ratio, a, b is a number from 0 to 1 and x is 1>x> 0.85.
(2)
x {(Bi _{1 - a} Sb _a ) ₂ (Se _{1 - b} Te _b ) ₃ } + 1-x (In ₄ Se ₃ )
Wherein, as molar ratio, a, b is a number from 0 to 1 and x is 1>x> 0.85. The method of claim 1,
The nanostructure is a nanocomposite thermoelectric material having a size of 10㎛ or less. The method of claim 1,
The thermoelectric material is a nanocomposite thermoelectric material having a thermoelectric performance index value ZT of 1 or more. The method of claim 1,
The thermoelectric material is a nanocomposite thermoelectric material produced by sputtering, or melting and cooling. The method of claim 4, wherein
The nanocomposite thermoelectric material is prepared by a sputtering method,
The sputtering method,
A nanocomposite thermoelectric material comprising sputtering a sputtering target including bismuth (Bi) and tellurium (Te) and a sputtering target including indium (In) and selenium (Se) simultaneously. The method of claim 4, wherein
The nanocomposite thermoelectric material is prepared by a melting and cooling method,
The melting and cooling method,
Melting elements constituting the thermoelectric material matrix and the nanostructure;
Quenching the melt obtained by the melting; And
A nanocomposite thermoelectric material comprising the step of heat-treating the quenched melt to form a nanostructure. Thermoelectric material matrix; And
As a thermoelectric material comprising a nanostructure dispersed in the matrix,
The thermoelectric material is produced by the sputtering method, or melting and cooling method,
The thermoelectric material is a thermoelectric material having a composition of the following formula (1) or (2).
(Formula 1)
x {(Bi _{1 - a} Sb _a ) ₂ (Se _{1 - b} Te _b ) ₃ } + 1-x (In ₂ Se ₃ )
Wherein, as molar ratio, a, b is a number from 0 to 1 and x is 1>x> 0.85.
(2)
x {(Bi _{1 - a} Sb _a ) ₂ (Se _{1 - b} Te _b ) ₃ } + 1-x (In ₄ Se ₃ )
Wherein, as molar ratio, a, b is a number from 0 to 1 and x is 1>x> 0.85. The method of claim 7, wherein
The thermoelectric material matrix is
Thermoelectric material comprising bismuth (Bi) and tellurium (Te). The method of claim 7, wherein
The nanostructure, the thermoelectric material containing indium (In) and selenium (Se). The method of claim 7, wherein
The thermoelectric material is a thermoelectric material having a thermoelectric performance index value ZT of 1 or more. The method according to any one of claims 7 to 10,
The thermoelectric material is manufactured by a sputtering method,
The sputtering method,
A thermoelectric material comprising sputtering a sputtering target for a thermoelectric material matrix and a sputtering target for a nanostructure simultaneously. The method according to claim 7 to 10,
The thermoelectric material is prepared by melting and cooling methods,
The melting and cooling method,
Melting elements constituting the thermoelectric material matrix and the nanostructure;
Quenching the melt obtained by the melting; And
Thermoelectric material comprising the step of heat-treating the quenched melt to form a nanostructure. As a method of manufacturing a thermoelectric material,
The thermoelectric material may include a thermoelectric material matrix; And nanostructures dispersed in the matrix,
The method includes simultaneously sputtering a sputtering target for a thermoelectric material matrix and a sputtering target for a nanostructure,
The thermoelectric material is a method of manufacturing a thermoelectric material having a composition of the following formula (1) or (2):
(Formula 1)
x {(Bi _{1 - a} Sb _a ) ₂ (Se _{1 - b} Te _b ) ₃ } + 1-x (In ₂ Se ₃ )
Wherein, as molar ratio, a, b is a number from 0 to 1 and x is 1>x> 0.85.
(2)
x {(Bi _{1 - a} Sb _a ) ₂ (Se _{1 - b} Te _b ) ₃ } + 1-x (In ₄ Se ₃ ),
Wherein, as molar ratio, a, b is a number from 0 to 1 and x is 1>x> 0.85. The method of claim 13,
The thermoelectric material is a method of manufacturing a thermoelectric material having a thermoelectric performance index value ZT of 1 or more. The method according to claim 13 or 14,
The method comprises:
Determining the sputtering power required to obtain a desired composition of thermoelectric material; And
A method of manufacturing a thermoelectric material comprising sputtering at the determined sputtering power. The method of claim 15,
Determining the sputtering power,
A sputtering target of a thermoelectric material matrix and a sputtering target of a nanostructure are separately sputtered, and the thickness of each obtained film is measured and compared. As a method of manufacturing a thermoelectric material,
The thermoelectric material may include a thermoelectric material matrix; And nanostructures dispersed in the matrix,
The method comprises:
Melting the thermoelectric material matrix and the elements constituting the nanostructure together;
Quenching the melt obtained by the melting; And
Heat treating the quenched melt to form nanostructures,
The thermoelectric material is a method of manufacturing a thermoelectric material which is a thermoelectric material having a composition of Formula 1 or 2 below:
(Formula 1)
x {(Bi _{1 - a} Sb _a ) ₂ (Se _{1 - b} Te _b ) ₃ } + 1-x (In ₂ Se ₃ )
Wherein, as molar ratio, a, b is a number from 0 to 1 and x is 1>x> 0.85.
(2)
x {(Bi _{1 - a} Sb _a ) ₂ (Se _{1 - b} Te _b ) ₃ } + 1-x (In ₄ Se ₃ )
Wherein, as molar ratio, a, b is a number from 0 to 1 and x is 1>x> 0.85. The method of claim 17,
The thermoelectric material is a method of manufacturing a thermoelectric material having a thermoelectric performance index value ZT of 1 or more. The method according to claim 17 or 18,
Between melting the element and quenching the melt,
The method of manufacturing a thermoelectric material further comprising the step of maintaining each element in a molten state for at least 10 hours to be sufficiently mixed.

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