KR102151240B1 - Thermoelectric materials, and thermoelectric module and thermoelectric apparatus comprising the same - Google Patents

Abstract

The present invention relates to a thermoelectric material comprising the compound of Formula 1:
<Formula 1>
A _{4- a} M _{b M'c} (B _{1- x B'x} ) _{3- d} X _e
In the formula,
Wherein A represents a group 13 element,
The M and M'are different from each other, and M and M'represent a Group 14 or transition metal element,
B and B'are different from each other, B and B'represent a chalcogen element,
X represents a halogen element,
Wherein a is -1<a<1, b is 0<b<1, c is 0<c<1, x is 0≦x<1, and d is 0≦d<1, and , The e is 0≤e<1.

Description

Thermoelectric materials, thermoelectric modules and thermoelectric devices including them {THERMOELECTRIC MATERIALS, AND THERMOELECTRIC MODULE AND THERMOELECTRIC APPARATUS COMPRISING THE SAME}

The present invention relates to a thermoelectric material, a thermoelectric module including the same, and a thermoelectric device.

In general, thermoelectric materials are materials that can be applied to active cooling and waste heat power generation by using the Peltier effect and/or the Seebeck effect.

A diagram showing the Peltier effect is shown in FIG. 1. Referring to FIG. 1, the Peltier effect is a phenomenon in which holes of a p-type material and electrons of an n-type material move when a DC voltage is applied from an external power source, thereby causing heat generation and endothermic heat at both ends of the material.

A diagram showing the Seebeck effect is shown in FIG. 2. Referring to FIG. 2, when heat is supplied from an external heat source, electrons and holes move, and current flows in the material, causing power generation.

Active cooling using such a thermoelectric material improves the thermal stability of the device, has no vibration and noise, and does not use a separate condenser and refrigerant, and is therefore recognized as a small volume and environmentally friendly method. As an application field of such active cooling using thermoelectric materials, it can be used for non-refrigerant refrigerators, air conditioners, and various micro cooling systems. In particular, when thermoelectric elements are attached to various memory elements, the volume is reduced compared to the conventional cooling method. Since it can be maintained at a uniform and stable temperature, the performance of the device can be improved.

On the other hand, if thermoelectric materials are used for thermoelectric power generation using the Seebeck effect, waste heat can be used as an energy source, so energy such as automobile engines and exhaust systems, waste incinerators, waste heat from steel mills, and power of medical devices in the human body using human heat It can be applied to various fields that increase the efficiency of the product or collect and use waste heat.

As a factor for measuring the performance of such a thermoelectric material, a dimensionless figure of merit ZT value defined as in Equation 1 below is used:

<Equation 1>

In the formula, S is the Seebeck coefficient, σ is the electrical conductivity, T is the absolute temperature, and κ thermal conductivity.

In order to increase the dimensionless figure of merit ZT, it is necessary to find a material with high Seebeck coefficient and high electrical conductivity and low thermal conductivity.

However, the general Indium Selenide In ₄ Se _{3 -x} thermoelectric material is an n-type crystal material having ZT 1.48 and has a current density of about 10 ¹⁸ cm ^-3 . This degree of current density is less than 10 ¹⁹ ~ 10 ²⁰ cm ^-3 , which is the optimized current density of the thermoelectric material, so thermoelectric property optimization has not been achieved.

In order to improve the current density through electron doping, the chlorine-doped Indium Selenide In ₄ Se _{3 - x} Cl _{0 .03} thermoelectric material improves the current density to 10 ¹⁹ cm ^-3 , so the maximum ZT value is improved to 1.53 and at low temperatures. It has a wide operating temperature due to its size improvement in characteristics.

However, from the Boltzmann transport calculation, both In ₄ Se _{3 -x} (0.22 eV) and In ₄ Se _{3 -x} Cl _0.03 (0.34 eV) are far away from the region with the optimal power factor S2σ (0.8 eV), resulting in more electron doping. It must be done.

An object of the present invention is to provide a thermoelectric material having high Seebeck coefficient and high electrical conductivity and very low thermal conductivity, a thermoelectric module including the same, and a thermoelectric device.

However, the technical problem to be achieved by the present invention is not limited to the above-mentioned problems, and other problems that are not mentioned will be clearly understood by those skilled in the art from the following description.

The present invention provides a thermoelectric material including the compound of Formula 1:

<Formula 1>

A _{4- a} M _{b M'c} (B _{1- x B'x} ) _{3- d} X _e

In the formula,

Wherein A represents a group 13 element,

The M and M'are different from each other, and M and M'represent a Group 14 or transition metal element,

B and B'are different from each other, B and B'represent a chalcogen element,

X represents a halogen element,

Wherein a is -1<a<1, b is 0<b<1, c is 0<c<1, x is 0≦x<1, and d is 0≦d<1, and , The e is 0≤e<1.

The d may be 0.1≦d≦0.5.

The e may be 0≦e≦0.06.

The compound of Formula 1 may have an irregular arrangement in an in-plane direction and a layered structure having a regular arrangement in an out-of-plane direction.

The compound of Formula 1 may form a covalent bond in an in-plane direction and an ionic bond and/or a Van der Waals bond in an out-of-plane direction.

The compound of Formula 1 may have lattice distortion due to current density.

The compound of Formula 1 may be 10 ¹⁶ cm ^-3 to 10 ²⁰ cm ^-3 .

The compound of Formula 1 may have a thermal conductivity of 2W/mK or less at room temperature.

The compound of Formula 1 may have a polycrystalline structure or a single crystal structure.

The compound of Formula 1 may have a density corresponding to 80% to 100% of the theoretical density.

In one embodiment of the present invention, there is provided a thermoelectric module comprising a first electrode, a second electrode, and a thermoelectric element interposed between the first electrode and the second electrode, the thermoelectric element including the thermoelectric material. .

In another embodiment of the present invention, a heat supply source, a thermoelectric element absorbing heat from the heat supply source, a first electrode disposed to contact the thermoelectric element, and a first electrode disposed to face the first electrode and contacting the thermoelectric element It provides a thermoelectric device comprising a thermoelectric module having a second electrode, wherein the thermoelectric element includes the thermoelectric material.

The thermoelectric material according to the present invention is characterized in that two or more types of Group 14 or transition metal elements are added, or two or more types of Group 14 or transition metal elements and halogen elements are added, and have high Seebeck coefficient and electrical conductivity and thermal conductivity. Is very low, and the figure of merit is excellent. Therefore, it can be usefully used for refrigerant-free refrigerators, air conditioners, waste heat power generation, thermoelectric nuclear power generation for military aerospace, micro cooling systems, and the like.

1 is a schematic diagram showing thermoelectric cooling by a Peltier effect.
2 is a schematic diagram showing thermoelectric power generation by the Seebeck effect.
3 is a schematic diagram showing the crystal structure of In ₄ Se ₃ .
4 is a diagram showing electrical resistance according to temperature of In ₄ Pb _{0 .01} Sn _{0 .03} Se _{3 -d} according to an embodiment of the present invention.
5 is a diagram showing the Seebeck coefficient according to the temperature of In ₄ Pb _{0 .01} Sn _{0 .03} Se _{3 -d} according to an embodiment of the present invention.
6 is a diagram illustrating a power factor (S ² σ) according to temperature of In ₄ Pb _{0 .01} Sn _{0 .03} Se _{3 -d} according to an embodiment of the present invention.
FIG. 7 is a diagram showing thermal conductivity according to temperature of In ₄ Pb _{0 .01} Sn _{0 .03} Se _{3 -d} according to an embodiment of the present invention.
8 is a diagram showing a dimensionless figure of merit (ZT) value according to temperature of In ₄ Pb _{0 .01} Sn _{0 .03} Se _{3 -d} according to an embodiment of the present invention.
9 is a diagram showing electrical resistance according to temperature of In ₄ Pb _{0 .01} Sn _{0 .03} Se _{2 .9} Cl _e according to an embodiment of the present invention.
10 is a diagram showing the Seebeck coefficient according to the temperature of In ₄ Pb _{0 .01} Sn _{0 .03} Se _{2 .9} Cl _e according to an embodiment of the present invention.
11 is a diagram showing a power factor (S ² σ) according to the temperature of In ₄ Pb _{0 .01} Sn _{0 .03} Se _{2 .9} Cl _e according to an embodiment of the present invention.

In manufacturing thermoelectric materials, the present inventors added two or more types of Group 14 or transition metal elements, or by adding two or more types of Group 14 or transition metal elements and halogen elements, thereby increasing the Seebeck coefficient and electrical conductivity and reducing the thermal conductivity very much. And completed the present invention.

Hereinafter, the present invention will be described in detail.

The present invention provides a thermoelectric material including the compound of Formula 1:

<Formula 1>

A _{4- a} M _{b M'c} (B _{1- x B'x} ) _{3- d} X _e

In the formula,

Wherein A represents a group 13 element,

The M and M'are different from each other, and M and M'represent a Group 14 or transition metal element,

B and B'are different from each other, B and B'represent a chalcogen element,

X represents a halogen element,

Wherein a is -1<a<1, b is 0<b<1, c is 0<c<1, x is 0≦x<1, and d is 0≦d<1, and , The e is 0≤e<1.

Specifically, the thermoelectric material according to the present invention is characterized in that two or more types of Group 14 or transition metal elements are added, or two or more types of Group 14 or transition metal elements and a halogen element are added.

In this case, A represents a group 13 element, and is preferably In or Ga, but is not limited thereto.

The M and M'are different from each other, and M and M'represent Group 14 or a transition metal element, and are preferably Pb or Sn, but are not limited thereto.

The B and B'are different from each other, and B and B'represent a chalcogen group element, preferably S, Se or Te, and more preferably Se or Te, but are not limited thereto.

The X represents a halogen element, and is preferably Cl or I, but is not limited thereto.

In addition, a may be -1<a<1, and preferably 0≦a<1.

Wherein b is 0<b<1, and c is 0<c<1, the thermoelectric material according to the present invention is characterized in that two or more types of Group 14 or transition metal elements are added.

The d may be 0≦d<1, preferably 0.1≦d≦0.5.

The e may be 0≦e<1, and preferably 0≦e≦0.06.

The compound of Formula 1 may have an irregular arrangement in an in-plane direction and a layered structure having a regular arrangement in an out-of-plane direction.

In addition, the compound of Formula 1 can form a covalent bond in the in-plane direction, and an ionic bond and/or a Van der Waals bond in the out-of-plane direction, so that the thermal conductivity is very low.

In addition, the compound of Formula 1 may have lattice distortion due to a current density, and in this case, the current density may be 10 ¹⁶ cm ^-3 to 10 ²⁰ cm ^-3 .

The compound of Formula 1 may not have lattice distortion, but may have lattice distortion according to a change in current density. In particular, an increase in the current density is more preferable because the lattice of the compound is distorted due to a strong interaction between electrons and surrounding atoms in an appropriate region, thereby reducing thermal conductivity.

In other words, when the current density is less than 10 ¹⁶ cm ^-3 , there is no lattice distortion due to the current density, but when the current density is 10 ¹⁶ cm ^-3 to 10 ²⁰ cm ^-3 , the lattice distortion due to the current density will occur. I can.

As a method of causing lattice distortion by increasing the current density as described above, a method of changing physical properties by changing the conditions of the synthesis method of the compound of Formula 1, a method of adding a doping element, or a method of inducing defects. Etc. can be used.

As conditions on the manufacturing process for the change of the physical properties, the firing temperature or the firing time can be adjusted or the pressure conditions can be changed in the firing process, and as a method of inducing the defect, the M component, which is a raw material in the preparation of the compound of Formula 1 And/or by adding component B less than stoichiometric.

By changing the current density as described above, the compound of Formula 1 can exhibit a layered structure having an irregular arrangement in an in-plane direction and a regular arrangement in an out-of-plane direction, thereby exhibiting low thermal conductivity.

In the compound of Formula 1, the A component is arranged almost one-dimensionally in the lattice structure, so that electrons or holes move along this path, so that the Seebeck coefficient is improved due to low-dimensional conduction characteristics.

In the compound of Formula 1, the doping component M'component and B'component are selectively added to the basic components M and B components to improve electrical conductivity, thereby increasing the ZT value of the following equation:

<Equation 1>

In the formula, S is the Seebeck coefficient, σ is the electrical conductivity, T is the absolute temperature, and κ is the thermal conductivity.

The M'component and B'component, which are doping components, may be added in the form of a one-component system, a two-component system, or a three-component system, and in the case of a two-component system, the molar ratio may be added in a ratio of 1:9 to 9:1, In the case of a three-component system, the molar ratio may be added in a ratio of 1:0.1-0.9:0.1-0.9, but is not limited thereto.

Each component constituting the compound of Formula 1 is bonded to each other to form a layered structure, and in these layered structures, covalent bonds are formed in the in-plane phase, and the bonds between these layers are ionic bonds and/or half Forms a der Waals bond.

In general, thermal conductivity (k _tot ) can be _classified into thermal conductivity (k _ph ) due to lattice vibration and thermal conductivity (k _el ) due to electrons, such as k _tot = k _el +k _ph . Electronic thermal conductivity is a dependent variable of electrical conductivity because it is proportional to electrical conductivity (ρ) and temperature (T) according to the Wiedemann-Frantz law as shown in Equation 2.

<Equation 2>

K _el =LT/ρ

In the formula, T is temperature, ρ is electrical conductivity, L = 2.44 X 10 ^-8 ΩW/K ² , and K is absolute temperature.

Therefore, a good thermoelectric material must have a low lattice thermal conductivity, which can be obtained through control of the lattice structure.

When the M component and B component shortfalls are generated in the compound of Formula 1, the current density increases, and the increased current density distorts the lattice due to interactions with neighboring atoms, thereby reducing thermal conductivity. The lattice distortion occurs due to the strong interaction between electrons and lattice vibration, and serves to reduce thermal conductivity.

Therefore, in the compound of Formula 1, each layer in the in-plane direction forms a strong bond by covalent bonds in the presence of lattice distortion, and interlayer bonds, that is, ionic bonds or van der bonds in the out-of-plane direction. Because the weak bond is formed by the Bals coupling, it is difficult to transmit the phonon in the out-of-plane direction. In the in-plane, thermal conductivity in both the in-plane and out-of-plane directions due to lattice distortion. Becomes lower. For example, the compound of Formula 1 may have a thermal conductivity of 2W/mK or less at room temperature.

In addition, since the compound of Formula 1 has a characteristic in which the component A, for example In, is arranged one-dimensionally, it exhibits low-dimensional conduction characteristics by them, thereby improving the Seebeck coefficient characteristics.

In general, it is known that the lower the dimensional conduction characteristic, the higher the energy state density at the Fermi level, and if the energy state density (density of state) has a sharp singularity, the Seebeck coefficient increases as shown in Equation 3 below:

<Equation 3>

In the formula, S is the Seebeck coefficient, ε is the energy, and E _F is the Fermi energy.

As the compound of Formula 1 has low-dimensional electrical properties in its lattice structure, it can be interpreted that the energy state density increases at the Fermi level, and has a high Seebeck coefficient at the higher energy state density.

The compound of Formula 1 exhibits low thermal conductivity and increases the Seebeck coefficient due to the low-dimensional conduction characteristics of electrons. Therefore, the characteristics required as a thermoelectric material are satisfied.

The compound of Formula 1 may have a single crystal structure or a polycrystalline structure while including lattice distortion as described above. When the compound of Formula 1 is used as a thermoelectric material, such a single crystal structure or a polycrystalline structure may affect the properties of the thermoelectric material.

In addition, when the compound of Formula 1 is used as a thermoelectric material, they are cut into a predetermined shape and used, and may have different characteristics depending on the cutting direction. For example, when the compound has a single crystal structure, it is preferable that the cutting direction is perpendicular to the growth direction when forming the thermoelectric element.

The thermoelectric material has a polycrystalline structure or a single crystal structure, and the synthesis method of the compound of Formula 1 is divided into a polycrystalline synthesis method and a single crystal growth method.

First, looking at the polycrystalline synthesis method, there are an ampoule method, an arc melting method, and a solid state reaction method, and brief descriptions of these are as follows.

(1) Ampoule (Ampoule) usage: a method comprising the step of heat-treating by placing the source element in a quartz tube or an ampoule made of metal and sealing in a vacuum;

(2) Arc melting method: A method comprising the step of making a sample by discharging the raw material element into a chamber and discharging the arc in an inert gas atmosphere to melt the raw material element;

(3) Solid state reaction: A method comprising the steps of mixing the powder well and processing it hard and then heat-treating or heat-treating the mixed powder and then processing and sintering.

Next, looking at the single crystal growth method, there are a metal flux method, a Bridgeman method, and the like, and brief descriptions thereof are as follows.

(1) Metal flux method: a method comprising the step of growing a crystal by putting an element providing an atmosphere in a crucible and heat-treating at a high temperature so that the raw element and the raw element can grow well into a crystal at high temperature;

(2) Bridgeman method: Put the raw material in a crucible, heat it at high temperature until the raw material element dissolves at the end of the crucible, and then slowly move the high-temperature region to dissolve the sample locally while dissolving the entire sample into the high-temperature region. A method comprising passing through to grow a crystal;

(3) Optical floating zone method: The raw material elements are made into a rod shape into a seed rod and a feed rod, and then the sample is locally heated by collecting the light from the lamp at one focus. A method comprising the step of growing a crystal by slowly pulling the dissolved portion upward while dissolving it;

(4) Vapor transport method: A step in which a raw material element is placed under the quartz tube, the raw material element part is heated, and the upper part of the quartz tube is placed at a low temperature to evaporate the raw material and cause a solid phase reaction at a low temperature to grow crystals. How to include.

In the synthesis method of the compound of Formula 1, when the current density is optimized through selective element doping, when two-band conduction in which electrons and holes coexist occurs, power is generated by making only one of the electrons or holes conductive. It makes a thermoelectric material with a large factor and very small thermal conductivity.

The doping process of such a doping element may be performed by adding it as a part of the raw material element in the polycrystalline growth method or the single crystal growth method.

Meanwhile, in the case of a polycrystalline compound, in addition to the doping process of the doping element, it is possible to additionally perform a densification process. Additional electrical conductivity can be improved by such a high density process.

Examples of the densification process include the following three processes:

(1) Hot pressing method: a method of applying a powder compound as an object to a mold having a predetermined shape and molding at a high temperature, for example, 300 to 800°C and high pressure, for example, 30 to 300 MPa;

(2) Spark plasma sintering method: high voltage current to a powder compound as an object, for example

A method of sintering the material in a short time by energizing 50 to 500 A;

(3) Hot Posing Method: A method of processing by extruding and sintering the object powder by applying a high temperature, for example, 300 to 700°C during pressure molding.

Through the densification process, the thermoelectric material may have a density corresponding to 80% to 100% of the theoretical density, and it is preferable to have a density corresponding to 95% to 100% of the theoretical density, but is not limited thereto. According to the density of the thermoelectric material, the ionic conductivity may be increased.

The compound of Formula 1 exhibits low thermal conductivity through control of the lattice structure, and at the same time, improves the Seebeck coefficient cancellation phenomenon of electron-holes by injecting electrons and holes through selective doping treatment, thereby increasing the Seebeck coefficient and increasing the current density. Since electrical conductivity can be improved through optimization, high thermoelectric performance can be expected, and thus, it has a use as an excellent thermoelectric material.

The thermoelectric material may be formed by cutting, or the like, to form a thermoelectric device, and the thermoelectric device may be a p-type thermoelectric device or an n-type thermoelectric device. Such a thermoelectric device refers to a thermoelectric material formed in a predetermined shape, for example, a rectangular parallelepiped shape.

Meanwhile, the thermoelectric device may be a device that is combined with an electrode to exhibit a cooling effect by applying a current or a device capable of exhibiting a power generation effect by a temperature difference.

In one embodiment of the present invention, there is provided a thermoelectric module comprising a first electrode, a second electrode, and a thermoelectric element interposed between the first electrode and the second electrode, the thermoelectric element including the thermoelectric material. .

In another embodiment of the present invention, a heat supply source, a thermoelectric element absorbing heat from the heat supply source, a first electrode disposed to contact the thermoelectric element, and a first electrode disposed to face the first electrode and contacting the thermoelectric element It provides a thermoelectric device comprising a thermoelectric module having a second electrode, wherein the thermoelectric element includes the thermoelectric material.

The thermoelectric material according to the present invention is characterized in that two or more types of Group 14 or transition metal elements are added, or two or more types of Group 14 or transition metal elements and halogen elements are added, and have high Seebeck coefficient and electrical conductivity and thermal conductivity. Is very low, and the figure of merit is excellent. Therefore, it can be usefully used for refrigerant-free refrigerators, air conditioners, waste heat power generation, thermoelectric nuclear power generation for military aerospace, micro cooling systems, and the like.

Hereinafter, a preferred embodiment is presented to aid the understanding of the present invention. However, the following examples are provided for easier understanding of the present invention, and the contents of the present invention are not limited by the following examples.

[ Example ]

Example

For an embodiment of the present invention, compounds for thermoelectric materials In ₄ Pb _{0 .01} Sn _{0 .03} Se _{3 -d} (3-d = 2.5, 2.6, 2.7, 2.8, 2.9) and In ₄ Pb _{0 .01} Sn _{0 .03} Se _{2 .9} Cl _e (e = 0.0, 0.02, 0.04, 0.06) was synthesized using a polycrystalline method in the following manner.

① In, Se, Pb, Sn elements and InCl ₃ powder were weighed according to the composition ratio, placed in a crystal tube, and sealed in a vacuum.

② Heat treatment was performed at 1100°C for 24 hours and at 560°C for 24 hours.

③ For uniform composition ratio, the ingot was put in an agate mortar, made into powder, and then put into a crystal tube and heat-treated at 560°C for 24 hours.

④ Put the ingot back into the agate mortar to make powder, and then put the powder into a carbon mold and hot press sintering for 5 minutes under a pressure of 70 MPa at 450°C to prepare a sintered body.

⑤ The sintered body was processed according to the standard and measured thermoelectric properties.

4 is a diagram showing electrical resistance according to temperature of In ₄ Pb _{0 .01} Sn _{0 .03} Se _{3 -d} according to an embodiment of the present invention. Referring to FIG. 4, the electrical resistance of In ₄ Pb _{0 .01} Sn _{0 .03} Se _{3 -d} at room temperature tended to decrease as Se defects increased, and In ₄ Pb _{0 .01} Sn _{0 .03} Se at high temperature The electrical resistance of _{3 -d} showed a complicated pattern. It is presumed that a complicated pattern occurred due to the possibility of coexistence of electrons/holes due to defect induction and competition by charge density.

5 is a diagram showing the Seebeck coefficient according to the temperature of In ₄ Pb _{0 .01} Sn _{0 .03} Se _{3 -d} according to an embodiment of the present invention. Referring to FIG. 5, the Seebeck coefficient of In ₄ Pb _{0 .01} Sn _{0 .03} Se _{3 -d} did not change significantly according to Se defects.

6 is a diagram illustrating a power factor (S ² σ) according to temperature of In ₄ Pb _{0 .01} Sn _{0 .03} Se _{3 -d} according to an embodiment of the present invention. 6, the power factor is a result obtained from the measurement of the Seebeck coefficient, and the power factor of In ₄ Pb _{0 .01} Sn _{0 .03} Se _{3 -d} at about 520 K is about 1.15 mWm ^-1 when Se 2.8 The highest value was shown as K ^-2 , and the power factor of In ₄ Pb _{0 .01} Sn _{0 .03} Se _{3 -d} at high temperature showed a tendency not to be sensitive to temperature.

FIG. 7 is a diagram showing thermal conductivity according to temperature of In ₄ Pb _{0 .01} Sn _{0 .03} Se _{3 -d} according to an embodiment of the present invention. Referring to FIG. 7, the thermal conductivity of In ₄ Pb _{0 .01} Sn _{0 .03} Se _{3 -d} tended to increase with increasing Se defects, and decreased with increasing temperature.

8 is a diagram showing a dimensionless figure of merit (ZT) value according to temperature of In ₄ Pb _{0 .01} Sn _{0 .03} Se _{3 -d} according to an embodiment of the present invention. Referring to FIG. 8, at about 725 K, the ZT value of Pb _{0 .01} Sn _{0 .03} Se _{3 -d} was about 1.2 when Se 2.9 was the highest.

9 is a diagram showing electrical resistance according to temperature of In ₄ Pb _{0 .01} Sn _{0 .03} Se _{2 .9} Cl _e according to an embodiment of the present invention. Referring to FIG. 9, the electrical resistance of In ₄ Pb _{0 .01} Sn _{0 .03} Se _{2 .9} Cl _e tended to increase as the Cl doping amount increased.

10 is a diagram showing the Seebeck coefficient according to the temperature of In ₄ Pb _{0 .01} Sn _{0 .03} Se _{2 .9} Cl _e according to an embodiment of the present invention. Referring to FIG. 10, the Seebeck coefficient of In ₄ Pb _{0 .01} Sn _{0 .03} Se _{2 .9} Cl _e did not change significantly depending on the amount of Cl doping.

11 is a diagram showing a power factor (S ² σ) according to the temperature of In ₄ Pb _{0 .01} Sn _{0 .03} Se _{2 .9} Cl _e according to an embodiment of the present invention. Referring to FIG. 11, the power factor is a result obtained from the measurement of the Seebeck coefficient. The power factor of In ₄ Pb _{0 .01} Sn _{0 .03} Se _{2 .9} Cl _e decreases as the amount of Cl doping increases, but In at high temperature, In The power factor of ₄ Pb _{0 .01} Sn _{0 .03} Se _{2 .9} Cl _e tended to increase when Cl 0.02 and Cl 0.04 were used. In addition, the power factor of In ₄ Pb _{0 .01} Sn _{0 .03} Se _{2 .9} Cl _e at about 520 K showed the highest value of about 1.0 mWm ^-1 K ^-2 at Cl 0, and In ₄ Pb at high temperature The power factor of _0.01 Sn _0.03 Se _2.9 Cl _e tended to be insensitive to temperature.

The above description of the present invention is for illustrative purposes only, and those of ordinary skill in the art to which the present invention pertains can understand that it is possible to easily transform it into other specific forms without changing the technical spirit or essential features of the present invention. will be. Therefore, it should be understood that the embodiments described above are illustrative in all respects and not limiting.

Claims (12)

Thermoelectric material containing the compound of Formula 1:
<Formula 1>
A _{4- a} M _{b M'c} (B _{1- x B'x} ) _{3- d} X _e
In the formula,
Wherein A represents a group 13 element,
The M and M'are different from each other, and M and M'represent a Group 14 or transition metal element,
B and B'are different from each other, B and B'represent a chalcogen element,
X represents a halogen element,
Wherein a is -1<a<1, b is 0<b<1, c is 0<c<1, x is 0≦x<1, and d is 0≦d<1, and , The e is 0≤e<1.
The method of claim 1,
The d is a thermoelectric material of 0.1≦d≦0.5.
The method of claim 1,
The thermoelectric material e is 0≤e≤0.06.
The method of claim 1,
The compound of Formula 1 has an irregular arrangement in an in-plane direction, and a thermoelectric material exhibiting a layered structure having a regular arrangement in an out-of-plane direction.
The method of claim 1,
The compound of Formula 1 forms a covalent bond in an in-plane direction, an ionic bond and/or a Van der Waals bond in an out-of-plane direction.
The method of claim 1,
The compound of Formula 1 is a thermoelectric material having lattice distortion due to current density.
The method of claim 6,
The current density is 10 ¹⁶ cm ^-3 to 10 ²⁰ cm ^-3 thermoelectric material.
The method of claim 1,
The thermoelectric material of the compound of Formula 1 has a thermal conductivity of 2W/mK or less at room temperature.
The method of claim 1,
The compound of Formula 1 is a thermoelectric material having a polycrystalline structure or a single crystal structure.
The method of claim 1,
The thermoelectric material of the compound of Formula 1 has a density corresponding to 80% to 100% of the theoretical density.
A first electrode, a second electrode, and a thermoelectric element interposed between the first electrode and the second electrode,
A thermoelectric module, wherein the thermoelectric element includes the thermoelectric material according to any one of claims 1 to 10.
A thermoelectric module having a heat supply source, a thermoelectric element absorbing heat from the heat supply source, a first electrode disposed to contact the thermoelectric element, and a second electrode disposed to face the first electrode and contacting the thermoelectric element And,
A thermoelectric device including the thermoelectric material according to any one of claims 1 to 10.

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