KR102290764B1 - Tetrahedrite-based thermoelectric materials and method for preparing the same - Google Patents

Abstract

The present invention relates to a thermoelectric material including a tetrahedrite-based compound doped with Zn and Bi represented by the following formula (1). Accordingly, the tetrahedrite-based thermoelectric material of the present invention reduces electron thermal conductivity by reducing carrier concentration by Zn substitution, optimizes the output factor, and reduces lattice thermal conductivity by additional phonon scattering by replacing Bi equivalent to Sb. Through this, it is possible to improve the thermoelectric figure of merit (ZT).
[Formula 1]
Cu _12-x Zn _x Sb _4-y Bi _y S ₁₃
In Formula 1,
0.1 ≤ x ≤ 0.4, and 0.1 ≤ y ≤ 0.4.

Description

Tetrahedrite-based thermoelectric materials and method for preparing the same

The present invention relates to a tetrahedrite-based thermoelectric material and a method for manufacturing the same, and more particularly, to a tetrahedrite-based thermoelectric material doped with Zn and Bi and a method for manufacturing the same.

Thermoelectric conversion technology capable of direct conversion of thermal energy and electric energy is emerging as a promising eco-friendly energy system. Thermoelectric materials have different temperature ranges that show maximum performance, and it is known that Bi-Te-based materials are superior in normal temperature range, Pb-Te-based, skutterudite-based materials in medium temperature range, and Si-Ge-based materials in high temperature range. . However, there is a problem that most of them consist of toxic heavy metals or rare elements with limited reserves. Accordingly, a tetrahedrite compound composed of Cu and S, which has abundant reserves, is inexpensive, and is relatively light and non-toxic, is attracting attention as a promising p-type thermoelectric material in the mesophilic region. The main reason why tetrahedrite is attracting attention is because it shows low thermal conductivity and has high energy band degeneracy due to its symmetrical crystal structure, so it is useful for improving the output factor.

To obtain a high ZT according to the thermoelectric figure of merit relation, ZT = α ² σκ ^-1 T (α: Seebeck coefficient, σ: electrical conductivity, κ: thermal conductivity, T: absolute temperature), a high output factor (α ² σ) and Low thermal conductivity is required. However, since the Seebeck coefficient and the electrical conductivity have a trade-off relationship depending on the carrier concentration, the output factor is generally improved by optimizing the carrier concentration by doping. It is known that undoped tetrahedrite has a high hole concentration because the Fermi level is located in the valence band. Therefore, many studies have been conducted on the suppression of electron thermal conductivity and optimization of output factors by reducing the hole concentration by substituting a divalent or trivalent transition metal for Cu ^{+ sites.} Heo et al. obtained ZT = 1.13 @ 575 K _{from Cu 11} MnSb ₄ S ₁₃ substituted with Mn with a combination of high output factor and low thermal conductivity, and Lu et al. obtained ZT = 1 @ 720 K in _{Cu 11} ZnSb ₄ S _{13 .} values have been announced.

Korean Patent Publication No. 10-2015-0044883 Korean Patent Publication No. 10-2017-0102300

An object of the present invention is to reduce electron thermal conductivity through carrier concentration reduction by Zn substitution, optimize the output factor, and reduce lattice thermal conductivity by additional phonon scattering with Bi substitution equivalent to Sb. An object of the present invention is to provide an improved tetrahedrite-based thermoelectric material and a method for manufacturing the same.

According to one aspect of the invention,

A thermoelectric material including a tetrahedrite-based compound doped with Zn and Bi represented by the following Chemical Formula 1 is provided.

[Formula 1]

Cu _{12 - x} Zn _x Sb _{4 - y} Bi _y S ₁₃

In Formula 1,

0.1 ≤ x ≤ 0.4, and 0.1 ≤ y ≤ 0.4.

Preferably, in Formula 1,

x = 0.1, and may be 0.1 ≤ y ≤ 0.2.

The tetrahedrite-based compound doped with Zn and Bi may have a lattice constant in the range of 1.0339 to 1.0373 nm.

The tetrahedrite-based compound doped with Zn and Bi may have a Hall coefficient in the range ^{of 5.56 to 44.01 cm 3} C ^{−1 .}

The tetrahedrite-based compound doped with Zn and Bi may have a charge mobility in the range ^{of 606 to 1094 cm 2} V ⁻¹ s ^{−1 .}

The tetrahedrite-based compound doped with Zn and Bi may have a carrier concentration in the range ^{of 1.42 × 10 17} to 1.30 × 10 ^{18 .}

The thermoelectric material may be a P-type thermoelectric material.

According to another aspect of the present invention,

(a) preparing a mixed powder obtained by weighing and mixing copper (Cu), zinc (Zn), antimony (Sb) and sulfur (S) in a stoichiometric composition;

(b) preparing a tetrahedrite-based powder by mechanically alloying the mixed powder; and

(c) performing vacuum hot compression molding of the tetrahedrite-based powder to form a sintered compact; A manufacturing method is provided.

[Formula 1]

Cu _{12 - x} Zn _x Sb _{4 - y} Bi _y S ₁₃

In Formula 1,

0.1 ≤ x ≤ 0.4, and 0.1 ≤ y ≤ 0.4.

In step (b), the mechanical alloying may be performed by ball milling in a ratio of 1:10 to 1:30 with the mixed powder.

In step (b), the ball milling may be performed at 300 to 400 rpm for 20 to 30 hours.

In step (c), the vacuum hot compression molding may be performed at a temperature of 700 to 750 K.

In step (c), the vacuum hot compression molding may be performed at a pressure of 65 to 75 MPa.

The tetrahedrite-based thermoelectric material of the present invention reduces electron thermal conductivity by reducing carrier concentration by Zn substitution, optimizing the output factor, and thermoelectric performance by reducing lattice thermal conductivity by additional phonon scattering by replacing Bi equivalent to Sb. Index (ZT) can be improved.

1 is an X-ray diffraction analysis result of Experimental Example 1.
2 is an electron micrograph of the thermoelectric materials of Examples 1 to 5 in Experimental Example 2.
3 shows the element mapping results of the thermoelectric materials of Examples 1 to 5 in Experimental Example 2;
4 is an analysis result of the change in electrical conductivity of Experimental Example 3.
5 is an analysis result of a change in the Seebeck coefficient (α) of Experimental Example 4.
6 is an output factor analysis result of Experimental Example 5;
7 is a thermal conductivity change analysis result of Experimental Example 6.
8 is a thermoelectric figure of merit (ZT) analysis result of Experimental Example 7.

Since the present invention can apply various transformations and can have various embodiments, specific embodiments are illustrated in the drawings and described in detail in the detailed description. However, this is not intended to limit the present invention to specific embodiments, and it should be understood to include all modifications, equivalents, and substitutes included in the spirit and scope of the present invention. In describing the present invention, if it is determined that a detailed description of a related known technology may obscure the gist of the present invention, the detailed description thereof will be omitted.

Hereinafter, a thermoelectric material including the tetrahedrite-based compound of the present invention will be described.

The thermoelectric material containing the tetrahedrite-based compound of the present invention is characterized in that it includes the tetrahedrite-based compound double doped with Zn and Bi represented by the following formula (1).

[Formula 1]

Cu _{12 - x} Zn _x Sb _{4 - y} Bi _y S ₁₃

In Formula 1,

0.1 ≤ x ≤ 0.4, and 0.1 ≤ y ≤ 0.4.

Preferably, in Formula 1, x = 0.1, and 0.1 ≤ y ≤ 0.2.

The tetrahedrite-based compound doped with Zn and Bi may have a lattice constant in the range of 1.0339 to 1.0373 nm.

The tetrahedrite-based compound doped with Zn and Bi may have a Hall coefficient in the range ^{of 5.56 to 44.01 cm 3} C ^{−1 .}

The tetrahedrite-based compound doped with Zn and Bi may have a charge mobility in the range ^{of 606 to 1094 cm 2} V ⁻¹ s ^{−1 .}

The tetrahedrite-based compound doped with Zn and Bi may have a carrier concentration in the range ^{of 1.42 × 10 17} to 1.30 × 10 ^{18 .}

The thermoelectric material is a P-type thermoelectric material.

Hereinafter, a method for manufacturing a thermoelectric material including the tetrahedrite-based compound of the present invention will be described.

First, powdered copper ( Cu ), zinc( Zn ), antimony ( Sb ) and sulfur (S) stoichiometry by composition by weighing A mixed powder is prepared (step a).

It is preferable to use copper, zinc, antimony, and sulfur powders having an average particle diameter of 30 to 200 μm.

After that, the mixed powder is mechanically by mechanical alloying tetrahedrite system A powder is prepared (step b).

The mechanical alloying is preferably performed by ball milling in a ratio of 1:10 to 1:30 with the mixed powder and balls, and more preferably 1:15 to 1:25.

The ball milling is preferably performed at 300 to 400 rpm for 20 to 30 hours, and more preferably at 330 to 370 rpm for 22 to 26 hours.

Next, the tetrahedrite system vacuum the powder hot compression molding to form a sintered body (step c).

The vacuum hot compression molding may be performed at a temperature of 700 to 750 K and a pressure of 65 to 75 MPa.

In particular, although not explicitly described in the following examples, in the method for manufacturing a thermoelectric material according to the present invention, the ratio of the mixed powder to the balls in the ball milling of step (b), the speed and time of the ball milling, the step (c) ) to prepare a thermoelectric material containing a tetrahedrite-based compound doped with Zn and Bi while changing the temperature and pressure conditions of vacuum hot compression molding.

Electrochemical property tests were performed on the thus-prepared thermoelectric material including the tetrahedrite-based compound doped with Zn and Bi to confirm thermal conductivity, output factor, and thermoelectric figure of merit. As a result, unlike other conditions and other numerical ranges, electron thermal conductivity is reduced only when all of the following conditions are satisfied, the output factor is optimized, and lattice thermal conductivity is reduced by additional phonon scattering by replacing Bi, which is equivalent to Sb. Through this, it was possible to obtain a tetrahedrite-based thermoelectric material with improved thermoelectric performance index (ZT). Such manufacturing conditions are as follows.

In step (b), ball milling is performed at a ratio of mixed powder and balls 1:10 to 1:30, and is performed at 300 to 400 rpm for 20 to 30 hours, and vacuum hot compression molding in step (c) is 700 to 750 It is carried out at a temperature of K and a pressure of 65 to 75 MPa.

Hereinafter, preferred examples are presented to help the understanding of the present invention. However, these examples are for explaining the present invention in more detail, the scope of the present invention is not limited thereby, and it is common in the art that various changes and modifications are possible within the scope and spirit of the present invention. It will be self-evident to those with knowledge.

[Example]

Example 1 to 5

For _{the synthesis of Cu 12-x} Zn _x Sb _4-y Bi _y S ₁₃ (0.1 ≤ x ≤ 0.4 and 0.1 ≤ y ≤ 0.4) compounds, Cu (purity 99.9%, <45 μm), Zn ( Weigh and mix purity 99.9%, <75 μm), Sb (purity 99.999%, <75 μm), Bi (purity 99.999%, <180 μm), and S (purity 99.99%, <75 μm) to a stoichiometric composition Powder and steel balls (diameter 5 mm) were charged in a hardened steel jar at a ratio of 1:20, and mechanical alloying (MA) was performed at 350 rpm for 24 hours using a planetary ball mill (Fritsch, Pulverisette5). The synthesized tetrahedrite powder was charged into a graphite mold having an inner diameter of 10 mm and vacuum hot compression molding (HP) was performed at 723 K for 2 hours at a pressure of 70 MPa.

The chemical compositions of Examples 1 to 5 thus prepared are shown in Table 1 below, and the lattice constant and charge transfer characteristics at room temperature are summarized in Table 2.

division Cu _{12 - x} Zn _x Sb _{4 - y} Bi _y S ₁₃ Composition x y Nominal Actual Example 1 0.1 0.1 _{Cu 11 .9 Zn 0 .1 Sb 3} .9 Bi 0 .1 S 13 _{Cu 12 .82 Zn 0 .32 Sb 3} .84 Bi 0 .12 S 11 .9 Example 2 0.1 0.2 _{Cu 11 .9 Zn 0 .1 Sb 3} .8 Bi 0 .2 S 13 _{Cu 12 .59 Zn 0 .42 Sb 3} .72 Bi 0 .15 S 12 .12 Example 3 0.2 0.2 _{Cu 11 .8 Zn 0 .2 Sb 3} .8 Bi 0 .2 S 13 _{Cu 13 .07 Zn 0 .61 Sb 3} .4 Bi 0 .18 S 11 .73 Example 4 0.2 0.4 _{Cu 11 .8 Zn 0 .2 Sb 3} .6 Bi 0 .4 S 13 _{Cu 11 .45 Zn 0 .47 Sb 3} .97 Bi 0 .42 S 12 .69 Example 5 0.4 0.2 _{Cu 11 .6 Zn 0 .4 Sb 3} .8 Bi 0 .2 S 13 _{Cu 11 .90 Zn 0 .60 Sb 3} .90 Bi 0 .17 S 12 .42

division Lattice constant
[nm] odd coefficient
(Hall coefficient)
[cm ³ C ^-1 ] charge mobility
(Mobility)
[cm ² V ^-1 s ^-1 ] carrier concentration
(Carrier concentration)
[cm ^-3 ] Lorenz number
[10 ^-8 V ² K ^-2 ] Example 1 1.0339 5.56 980 1.12×10 ¹⁸ 1.81 Example 2 1.0341 4.80 1094 1.30×10 ¹⁸ 1.84 Example 3 1.0353 20.39 1037 3.06×10 ¹⁸ 1.68 Example 4 1.0357 10.03 719 6.23×10 ¹⁷ 1.74 Example 5 1.0373 44.01 606 1.42×10 ¹⁷ 1.60

[Experimental example]

Experimental method

The image of the HP specimen was analyzed using Cu Kα radiation (λ=0.15405 nm) with an X-ray diffractometer (XRD; Bruker, D2-Phaser). The microstructure was observed with a field emission scanning electron microscope (FESEM; JEOL, JSM-7610F), and the distribution and composition of the constituent elements were confirmed using an energy dispersive spectrometer (EDS; Oxford, X-Max50). The sintered body was cut into a cuboid shape of 3 mm × 3 mm × 9 mm for measuring Seebeck coefficient and electrical conductivity, and a disk shape of 10 mm (diameter) × 1 mm (thickness) for measuring thermal conductivity and Hall coefficient. The Hall coefficient was measured by applying a constant magnetic field of 1 T and a current of 100 mA at room temperature using the van der Pauw method. In the temperature range of 323 ~ 723 K, the Seebeck coefficient was measured using the temperature differential method and the electrical conductivity was measured using the ZEM-3 (Ulvac-Riko) instrument in a He atmosphere using the 4-probe method. Thermal conductivity can be obtained from thermal diffusivity, specific heat and density, and thermal diffusivity was measured by laser flash method using TC-9000H (Ulvac-Riko) equipment. The output factor and dimensionless figure of merit (ZT) were evaluated from the measured Seebeck coefficient, electrical conductivity and thermal conductivity.

Experimental example 1: X-ray diffraction analysis

Figure 1 is an embodiment 1-5 of the Cu ₁₂ after sintering _- shows the X-ray diffraction pattern of the _{y Bi y S 13 - x Zn} x Sb 4. All specimens were in good agreement with the ICDD standard diffraction data (PDF# 24-1318), indicating that the tetrahedrite phase was successfully synthesized. _{A Cu 3} SbS ₃ (skinnerite) secondary phase was detected with an increase in the doping amount (x and y). In particular, as the Bi doping amount increased, the formation of the secondary phase increased. As the Bi doping amount increased, the impurity phases (Cu ₃ SbS ₄ and Cu ₃ SbS ₃ ) increased, which is due to the low solubility of Bi in pure tetrahedrite. As shown in (b) of FIG. 1, the diffraction angle shifted to a lower angle as the doping amount increased, which is a result of increasing the lattice constant from 1.0339 nm to 1.0373 nm by doping, as shown in Table 2. Zn ^{2 +} ion radius (60 pm) is ^{larger than Cu +} (60 pm) or Cu ^{2 +} (57 pm) ion radius, Bi ^{3 +} ion radius (96 pm) is ^{larger than Sb 3 +} (76 pm) .

Experimental example 2: Morphological and compositional analysis

FIG. 2 is an electron microscope (FESEM) image of a cross section of _{Cu 12 - x} Zn _x Sb _{4 - y} Bi _y S ₁₃ of Examples 1 to 5 sintered. A sound sintered compact with almost 99% or more pores or cracks compared to the theoretical density was obtained by hot compression molding. There was no significant difference in microstructure according to the doping amount. In addition, it was confirmed that all constituent elements and doping elements were homogeneously distributed. Typically, _{11 .9} Cu Zn _{0 .1 .9} Sb ₃ shows an element mapping result for the Bi _{0 .1} S ₁₃ in Fig.

Experimental example 3: Analysis of changes in electrical conductivity

4 shows changes in electrical conductivity for _{Cu 12 − x} Zn _x Sb _{4 − y} Bi _y S ₁₃ of Examples 1 to 5 . In the case of Example 2 (x=0.1, y==0.2), which is a sample with a small doping amount, the electrical conductivity increased as the temperature increased, and then decreased at 623 K or more, which is a behavior that appears as a non-degenerate semiconductor changes to a metal-like conductivity am. However, as the doping amount of Zn and Bi increased, the non-degenerate semiconductor behavior was increased as the temperature increased. When Zn ²⁺ atoms ^{replace Cu +} sites, the electrical conductivity decreases because extra electrons fill the valence band holes. Therefore, as the amount of substitution of Zn increased, the electrical conductivity decreased, which is consistent with the results of the decrease in carrier concentration in Table 2. Since Bi doping is equivalent to Sb, it was expected that the change in electrical conductivity would not be affected. However, the electrical conductivity of the specimen doped with more Bi at the same Zn doping amount was higher. That is, Example 2 had higher electrical conductivity than Example 1 and Example 4 had higher electrical conductivity than Example 3, which is the same as the result of increasing carrier concentration by Bi doping, as shown in Table 2. Usually, Cu vacancy is known to have the lowest formation energy in Cu chalcogenide, and the fact that tetrahedrite has a high hole concentration is related to Cu vacancy acting as an acceptor.

Experimental example 4: Seebeck coefficient ( seebeck coefficient , α) change analysis

5 is a graph showing the change in Seebeck coefficient for _{Cu 12 - x} Zn _x Sb _{4 - y} Bi _y S ₁₃ of Examples 1 to 5; All specimens showed positive Seebeck coefficient values indicating p-type conduction characteristics in the measurement temperature range, and also coincided with the Hall coefficient sign in Table 2. In general, the Seebeck coefficient shows a maximum value as the temperature increases and then decreases again, which is due to bipolar conduction due to thermal excitation in the intrinsic conduction region. All specimens which temperature increases more and showed a behavior that the Seebeck coefficient is increased, a fifth embodiment of the _{Cu 11 .6 Zn 0 .4 Sb 3} .8 decreases Bi _{0 .2-} S ₁₃ specimens Seebeck coefficient from room temperature for showed different temperature dependence. It seems that the onset of bipolar conduction shifted to a lower temperature because of the low carrier concentration by Zn doping. Dose of Zn is increasing, Bi doping amount is increased, the lower the Seebeck coefficient, a fifth embodiment of the _{Cu 11 .6 Zn 0 .4 Sb 3} .8 Bi 0 .2 S 13 is 323-723 K in the temperature range 264 ~ 252 μVK ^-1 showed the maximum value.

Pisarenko relation α = (8/3)π ² k _B ² e ^-1 h ^-2 m ^* T(π/3n) ^2/3 According to ( k _B : Boltzmann constant, e : electron charge, m ^* : effective carrier mass, n : carrier concentration), the Seebeck coefficient and carrier concentration are inversely proportional to each other. coefficients are shown, which are consistent with the carrier concentration and electrical conductivity behaviors in Table 2.

Experimental example 5: output factor analysis

₆ shows the electrical conductivity and the output factor (PF = α ² σ) _{obtained from the Seebeck coefficient for Cu 12 − x} Zn _x Sb _{4 − y} Bi _y S 13 of Examples 1 to 5 . As the temperature increased, the output factor greatly increased, which is a result of the temperature dependence of the electrical conductivity of FIG. 4 and the Seebeck coefficient of FIG. 5 . Although the Seebeck coefficient increased as the doping amount of Zn increased, the decrease in electrical conductivity was more dominant and the output factor decreased. However, there was no significant difference in the output factor according to the Bi doping amount. Cu embodiment ₁₁ of Example _{1 .9 Zn 0 .1 Sb 3 .9} Bi 0 .1 S 13 as in Example 2 of _{Cu 11.9 Zn 0.1 Sb 3.8 Bi 0.2} S 13 yi eseo 723 K respectively, 0.83 and 0.84 ^-2 mWmK mWmK ^- The maximum output factor of ^{2 is shown.}

Experimental example 6: Thermal conductivity change analysis

] 을 사용하여 계산한 결과, 323 K에서 1.61 × 10^-8 ~ 1.84 × 10^-8 V²K^-2를, 723 K에서 1.61 × 10^-8 ~ 1.72 × 10^-8 V²K^-2의 값을 나타내었다. 표 2에는 각 시편의 323 K에서의 로렌츠 상수를 나타내었다. 7 shows the thermal conductivity _{of Cu 12 - x} Zn _x Sb _{4 - y} Bi _y S ₁₃ of Examples 1 to 5; Thermal conductivity can be represented by the sum of the thermal conductivity (κ _L) and thermal conductivity (κ _E) by the electron by the grid, the electron conductivity is Wiedemann-Franz formula: by (κ _E = LσT, L Lorenz number) can be calculated. In this case, the Lorentz constant is expressed as L = 1.5 + exp[

- the calculation by using, from 323 K ^{1.61 × 10 -8 ~ 1.84 × 10} -8 V 2 K -2 a, at ^{723 K 1.61 × 10 -8 ~ 1.72} × 10 -8 V 2 value of K ^-2 was shown. Table 2 shows the Lorentz constant at 323 K of each specimen.

Also increases the amount of doping of Zn, such as 7 (a) had the thermal conductivity is reduced, the thermal conductivity 723 of y = 0.2 the sample not doped Cu ₁₂ Sb ₄ S ₁₃ In the case of, as shown in Figure 7 (b) in the K 0.81 Wm ^-1 it exhibited a lower value than K ^-1. This is mainly due to the decrease in electron thermal conductivity due to the decrease in carrier concentration due to Zn substitution. The lattice thermal conductivity and thermal conductivity of all specimens ^{showed a value of 0.46 ~ 0.50 Wm -1} K ^-1 at 723 K, which is close to the theoretical minimum lattice thermal conductivity (~0.4 Wm ^-1 K ^{-1 ) in tetrahedrite.} am. This appears to be due to the additional point-defect phonon scattering by the double substitution of Zn and Bi.

Experimental example 7: Thermoelectric performance index ( ZT ) analysis

8 shows the thermoelectric figure of merit (ZT) for _{Cu 12 - x} Zn _x Sb _{4 - y} Bi _y S ₁₃ of Examples 1 to 5; According to this, the thermoelectric figure of merit (ZT) of all the specimens increased as the temperature increased. Example 1 _{Cu 11 .9 Zn 0 .1 Sb 3} .9 Bi- 0.1 S 13 found a ZT _max = 0.77 when the K 723, which relatively high power factor (0.83 mWm ^-1 K ^-2) and the low This is due to the thermal conductivity (0.76 Wm ^-1 K ^{-1 ).} However, as the doping amount of Zn and Bi increased, ZT decreased. By double substitution according to the present invention, ZT = 0.60 @ 723 K of undoped tetrahedrite reported by Barbier et al. and ZT = 0.52 @ 600 K of _{Cu 12} Sb ₄ S _{13 reported by Wang et al.} got it

Claims (12)

A thermoelectric material comprising a tetrahedrite-based compound doped with Zn and Bi represented by the following formula (1).
[Formula 1]
Cu _12-x Zn _x Sb _4-y Bi _y S ₁₃
In Formula 1,
0.1 ≤ x ≤ 0.4, and 0.1 ≤ y ≤ 0.4. According to claim 1,
In Formula 1,
A thermoelectric material, characterized in that x = 0.1, and 0.1 ≤ y ≤ 0.2. According to claim 1,
The tetrahedrite-based compound doped with Zn and Bi has a lattice constant in the range of 1.0339 to 1.0373 nm. According to claim 1,
The tetrahedrite-based compound doped with Zn and Bi has a Hall coefficient in the range of ^{5.56 to 44.01 cm 3} C ^{-1 .} According to claim 1,
The tetrahedrite-based compound doped with Zn and Bi has a charge mobility (Mobility) of 606 to 1094 cm ² V ^-1 s ^-1 Thermoelectric material, characterized in that the range. According to claim 1,
The tetrahedrite-based compound doped with Zn and Bi has a carrier concentration in the range of ^{1.42 × 10 17} to 1.30 × 10 ^{18 .} According to claim 1,
The thermoelectric material is a thermoelectric material, characterized in that the P-type thermoelectric material. (a) preparing a mixed powder obtained by weighing and mixing copper (Cu), zinc (Zn), antimony (Sb) and sulfur (S) in a stoichiometric composition;
(b) preparing a tetrahedrite-based powder by mechanically alloying the mixed powder; and
(c) performing vacuum hot compression molding of the tetrahedrite-based powder to form a sintered compact; manufacturing method.
[Formula 1]
Cu _12-x Zn _x Sb _4-y Bi _y S ₁₃
In Formula 1,
0.1 ≤ x ≤ 0.4, and 0.1 ≤ y ≤ 0.4. 9. The method of claim 8,
In step (b), the mechanical alloying is a method of manufacturing a thermoelectric material, characterized in that the ball milling is performed by ball milling in a ratio of 1:10 to 1:30 with the mixed powder. 10. The method of claim 9,
In step (b), the ball milling method of manufacturing a thermoelectric material, characterized in that performed for 20 to 30 hours at 300 to 400 rpm. 9. The method of claim 8,
In step (c), the vacuum hot compression molding is a method of manufacturing a thermoelectric material, characterized in that performed at a temperature of 700 to 750 K. 12. The method of claim 11,
In step (c), the vacuum hot compression molding is a method of manufacturing a thermoelectric material, characterized in that performed at a pressure of 65 to 75 MPa.

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