N-type Mg3 (Sb, Bi) 2 semiconductor material with ultrahigh conductivity as well as preparation method and application of n-type Mg3 (Sb, Bi) 2 semiconductor material

Abstract

The invention belongs to the technical field of semiconductor material synthesis, and particularly relates to an n-type Mg3 (Sb, Bi) 2 semiconductor material with ultrahigh conductivity and a preparation method and application thereof. The chemical formula of the n-type Mg < 3 > (Sb, Bi) < 2 > semiconductor material is Mg < 3.5-x-y > Bi < 1.5 > Sb < 0.5 > Y < x > Tay, wherein x is more than or equal to 0.005 and less than or equal to 0.03; 0 < = y < = 0.015; the conductivity of the n-type Mg3 (Sb, Bi) 2 semiconductor material at about 323 K can reach 1788 S cm <-1 >. A large amount of excessive Mg element is added in the preparation process, so that generation of Mg vacancies is remarkably inhibited, the structure of the material is compact, the use stability of the material is improved, the carrier concentration and mobility are improved, and the conductivity is optimized; the carrier concentration and mobility of the material are further increased by doping high-valence elements, and finally the n-type Mg3 (Sb, Bi) 2 semiconductor material with ultrahigh conductivity is obtained.

Description

Technical Field

[0001] The present invention belongs to the technical field of semiconductor material synthesis, and specifically relates to an n-type Mg with ultra-high conductivity. 3 (Sb,Bi) 2 Semiconductor materials, their preparation methods and applications. Background Art

[0002] Semiconductor materials are materials with electrical conductivity between conductors and insulators, with resistivity ranging from about 1mΩ·cm to 1GΩ·cm. These materials have unique physical and chemical properties, which make them widely used in electronic devices and circuits. The conductivity of semiconductor materials can be controlled by doping, temperature changes, and electric field effects, which is the basis of semiconductor technology.

[0003] Semiconductor materials have unique physical and chemical properties. In recent years, with the continuous development of the semiconductor material field, binary compound semiconductors, such as magnesium antimonide (Mg 3 Sb 2 ), lead sulfide (PbS), lead selenide (PbSe), zinc sulfide (ZnS), etc., are widely used in optoelectronic devices, solar cells, infrared detection and thermoelectric conversion due to their excellent performance, low price and high abundance of elements.

[0004] Mg 3 (Sb,Bi) 2 The base material is a type of Zintle phase thermoelectric material. Due to its complex network structure composed of chemical bonds and ionic bonds, it has the special properties of electronic crystal-phonon glass, and the raw materials are all non-toxic, cheap, and abundant elements. 3 Sb 2 The Mg atom has two different positions, ionic Mg(I) and covalent Mg(II). The [Mg 2 Sb 2 ] 2- layer, Mg(I) 2+ cation layer. Therefore, Mg 3 Sb 2 The bond characteristics of Mg are between ionic bonds and covalent bonds. This complex network structure of covalent bonds and ionic bonds conforms to the characteristics of phononic glass-electronic crystals, which can obtain higher carrier mobility and stronger phonon scattering. 3 (Sb,Bi) 2 Semiconductors can be widely used in thermoelectric fields, optoelectronic devices, temperature sensors, etc. Li et al. prepared nb-doped Mg by mechanical alloying. 3.1 nb 0.1 Sb1.5 Bi 0.49 Te 0.01 Semiconductor material, the peak conductivity reaches 900 S cm at 300 K -1 (J.-W. Li,Z. Han, J. Yu, H.-L. Zhuang, H. Hu, B. Su, H. Li, Y. Jiang, L. Chen, W. Liu,Q. Zheng, J.-F. Li, Wide-temperature-range thermoelectric n-type Mg 3 (Sb,Bi) 2 Lei et al. prepared Gd-doped Mg by vacuum melting and sintering at 1373 K for 12 h. 3.065 Sb 1.3 Bi 0.7 G 0.015 , with a slight excess of Mg, the peak conductivity is 900 S cm at room temperature. -1 (J. Lei, H. Wuliji, K. Zhao,T.-R. Wei, Q. Xu, P. Li, P. Qiu, X. Shi, Efficient lanthanide Gd dopingpromoting the thermoelectric performance of Mg 3 Sb 2 Tamaki et al. found that by co-doping Bi and Te at the Sb site and adding a small amount of excess Mg at the Mg site, the material chemical formula is Mg 3.2 Sb 1.5 Bi 0.49 Te 0.01 , which can turn the material into n-type and obtain very high conductivity, with the peak conductivity reaching 1200 S cm -1 . (H. Tamaki, HK Sato, T. Kanno,Isotropic Conduction network and Defect Chemistry in Mg 3+x Sb 2-Based Layered Zintl Compounds with High Thermoelectric Performance, Adv. Mater. 28 (2016) 10182-10187.). Yang et al. prepared Mn-doped Mg by mechanical alloying. 3.16 Mn 0.04 Bi 1.49 Sb 0.5 Te 0.01 Semiconductors, through the multifunctional vacancy compensation mechanism of Mn, greatly improve the carrier mobility, and obtain 1500 S cm at room temperature -1 Conductivity (K. Yang, X. Li, C. Sun, W. Song, W. Zhao, Q. Zhang, Robust RoomTemperature Thermoelectric Performance of Mg 3 (Sb,Bi) 2 ‐Based Alloys viaMultivalent Mn Doping, Adv. Funct. Mater.2315886).

[0005] The n-type Mg prepared by the above doping and experimental method 3 (Sb,Bi) 2 Semiconductors all use a small amount of excess Mg to obtain stable n-type conduction and improve conductivity. However, due to the low excess Mg, the influence of Mg vacancies cannot be further weakened, making their conductivity relatively low, which seriously limits the Mg 3 (Sb,Bi) 2 The further development and application of semiconductor materials in the fields of semiconductor energy conversion devices, optoelectronic devices, temperature sensors, etc. require modification research to improve Mg 3 (Sb,Bi) 2 The electrical conductivity of a semiconductor material. Summary of the invention

[0006] The present invention aims to provide an n-type Mg with ultra-high conductivity 3 (Sb,Bi) 2 Semiconductor material and its preparation method and application to solve the problem of Mg in the prior art 3 (Sb,Bi) 2 Technical problem of low electrical conductivity of semiconductor materials.

[0007] In order to achieve the above object, the present invention adopts the following technical solutions: In a first aspect, the present invention provides an n-type Mg with ultra-high conductivity 3 (Sb,Bi) 2 A method for preparing a semiconductor material comprises the following steps: Metal Mg, metal Bi, metal Sb, metal Y and metal Ta are ball-milled under argon protection to obtain a mixed powder; the mixed powder is subjected to spark plasma sintering to obtain the n-type Mg 3 (Sb,Bi) 2 Semiconductor materials.

[0008] Preferably, the metal Mg, metal Bi, metal Sb, metal Y and metal Ta are all powders, and the purity is greater than 99.9%.

[0009] Preferably, the purity of the argon gas is greater than 99.999%.

[0010] Preferably, the metal Sb and the metal Bi are pre-ground before ball milling.

[0011] Preferably, the ball milling conditions are: the rotation speed of the ball mill is 1000-1400 r / min, the ball milling time is 8-10 h, and the ball-to-material ratio is 10:1.

[0012] Preferably, the diameter of the mixed powder is less than 5 μm.

[0013] Preferably, the specific method of spark plasma sintering the mixed powder is: loading the mixed powder into a graphite mold, and wrapping and sealing it with carbon paper for sintering; wherein the sintering pressure is 60~80 Mpa, the sintering temperature is 700~800℃, the heating rate is 50~70℃ / min, and the insulation time is 2~5 min.

[0014] In a second aspect, the present invention provides an n-type Mg with ultra-high conductivity 3 (Sb,Bi) 2 Semiconductor materials, the n-type Mg 3 (Sb,Bi) 2 The chemical formula of semiconductor material is Mg 3.5-x-y Bi 1.5 Sb 0.5 Y x Ta y ; Among them, 0.005≤x≤0.03; 0≤y≤0.015.

[0015] Preferably, the n-type Mg 3 (Sb,Bi) 2 The electrical conductivity of semiconductor materials is 478~1788 S / cm.

[0016] In a third aspect, the present invention provides an n-type Mg with ultra-high conductivity 3 (Sb,Bi) 2 The application of semiconductor materials in semiconductor energy conversion devices, optoelectronic devices and temperature sensors.

[0017] Compared with the prior art, the present invention has the following beneficial effects: The present invention uses a simple mechanical alloying method: ball milling plus spark plasma sintering to prepare n-type Mg with good crystallinity, dense structure, strong repeatability and ultra-high conductivity. 3 (Sb,Bi) 2 Semiconductor material, its conductivity is 1788 S / cm; specifically, the present invention significantly inhibits the generation of Mg vacancies by adding a large amount of excess Mg element, making the material structure dense, increasing the material's use stability, and improving the carrier concentration and mobility, thereby optimizing the conductivity. Then, through the dual doping of Y and Ta, the high valence element doping further increases the material's carrier concentration and mobility, and finally obtains an n-type Mg with ultra-high conductivity. 3 (Sb,Bi) 2 Semiconductor materials. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings required for use in the embodiments are briefly introduced below. It should be understood that the following drawings only show certain embodiments of the present invention and therefore should not be regarded as limiting the scope. For ordinary technicians in this field, other related drawings can be obtained based on these drawings without creative work.

[0019] Figure 1 The n-type Mg prepared by mechanical alloying in Example 1-4 of the present invention 3 (Sb,Bi) 2 Conductivity diagram of semiconductor materials; Figure 2 The n-type Mg prepared by mechanical alloying in Example 2 and Example 5-7 of the present invention 3 (Sb,Bi) 2 Graph of the electrical conductivity of semiconductor materials. DETAILED DESCRIPTION

[0020] In order to enable those skilled in the art to understand the characteristics and effects of the present invention, the following is a general description and definition of the terms and expressions mentioned in the specification and claims. Unless otherwise specified, all technical and scientific terms used in the text are the common meanings understood by those skilled in the art for the present invention. In the event of a conflict, the definition in this specification shall prevail.

[0021] The theories or mechanisms described and disclosed herein, whether correct or incorrect, should not limit the scope of the present invention in any way, that is, the present invention can be implemented without being limited by any specific theory or mechanism.

[0022] In this article, all features such as values, quantities, contents and concentrations defined in the form of numerical ranges or percentage ranges are for simplicity and convenience only. Accordingly, the description of numerical ranges or percentage ranges should be considered to have included and specifically disclosed all possible secondary ranges and individual values ​​within the range (including integers and fractions).

[0023] In this document, unless otherwise specified, “includes,” “including,” “contains,” “has,” or similar terms cover the meanings of “consisting of” and “mainly consisting of,” for example, “A includes a” covers the meanings of “A includes a and other” and “A only includes a.”

[0024] In this document, in order to make the description concise, not all possible combinations of various technical features in various embodiments or examples are described. Therefore, as long as there is no contradiction in the combination of these technical features, the various technical features in various embodiments or examples can be combined arbitrarily, and all possible combinations should be considered to be within the scope of this specification.

[0025] The present invention is further described in detail below in conjunction with the accompanying drawings: The present invention provides an n-type Mg with high electrical conductivity 3 (Sb,Bi) 2 A method for preparing a semiconductor material comprises the following steps: Metal Mg, metal Bi, metal Sb, metal Y and metal Ta are ball-milled under argon protection to obtain a mixed powder; the mixed powder is subjected to spark plasma sintering to obtain the n-type Mg 3 (Sb,Bi) 2 Semiconductor material. The specific method of spark plasma sintering the mixed powder is as follows: the mixed powder is loaded into a graphite mold, and is wrapped and sealed with carbon paper for sintering; wherein the sintering pressure is 60-80 Mpa, the sintering temperature is 700-800°C, the heating rate is 50-70°C / min, and the holding time is 2-5 min.

[0026] The present invention uses a simple mechanical alloying method: ball milling plus spark plasma sintering to prepare n-type Mg with good crystallinity, dense structure, strong repeatability and ultra-high conductivity. 3 (Sb,Bi) 2 Semiconductor materials. Compared with Mg prepared by other doping and preparation methods 3 (Sb,Bi)2 Semiconductor, n-type Mg prepared by the present invention 3 (Sb,Bi) 2 Semiconductor material. The present invention adds a large amount of excess Mg element during the preparation process, thereby significantly inhibiting the generation of Mg vacancies, making the material structure dense, increasing the material's use stability, and improving the carrier concentration and mobility, thereby optimizing the conductivity. Then, through the dual doping of Y and Ta, the high-valence element doping further increases the material's carrier concentration and mobility, and finally obtains an n-type Mg with ultra-high conductivity. 3 (Sb,Bi) 2 Semiconductor materials.

[0027] Exemplarily, the metal Mg, metal Bi, metal Sb, metal Y and metal Ta are all powders with a purity greater than 99.9%, thereby avoiding the influence of impurities on the performance of the final product; the purity of the argon gas is greater than 99.999%, thereby ensuring that the metal powder will not react with oxygen in the air during the crushing or mixing process, preventing oxidation of the metal, and ensuring the quality and reactivity of the metal powder.

[0028] Exemplarily, before ball milling, the metal Sb and metal Bi are pre-ground to reduce the particle size of the metal Sb and Bi in advance so that they can be mixed more evenly during subsequent ball milling, while increasing the reaction area and reaction rate of the materials during ball milling and improving the ball milling efficiency.

[0029] Exemplarily, the ball milling conditions are: the ball mill speed is 1000-1400 r / min, the ball milling time is 8-10 h, and the ball-to-material ratio is 10:1.

[0030] Exemplarily, the diameter of the mixed powder is less than 5 μm, which helps to enhance the reactivity and alloying effect between metals.

[0031] The second object of the present invention is to provide an n-type Mg with ultra-high conductivity 3 (Sb,Bi) 2 Semiconductor materials, the n-type Mg 3 (Sb,Bi) 2 The chemical formula of semiconductor material is Mg 3.5-x-y Bi 1.5 Sb 0.5 Y x Ta y ; Among them, 0.005≤x≤0.03; 0≤y≤0.015.

[0032] The n-type Mg 3 (Sb,Bi) 2Semiconductor material, the conductivity can reach 1788 S cm at around 323 K -1 , much higher than the existing Mg 3 (Sb,Bi) 2 The electrical conductivity of semiconductor materials can greatly increase their application value in the near-room temperature range.

[0033] In a third aspect, the present invention provides an n-type Mg with ultra-high conductivity 3 (Sb,Bi) 2 Application of semiconductor materials in the fields of semiconductor energy conversion devices, optoelectronic devices and temperature sensors. 3 (Sb,Bi) 2 When semiconductor materials are used in the above fields, their ultra-high electrical conductivity can further improve their photoelectric conversion efficiency, thereby reducing costs and improving the cost performance of solar cells, and enhancing their application in the optoelectronic field. 3 (Sb,Bi) 2 The excellent thermoelectric properties and stability of semiconductor materials enable them to sensitively respond to temperature changes and convert them into electrical signals, improving their application in temperature sensors. And due to their excellent electrical properties and intrinsic low thermal conductivity, they have important application value in power generation and refrigeration in thermoelectric materials near room temperature.

[0034] The present invention will be further described below in conjunction with specific embodiments. It should be understood that these embodiments are only used to illustrate the present invention and are not intended to limit the scope of the present invention. In addition, it should be understood that after reading the content taught by the present invention, those skilled in the art can make various changes or modifications to the present invention, and these equivalent forms fall within the scope limited by the appended claims of the application equally.

[0035] The following examples use conventional instruments and equipment in the art. The experimental methods in the following examples where specific conditions are not specified are usually carried out under conventional conditions or under conditions recommended by the manufacturer. The various raw materials used in the following examples are conventional commercial products unless otherwise specified, and their specifications are conventional specifications in the art. In the specification of the present invention and the following examples, unless otherwise specified, "%" means weight percentage, "part" means weight part, and ratio means weight ratio.

[0036] Example 1 An n-type Mg with ultra-high conductivity 3 (Sb,Bi) 2 Method for preparing semiconductor material, the chemical formula of which is Mg 3.495 Bi 1.5 Sb 0.5 Y 0.005 , specifically including the following steps: Under argon environment, 1.8998g magnesium powder, 7g bismuth powder, 1.3598g antimony powder and 0.0198g yttrium powder were weighed and put into a ball mill. The mixture was milled for 8h by high-energy ball milling at a speed of 1400 rpm / min and a ball-to-material ratio of 10:1 to obtain a mixed powder. The mixed powder was placed in a spark plasma sintering mold at a sintering temperature of 700 °C, a sintering pressure of 60 Mpa, a heating rate of 50 °C / min, and a holding time of 2 min to obtain a bulk n-type Mg 3 (Sb,Bi) 2 Semiconductor materials.

[0037] The Y-doped Mg with high Mg content prepared in this example is characterized. 3.495 Bi 1.5 Sb 0.5 Y 0.005 The electrical conductivity of semiconductor materials is relatively high, with a conductivity of 478 S / cm at 323 K, such as Figure 1 shown.

[0038] Example 2 An n-type Mg with ultra-high conductivity 3 (Sb,Bi) 2 Method for preparing semiconductor material, the chemical formula of which is Mg 3.49 Bi 1.5 Sb 0.5 Y 0.01 , specifically including the following steps: Under argon environment, 2g magnesium powder, 7.3902g bismuth powder, 1.4356g antimony powder and 0.0209g yttrium powder were weighed and put into a ball mill. The high-energy ball milling method was used for 8h, the speed was 1400 rpm / min, and the ball-to-material ratio was 10:1 to obtain a mixed powder; the mixed powder was placed in a spark plasma sintering mold, the sintering temperature was 750℃, the sintering pressure was 70 Mpa, the heating rate was 60℃ / min, and the holding time was 3 min. Finally, a bulk n-type Mg 3 (Sb,Bi) 2 Semiconductor materials.

[0039] The Y-doped Mg with high Mg content prepared in this example is characterized. 3.49 Bi 1.5 Sb 0.5 Y 0.01 The electrical conductivity of semiconductor materials is relatively high, with a conductivity of 955 S / cm at 323 K, such as Figure 1 and Figure 2 shown.

[0040] Example 3 An n-type Mg with ultra-high conductivity 3 (Sb,Bi) 2 Method for preparing semiconductor material, the chemical formula of which is Mg 3.48 Bi 1.5 Sb 0.5 Y 0.02 , specifically including the following steps: Under argon environment, 2g magnesium powder, 7.4114g bismuth powder, 1.4397g antimony powder and 0.042g yttrium powder were weighed and put into a ball mill. The mixed powder was obtained by high-energy ball milling for 8h at a speed of 1400 rpm / min and a ball-to-material ratio of 10:1. The mixed powder was placed in a spark plasma sintering mold, and the sintering temperature was 800℃, the sintering pressure was 80 Mpa, the heating rate was 70℃ / min, and the holding time was 5 min. Finally, the bulk n-type Mg 3 (Sb,Bi) 2 Semiconductor materials.

[0041] The Y-doped Mg with high Mg content prepared in this example is characterized. 3.48 Bi 1.5 Sb 0.5 Y 0.02 The electrical conductivity of semiconductor materials is relatively high, with a conductivity of 1425 S / cm at 323 K, such as Figure 1 shown.

[0042] Example 4 An n-type Mg with ultra-high conductivity 3 (Sb,Bi) 2 Method for preparing semiconductor material, the chemical formula of which is Mg 3.47 Bi 1.5 Sb 0.5 Y 0.03 , specifically including the following steps: Under argon environment, 2g magnesium powder, 7.4328g bismuth powder, 1.4438g antimony powder and 0.0632g yttrium powder were weighed and put into a ball mill. The mixed powder was obtained by high-energy ball milling for 8h at a speed of 1400 rpm / min and a ball-to-material ratio of 10:1. The mixed powder was placed in a spark plasma sintering mold, and the sintering temperature was 780℃, the sintering pressure was 70 Mpa, the heating rate was 55℃ / min, and the holding time was 4 min. Finally, the bulk n-type Mg 3 (Sb,Bi) 2 Semiconductor materials.

[0043] The Y-doped Mg with high Mg content prepared in this example is characterized. 3.47 Bi 1.5 Sb0.5 Y 0.03 The electrical conductivity of semiconductor materials is relatively high, with a conductivity of 1579 S / cm at 323 K, such as Figure 1 shown.

[0044] Example 5 An n-type Mg with ultra-high conductivity 3 (Sb,Bi) 2 Method for preparing semiconductor material, the chemical formula of which is Mg 3.485 Bi 1.5 Sb 0.5 Y 0.01 Ta 0.005 , specifically including the following steps: Under argon environment, 2g magnesium powder, 7.4008g bismuth powder, 1.4376g antimony powder, 0.0209g yttrium powder and 0.0213g yttrium powder were weighed and put into a ball mill, and the ball milling was carried out for 9h by high-energy ball milling, the speed was 1300 rpm / min, and the ball-to-material ratio was 10:1 to obtain a mixed powder; the mixed powder was put into a spark plasma sintering mold, the sintering temperature was 700~800℃, the sintering pressure was 60~80 Mpa, the heating rate was 50~70℃ / min, the holding time was 2~5 min, and the holding time was 2 min, and finally a bulk n-type Mg 3 (Sb,Bi) 2 Semiconductor materials.

[0045] The Y / Ta co-doped Mg with high Mg content prepared in this embodiment is characterized. 3.485 Bi 1.5 Sb 0.5 Y 0.01 Ta 0.005 The electrical conductivity of semiconductor materials is relatively high, with a conductivity of 1424 S / cm at 323 K, such as Figure 2 shown.

[0046] Example 6 An n-type Mg with ultra-high conductivity 3 (Sb,Bi) 2 Method for preparing semiconductor material, the chemical formula of which is Mg 3.48 Bi 1.5 Sb 0.5 Y 0.01 Ta 0.01 , specifically including the following steps: Under argon environment, 2g magnesium powder, 7.4114g bismuth powder, 1.4397g antimony powder, 0.0209g yttrium powder and 0.0427g yttrium powder were weighed and put into a ball mill. The high-energy ball milling method was used for 9h, the speed was 1200 rpm / min, and the ball-to-material ratio was 10:1 to obtain a mixed powder; the mixed powder was placed in a spark plasma sintering mold, the sintering temperature was 720℃, the sintering pressure was 65Mpa, the heating rate was 65℃ / min, and the holding time was 5 min, and finally a bulk n-type Mg 3 (Sb,Bi) 2 Semiconductor materials.

[0047] The Y / Ta co-doped Mg with high Mg content prepared in this embodiment is characterized. 3.48 Bi 1.5 Sb 0.5 Y 0.01 Ta 0.01 The conductivity of semiconductor materials reaches the highest value, with a conductivity of 1788 S / cm at 323 K. Figure 2 shown.

[0048] Example 7 An n-type Mg with ultra-high conductivity 3 (Sb,Bi) 2 Method for preparing semiconductor material, the chemical formula of which is Mg 3.475 Bi 1.5 Sb 0.5 Y 0.01 Ta 0.015 , specifically including the following steps: Under argon environment, 2g magnesium powder, 7.4221g bismuth powder, 1.4418g antimony powder, 0.0209g yttrium powder and 0.0642g yttrium powder were weighed and put into a ball mill. The high-energy ball milling method was used for 10h, the speed was 1000 rpm / min, and the ball-to-material ratio was 10:1 to obtain a mixed powder; the mixed powder was placed in a spark plasma sintering mold, the sintering temperature was 700℃, the sintering pressure was 80Mpa, the heating rate was 70℃ / min, and the holding time was 5 min, and finally a bulk n-type Mg 3 (Sb,Bi) 2 Semiconductor materials.

[0049] The Y / Ta co-doped Mg with high Mg content prepared in this embodiment is characterized. 3.475 Bi 1.5 Sb 0.5 Y 0.01 Ta 0.015 The electrical conductivity of semiconductor materials is relatively high, with a conductivity of 1641 S / cm at 323 K, such as Figure 2 shown.

[0050] In summary, the n-type Mg 3 (Sb,Bi) 2 Semiconductor material, the conductivity can reach 1788 S cm at around 323 K -1 , much higher than the existing Mg 3 (Sb,Bi) 2 The electrical conductivity of the base semiconductor material can greatly increase its application value in the near-room temperature range.

[0051] The above are only preferred embodiments of the present invention and are not intended to limit the present invention. For those skilled in the art, the present invention may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A method for preparing an n-type Mg3(Sb,Bi)2 semiconductor material with ultra-high conductivity, characterized in that: The following steps are involved: Metal Mg, metal Bi, metal Sb, metal Y and metal Ta are ball-milled under argon protection to obtain mixed powder; the mixed powder is subjected to spark plasma sintering to obtain the Mg3(Sb,Bi)2 semiconductor material.

2. The preparation method according to claim 1, characterized in that: The metal Mg, metal Bi, metal Sb, metal Y and metal Ta are all powders, and the purity is greater than 99.9%.

3. The preparation method according to claim 1, characterized in that: The purity of the argon gas is greater than 99.999%.

4. The preparation method according to claim 1, characterized in that: Before ball milling, the metal Sb and the metal Bi are pre-milled.

5. The preparation method according to claim 1, characterized in that: The ball milling conditions are as follows: the rotation speed of the ball mill is 1000-1400 r / min, the ball milling time is 8-10 h, and the ball-to-material ratio is 10:

1.

6. The preparation method according to claim 1, characterized in that: The diameter of the mixed powder is less than 5 μm.

7. The preparation method according to claim 1, characterized in that: The specific method of spark plasma sintering the mixed powder is: loading the mixed powder into a graphite mold, and wrapping and sealing it with carbon paper for sintering; wherein the sintering pressure is 60-80 MPa, the sintering temperature is 700-800°C, the heating rate is 50-70°C / min, and the insulation time is 2-5 min.

8. An n-type Mg3(Sb,Bi)2 semiconductor material with ultra-high conductivity, characterized in that: The n-type Mg3(Sb,Bi)2 semiconductor material is prepared by the preparation method according to any one of claims 1 to 7, wherein the chemical formula of the n-type Mg3(Sb,Bi)2 semiconductor material is Mg 3.5-x- y Bi 1.5 Sb 0.5 Y x Ta y ; Among them, 0.005≤x≤0.03; 0≤y≤0.

015.

9. The n-type Mg3(Sb,Bi)2 semiconductor material with ultrahigh conductivity according to claim 8, characterized in that: The conductivity of the n-type Mg3(Sb,Bi)2 semiconductor material is 478~1788 S / cm.

10. Application of the n-type Mg3(Sb,Bi)2 semiconductor material with ultrahigh conductivity according to claim 8 in the fields of semiconductor energy conversion devices, optoelectronic devices and temperature sensors.

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