A magnesium-based thermoelectric high-flux thin film material and a preparation method and application thereof

Abstract

The application discloses a magnesium-based thermoelectric high-flux thin film material and a preparation method and application thereof. The preparation method comprises the following steps: plating a magnesium-based matrix thin film on the surface of a substrate; plating a doping element on the surface of the magnesium-based matrix thin film by vacuum evaporation and a discrete mask process; and then performing annealing treatment on the magnesium-based matrix thin film plated with the doping element in a vacuum device to obtain the magnesium-based thermoelectric high-flux thin film material. The magnesium-based thermoelectric high-flux thin film material is prepared by adopting a vacuum evaporation discrete mask mode and a form of mutual combination of thermal evaporation and electron beam evaporation. On one hand, the thin film material can meet the low-dimension and small-size requirements, and the small size can improve the integration density of a thermoelectric module, thereby increasing the power output, and the smaller the characteristic size of the thermoelectric device is, the greater the power density is; on the other hand, the preparation method has the characteristics of short preparation time, less raw material use, more preparation components, and is suitable for industrial large-scale production and screening.

Description

Technical Field

[0001] This invention relates to the field of thermoelectric thin film material preparation technology, and in particular to a magnesium-based thermoelectric high-flux thin film material, its preparation method and application. Background Technology

[0002] Thermoelectric materials are functional materials capable of converting thermal energy into electrical energy. Thermoelectric conversion technology has significant application prospects in fields such as waste heat recycling. Due to the constraints of intrinsic excitation in thermoelectric materials, they typically possess high dimensionless thermoelectric figures of merit (ZT) within a certain range, thus exhibiting strong selectivity in the operating temperature range of thermoelectric devices.

[0003] Achieving efficient energy conversion near room temperature is a prerequisite for expanding the applications of thermoelectric materials and devices. Rapid advancements in thermoelectric material research have led to unprecedented development; however, the number of thermoelectric materials truly available for commercial application remains limited. For example, the most widely used room-temperature thermoelectric material in commercial applications is still bismuth telluride-based compounds, discovered in 1950. In recent years, the discovery of novel magnesium-based room-temperature thermoelectric materials has changed the awkward situation where only bismuth telluride-based materials were available for room-temperature applications. However, research on thin-film thermoelectric devices based on novel room-temperature thermoelectric material systems is still scarce. The main reason for this is the complex and time-consuming fabrication processes of traditional thermoelectric materials, which is a significant factor contributing to the slow pace of room-temperature thermoelectric material development.

[0004] In recent years, the emergence of high-throughput material preparation technologies has greatly accelerated the research and development of new materials. However, current thermoelectric material preparation technologies are mainly based on bulk thermoelectric material preparation methods, which involve simultaneously preparing different powder raw materials and then sintering them. Although this method is faster than traditional thermoelectric material preparation, it still requires multiple molds and the simultaneous preparation of thermoelectric powders with different contents to prepare thermoelectric materials with different compositions, resulting in a long preparation time and a large consumption of raw material powders.

[0005] Therefore, existing technologies still need to be improved and developed. Summary of the Invention

[0006] In view of the shortcomings of the prior art, the purpose of this invention is to provide a magnesium-based thermoelectric high-flux thin film material, its preparation method and application, in order to solve the problems that the preparation process of magnesium-based thermoelectric thin film materials is relatively complex, time-consuming and requires a large amount of raw material powder.

[0007] The technical solution of the present invention is as follows:

[0008] A method for preparing a magnesium-based thermoelectric high-flux thin film material includes the following steps:

[0009] Multiple discrete magnesium-based substrate films are deposited on the substrate surface using discrete photomasks;

[0010] Vacuum evaporation is used to deposit doped elements onto the surface of the magnesium substrate thin film using a discrete mask process.

[0011] The magnesium-based substrate film coated with doped elements is then annealed in a vacuum apparatus to obtain the magnesium-based thermoelectric high-flux thin film material.

[0012] The method for preparing the magnesium-based thermoelectric high-flux thin film material, wherein one of the matrix elements of the magnesium-based substrate thin film is magnesium, and the other matrix element is selected from at least one of bismuth, tin, and tellurium.

[0013] The method for preparing the magnesium-based thermoelectric high-flux thin film material, wherein the step of depositing multiple discrete magnesium-based substrate thin films on the surface of a substrate using discrete photomasks, specifically includes:

[0014] The magnesium source is placed on an evaporation boat at one of the thermal evaporation sources, and vacuum deposition is performed using thermal evaporation with discrete mask plates.

[0015] At least one of the bismuth source, tin source, and tellurium source is placed on an evaporation boat at another thermal evaporation source, and vacuum evaporation is performed using discrete mask plates, either thermal evaporation or electron beam evaporation.

[0016] A magnesium-based substrate thin film was prepared on the surface of a substrate.

[0017] The method for preparing magnesium-based thermoelectric high-flux thin film material, wherein the distance between the thermal evaporation source and the substrate is 65-75 mm.

[0018] The method for preparing the magnesium-based thermoelectric high-flux thin film material, wherein the deposition rate of the magnesium-based substrate thin film is 0.1–0.2 nm / s, and the vacuum degree is 8 × 10⁻⁶. -7 ~10×10 -7 Pa.

[0019] The method for preparing magnesium-based thermoelectric high-flux thin film material, wherein the mask is a first-level discrete mask; the step of depositing dopant elements on the surface of the magnesium-based substrate thin film using a discrete masking process employs a hierarchical mask.

[0020] The method for preparing the magnesium-based thermoelectric high-flux thin film material, wherein the doping element is selected from one or more of silver, selenium, yttrium, scandium, aluminum, copper, and titanium.

[0021] The method for preparing the magnesium-based thermoelectric high-flux thin film material includes an annealing temperature of 300-350℃, an annealing time of 0.8-1.2h, and a vacuum degree of 8×10⁻⁶. -7Pa.

[0022] A magnesium-based thermoelectric high-flux thin film material, wherein the magnesium-based thermoelectric high-flux thin film material is prepared by the above-mentioned preparation method of magnesium-based thermoelectric high-flux thin film material.

[0023] Application of the magnesium-based thermoelectric high-flux thin film material in thermoelectric devices.

[0024] Beneficial Effects: This invention provides a magnesium-based thermoelectric high-throughput thin film material and its preparation method. The preparation method includes the following steps: depositing a magnesium-based substrate thin film on a substrate surface; using vacuum evaporation and discrete masking technology to deposit dopant elements on the surface of the magnesium-based substrate thin film; and then annealing the doped magnesium-based substrate thin film in a vacuum apparatus to obtain the magnesium-based thermoelectric high-throughput thin film material. This invention uses a vacuum evaporation discrete masking method, combining thermal evaporation and electron beam evaporation to prepare the magnesium-based thermoelectric high-throughput thin film material. On the one hand, this allows the thin film material to meet the requirements of low dimensionality and miniaturization. Miniaturization can increase the integration density of thermoelectric modules, thereby increasing power output. The smaller the feature size of the thermoelectric device, the greater the power density. On the other hand, the preparation method of the magnesium-based thermoelectric high-throughput thin film material has the advantages of short preparation time, low raw material consumption, and multiple components, and is suitable for large-scale industrial production and screening. Attached Figure Description

[0025] Figure 1 This is a process flow diagram of the preparation method of the magnesium-based thermoelectric high-flux thin film material of the present invention;

[0026] Figure 2 This is a schematic diagram illustrating the principle of electron beam sputtering and thermal evaporation deposition of thermoelectric thin films in the preparation method of magnesium-based thermoelectric high-flux thin film materials of the present invention.

[0027] Figure 3 This is a schematic diagram of a multi-stage mask in the preparation method of the magnesium-based thermoelectric high-flux thin film material of the present invention;

[0028] Figure 4 This is a schematic diagram of an elemental mask used in the preparation method of magnesium-based thermoelectric high-flux thin film material of the present invention;

[0029] Figure 5 This is a diagram showing the elemental distribution of the high-throughput magnesium bismuthate-based thermoelectric thin film prepared in Example 1 of this invention.

[0030] Figure 6 This is a Seebeck coefficient thermoelectric performance characteristic distribution diagram of the high-throughput magnesium bismuth-based thermoelectric thin film prepared in Example 1 of the present invention. Detailed Implementation

[0031] This invention provides a magnesium-based high-flux thermoelectric thin film material, its preparation method, and its application. To make the objectives, technical solutions, and effects of this invention clearer and more explicit, the invention is further described in detail below. It should be understood that the specific embodiments described herein are merely illustrative of the invention and are not intended to limit the invention.

[0032] In the implementation methods and claims, unless otherwise specified in the text, the terms "a," "an," "the," and "the" may also include plural forms. If the embodiments of the present invention involve descriptions of "first," "second," etc., such descriptions are for descriptive purposes only and should not be construed as indicating or implying their relative importance or implicitly specifying the number of indicated technical features. Therefore, a feature defined with "first" or "second" may explicitly or implicitly include at least one of those features.

[0033] It will be understood by those skilled in the art that, unless otherwise defined, all terms used herein (including technical and scientific terms) have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains. It should also be understood that terms such as those defined in general dictionaries should be understood to have the same meaning as in the context of the prior art, and should not be interpreted in an idealized or overly formal sense unless specifically defined as herein.

[0034] Currently, thermoelectric materials have evolved from bulk thermoelectric materials to low-dimensional thermoelectric materials such as nanowires, superlattices, and multilayer thin films. In recent years, the emergence of high-throughput material preparation technologies has greatly accelerated the research and development of new materials. However, current thermoelectric material preparation technologies are mainly based on methods for preparing bulk thermoelectric materials, i.e., by simultaneously preparing different powder raw materials and then sintering them. Although this method is faster than traditional thermoelectric material preparation, it is still in a trial-and-error experimental stage.

[0035] Based on this, such as Figure 1 As shown, this invention provides a method for preparing a magnesium-based thermoelectric high-flux thin film material, comprising the following steps:

[0036] Step S10: Deposit multiple discrete magnesium substrate films on the substrate surface using discrete photomasks;

[0037] Step S20: Vacuum evaporation is used to deposit doped elements onto the surface of the magnesium substrate thin film using a discrete mask process;

[0038] Step S30: Then, the magnesium-based substrate film coated with doped elements is annealed in a vacuum device to obtain the magnesium-based thermoelectric high-flux film material.

[0039] This invention employs vacuum evaporation to deposit a magnesium-based substrate thin film onto a substrate surface. Then, using a discrete masking process, different mask patterns are used based on the composition of the target material to prepare corresponding elemental metal layers on the magnesium-based substrate thin film, achieving elemental doping. After annealing in a vacuum apparatus, magnesium-based thermoelectric high-throughput thin film materials with different compositions are finally fabricated on the substrate in a single process. The magnesium-based thermoelectric high-throughput thin film materials prepared using a vacuum evaporation method combining thermal evaporation and electron beam evaporation, along with a discrete masking process, enable the miniaturization of thermoelectric devices. Miniaturization increases the integration density of thermoelectric modules, increases power output, and the smaller the feature size of the thermoelectric device, the higher the power density. Furthermore, this preparation method features short preparation time, low raw material consumption, and the ability to prepare multiple compositions.

[0040] In steps S10 and S20, the difference in composition at each composition point is achieved by using different mask sequences and deposition thicknesses and rates of dopant elements.

[0041] In some embodiments, the substrate is selected from alumina, silicon, silica, and glass.

[0042] In a preferred embodiment, the substrate is selected as alumina, which has a c-axis orientation and a high lattice matching degree with thermoelectric thin film materials, thereby inducing the magnesium-based substrate thin film to preferentially grow along the c-axis direction.

[0043] In some embodiments, before step S10, the substrate is further cleaned; specifically, the substrate is cleaned and dried by ultrasonic cleaning to obtain a clean substrate; the cleaning agent used for ultrasonic cleaning is acetone, alcohol and water; the substrate is placed in acetone, alcohol and water in sequence for ultrasonic cleaning; the drying method after cleaning is preferably to blow dry with high-purity nitrogen gas.

[0044] In some embodiments, one of the matrix elements of the magnesium-based substrate film is magnesium, and the other matrix element is selected from at least one of bismuth, tin, and tellurium. Then, the magnesium source is evaporated by a vacuum evaporation method of thermal evaporation, and at least one of the bismuth source, tin source, and tellurium source is evaporated by a vacuum evaporation method of thermal evaporation or electron beam evaporation, so that the magnesium-based substrate film deposited on the substrate has better performance.

[0045] In some embodiments, step S10 involves depositing multiple discrete magnesium-based substrate thin films on the substrate surface using discrete photomasks, specifically including:

[0046] Step S11: Place the magnesium source on the evaporation boat at one of the thermal evaporation sources, and use discrete mask plates to perform vacuum evaporation by thermal evaporation;

[0047] Step S12: Place at least one of the bismuth source, tin source, and tellurium source on an evaporation boat at another thermal evaporation source, and perform vacuum evaporation using discrete mask plates, either thermal evaporation or electron beam evaporation.

[0048] Step S13: A magnesium-based substrate film is formed on the surface of the substrate.

[0049] In a preferred embodiment, at least one of a bismuth source, a tin source, and a tellurium source is vacuum-deposited using electron beam evaporation. A magnesium substrate thin film is prepared by a combination of thermal evaporation of the magnesium source and electron beam evaporation of the doping elements, resulting in a large dimensionless thermoelectric figure of merit.

[0050] In some embodiments, the distance between the thermal evaporation source and the substrate is 65-75 mm.

[0051] In a preferred embodiment, the distance between the thermal evaporation source and the substrate is 70 mm.

[0052] In some embodiments, the deposition rate of the magnesium-based substrate film is 0.1–0.2 nm / s, and the vacuum degree is 6 × 10⁻⁶. -7 ~10×10 -7 Pa.

[0053] In a preferred embodiment, the deposition rate of the magnesium-based substrate film is 0.1 nm / s, and the vacuum degree is 8 × 10⁻⁶. -7 Pa.

[0054] In some embodiments, step S10 employs a single-stage discrete mask; the step utilizes a discrete mask process to deposit dopant elements onto the surface of the magnesium substrate thin film using a hierarchical mask. A single-layer magnesium substrate thin film is prepared on the substrate using a physical deposition method combined with discrete masks. Then, according to the composition of the target material, hierarchical masks with different mask patterns are used to prepare corresponding elemental metal layers on the surface of the magnesium substrate thin film. Finally, annealing is performed, thus enabling the simultaneous preparation of thermoelectric thin film materials with different doping compositions on the substrate. This method can simultaneously prepare thermoelectric thin film materials with different doping compositions and can significantly improve the preparation speed of hot spot thin film materials.

[0055] In some embodiments, the doping element includes, but is not limited to, one or more selected from silver, selenium, yttrium, scandium, aluminum, copper, and titanium. The impurity element is deposited on the magnesium substrate film using a vacuum evaporation method such as thermal evaporation or electron beam evaporation.

[0056] In some embodiments, in step S30, the magnesium-based substrate thin film coated with doped elements is subjected to diffusion annealing and uniform annealing in a vacuum device to obtain the magnesium-based thermoelectric high-flux thin film material.

[0057] In some embodiments, the annealing temperature in step S30 is 300-350°C, the annealing time is 0.8-1.2 h, and the vacuum degree is 8 × 10⁻⁶. -7 Pa.

[0058] In a preferred embodiment, the annealing treatment is performed at an annealing temperature of 325°C, an annealing time of 1 hour, and a vacuum degree of 8×10⁻⁶. -7 Pa. This annealing heat treatment condition can effectively improve the crystallinity of thermoelectric thin films, enabling the grains to preferentially oriented and grow along the c-axis.

[0059] In some embodiments, the thickness of the magnesium-based thermoelectric high-flux thin film material is 1 μm.

[0060] In this invention, magnesium-based thin films of different types and thicknesses are prepared on a substrate using discrete masks. Then, different doping elements are prepared on the magnesium-based thin films using masks with different patterns. The composition of the material is controlled by changing the thickness of the elemental metal. Finally, the prepared material is annealed. This allows for the simultaneous preparation of multiple discrete magnesium-based thermoelectric high-flux thin film materials with different compositions on a substrate.

[0061] In addition, the present invention also provides a magnesium-based thermoelectric high-flux thin film material, which is prepared by the above-described method for preparing magnesium-based thermoelectric high-flux thin film materials.

[0062] Furthermore, the present invention also provides an application of the aforementioned magnesium-based thermoelectric high-flux thin film material in thermoelectric devices.

[0063] The following examples further illustrate the present invention in detail. It should also be understood that the following examples are only for further explanation of the present invention and should not be construed as limiting the scope of protection of the present invention. Any non-essential improvements and adjustments made by those skilled in the art based on the above description of the present invention are within the scope of protection of the present invention.

[0064] Example 1

[0065] like Figure 2 The diagram shown illustrates the principle of electron beam sputtering and thermal evaporation deposition of thermoelectric thin films in the preparation method of magnesium-based thermoelectric high-flux thin film materials of this invention. For ease of understanding, the diagram is first presented below. Figure 2 The markings in the diagram are explained as follows: Preparation chamber A; Preparation chamber A includes a biaxial displacement stage 1, an observation window 2, a mask entry / exit chamber 3, a mask 4, a heating stage 5, a sample position 6, an evaporation source 7, and an electron beam 8; Partial view of the electron beam B; Partial view of the evaporation source C; Magnified schematic diagram of the prepared sample D, from top to bottom: thermal evaporation source or electron beam, mask, and sample substrate.

[0066] This embodiment uses magnesium and bismuth evaporators as matrix elements and silver, selenium, yttrium, and scandium as impurity elements. Taking the preparation method using high-throughput vacuum evaporation technology as an example, the specific steps are as follows:

[0067] Step S100: The magnesium and bismuth evaporation materials with a purity of 99.99% are cut into appropriate pieces and placed on the evaporation boat at the thermal evaporation source 7. The pieces are spread out to ensure that the magnesium and bismuth evaporation materials have a large contact surface with the evaporation boat, so that the deposited film is very uniform.

[0068] Step S200: Using alumina with a c-axis orientation as a substrate, the substrate is cleaned and dried by ultrasonic cleaning to obtain a clean alumina single crystal substrate. The alumina substrate with a c-axis orientation is used as the substrate for comprehensive thermal evaporation. It has a very high lattice matching degree with the magnesium bismuthide-based thermoelectric thin film, which can induce the preferential growth of the magnesium bismuthide-based thermoelectric thin film along the c-axis direction.

[0069] Specifically, the substrate is cleaned using acetone, alcohol, and water; preferably, the soaked alumina single crystal substrate is ultrasonically cleaned in acetone, alcohol, and water in sequence, and then dried with high-purity nitrogen.

[0070] Step S300: Before coating, first evacuate the vacuum coating system to a vacuum level of 8×10⁻⁶. -7 Pa, first use a baffle to block the sample position, preheat in power mode to further remove impurity molecules adsorbed on the surface of the evaporating material and the substrate, and adjust the distance between the evaporation source and the substrate to 70 mm; after preheating, open the baffle, first prepare the main magnesium metal film, the power is set to 15%, the substrate temperature is 50℃, the sample stage speed is 10 rad / min, and the evaporation rate is 0.1 nm / s; when preparing the bismuth metal film, the power is set to 16%, the substrate temperature is 50℃, the sample stage speed is 10 rad / min, the evaporation rate is 0.1 nm / s, and the atomic ratio is controlled at Mg:Bi = 3:2, to obtain the bismuthated magnesium substrate film.

[0071] Specifically, the mask used in the preparation of the main elements is a first-level discrete mask.

[0072] Step S400: Doping the magnesium bismuthide substrate thin film to obtain the magnesium bismuthide thermoelectric thin film;

[0073] like Figure 3 As shown (a schematic diagram of a multi-level mask in the preparation method of magnesium-based thermoelectric high-flux thin film materials), a hierarchical masking method is used when doping elements, and the material is prepared on a substrate by thermal evaporation or electron beam evaporation; in this case, electron beam evaporation is used, with silver, selenium, yttrium, and scandium used as doping elements in sequence. Figure 4The diagram shows an elemental mask with electron beam powers of 4%, 0.3%, 3%, and 2.5% (4%, 0.3%, 3%, and 2.5% correspond to the electron beam powers of silver, selenium, yttrium, and scandium, respectively). The substrate temperature during fabrication was 50°C, the sample stage was 10 rad / min, and the evaporation rate was 0.1 nm / s. Three sets of four-stage symmetrical masks were used to obtain 256 material composition types. The doping thickness gradient for each material was 3 nm, 6 nm, and 9 nm (meaning the thickness gradient between silver and selenium was 3 nm, between selenium and yttrium was 6 nm, and between yttrium and scandium was 9 nm).

[0074] Step S500: The obtained high-flux magnesium bismuthide thermoelectric thin film is annealed to obtain a magnesium-based high-flux thermoelectric thin film. The substrate of the magnesium-based thermoelectric thin film material is annealed in a vacuum apparatus at a temperature of 325°C for 1 hour, with a vacuum degree of 8×10⁻⁶. -7 Pa, film thickness 1μm, annealing heat treatment can effectively improve the crystallization performance of thermoelectric thin films, enabling grains to preferentially oriented and grow along the c-axis.

[0075] Finally, the composition of the obtained high-throughput magnesium bismuthate thermoelectric thin film was characterized by X-ray fluorescence spectroscopy, and the final result was as follows: Figure 5 The elemental distribution diagram shows that, through vacuum deposition discrete masking technology, each component point has a different composition.

[0076] The performance values ​​of thermoelectric materials are typically expressed using the dimensionless thermoelectric figure of merit (ZT). High conversion efficiency requires a large ZT value. Thermoelectric figure of merit ZT = S 2 σT / κ, where S is the Seebeck coefficient, σ is the electrical conductivity, κ is the thermal conductivity, and T is the absolute temperature. The prepared n-type pure Mg3Bi2 thin film has an in-plane resistivity of 11.07 μΩm and a Seebeck coefficient of -46.1 μV / K at room temperature, and can produce 192 μW / mK. 2 The power factor is high. Therefore, a high Seebeck coefficient, high electrical conductivity σ, and low thermal conductivity κ are key to improving ZT.

[0077] Below, we tested the Seebeck performance of the thermoelectric thin films prepared in the above embodiments using a room-temperature Seebeck scanning probe. The test results are shown in the appendix. Figure 6 As shown.

[0078] from Figure 6 It is known that the method of the present invention can prepare thermoelectric thin film materials with different doping components, which can greatly improve the preparation speed of thermoelectric thin film materials and screen out component points with potentially excellent performance.

[0079] In summary, this invention provides a magnesium-based thermoelectric high-throughput thin film material and its preparation method. The preparation method includes the following steps: depositing a magnesium-based substrate thin film on a substrate surface; using vacuum evaporation and a discrete mask process to deposit dopant elements on the surface of the magnesium-based substrate thin film; and then annealing the doped magnesium-based substrate thin film in a vacuum apparatus to obtain the magnesium-based thermoelectric high-throughput thin film material. This invention uses a vacuum evaporation discrete mask method, combining thermal evaporation and electron beam evaporation to prepare the magnesium-based thermoelectric high-throughput thin film material. On the one hand, this allows the thin film material to meet the requirements of low dimensionality and miniaturization. Miniaturization can increase the integration density of thermoelectric modules, thereby increasing power output, and the smaller the feature size of the thermoelectric device, the greater the power density. On the other hand, the preparation method of the magnesium-based thermoelectric high-throughput thin film material has the advantages of short preparation time, low raw material consumption, and multiple components, and is suitable for large-scale industrial production and screening.

[0080] It should be understood that the application of the present invention is not limited to the examples above. Those skilled in the art can make improvements or modifications based on the above description, and all such improvements and modifications should fall within the protection scope of the appended claims.

Claims

1. A method for preparing a magnesium-based thermoelectric high-flux thin film material, characterized in that, Including the following steps: A magnesium source is placed on an evaporation boat at one of the thermal evaporation sources, and vacuum evaporation is performed using a discrete mask. At least one of a bismuth source, a tin source, and a tellurium source is placed on an evaporation boat at another thermal evaporation source, and vacuum evaporation is performed using a discrete mask or an electron beam evaporation to prepare multiple discrete magnesium-based substrate films on the surface of an alumina substrate. Vacuum evaporation is used to deposit doped elements onto the surface of the magnesium substrate thin film using a discrete mask process. Then, the magnesium-based substrate film coated with doped elements is annealed in a vacuum device to obtain the magnesium-based thermoelectric high-flux film material. The mask is a first-level discrete mask; the step of depositing doped elements onto the surface of the magnesium substrate thin film using a discrete masking process employs a hierarchical mask. The doping element is selected from one or more of silver, selenium, yttrium, scandium, aluminum, copper, and titanium; the doping element is deposited on the magnesium substrate film using a vacuum evaporation method such as thermal evaporation or electron beam evaporation; the annealing treatment is performed at a temperature of 300-350℃, an annealing time of 0.8-1.2h, and a vacuum degree of 8×10⁻⁶. -7 Pa.

2. The method for preparing magnesium-based thermoelectric high-flux thin film material according to claim 1, characterized in that, The distance between the evaporation source and the substrate in the thermal evaporation is 65-75 mm.

3. The method for preparing magnesium-based thermoelectric high-flux thin film material according to claim 1, characterized in that, The deposition rate of the magnesium-based substrate thin film is 0.1~0.2 nm / s, and the vacuum degree is 6×10⁻⁶. -7 ~10×10 -7 Pa.

4. A magnesium-based high-flux thermoelectric thin film material, characterized in that, The magnesium-based thermoelectric high-flux thin film material is prepared using the preparation method of magnesium-based thermoelectric high-flux thin film material as described in any one of claims 1-3.

5. The application of the magnesium-based thermoelectric high-flux thin film material as described in claim 4 in thermoelectric devices.

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