A high-flux, high-precision material low-temperature thermoelectric property characterization device

Abstract

The application provides a device for high-throughput and accurate characterization of low-temperature thermoelectric properties of materials, characterized by comprising a vacuum cavity, a probe assembly, a base temperature control module, a temperature gradient generator, a vacuum system, a signal generation and acquisition module. The device provided by the application can adopt two measurement modes: a conventional straight-line four-point probe method and an improved Van der Pauw method. The conventional straight-line four-point probe method is used for measuring the Seebeck coefficient and electrical conductivity of a bulk sample with a regular shape. The improved Van der Pauw method can be used for measuring the Seebeck coefficient and electrical conductivity of a thin film with an irregular shape.

Description

Technical Field

[0001] This invention relates to the field of thermoelectric property measurement technology, and more particularly to a high-throughput, high-precision device for characterizing the low-temperature thermoelectric properties of materials. Background Technology

[0002] Thermoelectric energy conversion technology is a clean energy technology that enables direct and reversible conversion between thermal energy and electrical energy. It has broad application prospects in fields such as deep space and deep-sea exploration, waste heat recovery, semiconductor refrigeration, and self-powered human body sensors. The energy conversion efficiency of thermoelectric technology mainly depends on the thermoelectric figure of merit (ZT) of the thermoelectric material. The ZT value of a thermoelectric material is related to its Seebeck coefficient (S), electrical conductivity (σ), thermal conductivity (k), and ambient temperature (T), and is calculated using the following formula: ZT = (S... 2 ×σT) / k. To obtain a high thermoelectric figure of merit, thermoelectric materials should possess a high Seebeck coefficient, high electrical conductivity, and low thermal conductivity. Due to the interplay among these three parameters, it has long been difficult to significantly improve the ZT value of materials. Researchers often need to conduct extensive material screening and performance optimization to improve the thermoelectric figure of merit.

[0003] Currently, commercial thermoelectric property measuring instruments (such as the ZEM-3 thermoelectric property evaluation device from ADVANCE RIKO in Japan and the LSR-3 Seebeck coefficient / resistance tester from LINSEIS in Germany) can only test one sample per experiment. Given the lengthy time required for furnace heating, cooling, and temperature stabilization, the efficiency of using commercial thermoelectric property measuring instruments for material screening is relatively low.

[0004] Chinese patent application number 202010809811.1 discloses a high-throughput temperature-varying testing device for thermoelectric materials. This device can test the thermoelectric properties of materials within a temperature range from room temperature to 500°C. Its high-throughput property refers to testing different regions of a sample with a gradient distribution of components by moving a probe, thereby obtaining the correspondence between the components and their thermoelectric properties. Regarding resistivity testing, this patent uses a two-wire method; the presence of contact resistance and lead resistance affects measurement accuracy. Furthermore, the gradient sample is not cut, and the components are not electrically isolated, making it difficult to accurately obtain the Seebeck coefficient corresponding to each component. Therefore, the device disclosed in this patent can only serve as a rough screening method for the thermoelectric properties of materials.

[0005] In conclusion, developing a high-throughput, precise device for characterizing the thermoelectric properties of materials is of significant practical value for improving the research and development efficiency of high-performance thermoelectric materials. Summary of the Invention

[0006] To address the shortcomings and improvement needs of existing technologies, the present invention aims to provide a high-throughput, high-precision device for characterizing the low-temperature thermoelectric properties of materials, thereby improving the research and development efficiency of thermoelectric materials. This device can measure the in-plane thermoelectric properties of bulk and thin film materials within a range of 100-500K using either the conventional four-point linear probe method or a modified van der Burg method. The technical means employed in this invention are as follows:

[0007] A high-throughput, precise device for characterizing the low-temperature thermoelectric properties of materials includes: a vacuum chamber, a probe assembly, a base temperature control module, a temperature gradient generator, a vacuum system, and a signal generation and acquisition module; wherein: the vacuum chamber includes a sample chamber, a top cover plate, multiple bellows, and a vacuum-sealed end; the side wall of the sample chamber has multiple openings distributed at equal angles, the outer sides of which are connected to the bellows, and a flange joint is provided for connection to the vacuum system; the top cover plate has an observation window in the middle and multiple through holes on the edge; one end of the bellows is connected to the sample chamber, and the other end is connected to the vacuum-sealed end; the top cover plate and the sample chamber, the sample chamber and the bellows, and the bellows and the vacuum-sealed end are connected by fastening screws and sealed with O-rings to form a sealed chamber; the upper end of the vacuum-sealed end is provided with a single-core terminal or a double-core terminal for connecting the signal generation and acquisition module.

[0008] The probe assembly includes: multiple probe arms, multiple metal probes, multiple thermocouple probes, and multiple triaxial displacement stages; one end of each probe arm is detachably mounted on the vacuum-sealed end, and the other end is provided with a groove and a fastening screw for fixing the probe; the triaxial displacement stages are connected to the vacuum-sealed end and are used to drive the movement of the probe arms; the leads of the multiple metal probes are respectively connected to single-core terminals, and the leads of the multiple thermocouple probes are respectively connected to dual-core terminals; the base temperature control module includes: a liquid nitrogen conduction cooling stage, a metal base, a main heating rod, a first temperature probe, and a temperature controller; the liquid nitrogen conduction cooling stage is located at the bottom of the sample chamber, and the liquid nitrogen conduction cooling stage and the sample chamber are separated by multiple thermally insulating support columns; the metal base is located on the liquid nitrogen conduction cooling stage, the main heating rod and the first temperature probe are embedded in the metal base, and the leads are connected to the temperature controller for controlling the base temperature of the sample to be tested.

[0009] The temperature gradient generator includes: two thermally conductive insulating platforms, a gradient heating rod, and a voltage source; wherein, the first thermally conductive insulating platform is fixed to a metal base by fastening screws, the gradient heating rod is embedded in the first thermally conductive insulating platform, and the leads are connected to the positive and negative terminals of the voltage source; the second thermally conductive insulating platform is placed horizontally side by side with the first thermally conductive insulating platform, and two strip-shaped through holes are provided on both sides of the second thermally conductive insulating platform, which are connected to the metal base by fastening screws; the signal generation and acquisition module includes a constant current source, a digital multimeter with a multi-channel scanning card, and a channel switching switch.

[0010] Furthermore, the base temperature control module controls the temperature of the sample to be tested within the range of 100-500K by controlling the liquid nitrogen flow rate and the heating power of the main heating rod.

[0011] Furthermore, the temperature gradient generator is provided with two separate thermally conductive insulating platforms, one of which has a strip-shaped through hole; at the same time, multiple test samples can be placed side by side between the thermally conductive insulating platforms, and the thermoelectric properties of multiple test samples can be measured simultaneously during a single heating and cooling process.

[0012] Furthermore, there is an adjustable gap between the second thermally conductive insulating platform and the first thermally conductive insulating platform.

[0013] Furthermore, the sample to be tested is fixed on a thermally conductive insulating stage by adhesive bonding.

[0014] Furthermore, the triaxial displacement stage controls the movement of the metal probe and the thermocouple probe, forming a linear four-point probe arrangement or a van der Burg method probe arrangement. Compared with the prior art, the present invention has the following advantages:

[0015] (1) The base temperature control module is equipped with a liquid nitrogen conduction cold stage and a main heater, which can measure the thermoelectric properties of materials within a temperature range of 100K to 500K.

[0016] (2) The temperature gradient generator is equipped with two separate thermally conductive insulating stages, and the gap width between the thermally conductive insulating stages can be flexibly adjusted according to the size of the sample to be tested. Multiple samples to be tested can be placed side by side between the two thermally conductive insulating stages, and the thermoelectric properties of multiple samples to be tested can be measured simultaneously during a single heating and cooling process, thereby improving the research and development efficiency of thermoelectric materials.

[0017] (3) The device provided by this invention can employ two measurement modes: the conventional four-point probe method and the improved van der Burg method. The conventional four-point probe method is used to measure the Seebeck coefficient and conductivity of bulk samples with regular shapes. The improved van der Burg method can be used to measure the Seebeck coefficient and conductivity of thin films with irregular shapes. Attached Figure Description

[0018] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0019] Figure 1 A schematic diagram of the high-throughput, high-precision low-temperature thermoelectric property characterization device for materials provided by the present invention;

[0020] Figure 2 A schematic diagram of the internal structure of the high-throughput, high-precision low-temperature thermoelectric property characterization device for materials provided by the present invention;

[0021] Figure 3 This is a schematic diagram of the temperature gradient generator in this invention, and a schematic diagram of the relative positions of the probes when measuring the thermoelectric properties of materials using the four-point probe method.

[0022] Figure 4 This is a schematic diagram illustrating the working principle of measuring the thermoelectric properties of materials using the four-point linear probe method in this invention.

[0023] Figure 5 The Seebeck coefficients of niobium-doped strontium titanate, boron-doped silicon wafers, and molybdenum oxide at room temperature were measured using the four-point linear probe method in Example 1.

[0024] Figure 6 This is a schematic diagram showing the relative positions of the probes when measuring the thermoelectric properties of thin film materials using the improved van der Burg method in this invention.

[0025] Figure 7 This is a schematic diagram illustrating the working principle of measuring the thermoelectric properties of thin film materials using the improved van der Burg method in this invention.

[0026] Figure 8 In Example 2, the Seebeck coefficients of reduced strontium titanate, tellurium film, and copper-nickel alloy film were measured at room temperature using the improved van der Burg method.

[0027] Figure Descriptions: 1. Sample Chamber; 2. Top Cover; 3. Bellows; 4. Rubber O-ring; 5. First Fastening Screw; 6. Triaxial Displacement Stage; 7. Vacuum Sealing End; 8-1. First Single-Core Terminal; 8-2. Second Single-Core Terminal; 9-1. First Double-Core Terminal; 9-2. Second Double-Core Terminal; 10. Liquid Nitrogen Inlet / Outlet; 11. Flange Joint; 12. Bottom of Sample Chamber; 13. Thermal Insulation Support Column; 14. Probe Arm; 15-1. First Metal Probe; 15-2. Second Metal Probe; 16-1. First Thermal... 16-2. Second thermocouple probe; 17. Liquid nitrogen conduction cold stage; 18. Metal base; 19. Main heating rod; 20. First temperature probe; 21. Second fastening screw; 22. Gradient heating rod; 23. Bulk sample to be tested; 24-1. First thermally conductive insulating stage; 24-2. Second thermally conductive insulating stage; 25. Strip-shaped through hole; 26. Constant current source; 27. Multichannel scanning card; 28. Digital multimeter; 29. ​​Thin film sample to be tested; 30-1. First switching switch; 30-2. Second switching switch. Detailed Implementation

[0028] To enable those skilled in the art to better understand the present invention, the technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort should fall within the scope of protection of the present invention.

[0029] It should be noted that the terms "first," "second," etc., in the specification, claims, and accompanying drawings of this invention are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that such data can be interchanged where appropriate so that the embodiments of the invention described herein can be implemented in orders other than those illustrated or described herein. Furthermore, the terms "comprising" and "having," and any variations thereof, are intended to cover a non-exclusive inclusion; for example, a process, method, system, product, or apparatus that comprises a series of steps or units is not necessarily limited to those steps or units explicitly listed, but may include other steps or units not explicitly listed or inherent to such processes, methods, products, or apparatus.

[0030] Example 1

[0031] This embodiment discloses a high-throughput, high-precision device for characterizing the low-temperature thermoelectric properties of materials. For example... Figures 1 to 3 As shown, the device includes a vacuum chamber, probe assembly, base temperature control module, temperature gradient generator, vacuum system, and signal generation and acquisition module. The vacuum chamber includes a cylindrical sample chamber 1, a top cover 2, four bellows 3, and four vacuum-sealed terminals 7. The side wall of the sample chamber 1 has four circular openings distributed at equal angles, with the outer sides of the openings connected to the bellows 3. A flange joint 11 is also provided, connecting to the vacuum system. The top cover 2 has an observation window in the center and four through holes on its edge, connected to the sample chamber 1 by fastening screws 5 and sealed with rubber O-rings 4. The four bellows 3 are distributed at equal angles around the sample chamber 1, with one end connected to the sample chamber 1 and the other end connected to the vacuum-sealed terminals 7. The upper ends of the four vacuum-sealed terminals 7 are respectively provided with two single-core terminals (8-1, 8-2) and two double-core terminals (9-1, 9-2) for connecting to the signal generation and acquisition module.

[0032] The probe assembly includes four probe arms 14, two metal probes (15-1, 15-2), two thermocouple probes (16-1, 16-2), and four triaxial displacement stages 6. One end of each probe arm 14 is detachably mounted on a vacuum-sealed end 7, and the other end has a groove and a fastening screw for fixing the metal probes (15-1, 15-2) and the thermocouple probes (16-1, 16-2). The triaxial displacement stages 6 are fixed to the vacuum-sealed end 7 and are used to drive the movement of the probe arms 14. The leads of the first metal probe 15-1 and the second metal probe 15-2 are connected to the first single-core terminal 8-1 and the second single-core terminal 8-2, respectively. The leads of the first thermocouple probe 16-1 and the first thermocouple probe 16-2 are connected to the first double-core terminal 9-1 and the second double-core terminal 9-2, respectively.

[0033] The base temperature control module includes a liquid nitrogen conduction cooling stage 17, a metal base 18, a main heating rod 19, a first temperature probe 20, and a temperature controller. The liquid nitrogen conduction cooling stage 17 is connected to the bottom 12 of the sample chamber via three insulated support columns 13. The metal base 18 is located on the liquid nitrogen conduction cooling stage 17, and the main heating rod 19 and the first temperature probe 20 are embedded in the metal base 18. The lead wire of the main heating rod 19 is connected to the output terminal of the temperature controller, and the lead wire of the first temperature probe 20 is connected to the temperature signal input terminal of the temperature controller.

[0034] The temperature gradient generator includes two thermally conductive insulating platforms (24-1, 24-2), a gradient heating rod 22, and a voltage source. The first thermally conductive insulating platform 24-1 is fixed to the metal base 18 by fastening screws 22. The gradient heating rod 22 is embedded in the first thermally conductive insulating platform 24-1, and its leads are connected to the positive and negative terminals of the voltage source. The second thermally conductive insulating platform 24-2 is placed horizontally side-by-side with a gap between it and the first thermally conductive insulating platform 24-1. Two strip-shaped through holes 25 are provided on both sides of the second thermally conductive insulating platform 24-2. The gap width between the two thermally conductive insulating platforms is flexibly adjustable. After the installation position of the second thermally conductive insulating platform 24-2 is determined, it is fixed with fastening screws. The first thermally conductive insulating platform 24-1 is used to heat one end of the sample to be tested, while the second thermally conductive insulating platform 24-2 acts as a heat sink, thereby establishing a temperature gradient along the length of the sample.

[0035] The signal generation and acquisition module includes a constant current source 26, a digital multimeter 28 with a multi-channel scanning card 27, and a switch (30-1, 30-2).

[0036] When measuring Seebeck coefficient and conductivity using the linear four-point probe method, several elongated sample 23 are first placed across the first thermally conductive insulating stage 24-1 and the second thermally conductive insulating stage 24-2. The sample 23 is fixed to the thermally conductive insulating stage by adhesive bonding. Double-sided tape, lubricating grease, or insulating epoxy resin are preferred bonding methods. To reduce the contact resistance between the sample and the probes, a metal electrode of a certain thickness can be formed on the sample beforehand. After the sample is installed, the upper cover 2 is closed, and the vacuum system is activated to evacuate the air. After reaching a certain vacuum level, the predetermined temperature is reached by controlling the liquid nitrogen flow rate and the heating power of the main heating rod 19. After the temperature stabilizes, the triaxial displacement stage 6 is adjusted so that the four probes are perpendicularly pressed onto the surface of the sample 23, arranged in a straight line. Two metal probes (15-1, 15-2) are located on the outer side, and two thermocouple probes (16-1, 16-2) are located on the inner side. Figure 4 The wiring diagram shows two metal probes (15-1, 15-2) connected to the positive and negative terminals of the constant current source 26, and two thermocouple probes (16-1, 16-2) connected to the first and second channels of the multi-channel scanning card 27 to measure the temperature at two points on the sample. A wire is led out from each of the two thermocouple probes (15-1, 15-2) and connected to the third channel of the multi-channel scanning card 27 to measure the thermal voltage caused by the temperature difference. This shared electrode design ensures that the detection positions of the temperature difference and the corresponding thermal voltage remain consistent, effectively reducing measurement errors.

[0037] After wiring is complete, turn on the digital multimeter 28, close the first channel of the multi-channel scanning card 27, and measure the actual temperature of the sample surface through the thermocouple probe 16-2. After the sample temperature (denoted as T0) stabilizes, begin measuring the Seebeck coefficient of the sample. The Seebeck coefficient is measured using a non-steady-state method, i.e., a voltage pulse is applied to the gradient heating rod 22, causing the temperature of one end of the sample to rise. The magnitude and duration of the voltage pulse are controlled so that the temperature rise of the sample does not exceed 5K. Using the scanning function of the digital multimeter 28, continuously record the temperatures (T1, T2) and corresponding thermoelectric voltages ΔU of the two thermocouple probes (16-1, 16-2). Plot ΔU against ΔT = T1 - T2, take the negative slope of the curve, and subtract the Seebeck coefficient of the thermocouple wires to obtain the Seebeck coefficient of the sample at that temperature. Next, the conductivity of the test sample was measured using the four-wire method. A constant current source 26 was applied between the two outer metal probes (15-1, 15-2), while the two middle thermocouple probes (16-1, 16-2) collected the corresponding voltages. By changing the current magnitude and polarity, a current-voltage curve was obtained. The resistance R could be obtained from the slope of this curve. Furthermore, based on the cross-sectional area A of the test sample and the thermocouple probe spacing d, the conductivity σ of the test sample could be calculated as σ = d / (R×A). After measuring the Seebeck coefficient and conductivity of the first test sample, the four probes were moved and pressed vertically onto the second test sample. The above steps were repeated to measure the Seebeck coefficient and conductivity of the second test sample at temperature T0. Based on the above steps, the Seebeck coefficient and conductivity of niobium-doped strontium titanate, boron-doped silicon wafers, and molybdenum oxide at room temperature were measured using the linear four-point probe method. The dimensions of each sample and the measured conductivity are shown in Table 1, and the corresponding thermoelectric voltage (ΔU)-temperature difference (ΔT) curves are shown in Table 1. Figure 5 As shown, the slope of the ΔU-ΔT curve is taken as negative, and then the Seebeck coefficient of the conductor (copper: 1.9μV / K) is subtracted to obtain the corrected Seebeck coefficient of the sample.

[0038] Table 1

[0039]

[0040] Example 2

[0041] This embodiment, based on Embodiment 1, utilizes a modified van der Burg method to simultaneously measure the Seebeck coefficient and conductivity of thin film materials. After the base temperature control module reaches the set temperature, the triaxial displacement stage 6 drives four probes to be vertically pressed against the edge of the thin film sample 29 to be tested. The relative positions of the two metal probes (15-1, 15-2) and the two thermocouple probes (16-1, 16-2) are as follows: Figure 6As shown. To reduce the contact resistance between the probe and the sample, a metal electrode can be deposited beforehand at an appropriate location on the sample. According to... Figure 7 The instrument connection diagram shows the connection of the constant current source 26, multi-channel scanning card 27, digital multimeter 28, and switch (30-1, 30-2) to the four probes. After the wires are connected, first switch 30-1, 30-2 is switched to pin S1, and the digital multimeter 28 is turned on to measure the actual temperature of the sample surface. After the sample temperature (denoted as T0) stabilizes, the Seebeck coefficient is measured. A voltage pulse is applied to the gradient heating rod 22 through the voltage source to raise the temperature of one end of the sample. The magnitude and on-time of the voltage pulse are controlled so that the temperature rise of the sample does not exceed 5K. Using the scanning function of the digital multimeter 28, the temperatures (T1, T2) and corresponding thermoelectric voltages ΔU of the two thermocouple probes (16-1, 16-2) are continuously recorded. ΔU is plotted against ΔT = T1 - T2. The slope of the curve is negative, and after subtracting the Seebeck coefficient of the thermocouple wires, the Seebeck coefficient of the sample at that temperature can be obtained. Next, the sheet resistance (R0) of the sample was measured using the van der Burg method. S First, a constant current source 26 is used to input current between metal probes 15-1 and 15-2. The third channel of the multi-channel scanning card 27 is closed, and the potential difference between thermocouple probes 16-1 and 16-2 is measured using a digital multimeter 28. By changing the magnitude and polarity of the input current, the first current-voltage curve is obtained, and the resistance R1 is derived from the slope of this curve. Next, switches 30-1 and 30-2 are switched to pin S2, and a current source is used to input current between metal probe 15-1 and thermocouple probe 16-1. The potential difference between metal probe 15-2 and thermocouple probe 16-2 is measured using a digital multimeter. By changing the magnitude and polarity of the input current, the second current-voltage curve is obtained, and the resistance R2 is derived from the slope of this curve. The conductivity σ of the sample under test is calculated from R1 and R2 using the following formula:

[0042]

[0043]

[0044] In the formula, t is the thickness of the sample to be tested, and f(R1 / R2) is the geometric correction factor, which can be obtained by interpolation according to the literature (AARamadan, et al. Thin Solid Films, 1994, 239: 272-275). After the Seebeck coefficient and conductivity of the first sample to be tested are measured, the four probes are moved and pressed vertically onto the second sample to be tested. The above steps are repeated to measure the Seebeck coefficient and conductivity of the second sample to be tested at temperature T0. According to the above steps, the Seebeck coefficient and conductivity of reduced strontium titanate, tellurium film, and copper-nickel alloy film at room temperature are measured using the improved van der Burg method. The dimensions of each sample and the measured conductivity are shown in Table 2, and the corresponding thermal voltage (ΔU)-temperature difference (ΔT) curves are shown in Table 2. Figure 8 As shown, by taking the negative slope of the ΔU-ΔT curve and then subtracting the Seebeck coefficient of the conductor (copper: 1.9μV / K), the corrected Seebeck coefficient of the sample can be obtained.

[0045] Table 2

[0046]

[0047] The sequence numbers of the above embodiments of the present invention are for descriptive purposes only and do not represent the superiority or inferiority of the embodiments.

[0048] In the above embodiments of the present invention, the descriptions of each embodiment have different focuses. For parts not described in detail in a certain embodiment, please refer to the relevant descriptions of other embodiments.

[0049] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A device for high-throughput, precise characterization of low-temperature thermoelectric properties in materials, characterized in that, include: Vacuum chamber, probe assembly, base temperature control module, temperature gradient generator, vacuum system, signal generation and acquisition module; among which: The vacuum chamber includes a sample compartment, a top cover, multiple bellows, and a vacuum-sealed end. The sidewall of the sample compartment has multiple openings and flange joints; the outer sides of the openings are connected to the bellows, and the flange joints are connected to the vacuum system. The top cover has an observation window in the center and multiple through holes along its edges. One end of the bellows is connected to the sample compartment, and the other end is connected to the vacuum-sealed end. The top cover and sample compartment, the sample compartment and bellows, and the bellows and vacuum-sealed end are connected by fastening screws and sealed with O-rings to form a sealed chamber. The upper end of the vacuum-sealed end has a single-core or double-core terminal for connecting to a signal generation and acquisition module. The probe assembly includes: multiple probe arms, multiple metal probes, multiple thermocouple probes, and multiple triaxial displacement stages; one end of each probe arm is detachably mounted on the vacuum-sealed end, and the other end is provided with a groove and a fastening screw for fixing the probe; the triaxial displacement stages are connected to the vacuum-sealed end and are used to drive the movement of the probe arms; the leads of the multiple metal probes are respectively connected to single-core terminals, and the leads of the multiple thermocouple probes are respectively connected to dual-core terminals; The base temperature control module includes: a liquid nitrogen conduction cooling stage, a metal base, a main heating rod, a first temperature probe, and a temperature controller; the liquid nitrogen conduction cooling stage is located at the bottom of the sample chamber, and the liquid nitrogen conduction cooling stage and the sample chamber are separated by multiple thermally insulating support columns; the metal base is located on the liquid nitrogen conduction cooling stage, and the main heating rod and the first temperature probe are embedded in the metal base, with leads connected to the temperature controller for controlling the base temperature of the sample to be tested; The temperature gradient generator includes: two thermally conductive insulating platforms, a gradient heating rod, and a voltage source; wherein, the first thermally conductive insulating platform is fixed to a metal base by fastening screws, the gradient heating rod is embedded in the first thermally conductive insulating platform, and the lead wire is connected to the positive and negative terminals of the voltage source; the second thermally conductive insulating platform is placed horizontally side by side with the first thermally conductive insulating platform, and two strip-shaped through holes are provided on both sides of the second thermally conductive insulating platform, which are connected to the metal base by fastening screws; The signal generation and acquisition module includes a constant current source, a digital multimeter with a multi-channel scanning card, and a channel switching switch; The triaxial displacement stage controls the movement of the metal probe and thermocouple probe to form a linear four-point probe arrangement or a van der Burg method probe arrangement.

2. The device for high-throughput and accurate characterization of low-temperature thermoelectric properties in materials according to claim 1, characterized in that, The base temperature control module controls the temperature of the sample to be tested within the range of 100-500 K by controlling the liquid nitrogen flow rate and the heating power of the main heating rod.

3. The device for high-throughput and accurate characterization of low-temperature thermoelectric properties in materials according to claim 1, characterized in that, The temperature gradient generator is equipped with two separate thermally conductive insulating platforms, one of which has a strip-shaped through hole; at the same time, multiple test samples can be placed side by side between the thermally conductive insulating platforms, and the thermoelectric properties of multiple test samples can be measured simultaneously during a single heating and cooling process.

4. The device for high-throughput and accurate characterization of low-temperature thermoelectric properties in materials according to claim 1, characterized in that, There is an adjustable gap between the second thermally conductive insulating platform and the first thermally conductive insulating platform.

5. The apparatus for high-throughput and precise characterization of low-temperature thermoelectric properties in materials according to claim 1, characterized in that, The sample to be tested is fixed on a thermally conductive insulating platform by adhesive bonding.

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