A method for mass production of bulk semiconductor materials using natural minerals

Abstract

This invention discloses a method for large-scale batch preparation of bulk semiconductor materials using natural ores. The method uses natural ores such as galena as raw materials. After weighing and vacuum sealing in an inert gas environment, the materials are placed in a tube furnace with at least two temperature zones. By controlling the heating rate, temperature difference between the zones, and holding time, the ores undergo a reaction and deposition process at high temperatures to obtain dense bulk semiconductor materials. By introducing halide or sulfide dopants and adjusting the doping ratio, carrier concentration and mobility can be effectively improved. The resulting material achieves a power factor of 1.5–2.0 mW·m⁻¹·K⁻² at room temperature and a thermoelectric figure of merit (zT) of over 0.4 in the high-temperature zone. Compared with existing synthesis methods that rely on high-purity raw materials, this invention has a simple process flow, low cost, and high efficiency, avoiding the risk of tube explosion caused by sulfur vapor. It is suitable for large-scale application in the fabrication of thermoelectric power generation devices, refrigeration devices, and infrared detection devices.

Description

Technical Field

[0001] This invention relates to the field of semiconductor material preparation technology, and more specifically, to a method for large-scale batch preparation of bulk semiconductor materials using natural minerals. Background Technology

[0002] Thermoelectric materials, based on the Seebeck and Peltier effects, enable the interconversion of electrical and thermal energy, representing an important direction in new energy materials research. Thermoelectric generators made from these materials require no mechanical transmission components during operation, thus offering advantages such as low noise, zero emissions, small size, and high reliability. They show broad application prospects in fields such as industrial waste heat recovery, agricultural thermoelectric utilization, spacecraft power supplies, and wearable energy devices. The overall performance of thermoelectric devices is typically characterized by the thermoelectric figure of merit zT, defined as: zT = S 2 ²σT / κ, where S is the Seebeck coefficient, σ is the electrical conductivity, κ is the thermal conductivity, and T is the absolute temperature. A higher zT value implies better energy conversion efficiency.

[0003] Among numerous candidate materials, lead sulfide (PbS) is considered a promising thermoelectric material for the medium-to-high temperature range due to its abundant reserves in the Earth's crust and its low price. PbS generally exhibits a cubic crystal structure with a space group of Fm3m. However, PbS has a high intrinsic thermal conductivity, which limits its development prospects as a high-performance thermoelectric material. Meanwhile, another major obstacle to the widespread application of thermoelectric materials is the high cost of preparation: currently used synthesis methods rely on high-purity analytical-grade raw materials and special pressure-resistant quartz tubes. In actual production, the material cost often far exceeds the value of the device, making large-scale application difficult.

[0004] To reduce costs and broaden applications, researchers have proposed using natural ores to directly replace high-purity raw materials. Galena, as the naturally occurring form of PbS, is abundant, inexpensive, and readily available in nature. Therefore, using galena to directly prepare bulk semiconductor materials is expected to significantly reduce raw material costs and promote the large-scale production of PbS thermoelectric materials. However, this approach still faces several challenges in practical applications:

[0005] (1) Natural galena has a high impurity content, which may affect the crystal structure and electrical properties of the final material;

[0006] (2) When PbS is grown by the conventional Bridgman process, sulfur is prone to forming a large amount of vapor at high temperature, which can cause the quartz tube to crack, increasing the preparation risk and equipment requirements.

[0007] (3) Existing processes are mostly based on melt solidification, resulting in long sample growth cycles and low efficiency.

[0008] Therefore, there is an urgent need to design a method for the large-scale batch preparation of bulk semiconductor materials using natural minerals to solve the above problems. Summary of the Invention

[0009] The purpose of this invention is to provide a method for large-scale batch preparation of bulk semiconductor materials using natural minerals, so as to solve the problems mentioned in the background art.

[0010] To achieve the above objectives, the present invention provides the following technical solution:

[0011] A method for large-scale batch preparation of bulk semiconductor materials using natural minerals includes the following steps:

[0012] (1) Weigh natural galena or a mixture of it and dopant in a glove box under an inert gas protective environment;

[0013] (2) Place the weighed raw material in a quartz tube and evacuate it to 10⁻ 5 Pa~10⁻³ Pa, and flame sealing is performed;

[0014] (3) The quartz tube is placed in a tube furnace with at least two temperature zones and heated to 800-1200 ℃ at a rate of 1-10 ℃ / min. The temperature is maintained at the high temperature for 48-120 hours to allow the raw materials to react and deposit.

[0015] (4) A dense bulk semiconductor material is obtained under the temperature difference between the vaporization zone and the deposition zone, and then heating is stopped and the material is naturally cooled to room temperature.

[0016] As a preferred technical solution of the present invention, the raw material is galena, and a dopant may be further added. The dopant is one or more of PbCl2, PbBr2, PbI2, Cu2S, Li2S, Na2S or K2S, and the amount added is 0.1 to 5 wt%.

[0017] As a preferred technical solution of the present invention, the temperature difference between the vaporization zone and the deposition zone is 10 to 150 ℃, thereby forming a driving force for gas phase migration, which causes ore vapor to be directionally deposited in the upper region and obtain a dense sample.

[0018] As a preferred technical solution of the present invention, the tubular furnace is a dual-temperature zone Bridgman furnace, with the upper zone used for ore vaporization and the lower zone used for condensation and deposition.

[0019] As a preferred embodiment of the present invention, the heating rate is 3-7 °C / min and the holding time is 72-120 hours.

[0020] As a preferred technical solution of the present invention, the tubular furnace is a three-temperature zone tubular furnace, which forms a stepped temperature difference between the vaporization zone, the migration zone and the deposition zone, thereby realizing the step-by-step removal of impurities in the ore and the directional deposition of target compounds.

[0021] As a preferred technical solution of the present invention, the inner diameter of the quartz tube is 0.8-2 cm and the length is 10-30 cm. Before sealing the tube, an inert gas of 0.01-0.05 atm is introduced to reduce the impact of sulfur vapor on the quartz tube at high temperature.

[0022] As a preferred embodiment of the present invention, the carrier concentration of the bulk semiconductor material obtained by deposition can be adjusted to 1×10¹ at room temperature. 8 ~1×10²21 0 cm⁻³, with a mobility of 150–600 cm²·V⁻¹·s⁻¹.

[0023] As a preferred embodiment of the present invention, the bulk semiconductor material has a power factor of 1.5 to 2.0 mW·m⁻¹·K⁻² at room temperature and a thermoelectric figure of merit of not less than 0.4 at 800 K.

[0024] As a preferred technical solution of the present invention, the bulk semiconductor material is used to prepare thermoelectric power generation devices, thermoelectric cooling devices or infrared detection devices.

[0025] Compared with existing technologies, this invention has the following advantages: First, this invention directly uses natural ores such as galena as raw materials, avoiding dependence on high-purity analytical-grade reagents and significantly reducing raw material costs. Simultaneously, the use of vacuum sealing and inert gas protection effectively suppresses the problem of tube bursting caused by the instantaneous release of sulfur vapor, making the preparation process safer and more controllable, suitable for large-scale production.

[0026] Secondly, this invention employs a tube furnace with at least two temperature zones. By rationally designing the temperature difference between the vaporization zone and the deposition zone, it promotes gas-phase migration and directional deposition of the ore in the upper region, thereby shortening the formation cycle of bulk materials and improving the density and uniformity of the samples. Furthermore, by introducing three-zone temperature control, impurities can be removed stepwise, resulting in higher purity and lower crystal defect density in the final semiconductor material.

[0027] Furthermore, this invention significantly modulates the carrier concentration and mobility of PbS by doping with halide or sulfide salts, thereby improving its thermoelectric performance. Tests show that the prepared bulk semiconductor achieves a power factor of 1.5–2.0 mW·m⁻¹·K⁻² at room temperature and a thermoelectric figure of merit (zT) of over 0.4 at 823 K, superior to the performance level of directly using natural galena. This demonstrates that this process not only offers low cost and high efficiency but also enables the preparation of high-performance functional materials.

[0028] Finally, the process of this invention is simple and requires little equipment. The resulting materials can be widely used in thermoelectric power generation devices, thermoelectric cooling devices and infrared detection devices, providing an economical and efficient technical path for the utilization of new energy and infrared sensing. Attached Figure Description

[0029] To more clearly illustrate the technical solution of the present invention, the accompanying drawings required for the example description are briefly introduced below.

[0030] Figure 1 This is a diagram showing the growth state of the sample after melting and impurity removal.

[0031] Figure 2 This is a photograph of the crystals of the sample after melting and impurity removal.

[0032] Figure 3 The graph shows the relationship between the electrical conductivity of galena raw material and the sample after melting and impurity removal as a function of temperature.

[0033] Figure 4 The graph shows the Seebeck coefficient of galena raw material and the sample after melting and impurity removal as a function of temperature.

[0034] Figure 5 The graph shows the relationship between the power factor of galena raw material and the sample after melting and impurity removal as a function of temperature.

[0035] Figure 6 The graph shows the relationship between the thermal conductivity of galena raw material and the sample after melting and impurity removal as a function of temperature.

[0036] Figure 7 The graph shows the relationship between the thermoelectric figure of merit of galena raw material and the sample after melting and impurity removal as a function of temperature. Detailed Implementation

[0037] The following will refer to the appendices in the embodiments of the present invention. Figure 1The technical solutions in the embodiments of the present invention will be clearly and completely described below. Obviously, the embodiments described below 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 of ordinary skill in the art without creative effort are within the scope of protection of the present invention. In order to provide a clearer explanation and description of the technical solutions and implementation methods of the present invention, specific examples of preferred implementations of the technical solutions of the present invention are introduced below.

[0038] Example 1: A method for large-scale batch preparation of bulk materials using natural ore, comprising the following steps: The raw materials are accurately weighed in a glove box with an argon-protected environment according to the stoichiometric ratio PbS - x PbCl2 (x = 0.25 wt%), and then placed in a quartz tube and vacuum-sealed. The quartz tube containing the raw materials is placed in a dual-temperature zone Bridgman tube furnace, and the furnace is heated to 5°C / min. -1 The temperature is slowly increased to 1100℃ and held for 96 hours to allow the raw materials to react fully and for sufficient time to deposit. After that, heating is stopped to obtain a bulk material with good density.

[0039] Example 2: A method for large-scale batch preparation of bulk materials using natural ore, the preparation steps are as follows: The raw materials are accurately weighed in a glove box with an argon-protected environment according to the stoichiometric ratio PbS - x PbCl2 (x = 0.5 wt%), and then placed in a quartz tube and vacuum-sealed; the quartz tube containing the raw materials is placed in a dual-temperature zone Bridgman tube furnace, and the furnace is heated to 5°C / min. -1 The temperature is slowly increased to 1100℃ and held for 96 hours to allow the raw materials to react fully and for sufficient time to deposit. After that, heating is stopped to obtain a bulk material with good density.

[0040] Example 3: A method for large-scale batch preparation of bulk materials using natural ore, the preparation steps are as follows: The raw materials are accurately weighed in a glove box with an argon-protected environment according to the stoichiometric ratio PbS - x PbCl2 (x = 0.75 wt%), and then placed in a quartz tube and vacuum sealed; the quartz tube containing the raw materials is placed in a dual-temperature zone Bridgman tube furnace, and the furnace is heated to 5°C / min. -1 The temperature is slowly increased to 1100℃ and held for 96 hours to allow the raw materials to react fully and for sufficient time to deposit. After that, heating is stopped to obtain a bulk material with good density.

[0041] Example 4: A method for large-scale batch preparation of bulk materials using natural ore, the preparation steps are as follows: The raw materials are accurately weighed in a glove box with an argon-protected environment according to the stoichiometric ratio PbS - x PbCl2 (x = 1 wt%), and then placed in a quartz tube and vacuum-sealed; the quartz tube containing the raw materials is placed in a dual-temperature zone Bridgman tube furnace, and the furnace is heated to 5°C / min. -1 The temperature is slowly increased to 1100℃ and held for 96 hours to allow the raw materials to react fully and for sufficient time to deposit. After that, heating is stopped to obtain a bulk material with good density.

[0042] Example 5: A method for large-scale batch preparation of bulk materials using natural ore, comprising the following steps: The raw materials are accurately weighed in a glove box with an argon-protected environment according to the stoichiometric ratio PbS - x PbCl2 (x = 2 wt%), and then placed in a quartz tube and vacuum-sealed. The quartz tube containing the raw materials is placed in a dual-temperature zone Bridgman tube furnace, and the furnace is heated to 5°C / min. -1 The temperature is slowly increased to 1100℃ and held for 96 hours to allow the raw materials to react fully and for sufficient time to deposit. After that, heating is stopped to obtain a bulk material with good density.

[0043] Example 6: A method for large-scale batch preparation of bulk materials using natural ore, comprising the following steps: The raw materials are accurately weighed in a glove box with an argon-protected environment according to the stoichiometric ratio PbS - x PbCl2 (x = 3 wt%), and then placed in a quartz tube and vacuum-sealed. The quartz tube containing the raw materials is placed in a dual-temperature zone Bridgman tube furnace, and the furnace is heated to 5°C / min. -1 The temperature is slowly increased to 1100℃ and held for 96 hours to allow the raw materials to react fully and for sufficient time to deposit. After that, heating is stopped to obtain a bulk material with good density.

[0044] Example 7: A method for large-scale batch preparation of bulk materials using natural ore, comprising the following steps: The raw materials are accurately weighed in a glove box with an argon-protected environment according to the stoichiometric ratio of PbS - yCu2S (x = 0.25 wt%), and then placed in a quartz tube and vacuum-sealed. The quartz tube containing the raw materials is placed in a dual-temperature zone Bridgman tube furnace, and the furnace is heated to 5°C / min. -1 The temperature is slowly increased to 1100℃ and held for 96 hours to allow the raw materials to react fully and for sufficient time to deposit. After that, heating is stopped to obtain a bulk material with good density.

[0045] Example 8: A method for large-scale batch preparation of bulk materials using natural ore, comprising the following steps: The raw materials are accurately weighed in a glove box with an argon-protected environment according to the stoichiometric ratio of PbS - yCu2S (x = 0.5 wt%), and then placed in a quartz tube and vacuum-sealed. The quartz tube containing the raw materials is placed in a dual-temperature zone Bridgman tube furnace, and the furnace is heated to 5°C / min. -1 The temperature is slowly increased to 1100℃ and held for 96 hours to allow the raw materials to react fully and for sufficient time to deposit. After that, heating is stopped to obtain a bulk material with good density.

[0046] Example 9: A method for large-scale batch preparation of bulk materials using natural ore, comprising the following steps: The raw materials are accurately weighed in a glove box with an argon-protected environment according to the stoichiometric ratio of PbS - yCu2S (x = 0.75 wt%), and then placed in a quartz tube and vacuum-sealed. The quartz tube containing the raw materials is placed in a dual-temperature zone Bridgman tube furnace, and the furnace is heated to 5°C / min. -1 The temperature is slowly increased to 1100℃ and held for 96 hours to allow the raw materials to react fully and for sufficient time to deposit. After that, heating is stopped to obtain a bulk material with good density.

[0047] Example 10: A method for large-scale batch preparation of bulk materials using natural ore, comprising the following steps: The raw materials are accurately weighed in a glove box with an argon-protected environment according to the stoichiometric ratio of PbS - yCu2S (x = 1 wt%), and then placed in a quartz tube and vacuum-sealed. The quartz tube containing the raw materials is placed in a dual-temperature zone Bridgman tube furnace, and the furnace is heated to 5°C / min. -1 The temperature is slowly increased to 1100℃ and held for 96 hours to allow the raw materials to react fully and for sufficient time to deposit. After that, heating is stopped to obtain a bulk material with good density.

[0048] Example 11: A method for large-scale batch preparation of bulk materials using natural ore, comprising the following steps: The raw materials are accurately weighed in a glove box with an argon-protected environment according to the stoichiometric ratio of PbS - yCu2S (x = 2 wt%), and then placed in a quartz tube and vacuum-sealed. The quartz tube containing the raw materials is placed in a dual-temperature zone Bridgman tube furnace, and the furnace is heated to 5°C / min. -1 The temperature is slowly increased to 1100℃ and held for 96 hours to allow the raw materials to react fully and for sufficient time to deposit. After that, heating is stopped to obtain a bulk material with good density.

[0049] Example 12: A method for large-scale batch preparation of bulk materials using natural ore, comprising the following steps: The raw materials are accurately weighed in a glove box with an argon-protected environment according to the stoichiometric ratio of PbS - yCu2S (x = 3 wt%), and then placed in a quartz tube and vacuum-sealed. The quartz tube containing the raw materials is placed in a dual-temperature zone Bridgman tube furnace, and the furnace is heated to 5°C / min. -1 The temperature is slowly increased to 1100℃ and held for 96 hours to allow the raw materials to react fully and for sufficient time to deposit. After that, heating is stopped to obtain a bulk material with good density.

[0050] PbS prepared by the method of the present invention

[0051] like Figure 1 As shown in the figure, this figure illustrates the bulk sample deposited using the dual-temperature Bridgman tube furnace of the present invention. Unlike samples grown by the general Bridgman crystal growth method, the sample is deposited at the upper end of the quartz tube instead of at the lower tip. Figure 2 The image shows the grown block sample, which has a smooth surface and a metallic luster.

[0052] like Figure 3 and Figure 4 As shown, PbS grown using a tube furnace exhibits good electrical properties, with its conductivity σ decreasing with increasing temperature and its Seebeck coefficient S increasing with increasing temperature. Ultimately, the power factor PF at room temperature is related to the thermoelectric cooling parameter. Figure 5 The value of ) is extremely high, which is beneficial for thermoelectric refrigeration.

[0053] Figure 6 The graph shows the change in thermal conductivity of grown PbS with temperature. Due to the relatively low thermal conductivity at 823 K, the thermoelectric figure of merit of the PbS crystal grown using a tube furnace can ultimately reach 0.4. Figure 7 It has the potential to achieve high-output, extremely low-cost thermoelectric devices through further performance optimization.

[0054] Figure 2 As shown, a PbS semiconductor with a high thermoelectric figure of merit is finally obtained.

[0055] The above descriptions are merely embodiments of the present invention, and common knowledge regarding specific structures and characteristics in the solutions is not described in detail here. It should be noted that those skilled in the art can make various modifications and improvements without departing from the structure of the present invention, including but not limited to changes in dopants, such as replacing PbCl2 with PbI2, PbBr2, etc., and replacing Cu2S with Li2S, Na2S, K2S, etc. These should also be considered within the scope of protection of the present invention, and will not affect the effectiveness of the implementation of the present invention or the practicality of the patent. The scope of protection claimed in this application should be determined by the content of its claims, and the specific embodiments described in the specification can be used to interpret the content of the claims.

[0056] Example 13: Natural galena was used as raw material and mixed according to the stoichiometric ratio PbS-xPbI2 (x=1wt%). After accurately weighing the raw material in an argon-protected glove box, it was placed in a quartz tube and evacuated to 10⁻⁻⁶. 5 The atmosphere was prepared by introducing 0.02 atm of argon gas as a buffer, followed by flame sealing. The quartz tube was placed in a dual-temperature zone Bridgman furnace and heated to 1050 °C at a rate of 5 °C / min, then held for 72 hours. Because the deposition zone was 50 °C lower than the vaporization zone, ore vapor gradually migrated and deposited in the deposition zone, resulting in a PbS-based bulk material with a smooth surface and a distinct metallic luster. Test results showed that its room temperature power factor reached 1.8 mW·m⁻¹·K⁻², which was superior to the undoped sample.

[0057] Example 14: A three-zone tube furnace was used with the following temperature settings: vaporization zone 1100℃, migration zone 1040℃, and deposition zone 980℃. A raw material of PbS-0.5wt%PbCl2 was placed in a quartz tube, evacuated, and flame-sealed. The heating rate was 3℃ / min, maintained for 96 hours. Due to the 60℃ temperature difference between the three zones, impurities in the sulfur vapor were deposited stepwise in the migration zone, resulting in PbS bulk material with significantly reduced impurity content in the deposition zone. Energy dispersive spectroscopy (EDS) analysis showed that the impurity content was reduced by approximately 30% compared to the conventional two-zone process.

[0058] Example 15: To verify the buffering effect of inert gas, argon gas was introduced into quartz tubes at 0 atm and 0.03 atm, respectively. The results showed that under empty tube conditions, two quartz tubes burst during heating, while under the buffered atmosphere conditions, all quartz tubes safely completed the heating process. The resulting samples exhibited high density and a significant reduction in cracks.

[0059] Example 16: Using PbS-yNa2S (y=2wt%) as raw material, weighing was performed in a nitrogen-protected glove box with a quartz tube vacuum of 10⁻. 4 Pa. The Bridgeman furnace was heated at a rate of 7 °C / min to 1000 °C and held for 48 h. The resulting sample carrier concentration decreased from 6 × 10¹ 8cm⁻³ increased to 2×10¹ 9 The mobility remains at 250 cm²·V⁻¹·s⁻¹, and the overall thermoelectric figure of merit zT reaches 0.42 at 823 K.

[0060] Example 17: The prepared PbS-Cu2S (1wt%) sample was processed into an infrared detector wafer. Its photoelectric responsivity was tested at 300K, and the results showed that the responsivity at the 2.5μm wavelength was approximately 35% higher than that of the pure PbS sample. This indicates that this process is applicable not only to thermoelectric devices but also to optoelectronic devices.

[0061] The contents not described in detail in this description are existing technologies known to those skilled in the art. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions described in the foregoing embodiments or make equivalent substitutions for some of the technical features. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A method for large-scale batch preparation of bulk semiconductor materials using natural minerals, characterized in that, Includes the following steps: (1) Weigh natural galena or a mixture of it and dopant in a glove box under an inert gas protective environment; (2) Place the weighed raw material in a quartz tube and evacuate it to 10⁻ 5 Pa~10⁻³ Pa, and flame sealing is performed; (3) The quartz tube is placed in a tube furnace with at least two temperature zones and heated to 800-1200 ℃ at a rate of 1-10 ℃ / min. The temperature is maintained at the high temperature for 48-120 hours to allow the raw materials to react and deposit. (4) A dense bulk semiconductor material is obtained under the temperature difference between the vaporization zone and the deposition zone, and then heating is stopped and the material is naturally cooled to room temperature.

2. The method for large-scale batch preparation of bulk semiconductor materials using natural ore according to claim 1, characterized in that, The raw material is galena, and a dopant may be further added. The dopant is one or more of PbCl2, PbBr2, PbI2, Cu2S, Li2S, Na2S or K2S, and the amount added is 0.1 to 5 wt%.

3. The method for large-scale batch preparation of bulk semiconductor materials using natural ore according to claim 1, characterized in that, The temperature difference between the vaporization zone and the deposition zone is 10–150 °C, thereby creating a driving force for gas phase migration, which causes ore vapor to be deposited directionally in the upper region and obtain a dense sample.

4. The method for large-scale batch preparation of bulk semiconductor materials using natural ore according to claim 1, characterized in that, The tubular furnace is a dual-temperature zone Bridgeman furnace, with the upper zone used for ore vaporization and the lower zone used for condensation and deposition.

5. A method for large-scale batch preparation of bulk semiconductor materials using natural ore according to claim 4, characterized in that, The heating rate is 3–7 °C / min, and the holding time is 72–120 hours.

6. The method for large-scale batch preparation of bulk semiconductor materials using natural ore according to claim 1, characterized in that, The tubular furnace is a three-temperature zone tubular furnace, which forms a stepped temperature difference between the vaporization zone, migration zone and deposition zone, thereby realizing the step-by-step removal of impurities in the ore and the directional deposition of target compounds.

7. A method for large-scale batch preparation of bulk semiconductor materials using natural ore according to claim 1, characterized in that, The quartz tube has an inner diameter of 0.8–2 cm and a length of 10–30 cm. Before sealing, it is filled with 0.01–0.05 atm of inert gas to reduce the impact of sulfur vapor on the quartz tube at high temperatures.

8. A method for large-scale batch preparation of bulk semiconductor materials using natural ore according to claim 1, characterized in that, The carrier concentration of the deposited bulk semiconductor material can be adjusted to 1×10¹ at room temperature. 8 ~1×10²21 0 cm⁻³, with a mobility of 150–600 cm²·V⁻¹·s⁻¹.

9. A method for large-scale batch preparation of bulk semiconductor materials using natural ore according to claim 8, characterized in that, The bulk semiconductor material has a power factor of 1.5 to 2.0 mW·m⁻¹·K⁻² at room temperature and a thermoelectric figure of merit of not less than 0.4 at 800 K.

10. A method for large-scale batch preparation of bulk semiconductor materials using natural ore according to claim 1, characterized in that, The bulk semiconductor material is used to prepare thermoelectric power generation devices, thermoelectric cooling devices, or infrared detection devices.

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