A quartz crucible

Abstract

The utility model discloses a quartz crucible. The quartz crucible comprises a quartz crucible body and a coating arranged on the outer wall of the quartz crucible body, and the coating is an aluminum hydroxide coating or a diatomic aluminum oxide coating. The utility model discloses can effectively promote the thickness of the reduction of crystallization layer, improves the high temperature mechanical strength of quartz crucible, and prolongs the service life of crucible through setting aluminum hydroxide coating or diatomic aluminum oxide coating on the outer wall of quartz crucible body.

Description

Technical Field

[0001] This utility model relates to the technical field of quartz crucibles for photovoltaic applications, and specifically to a quartz crucible. Background Technology

[0002] As a key auxiliary material for manufacturing solar-grade monocrystalline silicon, the performance optimization of quartz crucibles for photovoltaic applications has become one of the core issues for improving the cost-effectiveness of monocrystalline silicon pulling.

[0003] The preparation method of Czochralski-grown single-crystal silicon mainly involves heating and melting polycrystalline silicon material in a quartz crucible, introducing a seed crystal, and slowly pulling it to form a single-crystal silicon rod. During the high-temperature process, the thickness of the crystalline layer in the quartz crucible increases, which affects the stability of the crucible and the quality of the single-crystal silicon. To address this issue, a coating process is used to uniformly cover the surface of the quartz crucible. This process promotes the rapid growth of dense β-cristobalite on the crucible surface, thereby preventing the molten silicon from eroding the crucible body. Therefore, coating the surface of the quartz crucible is a particularly important step in the production process.

[0004] Traditionally, the alkaline earth metal barium (Ba) is commonly used as a coating material. In practice, after cleaning and drying the crucible, a barium hydroxide (Ba(OH)2) solution is applied. However, Ba(OH)2 readily reacts with carbon dioxide (CO2) in the air, rapidly forming barium carbonate (BaCO3). In the high-temperature environment of Czochralski single-crystal silicon, barium carbonate (BaCO3) further decomposes and reacts chemically with the silicon dioxide (SiO2) of the quartz crucible to form barium silicate (BaSiO3). Barium silicate exists in a white, dense, orthorhombic crystal form, effectively adhering to the outer wall of the crucible to form a protective layer. Although the barium (Ba) coating physically enhances the strength of the crucible, as an alkaline earth metal, barium (Ba) can displace Si atoms from the {SiO4} tetrahedrons, inducing the quartz crucible body to transform from an amorphous glassy state to β-cuboidal quartz. Practice has shown that barium coatings tend to form a thick crystallization layer during crystal pulling, leading to rapid consumption of the quartz crucible material and significantly shortening its effective working time at high temperatures. Furthermore, barium hydroxide is highly toxic and poses a serious threat to human health.

[0005] Therefore, developing a novel coating technology to enhance the high-temperature mechanical strength of quartz crucibles, extend their service life, and reduce their harm to the human body has become an urgent research need. Summary of the Invention

[0006] In view of the above-mentioned technical problems existing in the prior art, the purpose of this utility model is to provide a quartz crucible.

[0007] To achieve the above objectives, the present invention adopts the following technical solution:

[0008] This utility model provides a quartz crucible, which includes a quartz crucible body and a coating disposed on the outer wall of the quartz crucible body. The coating is an aluminum hydroxide coating or an aluminum oxide coating.

[0009] This invention effectively improves the high-temperature mechanical strength of the quartz crucible and extends its service life by applying an aluminum hydroxide coating or an aluminum oxide coating to the outer wall of the quartz crucible body.

[0010] Compared to barium hydroxide coatings, the coating of this invention has lower toxicity and poses less potential harm to the human body, thus enhancing the health and safety of operators during the production and use of quartz crucibles.

[0011] In one embodiment, the coating is an aluminum hydroxide coating. This coating has several beneficial effects: First, it effectively reduces the thickness of the crystallized layer during the crystal pulling process, thereby lowering the risk of structural damage to the crucible due to crystallization during use. Second, according to Doremus's research, the viscosity of silica is closely related to the mobility of oxygen vacancies. Aluminum interacts with oxygen to form complex aluminum-silicon-oxygen anion clusters, which reduces the mobility of oxygen vacancies, making the glass structure more compact. This significantly enhances the viscosity of the quartz crucible, improving its mechanical stability. Third, the OH groups in the quartz glass... - The stability is reduced, decreasing the content of hydroxyl groups that negatively affect the performance of the quartz crucible. Fourth,

[0012] Unlike barium hydroxide, aluminum hydroxide is relatively chemically stable at room temperature and does not react. However, at high temperatures (e.g., above 500°C), the crystal structure of aluminum hydroxide changes, water molecules gradually detach, and ultimately aluminum oxide (Al₂O₃) and water vapor (H₂O) are formed. This reaction is exothermic and therefore generates a large amount of heat. The specific chemical reaction equation is as follows:

[0013]

[0014] This reaction forms a dense α-Al₂O₃ crystalline layer on the outer surface of the quartz crucible. α-Al₂O₃ possesses strong thermodynamic stability, exhibiting good insulation, excellent chemical stability, and high hardness even at high temperatures, preventing crystallization, softening, deformation, and edge collapse of the crucible. Fifth, the coating of this invention has excellent corrosion resistance (e.g., resistance to weak acids, weak alkalis, strong acids, and strong alkalis). The combined effect of these factors significantly extends the service life of the crucible.

[0015] In another embodiment, the coating is an aluminum oxide coating. The aluminum oxide coating has good density, which ensures a tight bond between the coating and the surface of the quartz crucible, reducing crystallization. Furthermore, it remains stable at high temperatures, making it less prone to peeling or aging during prolonged high-temperature use, thus avoiding crystallization caused by coating problems.

[0016] The following are preferred technical solutions of this utility model, but are not intended to limit the technical solutions provided by this utility model. Through the following preferred technical solutions, the technical objectives and beneficial effects of this utility model can be better achieved and realized.

[0017] Preferably, the areal density of the coating is 0.5 g / cm³. 2 -2.5g / cm 2 For example, it could be 0.5g / cm³. 2 0.7g / cm 2 0.8g / cm 2 1g / cm 2 1.2g / cm 2 1.4g / cm 2 1.5g / cm 2 1.7g / cm 2 1.9g / cm 2 2g / cm 2 2.1g / cm 2 2.2g / cm 2 2.3g / cm 2 Or 2.5g / cm 2 The areal density of the coating is based on the quartz crucible body. If the areal density is too low, the coating will not completely cover the crucible body, resulting in the crucible body being exposed, which may lead to problems such as pinholes and cracks during use. If the areal density is too high, it will increase costs and reduce heat transfer efficiency, prolong melting time, and increase energy consumption.

[0018] In this invention, areal density refers to the mass of the coating attached to the covered area of ​​the crucible body.

[0019] Preferably, the coating thickness is 1μm-10μm, for example, it can be 1μm, 1.5μm, 2μm, 2.5μm, 3μm, 3.5μm, 4μm, 4.5μm, 5μm, 5.5μm, 6μm, 6.5μm, 7μm, 7.5μm, 8μm, 8.5μm, 9μm, 9.5μm, or 10μm. If the coating thickness is too small, the protective effect on the crucible body will decrease, and crystallization will easily occur; if the coating thickness is too large, it will increase costs, reduce heat transfer efficiency, prolong melting time, and increase energy consumption.

[0020] As a preferred embodiment of the quartz crucible of this invention, the coating comprises a bottom layer and a top layer sequentially disposed along a direction away from the crucible body. The areal density of the bottom layer relative to the crucible body is σ1, and the areal density of the top layer relative to the bottom layer is σ2, where σ2 > σ1. Using a smaller areal density in the bottom layer and a larger areal density in the top layer ensures good permeability of the bottom layer while providing effective protection through the top layer.

[0021] Preferably, σ² is 1.5 g / cm³. 2 -2.5g / cm 2 σ1 is 0.5 g / cm 2 -1.0g / cm 2 Within this range, the bottom and top layers can work together better, which is beneficial for protecting the crucible body.

[0022] Preferably, an intermediate layer is further provided between the bottom layer and the top layer, wherein the areal density of the intermediate layer relative to the bottom layer is σ3, and σ2>σ3>σ1. The intermediate layer serves as a transition layer, which can improve the bonding between the bottom layer and the top layer.

[0023] As a preferred embodiment of the quartz crucible of this invention, the coating comprises a bottom layer and a top layer sequentially disposed along a direction away from the crucible body. Both the bottom layer and the top layer are aluminum hydroxide coatings. The thickness of the bottom layer is h1, and the thickness of the top layer is h2, where h2 > h1. Using a smaller thickness for the bottom layer and a larger thickness for the top layer ensures good permeability of the bottom layer while providing effective protection through the top layer.

[0024] Preferably, h2 is 6μm to 10μm and h1 is 1μm to 3μm. Within this range, the bottom and top layers can better cooperate, which is beneficial to the protection of the crucible body.

[0025] Preferably, an intermediate layer is further provided between the bottom layer and the top layer, the thickness of the intermediate layer being h3, where h2>h3>h1. The intermediate layer serves as a transition layer, which can improve the bonding between the bottom layer and the top layer.

[0026] As a preferred embodiment of the quartz crucible of this invention, the coating is applied to a region extending from the opening to a distance of 15cm-25cm (e.g., 15cm, 16cm, 17cm, 18cm, 20cm, 22cm, 23cm, or 25cm). Since the quartz crucible is typically not filled completely during use (e.g., for the preparation of Czochralski single-crystal silicon), softening is more likely to occur near the opening. Therefore, it is preferable to apply the coating at the aforementioned location, which effectively ensures the stability and service life of the quartz crucible while reducing the cost of the coating.

[0027] The quartz crucible of this invention is prepared by the following method, which includes the following steps:

[0028] Provides the quartz crucible body;

[0029] Aluminum hydroxide and / or aluminum oxide are dispersed in water to obtain a suspension, and the suspension is coated on the surface of the outer wall of the quartz crucible body to obtain the quartz crucible.

[0030] Steps (1) and (2) are not in any particular order.

[0031] The above method effectively forms a coating on the surface of the quartz body using only solution coating and drying, effectively protecting the quartz crucible, improving its high-temperature mechanical strength, and extending its service life. This method is simple, easy to operate, low-cost, and highly efficient, making it suitable for large-scale production.

[0032] Preferably, the mass ratio of the aluminum hydroxide and / or aluminum oxide to the mass of the water is 1:(8-20), for example, it can be 1:8, 1:9, 1:10, 1:11, 1:12, 1:13, 1:14, 1:15, 1:16, 1:17, 1:18, 1:19 or 1:20, etc.

[0033] Preferably, the method for preparing the suspension includes: adding aluminum hydroxide and / or aluminum oxide to boiling water, and then stirring at 70℃-90℃ (e.g., 70℃, 75℃, 80℃, 85℃, or 90℃, etc.) until the suspension is uniform and free of sediment. Heating and stirring ensure a uniform suspension without sedimentation, thus improving the coating effect.

[0034] Preferably, during the coating process, the temperature of the quartz crucible is 80℃~100℃, for example, 80℃, 85℃, 90℃, 95℃, or 100℃. Coating the suspension under these conditions is beneficial for obtaining suitable coating adhesion strength.

[0035] In one embodiment, after the crucible body is molded, cleaned and baked, it has a certain temperature. At this time, the suspension is directly coated to ensure the bonding strength of the coating.

[0036] Preferably, the suspension includes an independent bottom suspension and a surface suspension. The concentration of the bottom suspension is a, and the concentration of the surface suspension is b, where a < b. The coating method is as follows: coat the bottom suspension on the outer wall surface of the quartz crucible body to form a bottom layer on the outer wall of the quartz crucible body; coat the surface suspension on the surface of the bottom layer to form a surface layer on the surface of the bottom layer.

[0037] Preferably, the suspension further includes an intermediate layer suspension independent of the bottom suspension and the surface suspension. The concentration of the intermediate layer suspension is c, where a < c < b. The coating method is as follows: coat the bottom suspension on the outer wall surface of the quartz crucible body to form a bottom layer on the outer wall of the quartz crucible body; coat the intermediate layer suspension on the surface of the bottom layer to form an intermediate layer on the surface of the bottom layer; coat the surface suspension on the surface of the intermediate layer to form a surface layer on the surface of the intermediate layer.

[0038] Preferably, a is 5% - 6.5%, for example, it can be 5%, 5.2%, 5.3%, 5.4%, 5.5%, 5.6%, 5.8%, 6%, 6.1%, 6.3% or 6.5%, etc.

[0039] Preferably, b is 8% - 9.5%, for example, it can be 8%, 8.2%, 8.4%, 8.6%, 8.8%, 9%, 9.1%, 9.3% or 9.5%, etc.

[0040] Preferably, c is 11% - 12.5%, for example, it can be 11%, 11.2%, 11.5%, 11.7%, 12%, 12.2%, 12.3% or 12.5%, etc.

[0041] When there is more than one type of suspension, after coating one solution and drying it, another solution can be coated; or after coating multiple solutions one by one, direct one-step drying can be carried out.

[0042] The above method does not specifically limit the coating method. For example, an automatic coater can be used for coating.

[0043] Compared with the prior art, the present utility model has the following beneficial effects:

[0044] By providing an aluminum hydroxide coating or an aluminum oxide coating on the outer wall of the quartz crucible body, the present utility model can effectively reduce the thickness of the devitrified layer, improve the high-temperature mechanical strength of the quartz crucible, and extend the service life of the crucible. Attached Figure Description

[0045] Figure 1 This is a schematic diagram of the structure of the quartz crucible of this utility model, wherein 1 is the crucible body and 2 is the coating.

[0046] Figure 2 This is a test diagram of the thickness of the crystallization layer in Example 1.

[0047] Figure 3 This is a test image of the thickness of the crystallization layer in Comparative Example 1. Detailed Implementation

[0048] The technical solution of this utility model will be further described below with reference to the accompanying drawings and specific embodiments.

[0049] The specific embodiments described herein are for illustrative purposes only and are not intended to limit the scope of the invention.

[0050] Example 1

[0051] This embodiment provides a quartz crucible, the structural schematic of which can be found in the figure below. Figure 1 The quartz crucible includes a quartz crucible body 1 and a coating 2 disposed on the outer wall of the quartz crucible body 1. The coating 2 is an aluminum hydroxide coating, and the areal density of the coating 2 is 0.5 g / cm³. 2 The thickness of the coating 2 is 1 μm.

[0052] This embodiment also provides a method for preparing the above-mentioned quartz crucible, including the following steps:

[0053] (1) Weigh 1g of aluminum hydroxide on an electronic scale, ensuring that the drug is kept dry or contaminated during the weighing process to ensure the accuracy and reliability of the experimental results.

[0054] (2) Weighing pure water: Weigh the corresponding mass of pure water on an electronic platform scale according to the mass ratio of aluminum hydroxide to pure water of 1:20.

[0055] (3) Heating pure water: Use a quartz electric kettle to heat the pure water to 100°C. Pay attention to safety during the heating process to avoid scalding and spillage, and ensure that the pure water is fully boiled.

[0056] (4) Prepare aluminum hydroxide suspension: Pour heated pure water into a 500mL beaker, stir with a glass rod, slowly add the weighed aluminum hydroxide reagent, and continue stirring until a uniform suspension is formed.

[0057] (5) Heating and stirring the aluminum hydroxide suspension: Place the prepared aluminum hydroxide suspension on a magnetic stirrer, set the heating temperature to 85°C, and stir continuously to ensure that the suspension is uniform and free of sediment, thereby improving the coating effect.

[0058] (6) Aluminum liquid coating: Take the quartz crucible body after it has been shaped, cleaned and baked to a certain temperature (100℃), and coat the surface of the outer wall of the quartz crucible body with a uniformly stirred aluminum hydroxide suspension. The coating position is from the top opening to the area 20cm away from the top opening, to ensure that the coating thickness is consistent.

[0059] Example 2

[0060] This embodiment provides a quartz crucible, which includes a quartz crucible body and a coating disposed on the outer wall of the quartz crucible body. The coating is an aluminum hydroxide coating with an areal density of 2.5 g / cm³. 2 The coating has a thickness of 10 μm.

[0061] This embodiment also provides a method for preparing the above-mentioned quartz crucible, including the following steps:

[0062] (1) Weigh 1g of aluminum hydroxide on an electronic scale, ensuring that the drug is kept dry or contaminated during the weighing process to ensure the accuracy and reliability of the experimental results.

[0063] (2) Weighing pure water: Weigh the corresponding mass of pure water on an electronic platform scale according to the mass ratio of aluminum hydroxide to pure water of 1:8.

[0064] (3) Heating pure water: Use a quartz electric kettle to heat the pure water to 100°C. Pay attention to safety during the heating process to avoid scalding and spillage, and ensure that the pure water is fully boiled.

[0065] (4) Prepare aluminum hydroxide suspension: Pour heated pure water into a 500mL beaker, stir with a glass rod, slowly add the weighed aluminum hydroxide reagent, and continue stirring until a uniform suspension is formed.

[0066] (5) Heating and stirring the aluminum hydroxide suspension: Place the prepared aluminum hydroxide suspension on a magnetic stirrer, set the heating temperature to 70°C, and stir continuously to ensure that the suspension is uniform and free of sediment, thereby improving the coating effect.

[0067] (6) Aluminum liquid coating: Take the quartz crucible body after it has been shaped, cleaned and baked to a certain temperature (80℃), and coat the uniformly stirred aluminum hydroxide suspension evenly on the surface of the outer wall of the quartz crucible body. The coating position is from the top opening to the area 15cm away from the top opening, to ensure that the coating thickness is consistent.

[0068] Example 3

[0069] This embodiment provides a quartz crucible, which includes a quartz crucible body and a coating disposed on the outer wall of the quartz crucible body. The coating is an aluminum hydroxide coating with an areal density of 1.5 g / cm³.2 The coating has a thickness of 6 μm.

[0070] This embodiment also provides a method for preparing the above-mentioned quartz crucible, including the following steps:

[0071] (1) Weigh 1g of aluminum hydroxide on an electronic scale, ensuring that the drug is kept dry or contaminated during the weighing process to ensure the accuracy and reliability of the experimental results.

[0072] (2) Weighing pure water: Weigh the corresponding mass of pure water on an electronic platform scale according to the mass ratio of aluminum hydroxide to pure water of 1:10.

[0073] (3) Heating pure water: Use a quartz electric kettle to heat the pure water to 100°C. Pay attention to safety during the heating process to avoid scalding and spillage, and ensure that the pure water is fully boiled.

[0074] (4) Prepare aluminum hydroxide suspension: Pour heated pure water into a 500mL beaker, stir with a glass rod, slowly add the weighed aluminum hydroxide reagent, and continue stirring until a uniform suspension is formed.

[0075] (5) Heating and stirring the aluminum hydroxide suspension: Place the prepared aluminum hydroxide suspension on a magnetic stirrer, set the heating temperature to 90°C, and stir continuously to ensure that the suspension is uniform and free of sediment, thereby improving the coating effect.

[0076] (6) Aluminum liquid coating: Take the quartz crucible body after it has been shaped, cleaned and baked to a certain temperature (85℃), and coat the uniformly stirred aluminum hydroxide suspension evenly on the surface of the outer wall of the quartz crucible body. The coating position is from the top opening to the area 20cm away from the top opening, to ensure that the coating thickness is consistent.

[0077] Example 4

[0078] A quartz crucible is provided, comprising a quartz crucible body and a coating disposed on the outer wall of the quartz crucible body. The coating is an aluminum hydroxide coating and has a multi-layer structure, comprising a bottom layer and a top layer sequentially disposed along a direction away from the crucible body. The areal density of the bottom layer is 0.6 g / cm³. 2 The thickness of the bottom layer is 2 μm; the areal density of the surface layer is 2.3 g / cm³. 2 The thickness of the surface layer is 8 μm.

[0079] This embodiment also provides a method for preparing the above-mentioned quartz crucible, including the following steps:

[0080] (a) Preparation of the bottom suspension:

[0081] (1) Weigh 1g of aluminum hydroxide on an electronic scale, ensuring that the drug is kept dry or contaminated during the weighing process to ensure the accuracy and reliability of the experimental results.

[0082] (2) Weighing pure water: Weigh the corresponding mass of pure water on an electronic platform scale according to the mass ratio of aluminum hydroxide to pure water of 1:18.

[0083] (3) Heating pure water: Use a quartz electric kettle to heat the pure water to 100°C. Pay attention to safety during the heating process to avoid scalding and spillage, and ensure that the pure water is fully boiled.

[0084] (4) Prepare aluminum hydroxide suspension: Pour heated pure water into a 500mL beaker, stir with a glass rod, slowly add the weighed aluminum hydroxide reagent, and continue stirring until a uniform suspension is formed.

[0085] (5) Heating and stirring the aluminum hydroxide suspension: Place the prepared aluminum hydroxide suspension on a magnetic stirrer, set the heating temperature to 85°C, and stir continuously to ensure that the suspension is uniform and free of sediment, thereby improving the coating effect.

[0086] (ii) Preparation of surface suspension:

[0087] Following the same method as steps (1)-(5), only adjust the mass ratio of aluminum hydroxide to pure water to 1:9.

[0088] (III) Coating with aluminum liquid: Take the quartz crucible body that has been shaped, cleaned and baked to a certain temperature (100℃), and evenly coat the well-stirred bottom suspension onto the outer wall surface of the quartz crucible body. The coating position is from the top opening to the area 20cm away from the top opening, ensuring that the coating thickness is consistent. After the bottom suspension dries to form the bottom layer, the same method is used to coat the surface of the bottom layer with the top suspension. After the surface suspension dries, the surface layer is obtained.

[0089] Example 5

[0090] A quartz crucible is provided, comprising a quartz crucible body and a coating disposed on the outer wall of the quartz crucible body. The coating is an aluminum hydroxide coating and has a multi-layer structure, comprising a bottom layer and a top layer sequentially disposed along a direction away from the crucible body. The areal density of the bottom layer is 0.6 g / cm³. 2 The thickness of the bottom layer is 2 μm; the areal density of the intermediate layer is 1.4 g / cm³. 2 The thickness of the bottom layer is 5 μm; the areal density of the surface layer is 2.3 g / cm³. 2 The thickness of the surface layer is 8 μm.

[0091] This embodiment also provides a method for preparing the above-mentioned quartz crucible, including the following steps:

[0092] (a) Preparation of the bottom suspension:

[0093] (1) Weigh 1g of aluminum hydroxide on an electronic scale, ensuring that the drug is kept dry or contaminated during the weighing process to ensure the accuracy and reliability of the experimental results.

[0094] (2) Weighing pure water: Weigh the corresponding mass of pure water on an electronic platform scale according to the mass ratio of aluminum hydroxide to pure water of 1:18.

[0095] (3) Heating pure water: Use a quartz electric kettle to heat the pure water to 100°C. Pay attention to safety during the heating process to avoid scalding and spillage, and ensure that the pure water is fully boiled.

[0096] (4) Prepare aluminum hydroxide suspension: Pour heated pure water into a 500mL beaker, stir with a glass rod, slowly add the weighed aluminum hydroxide reagent, and continue stirring until a uniform suspension is formed.

[0097] (5) Heating and stirring the aluminum hydroxide suspension: Place the prepared aluminum hydroxide suspension on a magnetic stirrer, set the heating temperature to 85°C, and stir continuously to ensure that the suspension is uniform and free of sediment, thereby improving the coating effect.

[0098] (ii) Preparation of intermediate layer suspension:

[0099] Following the same method as steps (1)-(5), only adjust the mass ratio of aluminum hydroxide to pure water to 1:13.

[0100] (III) Preparation of surface suspension:

[0101] Following the same method as steps (1)-(5), only adjust the mass ratio of aluminum hydroxide to pure water to 1:9.

[0102] (iv) Coating with aluminum liquid: Take the quartz crucible body that has been shaped, cleaned and baked to a certain temperature (100℃), and evenly coat the well-stirred bottom suspension onto the surface of the outer wall of the quartz crucible body. The coating position is from the top opening to the area 20cm away from the top opening, ensuring that the coating thickness is consistent. After the bottom suspension dries to form the bottom layer, the intermediate layer suspension is coated onto the surface of the bottom layer in the same way. After the intermediate layer suspension dries to form the intermediate layer, the surface layer suspension is coated onto the surface of the intermediate layer in the same way. After the surface suspension dries, the surface layer is obtained.

[0103] Example 6

[0104] A quartz crucible is provided, the quartz crucible comprising a quartz crucible body and a coating disposed on the outer wall of the quartz crucible body, the coating being an aluminum oxide layer.

[0105] The difference between its preparation method and that of Example 1 is that the aluminum hydroxide in step (1) is replaced with aluminum oxide.

[0106] Comparative Example 1

[0107] A quartz crucible is provided, which differs from Embodiment 1 in that no coating is provided on the outer wall of the quartz crucible body.

[0108] Application examples

[0109] Czochralski single-crystal silicon was prepared using the quartz crucibles used in Examples 1-6 and Comparative Example 1, respectively. The specific methods are as follows:

[0110] (1) Place the silicon raw material in a quartz crucible and heat it to melt it to obtain molten silicon liquid; the silicon raw material includes Ba powder;

[0111] (2) Using a high-purity single-crystal silicon seed crystal as the starting point, the molten silicon liquid is crystallized and grown on the surface of the seed crystal by rotating and pulling to obtain single-crystal silicon.

[0112] The thickness of the crystallized layer after use of the quartz crucible was measured. The results are shown in Table 1. Figure 2 and Figure 3 .in, Figure 2 The thickness test of the crystallization layer corresponding to Example 1, Figure 3 Thickness test of the crystallization layer in response ratio 1.

[0113]

[0114] In summary, by applying an aluminum hydroxide coating or an aluminum oxide coating to the outer wall of the quartz crucible body, this invention can effectively reduce the thickness of the crystallization layer, improve the high-temperature mechanical strength of the quartz crucible, and extend the service life of the crucible.

[0115] Meanwhile, a comparison between Example 1 and Examples 4-5 shows that the multilayer coating can better reduce the thickness of the crystallization layer and achieve a better protective effect.

[0116] The applicant declares that this utility model is illustrated through the above embodiments, but it is not limited to the above detailed methods, meaning that this utility model cannot be implemented without relying on the above detailed methods. Those skilled in the art should understand that any improvements to this utility model, equivalent substitutions of raw materials, additions of auxiliary components, and selection of specific methods, etc., all fall within the protection and disclosure scope of this utility model.

Claims

1. A quartz crucible, characterized in that, The quartz crucible includes a quartz crucible body and a coating disposed on the outer wall of the quartz crucible body, wherein the coating is an aluminum hydroxide coating or an aluminum oxide coating.

2. The quartz crucible according to claim 1, characterized in that, The areal density of the coating is 0.5 g / cm³. 2 -2.5g / cm 2 .

3. The quartz crucible according to claim 1, characterized in that, The thickness of the coating is 1μm-10μm.

4. The quartz crucible according to claim 1, characterized in that, The coating comprises a bottom layer and a top layer disposed sequentially along the direction away from the crucible body. The areal density of the bottom layer relative to the crucible body is σ1, and the areal density of the top layer relative to the bottom layer is σ2, where σ2 > σ1.

5. The quartz crucible according to claim 4, characterized in that, σ² is 1.5 g / cm³ 2 -2.5g / cm 2 σ1 is 0.5 g / cm 2 -1.0g / cm 2 .

6. The quartz crucible according to claim 4, characterized in that, An intermediate layer is provided between the bottom layer and the top layer, and the areal density of the intermediate layer relative to the bottom layer is σ3, where σ2>σ3>σ1.

7. The quartz crucible according to claim 1, characterized in that, The coating comprises a bottom layer and a top layer arranged sequentially along the direction away from the crucible body. Both the bottom layer and the top layer are aluminum hydroxide coatings. The thickness of the bottom layer is h1, and the thickness of the top layer is h2, where h2 > h1.

8. The quartz crucible according to claim 7, characterized in that, h2 is 6μm~10μm, and h1 is 1μm~3μm.

9. The quartz crucible according to claim 7, characterized in that, An intermediate layer is provided between the bottom layer and the top layer, and the thickness of the intermediate layer is h3, where h2>h3>h1.

10. The quartz crucible according to claim 1, characterized in that, The coating is applied to the area from the opening of the quartz crucible to a distance of 15cm-25cm from the opening.

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