Cadmium telluride coating device and short circuit prevention method

Abstract

The invention relates to a cadmium telluride film coating device and a short circuit prevention method, belongs to the technical field of cadmium telluride film coating, and solves the technical problem of conduction between an electrode and a crucible wall due to cadmium telluride deposition during current cadmium telluride film coating. The cadmium telluride coating device comprises a vacuum container, a heating container, a cover plate and an insulating part, the heating container is installed in the vacuum container, and an opening is formed in the top of the heating container; the cover plate is mounted above the heating container; the top surface of the heating container is a mounting surface, the insulating part is mounted on the mounting surface and located between the cover plate and the heating container, the inner wall of the heating container protrudes out of the inner wall of the insulating part, so that a step part is formed between the inner wall of the insulating part and the inner wall of the heating container, and the electrode is located above the insulating part. According to the cadmium telluride coating device, cadmium telluride deposited on the step part is reduced, the insulating property of the insulating part is improved, and conduction between the heating container and the electrode is reduced.

Description

Technical Field

[0001] This invention belongs to the field of cadmium telluride coating technology, and specifically relates to a cadmium telluride coating device and a short-circuit prevention method. Background Technology

[0002] Cadmium telluride thin-film solar cells are currently the second most popular thin-film photovoltaic technology on the market. Their core advantages lie in low manufacturing costs, good low-light power generation performance, and short energy payback period. The most mainstream mass production technologies are closed-space sublimation and vapor transport deposition.

[0003] In both processes, high-purity cadmium telluride raw materials are placed in a high-temperature resistant crucible. The crucible is heated to over 600°C, causing the cadmium telluride to sublimate and generate gaseous molecules. These molecules deposit and crystallize on an adjacent, cooler glass substrate, forming a light-absorbing layer. After each process cycle, some residual cadmium telluride condenses on the upper edge of the relatively cooler crucible sidewall and in areas near the electrode connections. These deposits form a continuous, physically uncontrolled thin film on the crucible wall. When this film connects different parts of the crucible with potential differences, it creates an unintended conductive path, leading to substandard crucible insulation resistance, performance degradation, or even tripping and shutdown. Summary of the Invention

[0004] This invention provides a cadmium telluride coating apparatus and a short-circuit prevention method to solve the technical problem of cadmium telluride deposition causing conductivity between the electrode and the crucible wall during current cadmium telluride coating processes.

[0005] This invention is achieved through the following technical solution: A cadmium telluride coating device includes a vacuum container, a heating container, a cover plate, and an insulating component. The heating container is installed inside the vacuum container and has an opening at its top. The cover plate is installed above the heating container. The top surface of the heating container is a mounting surface. The insulating component is installed on the mounting surface and located between the cover plate and the heating container. The inner wall of the heating container protrudes beyond the inner wall of the insulating component, forming a step between the inner wall of the insulating component and the inner wall of the heating container. The electrode is located above the insulating component.

[0006] Optionally, the insulating member includes a body portion and a protrusion portion, wherein the body portion is mounted on the mounting surface, the body portion is annular, and a stepped portion is formed between the inner wall of the body portion and the inner wall of the heating container; the protrusion portion is mounted on the inner wall of the body portion and extends toward the centerline of the heating container.

[0007] Optionally, the distance between the protrusion near the heating container and the mounting surface gradually increases from the side of the protrusion near the body portion toward the side away from the insulator.

[0008] Optionally, the distance between the side of the protrusion away from the heating container and the mounting surface gradually increases from the side of the protrusion closer to the body portion towards the side away from the insulator.

[0009] Optionally, a plurality of protrusions are provided, and the plurality of protrusions are arranged in a direction parallel to the axis of the heating container.

[0010] Optionally, in any two adjacent insulating members, the distance between the protrusion closer to the heating container and the center line of the heating container is greater than the distance between the protrusion closer to the cover plate and the center line of the heating container.

[0011] Optionally, the distance between the end of the protrusion away from the body portion and the body portion is greater than 10 mm.

[0012] Optionally, the vacuum container has an exhaust pipe for discharging air and cadmium telluride.

[0013] A method for preventing short circuits in a cadmium telluride coating apparatus includes placing the heating container, the insulating component, and the insulating cover plate inside a vacuum container, so that the pressure inside the vacuum container is 0-10 Pa; heating the vacuum container to raise the temperature inside the vacuum container to 500°C to 700°C; and heating the heating container to raise the temperature inside the heating container to 380°C to 420°C.

[0014] Before the temperature inside the heating container rises to 380°C to 420°C, the heating container is preheated to maintain the temperature inside the heating container at 300°C to 400°C.

[0015] Compared with the prior art, the present invention has the following advantages: The present invention provides a cadmium telluride coating device and a short-circuit prevention method, comprising a vacuum container, a heating container, a cover plate, and an insulating component. The heating container is installed inside the vacuum container and has an opening at the top. The cover plate is installed above the heating container. The top surface of the heating container is a mounting surface. The insulating component is installed on the mounting surface and is located between the cover plate and the heating container. The inner wall of the heating container protrudes beyond the inner wall of the insulating component, so that a step is formed between the inner wall of the insulating component and the inner wall of the heating container. The electrode is located above the insulating component.

[0016] With the above structure, the cadmium telluride coating apparatus provided by the present invention, during cadmium telluride coating, heats the cadmium telluride raw material in a heating container, and the cadmium telluride sublimates and moves upward, passing through the holes in the cover plate to coat the target part. As the cadmium telluride moves upward, some of it is deposited on the inner wall of the heating container. The heating container and the cover plate are separated by an insulating component, and the electrode is located above the insulating component. The insulating component reduces the possibility of cadmium telluride sublimation and deposition on the inner wall of the heating container causing conductivity between the heating container and the electrode. At the same time, since cadmium telluride is more likely to move upward during sublimation, the amount of cadmium telluride deposited at the step between the inner wall of the insulating component and the inner wall of the heating container is significantly reduced, thereby reducing the possibility of cadmium telluride deposition between the heating container and the insulating component causing conductivity between the electrode and the heating container, and thus improving the insulation performance of the insulating component. Attached Figure Description

[0017] 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 only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0018] Figure 1 This is a schematic diagram of the structure of a cadmium telluride coating device provided by the present invention; Figure 2 This is a schematic diagram of the structure of the heating container in an embodiment of the present invention; Figure 3 This is a schematic diagram of one embodiment of the insulating component in this invention. Figure 4 This is a schematic diagram of another embodiment of the insulating component in this invention; Figure 5 This is a schematic diagram of another embodiment of the insulating component in this invention; Figure 6 This is a structural schematic diagram of another embodiment of the insulating element in this invention.

[0019] In the picture: 1-Vacuum container, 2-Heating container, 3-Cover plate, 4-Insulating component, 41-Body part, 42-Protrusion. Detailed Implementation

[0020] In the description of this application, it should be understood that the terms "center", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this application.

[0021] The terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Therefore, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this application, unless otherwise stated, "a plurality of" means two or more.

[0022] In the description of this application, it should be noted that, unless otherwise expressly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection between two components. Those skilled in the art can understand the specific meaning of the above terms in this application based on the specific circumstances.

[0023] To make the objectives, technical solutions, and advantages of this invention clearer, the technical solutions of this invention will be described in detail below. Obviously, the described embodiments are merely some embodiments of this invention, and not all embodiments. Based on the embodiments of this invention, all other implementation methods obtained by those skilled in the art without creative effort are within the scope of protection of this invention.

[0024] This invention provides a cadmium telluride coating apparatus and a short-circuit protection method, solving the technical problem described above. The cadmium telluride coating apparatus includes a vacuum container 1, a heating container 2, a cover plate 3, and an insulating component 4, wherein: like Figure 1 As shown, vacuum container 1 is used to provide a near-vacuum environment during cadmium telluride coating. The vacuum environment can reduce gas interference, thereby improving the quality and efficiency of coating.

[0025] like Figures 1-2 As shown, the heating container 2 is installed inside the vacuum container 1. The heating container 2 is used to heat cadmium telluride, thereby causing the cadmium telluride to sublimate and coat the target part. The target part to be coated is located above the heating container 2. After being heated inside the heating container 2, the cadmium telluride sublimates and moves toward the target part through the opening.

[0026] like Figures 1-2 As shown, the cover plate 3 is installed above the heating container 2. The cover plate 3 has holes for cadmium telluride to pass through. The target part to be coated is located above the cover plate 3. After passing through the holes in the cover plate 3, the cadmium telluride moves toward the target part.

[0027] like Figures 1-2 As shown, the top surface of the heating container 2 is the mounting surface. The insulating component 4 is mounted on the mounting surface and is located between the cover plate 3 and the heating container 2. That is, the cover plate 3 is mounted on the insulating component 4. The electrode is located above the insulating component 4. The electrode can be arranged according to specific circumstances, but the position of the electrode must be above the insulating component 4. That is, the electrode must pass through the insulating component 4 to communicate with the heating container. The insulating component 4 is used to isolate the electrode and the heating container 2, reducing the communication between the electrode and the heating container 2. The inner wall of the heating vent protrudes from the inner wall of the insulating component 4, so that the inner wall of the insulating component 4 is flush with the inner wall of the heating container 2. A step is formed between the inner wall of the insulating component 4 and the inner wall of the heating container 2, meaning the distance between them is greater than zero. This step can be either a plane or an inclined plane. The step reduces the movement of sublimated cadmium telluride towards the insulation direction. At the same time, since cadmium telluride is more likely to move upward when sublimated, the amount of cadmium telluride deposited at the step between the inner wall of the insulating component 4 and the inner wall of the heating container 2 will be significantly reduced. This reduces the deposition of cadmium telluride between the heating container 2 and the insulating component 4, thereby improving the insulation performance of the insulating component 4 and reducing the conductivity between the heating container 2 and the electrode. The insulating component 4 can be a quartz glass plate.

[0028] An optional implementation method of this embodiment is as follows: Figures 3-6 As shown, the insulating element 4 includes a body portion 41 and a protrusion 42. The body portion 41 is mounted on the mounting surface and is annular. A step is formed between the inner wall of the body portion 41 and the inner wall of the heating container 2, thereby ensuring that the cover plate 3 and the heating container 2 are separated by the insulating element 4. The step reduces the deposition of cadmium telluride, thereby reducing the conductivity between the heating container 2 and the electrode. The protrusion 42 is mounted on the inner wall of the body portion 41 and extends towards the centerline of the heating container 2. Optionally, the protrusion 42 can be mounted at one end of the body portion 41 near the heating container 2, so that the protrusion 42 is located above the step and reduces the deposition of cadmium telluride. More preferably, the protrusion 42 can be located between the two ends of the body portion 41. In this way, not only can the step between the inner wall of the body portion 41 and the inner wall of the heating container 2 reduce the deposition of cadmium telluride, but the protrusion 42 also has the same function as the step, further increasing the area where cadmium telluride is not easily deposited, thereby better reducing the conductivity between the heating container 2 and the electrode.

[0029] An optional implementation method of this embodiment is as follows: Figure 4-5As shown, the distance between the side of the protrusion 42 near the heating container 2 and the mounting surface gradually increases from the side of the protrusion 42 near the body part 41 toward the side away from the insulating member 4. That is, the side of the protrusion 42 near the heating container 2 is a surface that gradually moves away from the end near the body part 41 toward the end away from the body part 41. This can increase the movement of cadmium telluride along the side of the protrusion 42 near the heating container 2 toward the center line of the heating container 2 when some cadmium telluride enters below the protrusion 42, thereby reducing the deposition of cadmium telluride on the side of the protrusion 42 near the heating container 2.

[0030] An optional implementation of this embodiment is as follows: the distance between the side of the protrusion 42 away from the heating container 2 and the mounting surface gradually increases from the side of the protrusion 42 closer to the body part 41 towards the side away from the insulating member 4, such as... Figure 5 As shown, since cadmium telluride coating is required, and reheating causes cadmium telluride to sublimate and deposit on the target part, the cadmium telluride heated in the heating container 2 will move towards the opening. Therefore, more cadmium telluride will sublimate and move towards the opening. Some of the cadmium telluride will move horizontally and adhere to the heating container 2 or the insulating part 4, while a smaller portion will descend and deposit on the side of the protrusion 42 away from the heating container 2. The protrusion 42 away from the heating container 2 is configured in the above-described shape to reduce the adhesion of cadmium telluride to the protrusion 42 when it moves horizontally, reduce the deposition of cadmium telluride on the side of the protrusion 42 away from the protrusion 42, reduce the formation of a continuous conductive area of ​​cadmium telluride, and increase insulation performance.

[0031] An optional implementation method of this embodiment is as follows: Figures 3-6 As shown, there are multiple protrusions 42 arranged in a direction parallel to the axis of the heating container 2. Since the side of the protrusion 42 away from the heating container 2 is less prone to cadmium telluride deposition than the vertical surface or the side of the protrusion 42 close to the heating container 2, the multiple protrusions 42 can increase the area where cadmium telluride is less likely to be deposited, thereby better reducing the conductivity between the heating container 2 and the electrode and improving the insulation performance.

[0032] An optional implementation of this embodiment is as follows: In any two adjacent insulating components 4, such as Figure 6As shown, the distance between the protrusion 42 near the heating container 2 and the center line of the heating container 2 is greater than the distance between the protrusion 42 near the cover plate 3 and the center line of the heating container 2. Since cadmium telluride needs to be coated on the target part, more cadmium telluride will move towards the opening direction during cadmium telluride sublimation. The distance between the inner wall of the insulating part 4 and the center line of the heating container 2 is greater than the distance between the inner wall of the heating container 2 and the center line of the heating container 2. In the horizontal direction at the same height, among the cadmium telluride moving towards the inner wall of the body part 41, the one further away from the body part 41 is more... The closer the cadmium telluride, the less there will be. If all the protrusions 42 are of the same size, when cadmium telluride moves towards the opening direction through one of the protrusions 42 and then moves to the next protrusion 42, the amount of cadmium telluride deposited in the next protrusion 42 gradually decreases from the end away from the body part 41 to the end closer to the body part 41. Therefore, setting the protrusions 42 to the above structure can reduce the amount of deposits at the end of the protrusions 42 away from the body part 41, reduce the adhesion of cadmium telluride to the protrusions 42, and reduce the possibility of cadmium telluride deposition and conduction.

[0033] An optional implementation of this embodiment is as follows: When the distance between the end of the protrusion 42 away from the body part 41 and the body part 41 is greater than 10 mm, and the distance between the end of the protrusion 42 away from the body part 41 and the body part 41 is less than 10 mm, cadmium telluride is deposited on the insulating component 4, which increases the possibility of the insulating component 4 and the heating container 2 being connected. The greater the distance between the end of the protrusion 42 away from the body part 41 and the body part 41, the less cadmium telluride will be deposited on the end of the protrusion 42 closer to the body part 41. The distance between the end of the protrusion 42 away from the body part 41 and the body part 41 can be determined according to specific circumstances.

[0034] An optional implementation of this embodiment is as follows: The vacuum container 1 has an exhaust pipe for discharging air and cadmium telluride. Multiple exhaust pipes can be provided. The exhaust pipes can extract the air from the vacuum container 1. At the same time, during the coating process, sublimated cadmium telluride may enter the vacuum container 1. The exhaust pipes can be used to discharge the sublimated cadmium telluride to the outside of the vacuum container 1.

[0035] The short-circuit prevention method for the cadmium telluride coating apparatus includes placing a heating container 2, an insulating component 4, and an insulating cover plate 3 inside a vacuum container 1, maintaining the pressure inside the vacuum container 1 at 0-10 Pa; heating the vacuum container 1 to raise its temperature to 500°C to 700°C, preferably maintaining it at 640°C; and heating the heating container 2 to raise its temperature to 380°C to 420°C, preferably maintaining it at 400°C. The 400°C temperature inside the heating container 2 ensures sufficient reactivity of the cadmium telluride. Under this temperature and pressure setting, because the cover plate 3 and the insulating component 4 are closer to the vacuum container 1, residual cadmium telluride deposited near them during the production process is more likely to sublimate. Because the temperature of cadmium telluride inside container 2 is significantly lower than that at the opening, the cadmium telluride inside heating container 2 is limited by temperature and is less likely to sublimate compared to the cover plate 3 and the insulating component 4. The cadmium telluride deposited in the cover plate 3, the insulating component 4, and the vacuum container 1 is discharged through the exhaust pipe after sublimation by heating. When cadmium telluride is removed by physical means (such as scrapers, spatulas, wire brushes, or grinding heads), it will damage the cover plate 3, the insulating component 4, and the vacuum container 1. The damage caused by physical removal of cadmium telluride in the cover plate 3, the insulating component 4, and the vacuum container 1 can increase the adhesion area of ​​cadmium telluride and increase the difficulty of subsequent removal. By using this method to remove cadmium telluride, not only can the cadmium telluride in the cover plate 3, the insulating component 4, and the vacuum container 1 be removed, but damage to the cover plate 3, the insulating component 4, and the vacuum container 1 can also be reduced.

[0036] Before the temperature inside the heating container 2 rises to 380°C to 420°C, the temperature inside the heating container 2 is kept at 300°C to 400°C and maintained. Preferably, the temperature inside the heating container 2 is maintained at 400°C, which is lower than the temperature at which cadmium telluride sublimates in large quantities. The heating container 2 is preheated using this temperature and maintained for a period of time. Preheating can degas and pre-sublimate the cadmium telluride inside the heating container 2, purifying the environment inside the vacuum container 1.

[0037] The above description is merely a specific embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the technical scope described in the present invention should be included within the scope of protection of the present invention. Therefore, the scope of protection of the present invention should be determined by the scope of the claims.

Claims

1. A cadmium telluride coating apparatus, characterized in that, include: Vacuum container; A heating container is installed inside the vacuum container, and the heating container has an opening at the top; A cover plate is installed above the heating container; An insulating component is provided, wherein the top surface of the heating container is a mounting surface, the insulating component is mounted on the mounting surface and located between the cover plate and the heating container, the inner wall of the heating container protrudes from the inner wall of the insulating component, so that a step is formed between the inner wall of the insulating component and the inner wall of the heating container, and the electrode is located above the insulating component.

2. The cadmium telluride coating apparatus according to claim 1, characterized in that, The insulating component includes: The main body is mounted on the mounting surface. The main body is annular, and a stepped portion is formed between the inner wall of the main body and the inner wall of the heating container. The protrusion is installed on the inner wall of the main body and extends toward the centerline of the heating container.

3. The cadmium telluride coating apparatus according to claim 2, characterized in that, The distance between the protrusion near the heating container and the mounting surface gradually increases from the side of the protrusion closer to the body portion toward the side farther from the insulator.

4. The cadmium telluride coating apparatus according to claim 2, characterized in that, The distance between the side of the protrusion away from the heating container and the mounting surface gradually increases from the side of the protrusion closer to the body portion toward the side away from the insulator.

5. The cadmium telluride coating apparatus according to claim 2, characterized in that, The protrusions are provided in multiple ways, and the multiple protrusions are arranged in a direction parallel to the axis of the heating container.

6. The cadmium telluride coating apparatus according to claim 5, characterized in that, In any two adjacent insulating components, the distance between the protrusion closer to the heating container and the center line of the heating container is greater than the distance between the protrusion closer to the cover plate and the center line of the heating container.

7. The cadmium telluride coating apparatus according to claim 2, characterized in that, The distance between the end of the protrusion furthest from the body portion and the body portion is greater than 10 mm.

8. The cadmium telluride coating apparatus according to claim 1, characterized in that, The vacuum container has an exhaust pipe for discharging air and cadmium telluride.

9. A short-circuit prevention method for a cadmium telluride coating apparatus according to any one of claims 1-8, characterized in that, The heating container, the insulating component, and the insulating cover are placed inside a vacuum container, and the pressure inside the vacuum container is set at 0-10 Pa. Heating the inside of the vacuum container raises the temperature inside to 500°C to 700°C. The heating container is heated to raise the temperature inside the heating container to 380°C to 420°C.

10. A short-circuit prevention method for a cadmium telluride coating apparatus according to claim 9, characterized in that, Before the temperature inside the heating container rises to 380°C to 420°C, the heating container is preheated to maintain the temperature inside the heating container at 300°C to 400°C.

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