A processing device and a processing method for reducing the light-induced degradation of a solar cell

Abstract

The present invention discloses a processing device and a processing method for reducing the light-induced attenuation of a solar cell. The processing method includes: heating the solar cell wafer to a preset temperature; performing a light irradiation treatment on the heated solar cell wafer; cooling the solar cell wafer after the light irradiation treatment and maintaining the light irradiation during the cooling process. The processing device includes a box body and a heating zone, a light irradiation zone, and a cooling zone that are sequentially arranged along the length direction of the box body. The cooling zone is provided with a light irradiation device. The processing device and the processing method for reducing the light-induced attenuation of the solar cell provided by the present invention can convert the B-O complexes in the attenuation state and the annealing state into the regenerated state, improving the performance of the silicon crystal solar cell.

Description

Technical Field

[0001] The present invention relates to the technical field of solar cells, and particularly relates to a processing device for reducing the light-induced degradation of solar cells. The present invention also relates to a processing method for reducing the light-induced degradation of solar cells. Background Art

[0002] For boron-doped crystalline silicon solar cells, when they are exposed to light, the electrical performance of the cell wafers will decay and finally tend to a relatively stable state. This phenomenon is called the light-induced degradation of solar cells. The main reason is that metastable defects (i.e., B-O complexes) in monocrystalline silicon are activated under certain conditions to form deep-level recombination centers. Hereinafter, the phenomenon of attenuation caused by B-O complexes under light is called BO-LID, that is, light-induced degradation.

[0003] BO-LID is a relatively complex but solvable problem. Generally, the morphology of B-O complexes in boron-doped crystalline silicon solar cells is divided into three states: the annealed state, the attenuated state, and the regenerated state. In the annealed state, there are free B-O complexes, which are the inducement for recombination; in the attenuated state, the B-O complexes are activated to form defects. After long-term exposure to sunlight, the boron-doped crystalline silicon solar cells will tend to a relatively stable state, and most of the B-O complexes at this time are in the attenuated state; the regenerated state is a relatively stable state, and its defects are passivated compared with the attenuated state. Generally, the larger the proportion of the regenerated state of B-O complexes in crystalline silicon solar cells, the smaller the attenuation. The rates of mutual transformation of the three states of B-O complexes are different at different temperatures and during different processing procedures.

[0004] BO-LID can gradually "recover" at higher exposure temperatures. This process is also called "light-induced regeneration LIR". As the temperature continues to rise, this attenuation cycle becomes extremely fast and can reach within dozens of seconds. Therefore, in the industrial production of crystalline silicon solar cells, a furnace can be used for rapid "anti-BO-LID" treatment, and after this treatment process, it is sought to generate more regenerated states in the cell wafers, thereby reducing the light-induced degradation of boron-doped crystalline silicon solar cells.

[0005] Therefore, how to reduce the attenuation of crystalline silicon solar cells has become a technical problem that needs to be solved by those skilled in the art. Summary of the Invention

[0006] The object of the present invention is to provide a processing method for reducing the light-induced degradation of solar cells, which can convert B-O complexes into the regenerated state and inhibit the transformation into the annealed state and the attenuated state, thereby improving the performance of solar cells. Another object of the present invention is to provide a processing device for reducing the light-induced degradation of solar cells.

[0007] To achieve the above object, the present invention provides a treatment method for reducing the light-induced attenuation of a solar cell, including:

[0008] Heating the solar cell to a preset temperature;

[0009] Performing light treatment on the heated solar cell;

[0010] Cooling the solar cell after the light treatment and maintaining the light during the cooling process.

[0011] Optionally, the preset temperature is 200 - 300 °C.

[0012] Optionally, the step of cooling the solar cell after the light treatment is: blowing cooling air to the solar cell.

[0013] The present invention also provides a treatment device for reducing the light-induced attenuation of a solar cell, including a box body and a heating area, a light treatment area, and a cooling area arranged in sequence along the length direction of the box body. The cooling area is provided with a light device.

[0014] Optionally, the heating area and the light treatment area are provided with a first conveying device for conveying the solar cell from the heating area to the light treatment area, and the cooling area is provided with a second conveying device connected to the first conveying device for outputting the solar cell from the box body.

[0015] Optionally, the first conveying device is a ceramic roller, and the second conveying device is a pair of parallel and alternately arranged conveyor belts. A cooling fan is provided directly below the pair of conveyor belts.

[0016] Optionally, an LED lamp tube is provided above the ceramic roller in the light treatment area, and a temperature control fan is provided below the ceramic roller in the light treatment area.

[0017] Optionally, a slide rail is provided above the box body in the cooling area. The slide rail is parallel to the conveyor belt, and the light device is an LED lamp board arranged on the slide rail and slidable along the length direction of the slide rail.

[0018] Optionally, halogen lamp tubes are provided oppositely above and below the ceramic roller in the heating area.

[0019] Optionally, a reflecting mirror is provided at the bottom of the box body. The reflecting mirror is laid flat along the length direction of the box body below the heating area, the light treatment area, and the cooling area.

[0020] Compared with the above background art, the present invention heats and irradiates the solar cell, and under the preset heating temperature, the light irradiation makes the BO-LID gradually recover, and more of the B-O complexes change from the annealed state and the attenuated state to the regenerated state, that is, light-induced regeneration LIR. To avoid the transformation of the regenerated B-O complexes into the attenuated state and the annealed state during the cooling process, through a large number of experiments, it is found that increasing the light irradiation during the cooling process can effectively inhibit the transformation of the B-O complexes into the attenuated state and the annealed state, significantly increasing the proportion of the regenerated B-O complexes and improving the performance of the solar cell. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] In order to more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the following will briefly introduce the drawings required for the description of the embodiments or the prior art. Obviously, the drawings in the following description are only the embodiments of the present invention. For those of ordinary skill in the art, without creative efforts, other drawings can also be obtained based on the provided drawings.

[0022] Figure 1 It is a flowchart of the method for reducing the light-induced attenuation of a solar cell provided by an embodiment of the present invention;

[0023] Figure 2 It is a structural diagram of the device for reducing the light-induced attenuation of a solar cell provided by an embodiment of the present invention;

[0024] Figure 3 For Figure 2 a schematic diagram of the partition of the heating zone, the light irradiation zone, and the cooling zone in

[0025] Figure 4 For Figure 2 a front view of

[0026] Wherein:

[0027] 1 - box body, 2 - reflector, 3 - upper halogen lamp tube, 4 - lower halogen lamp tube, 5 - ceramic roller, 6 - LED lamp tube, 7 - temperature control fan, 8 - conveyor belt, 9 - conveyor belt roller, 10 - cooling fan, 11 - slide rail, 12 - LED lamp board. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0028] The following will clearly and completely describe the technical solutions in the embodiments of the present invention with reference to the drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts belong to the scope of protection of the present invention.

[0029] To enable those skilled in the art of the present technology to better understand the solution of the present invention, the present invention will be further described in detail below in conjunction with the accompanying drawings and specific embodiments.

[0030] Please refer to Figures 1 to 4 , Figure 1 which is a flowchart of the method for reducing the light-induced degradation of a solar cell provided by an embodiment of the present invention, Figure 2 and which is a structural diagram of the device for reducing the light-induced degradation of a solar cell provided by an embodiment of the present invention. Figure 3 is Figure 2 a schematic diagram of the zoning of the heating zone, the light irradiation zone, and the cooling zone of Figure 4 is Figure 2 a front view of

[0031] The method for reducing the light-induced degradation of a solar cell provided by the present invention is as shown in Figure 1 and includes:

[0032] Step S1: Heating the solar cell to a preset temperature;

[0033] Step S2: Performing a light irradiation treatment on the heated solar cell;

[0034] Step S3: Cooling the solar cell after the light irradiation treatment and maintaining the light irradiation during the cooling process.

[0035] Among them, the preset temperature in Step S1 is specifically 200 - 300 °C in the treatment method provided in the present application. The heating method can use a halogen lamp tube to irradiate and heat the solar cell or slowly heat it with a conventional heating device; by heating through light irradiation, the safety of heating the solar cell can be ensured; then Step S2 is carried out, and the solar cell heated to the preset temperature is exposed to light irradiation to promote photo-regeneration. Specifically, an LED lamp tube can be used to irradiate the solar cell, and by reasonably arranging the layout of the LED lamp tubes, the uniformity of the light irradiation can be ensured; finally, Step S3 is carried out, which is also the most critical step in the method for reducing the light-induced degradation of a solar cell. The solar cell after the light irradiation treatment is cooled, and at the same time, the light irradiation is maintained during the cooling process. Specifically, a cooling fan can be used to blow cooling air towards the solar cell, and then the LED lamp tube is used to maintain the light irradiation. While the cooling fan accelerates the cooling of the solar cell, the light irradiation inhibits the instability of the re-formed B-O complex from transforming into the attenuation state and the annealing state, increases the proportion of the re-formed B-O complex, reduces the light-induced degradation, and improves the performance of the solar cell.

[0036] The present invention also provides a processing device for reducing the light-induced attenuation of solar cells, the device includes a box 1, and the box 1 is correspondingly arranged in sequence along the length direction as a heating zone, an illumination zone and a cooling zone, and the cooling zone is also provided with an illumination device for maintaining illumination during the cooling process of the solar cell. The heating zone is used to heat the solar cell so that the solar cell is heated to a preset temperature, and the illumination zone is used to expose the heated solar cell so that the BO-LID is gradually restored by exposure at a preset heating temperature, that is, the light-induced regeneration LIR, and the cooling zone is used to cool the solar cell after light-induced regeneration, and at the same time, by increasing illumination during the cooling process to inhibit the instability of the regenerated BO complex to the annealing state and the attenuation state, the proportion of the regenerated BO complex during the light-induced regeneration process is increased, and the performance of the solar cell is improved.

[0037] Among them, a first conveying device is provided between the heating zone and the illumination zone in the box body 1, and the first conveying device is used to convey the solar cells in the heating zone to the illumination zone. The cooling zone is provided with a second conveying device connected to the end of the first conveying device and used to output the solar cells cooled in the cooling zone to the box body 1.

[0038] The first conveying device can specifically be a plurality of ceramic rollers 5 which are arranged parallel to the bottom plate of the box body 1 and parallel to each other. A heating device is arranged in the heating zone, and the heating device specifically uses a halogen lamp tube for light heating, such as Figure 2 and Figure 3 As shown, an upper halogen lamp 3 is arranged above the ceramic roller 5 in the heating zone, and a lower halogen lamp 4 is arranged below the ceramic roller 5 in the heating zone. The temperature of the solar cell is detected manually or automatically by a temperature measuring device. When the temperature of the solar cell reaches a preset temperature, the ceramic roller 5 is controlled to start running, and the ceramic roller 5 transports the cell in the heating zone to the illumination zone for photoregeneration.

[0039] An LED lamp tube 6 for irradiating the solar cell is arranged above the ceramic roller 5 in the illumination zone, and a temperature-controlled fan 7 is arranged below. The illumination zone is composed of multiple areas along the conveying direction of the ceramic roller 5, and each area has an independent LED lamp tube 6 and a temperature-controlled fan 7. Such a structure is conducive to better controlling the temperature and light intensity of each area in the illumination zone, and promoting the conversion of BO complexes in the annealed state and the decayed state to the regenerated ecology to the maximum extent. The temperature-controlled fan 7 can be an ordinary fan, or it can be an electric fan including an electric heating device for blowing out hot air. The electric fan is adjusted to start the electric heating device to blow out cold air or hot air of different temperatures according to the temperature control requirements of each area. Both the electric heating fan and the electric heating device belong to existing equipment, and this application will no longer explain their working principles and working circuits.

[0040] To improve the cooling effect on solar cells, the second conveying device in the cooling zone preferably adopts a pair of conveyor belts 8 arranged in parallel at intervals, and cooling fans 10 are arranged directly below the pair of conveyor belts 8. When the solar cells are cooled and conveyed in the cooling zone, the solar cells are placed between the pair of conveyor belts 8, so that the cooling air blown out by the cooling fans 10 can fully act on the solar cells and accelerate the cooling speed. The conveyor belts 8 are driven to move by the conveyor belt rollers 9, and the conveyor belts 8 drive the solar cell output box 1. A refrigeration device can also be added, and the cold air of the refrigeration device is led to the air inlet of the cooling fan 10, so that the cooling fan 10 blows out cold air, further improving the cooling speed of the solar cells and suppressing the light-induced degradation.

[0041] The lighting device in the cooling zone adopts an LED light board 12 arranged above the conveyor belt 8, and a number of LED lamp beads or lamp tubes are fixed on the LED light board 12. Specifically, slide rails 11 are arranged on the opposite side walls of the box 1, and the slide rails 11 are arranged parallel to the conveyor belt 8. The LED light board 12 is arranged on the slide rails 11 and can slide along the length direction of the slide rails 11. The LED light board 12 is specifically set in two groups, and the length of the two groups of LED light boards 12 is less than the length of the conveyor belt 8, so that the position of the LED light board 12 on the slide rails 11 can be adjusted according to the lighting requirements during the cooling process, so as to achieve the best inhibitory effect on the light-induced degradation during the cooling process.

[0042] To optimize the above embodiments, the processing device for reducing the light-induced degradation of solar cells provided by the present invention further includes a reflecting mirror 2 arranged on the bottom plate of the box 1. The reflecting mirror 2 is arranged across the heating zone, the lighting zone and the cooling zone along the length direction of the box 1, and the reflecting mirror 2 is located below the lower halogen lamp tube 4, the temperature control fan 7 and the cooling fan 10. The arrangement of the reflecting mirror 2 can effectively reflect the light emitted by the lamp tubes in each area to the solar cells, increasing the utilization rate of light without increasing the lighting device; especially when processing double-sided solar cells, the reflected light can increase the total carrier injection amount of the double-sided solar cells, and the anti-degradation treatment effect is better.

[0043] It should be noted that in this specification, relational terms such as first and second are only used to distinguish one entity from several other entities, and do not necessarily require or imply any such actual relationship or order between these entities.

[0044] The above has introduced in detail the light-induced attenuation treatment equipment and treatment method provided by the present invention. Specific examples are used in this article to elaborate on the principle and implementation manner of the present invention. The description of the above embodiments is only used to help understand the method of the present invention and its core idea. It should be noted that for those of ordinary skill in the art, without departing from the principle of the present invention, several improvements and modifications can be made to the present invention, and these improvements and modifications also fall within the protection scope of the claims of the present invention.

Claims

1. A treatment method for reducing the light-induced degradation of a solar cell, characterized in that, Including: Heating the solar cell to a preset temperature; Performing a light treatment on the solar cell heated to the preset temperature, so that BO-LID gradually recovers under exposure at the preset heating temperature, and more B-O complexes are transformed from the annealed state and the attenuated state to the regenerated state; the phenomenon that the B-O complex causes attenuation under light is called BO-LID, that is, light-induced attenuation; Cooling the solar cell after photo-induced regeneration, and maintaining light during the cooling process to inhibit the destabilization of the regenerated B-O complex to the annealed state and the attenuated state.

2. The treatment method for reducing the light-induced degradation of a solar cell according to claim 1, characterized in that, The preset temperature is 200~300 °C.

3. The treatment method for reducing the light-induced degradation of a solar cell according to claim 1, characterized in that, The step of cooling the solar cell after the light treatment is: blowing cooling air to the solar cell.

4. A treatment device for reducing the light-induced degradation of a solar cell, characterized in that, Including a box body (1) and a heating zone, a light zone, and a cooling zone arranged in sequence along the length direction of the box body (1); the heating zone is used to heat the solar cell to make the solar cell reach the preset temperature, the light zone is used to expose the solar cell heated to the preset temperature, so that BO-LID gradually recovers under exposure at the preset heating temperature, and more B-O complexes are transformed from the annealed state and the attenuated state to the regenerated state, and the cooling zone is used to cool the solar cell after photo-induced regeneration, and at the same time, by increasing light during the cooling process, inhibit the destabilization of the regenerated B-O complex to the annealed state and the attenuated state; The phenomenon that the B-O complex causes attenuation under light is called BO-LID, that is, light-induced attenuation; The heating zone and the light zone are provided with a first conveying device for conveying the solar cell from the heating zone to the light zone, and the cooling zone is provided with a second conveying device connected to the first conveying device for outputting the solar cell from the box body (1); The first conveying device is a ceramic roller (5), and the second conveying device is a pair of parallel and spaced conveyor belts (8); Above the ceramic roller (5) in the light zone, there is an LED lamp tube (6), below the ceramic roller (5) in the light zone, there is a temperature control fan (7), and there are multiple areas along the conveying direction of the ceramic roller (5) in the light zone, and each area is provided with the LED lamp tube (6) and the temperature control fan (7); Above the box body (1) in the cooling zone, there is a slide rail (11), the slide rail (11) is parallel to the conveyor belt (8), and the cooling zone is provided with an LED lamp board (12) arranged on the slide rail (11) and capable of sliding along the length direction of the slide rail (11); 5. The treatment device for reducing the light-induced degradation of a solar cell according to claim 4, characterized in that, Right below between the pair of conveyor belts (8), there is a cooling fan (10).

6. The treatment device for reducing the light-induced degradation of a solar cell according to claim 4, characterized in that, Above and below the ceramic roller (5) in the heating zone, there are halogen lamp tubes arranged oppositely.

7. The treatment device for reducing the light-induced degradation of a solar cell according to any one of claims 4 to 6, characterized in that, At the bottom of the box body (1), there is a reflector (2), and the reflector (2) is laid flat below the heating zone, the light zone, and the cooling zone along the length direction of the box body (1).

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