Solar cell and light injection passivation method thereof

Abstract

The invention relates to a solar cell and a light injection passivation method thereof. By analyzing and understanding the characteristics of the IBC battery and the principle of light injection and combining the characteristics of the IBC battery and the principle of light injection, the low-temperature light injection IBC battery efficiency improving process is developed in a matched mode, and the photoelectric conversion efficiency is obviously improved. The light injection passivation method comprises the following steps that a xenon lamp light source is adopted for carrying out light injection treatment on a solar cell, the temperature of the light injection treatment is 20-30 DEG C, and the solar cell is an interdigital back contact cell. According to the light injection passivation method of the solar cell, the characteristics of the IBC cell, especially a P-type silicon substrate IBC cell, are combined, the xenon lamp light source is adopted to carry out light injection treatment on the IBC cell, and the photoelectric conversion efficiency can be obviously improved at the low temperature within the range of 20-30 DEG C. Therefore, high-temperature heating conditions do not need to be provided, and the production cost can be reduced.

Description

Technical Field

[0001] The invention relates to the field of photovoltaic technology, in particular to a solar cell and a light injection passivation method thereof. Background Art

[0002] IBC cells (Interdigitated Back Contact) are back-contact cells without grid lines on the front, and their positive and negative electrodes are arranged in a finger-like manner on the back of the cell. Based on the existing silicon wafer types, the substrate of IBC cells is mainly P-type silicon and N-type silicon. Among them, N-type silicon is more popular because of its high tolerance. Although P-type silicon has cost advantages, due to its manufacturing process, the interstitial oxygen atoms and boron atoms in the P-type silicon wafer form BO complexes, which reduces the minority carrier lifetime and affects the efficiency of the cell and module. Therefore, improving the minority carrier lifetime is very important for IBC cells. The LID effect (light-induced attenuation effect) and LeTID effect (heat-assisted light-induced attenuation effect) of P-type silicon will greatly affect the minority carrier lifetime, resulting in a large attenuation of the battery efficiency. From a mechanistic point of view, the carrier transmission path is extended after the IBC battery process, the front and back sides are passivated by the film layer, the surface load rate is low, and the attenuation caused by the LID effect and LeTID effect is more serious.

[0003] At present, the processes for resisting LID effect and LeTID effect include electric injection process, light injection process and so on. Among them, the electric injection process is to inject current into the solar cell at a certain temperature. The electric injection process has the disadvantages of high power consumption, long process time, poor uniformity, and obvious fluctuations in efficiency improvement. The light injection process is to illuminate the solar cell under a certain temperature and a certain light intensity. Compared with the electric injection process, the light injection process has the advantages of lower energy consumption, shorter process time, and better uniformity. However, in traditional technology, the light injection process of solar cells needs to be combined with the electric injection process, and the required process equipment is relatively complicated, or it is necessary to use high-temperature heating conditions to significantly improve the light conversion efficiency of the cell, and the high-temperature heating conditions will make the production cost higher. Summary of the invention

[0004] Based on this, it is necessary to provide a solar cell and a light injection passivation method thereof to effectively improve the photoelectric conversion efficiency of the solar cell under lower temperature conditions.

[0005] One of the purposes of the present invention is to provide a method for light injection passivation of a solar cell, the scheme is as follows:

[0006] A method for light injection passivation of a solar cell comprises the following steps:

[0007] A xenon lamp light source is used to perform light injection treatment on the solar cell. The temperature of the light injection treatment is 20° C. to 30° C. The solar cell is an IBC cell (interdigitated back contact cell).

[0008] In one embodiment, the wavelength of the xenon lamp light source is 630nm to 685nm.

[0009] In one of the embodiments, the illumination power density of the light injection process is 900W / ㎡ to 1100W / ㎡.

[0010] In one embodiment, the light injection treatment time is more than 0.5 min.

[0011] In one embodiment, the light injection treatment time is 0.5 min to 10 min.

[0012] In one of the embodiments, the silicon substrate of the interdigitated back contact cell is P-type silicon.

[0013] In one embodiment, the solar cell includes a silicon substrate, a tunneling oxide layer, a doped polysilicon layer, a first electrode and a second electrode; the silicon substrate includes a first side and a second side arranged opposite to each other, the second side of the silicon substrate includes a first region and a second region, the tunneling oxide layer is arranged on the first region, the doped polysilicon layer is arranged on a side of the tunneling oxide layer away from the silicon substrate, the first electrode is connected to the second region, and the second electrode is connected to the doped polysilicon layer.

[0014] In one embodiment, the silicon substrate is P-type silicon.

[0015] In one of the embodiments, the first side has a suede structure.

[0016] In one embodiment, the first electrode is an aluminum electrode, and the second electrode is a silver electrode.

[0017] In one of the embodiments, the solar cell further includes a first anti-reflection film, and the first anti-reflection film is disposed on the first side of the silicon substrate.

[0018] In one embodiment, the first anti-reflection film includes a first aluminum oxide layer and a first silicon nitride layer, and the first aluminum oxide layer is disposed between the silicon substrate and the first silicon nitride layer.

[0019] In one embodiment, the solar cell also includes a second anti-reflection film, which is arranged on the doped polycrystalline silicon layer and the second region, the first electrode penetrates the second anti-reflection film and is connected to the second region, and the second electrode penetrates the second anti-reflection film and is connected to the doped polycrystalline silicon layer.

[0020] In one embodiment, the second anti-reflection film includes a second aluminum oxide layer and a second silicon nitride layer, and the second aluminum oxide layer is disposed between the silicon substrate and the second silicon nitride layer.

[0021] Another object of the present invention is to provide a solar cell, which is obtained by using the light injection passivation method described in any of the above embodiments.

[0022] Compared with the traditional solution, the above solar cell and its light injection passivation method have the following beneficial effects:

[0023] The present invention analyzes and understands the characteristics of IBC cells and the principles of light injection, combines the characteristics of the two, and develops a low-temperature light injection IBC cell efficiency improvement process, which achieves a significant improvement in photoelectric conversion efficiency. The above-mentioned light injection passivation method for solar cells, combined with the characteristics of IBC cells, especially P-type silicon substrate IBC cells, uses a xenon lamp light source to perform light injection treatment on the IBC cells, which can achieve a relatively significant improvement in photoelectric conversion efficiency at a relatively low temperature in the range of 20°C to 30°C. Therefore, the present invention does not need to provide high-temperature heating conditions, which can reduce production costs. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 FIG. 1 is a schematic structural diagram of a solar cell according to an embodiment of the present invention.

[0025] Description of reference numerals:

[0026] 100, solar cell; 110, silicon substrate; 120, tunneling oxide layer; 130, doped polysilicon layer; 140, first electrode; 150, second electrode; 160, first anti-reflection film; 161, first aluminum oxide layer; 162, first silicon nitride layer; 170, second anti-reflection film; 171, second aluminum oxide layer; 172, second silicon nitride layer. DETAILED DESCRIPTION

[0027] In order to make the above-mentioned objects, features and advantages of the present invention more obvious and easy to understand, the specific embodiments of the present invention are described in detail below in conjunction with the accompanying drawings. In the following description, many specific details are set forth to facilitate a full understanding of the present invention. However, the present invention can be implemented in many other ways different from those described herein, and those skilled in the art can make similar improvements without violating the connotation of the present invention, so the present invention is not limited by the specific embodiments disclosed below.

[0028] In the description of the present invention, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise", "axial", "radial", "circumferential" and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the referred device or element must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as limiting the present invention.

[0029] In addition, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" and "second" may explicitly or implicitly include at least one of the features. In the description of the present invention, the meaning of "plurality" is at least two, such as two, three, etc., unless otherwise clearly and specifically defined.

[0030] In the present invention, unless otherwise clearly specified and limited, the terms "installed", "connected", "connected", "fixed" and the like should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements, unless otherwise clearly defined. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0031] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as those generally understood by those skilled in the art of the present invention. The terms used herein in the specification of the present invention are only for the purpose of describing specific embodiments and are not intended to limit the present invention. The term "and / or" used herein includes any and all combinations of one or more related listed items.

[0032] A light injection passivation method for a solar cell according to an embodiment of the present invention comprises the following steps:

[0033] A xenon lamp light source is used to perform light injection treatment on the solar cell. The temperature of the light injection treatment is 20° C. to 30° C. Wherein, the solar cell is an IBC cell (interdigitated back contact cell).

[0034] The present invention injects light energy to combine H ions in the IBC battery with the BO complex, while eliminating the defect cache state in the IBC battery, thereby improving the photoelectric conversion efficiency of the IBC battery and suppressing the LID and LeTID effects of the P-type IBC battery.

[0035] The present invention analyzes and understands the characteristics of IBC cells and the principles of light injection, combines the characteristics of the two, and develops a low-temperature light injection IBC cell efficiency improvement process, which achieves a significant improvement in photoelectric conversion efficiency. The above-mentioned light injection passivation method for solar cells, combined with the characteristics of IBC cells, especially P-type silicon substrate IBC cells, uses a xenon lamp light source to perform light injection treatment on the IBC cells, which can achieve a relatively significant improvement in photoelectric conversion efficiency at a relatively low temperature in the range of 20°C to 30°C. Therefore, the present invention does not need to provide high-temperature heating conditions, which can reduce production costs.

[0036] In some of the examples, the wavelength of the xenon light source is 630nm to 685nm. In some of the examples, the wavelength of the xenon light source is 635nm to 685nm. In some of the examples, the wavelength of the xenon light source is 640nm to 685nm. In some of the examples, the wavelength of the xenon light source is 635nm to 680nm. In some of the examples, the wavelength of the xenon light source is 635nm to 675nm. In some specific examples, the wavelength of the xenon light source is 635nm, 638nm, 640nm, 642nm, 645nm, 648nm, 650nm, 652nm, 655nm, 658nm, 660nm, 662nm, 665nm, 668nm, 670nm, 672nm, 675nm, 678nm, 680nm, 682nm, 685nm, etc.

[0037] During the light injection process, two competing processes occur: the generation and disappearance of defects. The participation of light greatly accelerates the two defect reactions. Excessive light intensity and temperature will cause the defect passivation loss rate to be much higher than the defect formation rate. The defect reaction precursors remaining in the crystalline silicon will become the source of the LeTID effect.

[0038] During the light injection process, the illumination power density determines the concentration of carriers generated inside the solar cell. The concentration of carriers determines the combination state of defects.

[0039] Therefore, the temperature of the light injection process and the illumination power density of the light injection process need to be matched to suppress the LID effect and LeTID effect to the greatest extent and achieve an improvement in the photoelectric conversion efficiency.

[0040] In some of the examples, the temperature of the light injection process is 21° C. to 29° C. Further, in some of the examples, the temperature of the light injection process is 21° C. to 29° C. In some specific examples, the temperature of the light injection process is 20° C., 21° C., 22° C., 23° C., 24° C., 25° C., 26° C., 27° C., 28° C., 29° C., 30° C., etc.

[0041] In some of these examples, the illumination power density of the light injection process is 900W / ㎡~1100W / ㎡. Under the illumination power density in the range of 900W / ㎡-1100W / ㎡, extending the light injection process time can significantly improve the photoelectric conversion efficiency of the P-type IBC cell.

[0042] Further, in some of the examples, the lighting power density of the light injection process is 900W / ㎡ to 1100W / ㎡. In some specific examples, the lighting power density of the light injection process is 900W / ㎡, 910W / ㎡, 920W / ㎡, 930W / ㎡, 940W / ㎡, 950W / ㎡, 960W / ㎡, 970W / ㎡, 980W / ㎡, 990W / ㎡, 1000W / ㎡, 1010W / ㎡, 1020W / ㎡, 1030W / ㎡, 1040W / ㎡, 1050W / ㎡, 1060W / ㎡, 1070W / ㎡, 1080W / ㎡, 1090W / ㎡, 1100W / ㎡, etc.

[0043] In the above examples, by setting the illumination power density of the light injection process and the temperature of the light injection process, the combined effect of the two can maximize the photoelectric conversion efficiency.

[0044] Preferably, the time of light injection treatment is more than 0.5 min. In some examples, the time of light injection treatment is 0.5 min to 10 min. Further, in some examples, the time of light injection treatment is 0.5 min to 10 min. In some specific examples, the time of light injection treatment is 0.5 min, 1 min, 1.5 min, 2 min, 2.5 min, 3 min, 3.5 min, 4 min, 4.5 min, 5 min, 5.5 min, 6 min, 6.5 min, 7 min, 7.5 min, 8 min, 8.5 min, 9 min, 9.5 min, 10 min, etc.

[0045] In the present invention, the solar cell is an IBC cell. In some examples, the silicon substrate of the IBC cell is P-type silicon.

[0046] Please refer to Figure 1As shown, in one example, the solar cell 100 includes a silicon substrate 110 , a tunneling oxide layer 120 , a doped polysilicon layer 130 , a first electrode 140 and a second electrode 150 .

[0047] The silicon substrate 110 is preferably P-type silicon. The silicon substrate 110 includes a first side and a second side that are arranged opposite to each other. The first side can be used as the front side, and the second side can be used as the back side. The first side preferably has a suede structure.

[0048] The second side of the silicon substrate 110 includes a first region and a second region, wherein a tunneling oxide layer 120 is disposed on the first region. A doped polysilicon layer 130 is disposed on a side of the tunneling oxide layer 120 away from the silicon substrate 110. The doping type of the doped polysilicon layer 130 is the same as the doping type of the silicon substrate 110. The tunneling oxide layer 120 and the doped polysilicon layer 130 constitute a passivation contact structure.

[0049] The first electrode 140 and the second electrode 150 are distributed in an interdigitated shape on the second side of the silicon substrate 110. More specifically, the first electrode 140 is connected to the second region of the silicon substrate 110. The second electrode 150 is connected to the doped polysilicon layer 130. Preferably, the first electrode 140 is an aluminum electrode, and the second electrode 150 is a silver electrode.

[0050] In one example, the solar cell 100 further includes a first anti-reflection film 160. The first anti-reflection film 160 is disposed on a first side of the silicon substrate 110. The first anti-reflection film 160 is preferably a stacked structure of aluminum oxide and silicon nitride. More specifically, the first anti-reflection film 160 includes a first aluminum oxide layer 161 and a first silicon nitride layer 162. The first aluminum oxide layer 161 is disposed between the silicon substrate 110 and the first silicon nitride layer 162.

[0051] In one example, the solar cell 100 further includes a second anti-reflection film 170. The second anti-reflection film 170 is disposed on the doped polysilicon layer 130 and the second region. The second anti-reflection film 170 is preferably a stacked structure of aluminum oxide and silicon nitride. More specifically, the second anti-reflection film 170 includes a second aluminum oxide layer 171 and a second silicon nitride layer 172. The second aluminum oxide layer 171 is disposed between the silicon substrate 110 and the second silicon nitride layer 172. In this example, the first electrode 140 penetrates the second anti-reflection film 170 and is connected to the second region of the silicon substrate 110. The second electrode 150 penetrates the second anti-reflection film 170 and is connected to the doped polysilicon layer 130.

[0052] In one example, the method for preparing the solar cell 100 includes the following steps:

[0053] Forming a tunnel oxide layer 120 on the second side of the silicon substrate 110;

[0054] forming a doped polysilicon layer 130 on the tunneling oxide layer 120;

[0055] A first electrode 140 connected to the silicon substrate 110 and a second electrode 150 connected to the doped polysilicon layer 130 are prepared.

[0056] The first electrode 140 and the second electrode 150 may be formed by coating a conductive paste and then sintering the paste.

[0057] It can be understood that the light injection process is performed after the first electrode 140 and the second electrode 150 are prepared and formed.

[0058] During the light injection process, multiple solar cells to be processed can pass through the position of the xenon lamp light source in a chain transmission manner, realizing assembly line-type automated production and improving process production efficiency.

[0059] The present invention changes the state of the IBC battery, improves the carrier density, and simultaneously eliminates some defect cache states existing in the high-efficiency P-type IBC battery by performing low-temperature light injection treatment on the IBC battery. Combined with the characteristics of the IBC battery, especially the P-type silicon-based IBC battery, the IBC battery is light-injected using a xenon lamp light source, which can significantly improve the photoelectric conversion efficiency at a relatively low temperature in the range of 20°C to 30°C. Therefore, the present invention does not need to provide high-temperature heating conditions, which can reduce production costs.

[0060] The following specific examples are provided to further illustrate the present invention, but the present invention is not limited to the following specific examples. It should be understood that the attached claims summarize the scope of the present invention. Under the guidance of the concept of the present invention, those skilled in the art should be aware that certain changes made to the various embodiments of the present invention will be covered by the spirit and scope of the claims of the present invention.

[0061] Example 1

[0062] This embodiment provides a method for preparing a solar cell, comprising the following steps:

[0063] Provide a P-type silicon-based IBC cell with the first electrode and the second electrode sintered and metallized. Under normal pressure, use a xenon lamp light source to perform light injection treatment on the P-type silicon-based IBC cell. The wavelength of the xenon lamp light source is 630nm to 685nm. During the light injection treatment, the temperature is controlled at 20℃±0.5℃, and the lighting power density is 1000W / ㎡. The light injection treatment time is 3min.

[0064] Example 2

[0065] This embodiment provides a method for preparing a solar cell, comprising the following steps:

[0066] Provide a P-type silicon-based IBC cell with the first electrode and the second electrode sintered and metallized. Under normal pressure, use a xenon lamp light source to perform light injection treatment on the P-type silicon-based IBC cell. The wavelength of the xenon lamp light source is 630nm to 685nm. During the light injection treatment, the temperature is controlled at 25℃±0.5℃, and the lighting power density is 1000W / ㎡. The light injection treatment time is 3min.

[0067] Example 3

[0068] This embodiment provides a method for preparing a solar cell, comprising the following steps:

[0069] Provide a P-type silicon-based IBC cell with the first electrode and the second electrode sintered and metallized. Under normal pressure, use a xenon lamp light source to perform light injection treatment on the P-type silicon-based IBC cell. The wavelength of the xenon lamp light source is 630nm to 685nm. During the light injection treatment, the temperature is controlled at 30℃±0.5℃, and the lighting power density is 1000W / ㎡. The light injection treatment time is 3min.

[0070] Example 4

[0071] This embodiment provides a method for preparing a solar cell, comprising the following steps:

[0072] Provide a P-type silicon-based IBC cell with the first electrode and the second electrode sintered and metallized. Under normal pressure, use a xenon lamp light source to perform light injection treatment on the P-type silicon-based IBC cell. The wavelength of the xenon lamp light source is 630nm to 685nm. During the light injection treatment, the temperature is controlled at 25℃±0.5℃, and the lighting power density is 1000W / ㎡. The light injection treatment time is 0.5min.

[0073] Example 5

[0074] This embodiment provides a method for preparing a solar cell, comprising the following steps:

[0075] Provide a P-type silicon-based IBC cell with the first electrode and the second electrode sintered and metallized. Under normal pressure, use a xenon lamp light source to perform light injection treatment on the P-type silicon-based IBC cell. The wavelength of the xenon lamp light source is 630nm to 685nm. During the light injection treatment, the temperature is controlled at 25℃±0.5℃, and the lighting power density is 1000W / ㎡. The light injection treatment time is 10min.

[0076] Example 6

[0077] This embodiment provides a method for preparing a solar cell, comprising the following steps:

[0078] Provide a P-type silicon-based IBC cell with the first electrode and the second electrode sintered and metallized. Under normal pressure, use a xenon lamp light source to perform light injection treatment on the P-type silicon-based IBC cell. The wavelength of the xenon lamp light source is 630nm to 685nm. During the light injection treatment, the temperature is controlled at 25℃±0.5℃, and the lighting power density is 1000W / ㎡. The light injection treatment time is 20min.

[0079] Example 7

[0080] 10 Pcs of cells processed using the process of Example 2 were subjected to a LID light decay experiment.

[0081] Comparative Example 1

[0082] The difference between Comparative Example 1 and the above-mentioned Example 2 is that the temperature during the light injection process is different, and the other passivation conditions are the same. In the comparative example, the temperature is controlled at 200° C.±0.5° C.

[0083] Comparative Example 2

[0084] This embodiment provides a method for preparing a solar cell, comprising the following steps:

[0085] The difference between Comparative Example 2 and the above-mentioned Example 2 is that the illumination power density during the light injection process is different, and the other passivation conditions are the same. The illumination power density in the comparative example is 2000 W / ㎡.

[0086] Comparative Example 3

[0087] The method for preparing the solar cell of this comparative example comprises the following steps:

[0088] Provide a P-type silicon-based IBC cell with the first electrode and the second electrode sintered and metallized. Under normal pressure, use a xenon lamp light source to perform light injection treatment on the P-type silicon-based IBC cell. The wavelength of the xenon lamp light source is 630nm to 685nm. During the light injection treatment, the temperature is controlled at 200℃±0.5℃, and the lighting power density is 2000W / ㎡. The light injection treatment time is 3min.

[0089] Comparative Example 4

[0090] The difference between this comparative example and Example 2 is that the light source for the light injection treatment adopts an LED light source with a wavelength of 580nm-590nm.

[0091] Comparative Example 5

[0092] The difference between this comparative example and Example 2 is that the light source for the light injection treatment adopts an LED light source with a wavelength of 450nm-465nm.

[0093] Comparative Example 6

[0094] The difference between this comparative example and Example 6 is that the electrode sheet is not subjected to light injection treatment, that is, a light decay experiment is performed.

[0095] The solar cells obtained in the above-mentioned embodiments and comparative examples were subjected to electrical performance tests, and the test results are shown in Table 1. The data in Table 1 are the differences between the values ​​after the process and before the process.

[0096] Table 1

[0097]

[0098] It can be seen from the above embodiments that by using a xenon lamp light source to perform light injection treatment on the IBC cell, it is possible to significantly improve the photoelectric conversion efficiency at a relatively low temperature in the range of 20° C. to 30° C.

[0099] It can be seen from the test results of the embodiment that the temperature, lighting power density and process time of the light injection treatment have a significant impact on the passivation effect of the IBC battery. By controlling the lighting power density of the light injection treatment to 900W / ㎡~1100W / ㎡ and the temperature of the light injection treatment to 20℃~30℃, the combined effect of the two can achieve the maximum benefit, achieving efficiency improvement while suppressing the LID effect and LeTID effect.

[0100] When the light injection treatment time is in the range of 0.5min to 10min, the photoelectric conversion efficiency of the P-type IBC cell can be improved more significantly by extending the process time. However, when the process time is above 10min, the effect of improving the photoelectric conversion efficiency by extending the process time is not obvious.

[0101] The technical features of the above-described embodiments may be arbitrarily combined. To make the description concise, not all possible combinations of the technical features in the above-described embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0102] The above-mentioned embodiments only express several implementation methods of the present invention, and the descriptions thereof are relatively specific and detailed, but they cannot be understood as limiting the scope of the invention patent. It should be pointed out that, for ordinary technicians in this field, several variations and improvements can be made without departing from the concept of the present invention, and these all belong to the protection scope of the present invention. Therefore, the protection scope of the patent of the present invention shall be subject to the attached claims.

Claims

1. A method for light injection passivation of a solar cell, characterized in that: The following steps are involved: A xenon lamp light source is used to perform light injection treatment on the solar cell. The temperature of the light injection treatment is 20° C. to 30° C. The solar cell is an interdigitated back contact cell.

2. The light injection passivation method according to claim 1, characterized in that: The wavelength of the xenon lamp light source is 630nm-685nm.

3. The light injection passivation method according to claim 1, characterized in that: The lighting power density of the light injection treatment is 900W / ㎡ to 1100W / ㎡.

4. The light injection passivation method according to claim 1, characterized in that: The light injection treatment time is more than 0.5 min.

5. The light injection passivation method according to claim 4, characterized in that: The light injection treatment time is 0.5 min to 10 min.

6. The light injection passivation method according to any one of claims 1 to 5, characterized in that: The silicon substrate of the interdigitated back contact cell is P-type silicon.

7. The light injection passivation method according to any one of claims 1 to 5, characterized in that: The solar cell comprises a silicon substrate, a tunneling oxide layer, a doped polysilicon layer, a first electrode and a second electrode; the silicon substrate comprises a first side and a second side arranged opposite to each other, the second side of the silicon substrate comprises a first region and a second region, the tunneling oxide layer is arranged on the first region, the doped polysilicon layer is arranged on a side of the tunneling oxide layer away from the silicon substrate, the first electrode is connected to the second region, and the second electrode is connected to the doped polysilicon layer; Preferably, the silicon substrate is P-type silicon; Preferably, the first side has a suede structure; Preferably, the first electrode is an aluminum electrode, and the second electrode is a silver electrode.

8. The light injection passivation method according to claim 7, characterized in that: The solar cell further comprises a first anti-reflection film, wherein the first anti-reflection film is disposed on a first side of the silicon substrate; Preferably, the first anti-reflection film comprises a first aluminum oxide layer and a first silicon nitride layer, and the first aluminum oxide layer is disposed between the silicon substrate and the first silicon nitride layer.

9. The light injection passivation method according to claim 7, characterized in that: The solar cell further includes a second anti-reflection film, which is disposed on the doped polysilicon layer and the second region, the first electrode penetrates the second anti-reflection film and is connected to the second region, and the second electrode penetrates the second anti-reflection film and is connected to the doped polysilicon layer; Preferably, the second anti-reflection film includes a second aluminum oxide layer and a second silicon nitride layer, and the second aluminum oxide layer is disposed between the silicon substrate and the second silicon nitride layer.

10. A solar cell obtained by using the light injection passivation method according to any one of claims 1 to 9.

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