Solar cell, method for preparing same, photovoltaic module, and photovoltaic system

Abstract

This application relates to the technical field of solar cells, and particularly to a solar cell, a preparation method thereof, a photovoltaic module, and a photovoltaic system, so as to reduce the damage caused by laser-assisted sintering to the silicon-based bottom layer, thereby improving the cell performance. A preparation method of a solar cell, the solar cell having a light-receiving area and a non-light-receiving area, the solar cell comprising: a silicon-based bottom layer and a first electrode pattern disposed on a first side in the thickness direction of the silicon-based bottom layer and located in the non-light-receiving area, the first electrode pattern being prepared at least by a laser irradiation process; the method comprising: before preparing the first electrode pattern by the laser irradiation process, forming a first laser shielding layer on the first side of the silicon-based bottom layer and at least in a first area, the first area being the light-receiving area covered by extending a first distance from the edge of the first electrode pattern in a direction away from the first electrode pattern, the first laser shielding layer being used to shield at least the first area in the light-receiving area from laser irradiation.

Description

Technical Field

[0001] The present application relates to the technical field of solar cells, and in particular to a solar cell, a preparation method thereof, a photovoltaic module and a photovoltaic system. Background Art

[0002] With the development of solar cell technology, more and more types of solar cells have been developed. At present, the main types of solar cells mainly include Passivated Emitter and Rear Contact (PERC) cells, Tunnel Oxide Passivated Contact (TOPCON) solar cells, Hetero-Junction with Intrinsic Thin Film (HIT) solar cells, Interdigitated Back Contact (IBC) cells, etc.

[0003] With the development of these cell technologies, the grid line technology has increasingly become the key to restricting the cost and efficiency of the cells. At present, the most used grid line technology is still screen printing technology. In order to reduce the silver consumption, technologies such as laser transfer printing, electroplating, and silver-coated copper are all under research and development. At present, except for the combination of laser sintering technology with these technologies having relatively large research results, other technologies have not made great breakthroughs. Summary of the Invention

[0004] Based on this, it is necessary to provide a solar cell, a preparation method thereof, a photovoltaic module and a photovoltaic system, so as to reduce the damage caused by laser sintering to the silicon-based bottom layer, thereby improving the cell performance.

[0005] In a first aspect, a preparation method of a solar cell is provided. The solar cell has a light-receiving area and a non-light-receiving area. The solar cell includes: a silicon-based bottom layer and a first electrode pattern disposed on a first side in the thickness direction of the silicon-based bottom layer. The first electrode pattern is located in the non-light-receiving area of the solar cell, and the first electrode pattern is prepared at least by a laser irradiation process. The preparation method includes:

[0006] Before preparing the first electrode pattern by using the laser irradiation process, a first laser shielding layer is formed on the first side of the silicon-based bottom layer and at least in a first area. The first area refers to the light-receiving area covered by extending a first distance from the edge of the first electrode pattern in a direction away from the first electrode pattern. The first distance is 0.1 mm to 0.5 mm, and the first laser shielding layer is used to shield at least the first area in the light-receiving area from laser irradiation.

[0007] Optionally, the material of the first laser shielding layer is a conductive material;

[0008] Before preparing the first electrode pattern by using the laser irradiation process, form the first laser shielding layer on the first side of the silicon-based substrate and located in the light-receiving area and the non-light-receiving area;

[0009] And after preparing the first electrode pattern by using the laser irradiation process, remove the part of the first laser shielding layer located in the light-receiving area.

[0010] Optionally, forming the first laser shielding layer on the first side of the silicon-based substrate and located in the light-receiving area and the non-light-receiving area includes:

[0011] Form the first laser shielding layer on the first side of the silicon-based substrate and located in the light-receiving area and the non-light-receiving area by using magnetron sputtering or evaporation.

[0012] Optionally, the material of the first laser shielding layer is a conductive material;

[0013] Before preparing the first electrode pattern by using the laser irradiation process, by using a patterning process, form the first laser shielding layer on the first side of the silicon-based substrate and located in the first area and the non-light-receiving area;

[0014] And after preparing the first electrode pattern by using the laser irradiation process, remove the part of the first laser shielding layer located in the first area.

[0015] Optionally, forming the first laser shielding layer on the first side of the silicon-based substrate and located in the first area and the non-light-receiving area by using a patterning process includes:

[0016] Use a mask plate to shield the area in the light-receiving area except the first area, and form the first laser shielding layer on the first side of the silicon-based substrate and located in the first area and the non-light-receiving area by using magnetron sputtering or evaporation.

[0017] Optionally, the material of the first laser shielding layer includes one or more of copper, silver, aluminum, nickel, and tin.

[0018] Optionally, the thickness of the first laser shielding layer is 10 nm to 500 nm.

[0019] Optionally, before preparing the first electrode pattern by using the laser irradiation process, after forming the first laser shielding layer on the first side of the silicon-based substrate and at least in the first area, the preparation method further includes:

[0020] A second electrode pattern is formed on the first side of the silicon-based substrate and within the non-light-receiving area;

[0021] The first electrode pattern is prepared using a laser irradiation process, including:

[0022] The second electrode pattern is subjected to laser irradiation treatment to prepare the first electrode pattern.

[0023] Optionally, the solar cell further includes: a third electrode pattern disposed on the second side in the thickness direction of the silicon-based substrate, the third electrode pattern being within the non-light-receiving area of the solar cell; the preparation method further includes:

[0024] Before preparing the third electrode pattern using the laser irradiation process, a second laser shielding layer is formed on the second side of the silicon-based substrate and at least in a second region, where the second region refers to the light-receiving area covered by extending a second distance of 0.1 mm to 0.5 mm in a direction away from the third electrode pattern from the edge of the third electrode pattern, and the second laser shielding layer is used to shield at least the second region in the light-receiving area from laser irradiation.

[0025] Optionally, the material of the second laser shielding layer is a conductive material;

[0026] Before preparing the third electrode pattern using the laser irradiation process, the second laser shielding layer is formed on the second side of the silicon-based substrate and within the light-receiving area and the non-light-receiving area;

[0027] And after preparing the third electrode pattern using the laser irradiation process, the portion of the second laser shielding layer within the light-receiving area is removed.

[0028] Optionally, forming the second laser shielding layer on the second side of the silicon-based substrate and within the light-receiving area and the non-light-receiving area includes:

[0029] The second laser shielding layer is formed on the second side of the silicon-based substrate and within the light-receiving area and the non-light-receiving area using magnetron sputtering or evaporation.

[0030] Optionally, the material of the second laser shielding layer is a conductive material;

[0031] Before preparing the third electrode pattern using the laser irradiation process, a patterning process is used to form the second laser shielding layer on the second side of the silicon-based substrate and within the second region and the non-light-receiving area;

[0032] After preparing the third electrode pattern by using a laser irradiation process, the portion of the second laser shielding layer located in the second region is removed.

[0033] Optionally, a patterning process is used to form the second laser shielding layer on the second side of the silicon-based substrate and in the second region and the non-light-receiving region, including:

[0034] Using a mask plate to shield the regions in the light-receiving region other than the second region, and forming the second laser shielding layer on the second side of the silicon-based substrate and in the second region and the non-light-receiving region by magnetron sputtering or evaporation.

[0035] Optionally, the material of the second laser shielding layer includes one or more of copper, silver, aluminum, nickel, and tin.

[0036] Optionally, the thickness of the second laser shielding layer is 10 nm to 500 nm.

[0037] Optionally, before preparing the third electrode pattern by using a laser irradiation process, after forming the second laser shielding layer on the second side of the silicon-based substrate and at least in the second region, the preparation method further includes:

[0038] Forming a fourth electrode pattern on the second side of the silicon-based substrate and in the non-light-receiving region;

[0039] Using a laser irradiation process to prepare the third electrode pattern, including:

[0040] Performing a laser irradiation treatment on the fourth electrode pattern to prepare the third electrode pattern.

[0041] In a second aspect, a solar cell prepared by the preparation method as described in the first aspect is provided.

[0042] In a third aspect, a photovoltaic module is provided, including: a plurality of solar cells connected in series and / or in parallel;

[0043] At least one of the solar cells is the solar cell as described in the second aspect.

[0044] In a fourth aspect, a photovoltaic system is provided, including the photovoltaic module as described in the third aspect.

[0045] The beneficial effects of the above-mentioned solar cell, its preparation method, photovoltaic module, and photovoltaic system are as follows:

[0046] By forming a first laser shielding layer on the first side of the silicon-based substrate and at least in a first region, since this first laser shielding layer is used to shield at least the first region in the light-receiving region from laser irradiation, therefore, when preparing the first electrode pattern by a laser irradiation process subsequently, laser damage to the silicon-based substrate can be reduced, thereby improving the battery efficiency. At the same time, sintering the first electrode pattern with a laser can increase the contact performance between the first electrode pattern and the silicon-based substrate and reduce the contact impedance. And when the solar cell is a HIT cell, the contact performance between the first electrode pattern and the first transparent conductive oxide layer can be increased, the contact impedance can be reduced, and the low-temperature requirement of the HIT solar cell can also be met. When using a low-temperature silver paste to make the first electrode pattern, the resin component in the low-temperature silver paste can be completely sintered by laser sintering, thereby improving the conductivity and welding firmness of the first electrode pattern. BRIEF DESCRIPTION OF THE DRAWINGS

[0047] Figure 1 FIG. is a schematic cross-sectional structure diagram of a solar cell provided by an embodiment of the present application;

[0048] Figure 2 FIG. is a schematic flow diagram of forming a first electrode pattern on the first side of a silicon-based substrate provided by an embodiment of the present application;

[0049] Figure 3 FIG. is another schematic flow diagram of forming a first electrode pattern on the first side of a silicon-based substrate provided by an embodiment of the present application;

[0050] Figure 4 FIG. is a schematic flow diagram of forming a second electrode pattern on the second side of a silicon-based substrate provided by an embodiment of the present application;

[0051] Figure 5 FIG. is another schematic flow diagram of forming a second electrode pattern on the second side of a silicon-based substrate provided by an embodiment of the present application. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0052] To make the above objects, features, and advantages of the present application more obvious and understandable, the following detailed description of the specific embodiments of the present application will be made with reference to the accompanying drawings. Many specific details are set forth in the following description to fully understand the present application. However, the present application can be implemented in many other ways different from those described herein, and those skilled in the art can make similar improvements without departing from the connotation of the present application. Therefore, the present application is not limited by the specific embodiments disclosed below.

[0053] Unless the context otherwise requires, throughout the specification and claims, the term "comprising" is to be construed in an open, inclusive sense, i.e., "including, but not limited to". In the description of the specification, terms such as "one embodiment", "some embodiments", "exemplary embodiments", "exemplarily" or "some examples" are intended to indicate that a particular feature, structure, material or characteristic related to the embodiment or example is included in at least one embodiment or example of the present disclosure. The schematic representations of the above terms do not necessarily refer to the same embodiment or example. In addition, the specific features, structures, materials or characteristics described above may be included in any one or more embodiments or examples in any appropriate manner.

[0054] Exemplary embodiments are described herein with reference to cross-sectional views and / or plan views that are idealized exemplary drawings. In the drawings, the thickness of layers and regions is exaggerated for clarity. Thus, variations in the shape relative to the drawings due to, for example, manufacturing techniques and / or tolerances are contemplated. Accordingly, exemplary embodiments should not be construed as limited to the shapes of the regions shown herein, but include shape deviations caused by, for example, manufacturing. For example, an etched region shown as rectangular will generally have curved features. Thus, the regions shown in the drawings are schematic in nature, and their shapes are not intended to show the actual shape of the regions of the device and are not intended to limit the scope of the exemplary embodiments.

[0055] "A and / or B" includes the following three combinations: only A, only B, and the combination of A and B.

[0056] In this document, unless otherwise specified, "one or more" means one or greater than or equal to two.

[0057] In this document, terms such as "for example", "such as", "example", "for illustration" are used for descriptive purposes, indicating that there is an association in the covered content between the different technical solutions before and after, but should not be construed as a limitation on the previous technical solution, nor as a limitation on the scope of protection of this document. In this document, unless otherwise stated, A (such as B) means that B is a non-limiting example of A, and it can be understood that A is not limited to B.

[0058] In this document, "optionally", "optional", "option" mean that it may or may not be present, that is, it refers to any one of the two alternative schemes of "present" or "absent". If "optional" appears multiple times in a technical solution, unless otherwise specified and there are no contradictions or mutual constraints, each "optional" is independent of each other.

[0059] In this document, descriptions such as "optionally contain", "optionally include" mean "contain or not contain". "Optional component X" means that component X is present or absent, or means that the component X is contained or not contained.

[0060] In this text, in "the first aspect", "the second aspect", etc., the terms "first", "second", etc. are only for descriptive purposes and should not be construed as indicating or implying relative importance or quantity, nor should they be construed as implicitly specifying the importance or quantity of the indicated technical features.

[0061] It should be noted that when an element is referred to as "fixed to" or "disposed on" another element, it can be directly on the other element or there may also be an intermediate element. When an element is considered to be "connected" to another element, it can be directly connected to the other element or there may be an intermediate element at the same time. The terms "vertical", "horizontal", "upper", "lower", "left", "right" and similar expressions used in this text are only for illustrative purposes and do not represent the only implementation.

[0062] Unless otherwise defined, all technical and scientific terms used in this text have the same meaning as commonly understood by those skilled in the technical field to which this application belongs. The terms used in the specification of this application in this text are only for the purpose of describing specific embodiments and are not intended to limit this application.

[0063] In this text, among the technical features described in an open-ended manner, it includes a closed technical solution composed of the listed features, as well as an open technical solution including the listed features.

[0064] In this text, the meaning of "at least one" is more than one, such as one, two or more. The meaning of "multiple" or "several" is at least two, such as two, three, etc., and the meaning of "multiple layers" is at least two layers, such as two layers, three layers, etc., unless otherwise specifically defined. In the description of this application, the meaning of "several" is at least one, such as one, two, etc., unless otherwise specifically defined.

[0065] In this text, regarding a numerical interval (that is, a numerical range), unless otherwise specified, the distribution of the optional numerical values within this numerical interval is considered continuous, and it includes the two numerical endpoints (i.e., the minimum value and the maximum value) of this numerical interval, as well as each numerical value between these two numerical endpoints. Unless otherwise specified, when the numerical interval only refers to the integers within this numerical interval, it includes the two endpoint integers of this numerical range, as well as each integer between the two endpoints, which is equivalent to directly listing each integer. When providing multiple numerical ranges to describe features or characteristics, these numerical ranges can be combined. In other words, unless otherwise specified, the numerical ranges disclosed in this text should be understood to include any and all sub-ranges subsumed therein. The "numerical value" in this numerical interval can be any quantitative value, such as a number, a percentage, a ratio, etc. The "numerical interval" allows for a broad inclusion of numerical interval types such as a percentage interval, a ratio interval, a ratio interval, etc.

[0066] In this article, regarding the temperature parameter, unless otherwise specified, both constant temperature treatment and treatment within a certain temperature range are allowed. The constant temperature treatment allows the temperature to fluctuate within the accuracy range controlled by the instrument.

[0067] The fill factor (FF) used in this article refers to the ratio of the actual maximum achievable power (Pm or Vmp*Jmp) to the theoretical (not actually achievable) power (Jsc*Voc). Therefore, FF can be determined by the following formula:

[0068] FF = (Vmp*Jmp) / (Jsc*Voc)

[0069] Where Jmp and Vmp represent the current density and voltage at the maximum power point (Pm), respectively. This point is obtained by changing the resistance in the circuit until J*V is maximized; Jsc and Voc represent the short-circuit current and open-circuit voltage, respectively. The fill factor is a key parameter for evaluating solar cells. Commercial solar cells usually have a fill factor of about 60% or more.

[0070] The open-circuit voltage (Voc) used in this article is the potential difference between the anode and cathode of the device under the condition of no connected external load.

[0071] The power conversion efficiency (PCE) of the solar cell used in this article refers to the percentage of the power converted from absorbed light into electrical energy. The power conversion efficiency (PCE) of the solar cell can be calculated by dividing the maximum power point (Pm) by the incident light irradiance (E: W / m 2 ) and the surface area (Ac: m 2 ) of the solar cell. STC usually refers to the spectrum at a temperature of 25°C, an irradiance of 1000 W / m 2 , and an air mass of 1.5 (AM1.5).

[0072] In current battery technologies, heterojunction batteries have become one of the research hotspots of silicon-based solar cells due to their simple structure, low process temperature, good passivation effect, high open-circuit voltage, good temperature characteristics, and bifacial power generation.

[0073] Especially the advantage of HIT solar cells in the power generation over the entire life cycle. If the cost per watt gap between it and PERC cells can be reduced to about 0.1 yuan / W, a higher cost performance can be achieved. And with the reduction of the N-type silicon substrate thickness, the consumption of silver paste, and the cost reduction of equipment and targets, etc., the cost performance of HIT solar cells can be made higher and higher.

[0074] However, there are still great problems in reducing the cost of the paste. Especially due to the low-temperature process of HIT solar cells, traditional high-temperature silver paste cannot be used. Low-temperature silver paste has defects such as low conductivity and low welding tensile strength, resulting in a large consumption. Moreover, the low-temperature process makes it difficult for the resin component in the silver paste to be completely sintered, and the welding of the solder tape is difficult, posing a risk to the durability of the product.

[0075] Currently, in order to reduce silver consumption, technologies such as laser transfer printing, electroplating, and silver-coated copper are under research and development. Among them, the laser transfer printing technology is currently in the small-batch experimental research stage, and the line width can be about 23 microns. Although it helps with silver consumption and battery efficiency, the long-term stability of consumables and processes needs to be further considered. The electroplating process has high pollution and complex process flow. Although the grid lines can be made very thin to reduce the shading area, they are also prone to falling off, and the equipment investment is large. The silver-coated copper process is currently mostly used on the back of the battery and is still in the verification and improvement stage and cannot be put into production.

[0076] Laser sintering technology is a technology that uses the high-energy heat of a laser beam to irradiate an already formed electrode pattern or conductive paste, etc., so that the electrode pattern or conductive paste is combined with silicon or a transparent conductive oxide layer at high temperature. Among them, when the laser beam irradiates, it is mainly concentrated on the electrode pattern or conductive paste. However, for a solar cell, if the laser beam is not accurately controlled, it is easy to damage the silicon-based substrate at the edge of the electrode pattern, which is not conducive to improving the battery performance.

[0077] Based on this, on the one hand, some embodiments of the present application provide a method for manufacturing a solar cell, such as Figure 1 shown, the solar cell 1 has a light-receiving area S and a non-light-receiving area Z. The solar cell 1 includes: a silicon-based substrate 11 and a first electrode pattern 121 disposed on the first side 11a in the thickness direction of the silicon-based substrate 11. The first electrode pattern 121 is located in the non-light-receiving area Z of the solar cell 1, and the first electrode pattern 121 is at least prepared by a laser irradiation process. As Figure 1 、 Figure 2 and Figure 3 shown, the manufacturing method includes:

[0078] Before S202), preparing the first electrode pattern 121 by a laser irradiation process, in S201), forming a first laser shielding layer 131 on the first side 11a of the silicon-based substrate 11 and at least in the first region N. The first region N refers to the light-receiving area covered by extending a first distance from the edge of the first electrode pattern 121 in a direction away from the first electrode pattern 121. The first distance is 0.1 mm to 0.5 mm, and the first laser shielding layer 131 is used to shield at least the first region N in the light-receiving area S from laser irradiation.

[0079] Among them, a solar cell is a thin optoelectronic semiconductor sheet that directly generates electricity using sunlight. The light-receiving area of the solar cell refers to the area that can receive sunlight irradiation, facilitating the occurrence of the photovoltaic effect in the PN junction of the solar cell. It requires the light-receiving surface of the solar cell in this part of the area to be transparent so that sunlight can be incident on the PN junction of the solar cell. In order to lead out the electrical energy generated by the solar cell, grid lines are made on the front or back of the solar cell to collect photo-generated carriers. The area where the grid lines are located cannot transmit sunlight. Therefore, this part of the area can also be called the non-light-receiving area.

[0080] According to the different structures of the solar cell, the grid lines can be arranged on the front and / or back of the solar cell.

[0081] For example, the solar cell can be any one of a PERC cell, a TOPCon cell, a HIT solar cell, and an xBC cell, and no specific limitation is made here.

[0082] When the solar cell is a PERC cell, the silicon-based bottom layer 11 can be a P-type silicon substrate, and the grid lines can be arranged on the front and back of the PERC cell. At this time, the grid lines can include a first electrode pattern and a second electrode pattern. The first electrode pattern can be arranged on the front or back of the PERC cell, and the second electrode pattern can be arranged on the back or front of the PERC cell.

[0083] When the solar cell is a TOPCon cell, the silicon-based bottom layer 11 can be an N-type silicon substrate, and the grid lines can be arranged on the front and back of the TOPCon cell. At this time, the grid lines can include a first electrode pattern and a second electrode pattern. The first electrode pattern can be arranged on the front or back of the TOPCon cell, and the second electrode pattern can be arranged on the back or front of the TOPCon cell.

[0084] When the solar cell is a HIT solar cell, the silicon-based bottom layer 11 can be an N-type silicon substrate, and the grid lines can be arranged on the front and back of the HIT solar cell. At this time, the grid lines can include a first electrode pattern and a second electrode pattern. The first electrode pattern can be arranged on the front or back of the HIT solar cell, and the second electrode pattern can be arranged on the back or front of the HIT solar cell.

[0085] When the solar cell is an xBC cell, the silicon-based bottom layer 11 can be an N-type silicon substrate or a P-type silicon substrate, and the grid lines can be arranged on the back of the xBC cell. At this time, the grid lines can include a first electrode pattern, and the first electrode pattern can be arranged on the back of the xBC cell.

[0086] Here, it should be noted that the method for manufacturing a solar cell provided in the embodiments of the present application is applicable to any of the above-mentioned solar cells. Here, only taking the solar cell as a HIT solar cell as an example, the method for manufacturing the solar cell will be described in detail, without imposing any limitations on the methods for manufacturing other solar cells.

[0087] As Figure 1 and Figure 2 shown, in addition to including the above-mentioned silicon-based bottom layer 11 and the first electrode pattern 121 disposed on the first side 11a in the thickness direction of the silicon-based bottom layer 11, the HIT solar cell may further include a first intrinsic amorphous silicon layer 141, a first doped layer 151, and a first transparent conductive oxide layer 161 disposed between the silicon-based bottom layer 11 and the first electrode pattern 121. The first side 11a may be the front surface of the solar cell 1, that is, an example in which the first electrode pattern 121 is disposed on the front surface of the solar cell 1. At this time, as Figure 2 shown, before preparing the first electrode pattern 121 by using a laser irradiation process in S202), by forming a first laser shielding layer 131 on the first transparent conductive oxide layer 161 and at least in the first region N. Since the first region N refers to the light-receiving region covered by extending a first distance L from the edge of the first electrode pattern 121 in a direction away from the first electrode pattern 121, and the first distance is 0.1 mm to 0.5 mm. Therefore, the first laser shielding layer 131 is at least located within a certain region range (i.e., the first region) outside the edge of the first electrode pattern 121. In this way, when preparing the first electrode pattern 121 by using a laser irradiation process, due to the divergence of the laser, the laser irradiated into a certain region range (i.e., the first region) outside the edge of the first electrode pattern 121 can be blocked by the first laser shielding layer 131, thereby reducing the damage to at least the part of the light-receiving region S of the silicon-based bottom layer 11 located in the first region N, meeting the low-temperature requirements of the HIT solar cell, and thus improving the cell efficiency. At the same time, by using a laser irradiation to prepare the first electrode pattern 121, the first electrode pattern 121 can also be sintered again. For example, the first electrode pattern 121 may be a low-temperature silver paste, so that the resin component in the low-temperature silver paste can be completely sintered, thereby improving the conductivity and welding firmness of the first electrode pattern 121.

[0088] Among them, since the first laser shielding layer 131 is at least formed in the first region N, therefore, a mask plate can be used to shield the light-receiving region S and the non-light-receiving region Z of the silicon-based substrate 11 except for the first region N, and the first laser shielding layer 131 is formed in the first region N of the silicon-based substrate 11, so that the first laser shielding layer 131 can only cover the first region N, and further achieve the purpose of shielding the laser from irradiating the first region N of the silicon-based substrate 11. Alternatively, a whole-layer covering method can be adopted, so that the first laser shielding layer 131 is formed in both the light-receiving region S and the non-light-receiving region Z of the silicon-based substrate 11, and the purpose of shielding the laser from irradiating the first region N of the silicon-based substrate 11 can also be achieved, thereby reducing the damage caused by the laser to the first region N of the silicon-based substrate 11.

[0089] In some embodiments, such as Figure 2 shown, the material of the first laser shielding layer 131 is a conductive material;

[0090] Before S202), preparing the first electrode pattern 121 by using a laser irradiation process, in S201), a first laser shielding layer 131 is formed on the first side 11a of the silicon-based substrate 11 and located in the light-receiving region S and the non-light-receiving region Z;

[0091] And after S202), preparing the first electrode pattern 121 by using a laser irradiation process, in S203), the part of the first laser shielding layer 131 located in the light-receiving region S is removed.

[0092] In these embodiments, still taking this solar cell as an HIT solar cell as an example, such as Figure 2 shown, in S201), forming the first laser shielding layer 131 on the first side 11a of the silicon-based substrate 11 and located in the light-receiving region S and the non-light-receiving region Z may include: forming the first laser shielding layer 131 on the first transparent conductive oxide layer 161 and located in both the light-receiving region S and the non-light-receiving region Z, which can reduce the use of the mask plate, and after S202), forming the first electrode pattern 121 by using a laser irradiation process, by removing the part of the first laser shielding layer 131 located in the light-receiving region S, the first laser shielding layer 131 can be retained only in the non-light-receiving region Z, and the light-receiving region S of the silicon-based substrate 11 will not be shaded. At the same time, since the material of the first laser shielding layer 131 is a conductive material, therefore, the part of the first laser shielding layer 131 located in the non-light-receiving region Z can conduct electricity as a part of the first electrode pattern 121 and will not affect the conductivity of the first electrode pattern 121.

[0093] Exemplarily, the material of the first laser shielding layer 131 can be a metal conductive material.

[0094] In some embodiments, a first laser shielding layer 131 is formed on the first side 11a of the silicon-based bottom layer 11 and located in the light-receiving region S and the non-light-receiving region Z. It may include: forming the first laser shielding layer 131 on the first side 11a of the silicon-based bottom layer 11 and located in the light-receiving region S and the non-light-receiving region Z by using magnetron sputtering, evaporation or solution method.

[0095] In these embodiments, the shielding of the first region N can be achieved without a mask plate.

[0096] When forming the first laser shielding layer 131 on the first side 11a of the silicon-based bottom layer 11 and located in the light-receiving region S and the non-light-receiving region Z by using the solution method, taking the material of the first laser shielding layer 131 as a metal conductive material as an example, a solution of metal ions can be laid on the first side 11a of the silicon-based bottom layer 11 and located in the light-receiving region S and the non-light-receiving region Z to form a liquid film, and then the metal ions are reduced to metal by using a thermal reduction method so as to be deposited to form the first laser shielding layer 131.

[0097] In some embodiments, the material of the first laser shielding layer 131 includes one or more of copper, silver, aluminum, nickel and tin.

[0098] In these embodiments, these materials can play a role in shielding the laser. At the same time, by using these materials, when the non-light-receiving region Z is formed and retained, these materials can also increase the adhesion performance of the first electrode pattern 121 on the first transparent conductive oxide layer 161 as a part of the first electrode pattern 121. For example, when a conductive silver paste is formed on the part of the first laser shielding layer 131 located in the non-light-receiving region Z by screen printing subsequently, by reasonably selecting the material of the first laser shielding layer 131, such as selecting a material with adhesion performance, the first laser shielding layer 131 can also increase the adhesion performance of the conductive silver paste on the first transparent conductive oxide layer 161. At the same time, since the first laser shielding layer 131 itself is a conductive material, therefore, when the usage amount of the conductive silver paste is the same, the contact performance between the first laser shielding layer 131 and the first transparent conductive oxide layer 161 can be increased, the contact impedance can be reduced, and the conductive performance can be improved.

[0099] In some embodiments, the thickness of the first laser shielding layer 131 is 10 nm to 500 nm.

[0100] In these embodiments, by controlling the thickness of the first laser shielding layer 131 within the above range, the shielding of the first region N by the laser can be achieved, and at the same time, the conductive performance and adhesion performance of the first electrode pattern 121 can be improved to a certain extent.

[0101] In some embodiments, for S203), removing the part of the first laser blocking layer 131 located in the light-receiving region S may include: based on the different etching rates of the first laser blocking layer 131 and the first transparent conductive oxide layer 161 in the same etching process, the part of the first laser blocking layer 131 located in the light-receiving region S can be removed.

[0102] Exemplarily, when the material of the first laser blocking layer 131 is the above-mentioned metal material, based on the different corrosion resistance properties of the first laser blocking layer 131 and the first transparent conductive oxide layer 161 to chemical reagents, the part of the first laser blocking layer 131 located in the light-receiving region S can be removed.

[0103] Among them, the chemical reagent can exemplarily be any chemical reagent that can dissolve the material of the first laser blocking layer 131.

[0104] Exemplarily, taking the material of the first laser blocking layer 131 as copper as an example, the chemical reagent can be a mixed solvent of acid and oxide. The oxide is used to oxidize copper into copper ions, and the acid is used to dissolve the copper ions. For example, the chemical reagent can be any combination of sulfuric acid, hydrochloric acid, and nitric acid with hydrogen peroxide, ferric chloride, ferric nitrate, and sodium persulfate. Taking the material of the first laser blocking layer 131 as silver as an example, the chemical reagent can also be any combination of sulfuric acid, hydrochloric acid, and nitric acid with hydrogen peroxide, ferric chloride, ferric nitrate, and sodium persulfate. Taking the material of the first laser blocking layer 131 as aluminum as an example, the chemical reagent can be any one or two combinations of nitric acid, hydrochloric acid, and sulfuric acid. Taking the material of the first laser blocking layer 131 as tin as an example, the chemical reagent can be any one or two combinations of nitric acid, hydrochloric acid, and sulfuric acid. Taking the material of the first laser blocking layer 131 as nickel as an example, the chemical reagent can be any one or two combinations of nitric acid, hydrochloric acid, and sulfuric acid.

[0105] In some other embodiments, as Figure 3 shown, the material of the first laser blocking layer 131 is a conductive material;

[0106] Before S202), preparing the first electrode pattern 121 by a laser irradiation process, in S201), using a patterning process, form the first laser blocking layer 131 on the first side 11a of the silicon-based substrate 11 and located in the first region N and the non-light-receiving region Z;

[0107] And after S202), preparing the first electrode pattern 121 by a laser irradiation process, in S203), remove the part of the first laser blocking layer 131 located in the first region N.

[0108] In these embodiments, the first laser shielding layer 131 may be formed only in the first region N and the non-light-receiving region Z, so that the portion of the silicon-based substrate 11 irradiated by the laser in the first region N can be shielded, reducing damage to the portion of the silicon-based substrate 11 in the first region N caused by the laser.

[0109] Among them, patterning can be achieved through processes such as coating photoresist, exposure, and development, or patterning can also be achieved by directly depositing on the non-shielded area using a mask plate for shielding.

[0110] In some embodiments, S201): Using a patterning process, a first laser shielding layer 131 is formed on the first side 11a of the silicon-based substrate 11 and in the first region N and the non-light-receiving region Z, including:

[0111] Using a mask plate to shield the area in the light-receiving region S other than the first region N, and using magnetron sputtering, evaporation, or solution method to form a first laser shielding layer 131 on the first side 11a of the silicon-based substrate 11 and in the first region N and the non-light-receiving region Z.

[0112] In these embodiments, the first laser shielding layer 131 may be a metal conductive material. When prepared by the solution method, the description can refer to the above description of forming the first laser shielding layer 131 on the first side 11a of the silicon-based substrate 11 in the light-receiving region S and the non-light-receiving region Z, and will not be elaborated here.

[0113] In some embodiments, S203): Removing the portion of the first laser shielding layer 131 in the first region N can refer to the above description of removing the portion of the first laser shielding layer 131 in the light-receiving region S, and will not be elaborated here.

[0114] Among them, the specific preparation method of the above first electrode pattern 121 is not limited. In addition to being prepared by the laser irradiation process, the first electrode pattern 121 can also be prepared in combination with techniques such as screen printing, electroplating, laser transfer printing, and silver-coated silver. The specific preparation process of the first electrode pattern 121 is not limited here, and all preparation processes using the laser irradiation process to assist in sintering the first electrode pattern 121 are within the protection scope of this application.

[0115] In some embodiments, such as Figure 2 and Figure 3 shown, before S202): Using the laser irradiation process to prepare the first electrode pattern 121, after S201): Forming the first laser shielding layer 131 on the first side 11a of the silicon-based substrate 11 and at least in the first region N, the preparation method further includes:

[0116] S200): Forming a second electrode pattern 122 on the first side 11a of the silicon-based substrate 11 and in the non-light-receiving region Z;

[0117] S202), preparing the first electrode pattern 121 by using a laser irradiation process, including:

[0118] Performing laser irradiation treatment on the second electrode pattern 122 to prepare the first electrode pattern 121.

[0119] In these embodiments, the second electrode pattern 122 may be silver paste. After performing laser irradiation treatment on the second electrode pattern 122 by using the laser irradiation process, silver in the second electrode pattern 122 forms an ohmic contact with the first transparent conductive oxide layer 161 under ultra-high energy, or silver in the second electrode pattern 122 fuses with a part of the first laser shielding layer 131 located in the non-light-receiving area Z to form the first electrode pattern 121, both of which can improve the conductivity of the first electrode pattern 121 and its bonding performance with the silicon-based substrate.

[0120] In some embodiments, as Figure 1 shown, the solar cell 1 further includes: a third electrode pattern 123 disposed on the second side 11b in the thickness direction of the silicon-based substrate 11, and the third electrode pattern 123 is located in the non-light-receiving area Z of the solar cell 1; as Figure 1 , Figure 4 and Figure 5 shown, the preparation method further includes:

[0121] Before S302), preparing the third electrode pattern 123 by using a laser irradiation process, in S301), forming a second laser shielding layer 132 on the second side 11b of the silicon-based substrate 11 and at least in the second region P, where the second region P refers to the light-receiving area covered by extending a second distance of 0.1 mm to 0.5 mm in a direction away from the third electrode pattern 123 from the edge of the third electrode pattern 123, and the second laser shielding layer 132 is used to shield the second region P in the light-receiving area S from laser irradiation.

[0122] In these embodiments, contrary to the above-mentioned first electrode pattern 121, the third electrode pattern 123 is disposed on the back surface of the solar cell 1. At this time, as Figure 1As shown, the HIT solar cell may further include a second intrinsic amorphous silicon layer 142, a second doped layer 152, and a second transparent conductive oxide layer 162 disposed between the silicon-based bottom layer 11 and the third electrode pattern 123. At this time, similar to the above-mentioned first electrode pattern 121, before the third electrode pattern 123 is prepared by using a laser irradiation process in S302), by forming a second laser shielding layer 132 on the second transparent conductive oxide layer 162 and at least in the second region P, since the second laser shielding layer 132 is used to shield at least the second region P in the light-receiving region S from laser irradiation, therefore, when the third electrode pattern 123 is prepared by using a laser irradiation process, laser damage to the second region P of the silicon-based bottom layer 11 can be reduced, meeting the low-temperature requirements of the HIT solar cell, thereby improving the cell efficiency. At the same time, by using laser irradiation to prepare the third electrode pattern 123, the third electrode pattern 123 can be sintered again. For example, the third electrode pattern 123 can be a low-temperature silver paste, so that the resin component in the low-temperature silver paste can be completely sintered, thereby improving the conductivity and welding firmness of the third electrode pattern 123.

[0123] Among them, similar to the above-mentioned first laser shielding layer 132, the second laser shielding layer 132 can also be prepared by using a mask plate to shield the regions of the light-receiving region S of the silicon-based bottom layer 11 other than the first region N and the non-light-receiving region Z, or by depositing to cover the light-receiving region S and the non-light-receiving region Z entirely, both of which can achieve the purpose of shielding the light-receiving region S of the silicon-based bottom layer 11 from laser irradiation, thereby reducing laser damage to the light-receiving region S of the silicon-based bottom layer 11.

[0124] In some embodiments, as Figure 4 shown, the material of the second laser shielding layer 132 is a conductive material;

[0125] Before S302), when the third electrode pattern 123 is prepared by using a laser irradiation process, in S301), a second laser shielding layer 132 is formed on the second side 11b of the silicon-based bottom layer 11 and located in the light-receiving region S and the non-light-receiving region Z;

[0126] And after S302), when the third electrode pattern 123 is prepared by using a laser irradiation process, in S303), the part of the second laser shielding layer 132 located in the light-receiving region S is removed.

[0127] In these embodiments, similar to the first electrode pattern 121 described above, when the second laser blocking layer 132 is formed on the second transparent conductive oxide layer 162 and is located in both the light-receiving region S and the non-light-receiving region Z, the use of a mask plate can also be reduced. After the third electrode pattern 123 is formed by using a laser irradiation process, by removing the portion of the second laser blocking layer 132 located in the light-receiving region S, the light-receiving region S of the silicon-based substrate 11 will not be shaded. At the same time, since the material of the second laser blocking layer 132 is a conductive material, the portion of the second laser blocking layer 132 located in the non-light-receiving region Z can conduct electricity as part of the third electrode pattern 123 and will not affect the electrical conductivity of the third electrode pattern 123.

[0128] In some embodiments, the material of the second laser blocking layer 132 includes one or more of copper, silver, aluminum, nickel, and tin.

[0129] In these embodiments, similar to the material of the first laser blocking layer 132 described above, these materials can also improve the electrical conductivity of the third electrode pattern 123 and its adhesion performance on the second transparent conductive oxide layer 162 while blocking the laser. For the specific reasoning, reference can be made to the description of the first electrode pattern 121 above, and details will not be repeated here.

[0130] In some embodiments, the thickness of the second laser blocking layer 132 is 10 nm to 500 nm.

[0131] In these embodiments, by controlling the thickness of the second laser blocking layer 132 within the above range, it can also play a role in blocking the laser in the light-receiving region S, and at the same time, it can improve the electrical conductivity of the third electrode pattern 123 and its adhesion performance on the second transparent conductive oxide layer 162 to a certain extent.

[0132] In some embodiments, forming the second laser blocking layer 132 on the second side 11b of the silicon-based substrate 11 and in both the light-receiving region S and the non-light-receiving region Z may include: forming the second laser blocking layer 132 on the second side 11b of the silicon-based substrate 11 and in the light-receiving and non-light-receiving regions by using magnetron sputtering, evaporation, or solution method.

[0133] In these embodiments, the second region P can be blocked without a mask plate. For the specific preparation method, reference can be made to the description of the first laser blocking layer 131 above, and details will not be repeated here.

[0134] In some embodiments, for S303), removing the portion of the second laser blocking layer 132 located in the second region P can refer to the description of removing the portion of the first laser blocking layer 131 located in the light-receiving region S above, and details will not be repeated here.

[0135] In some other embodiments, such as Figure 5 shown, the material of the second laser shielding layer 132 is a conductive material;

[0136] Before preparing the third electrode pattern 123 by laser irradiation process, a patterning process is adopted to form the second laser shielding layer 132 on the second side 11b of the silicon-based substrate 11 and in the second region P and the non-light-receiving region Z;

[0137] And after preparing the third electrode pattern 123 by laser irradiation process, the part of the second laser shielding layer 132 located in the second region P is removed.

[0138] In these embodiments, the first laser shielding layer 132 can be formed only in the second region P and the non-light-receiving region Z, so that the laser irradiation on the part of the silicon-based substrate 11 located in the second region P can be blocked, reducing the damage to the part of the silicon-based substrate 11 located in the second region P caused by the laser.

[0139] Among them, patterning can be achieved through processes such as photoresist coating, exposure, and development, or patterning can also be directly achieved by depositing on the non-shielded area in a way of masking with a mask plate.

[0140] In some embodiments, adopting a patterning process to form the second laser shielding layer 132 on the second side 11b of the silicon-based substrate 11 and in the second region P and the non-light-receiving region Z includes:

[0141] Using a mask plate to shield the area in the light-receiving region S except the second region P, and forming the second laser shielding layer 132 on the second side 11b of the silicon-based substrate 11 and in the second region P and the non-light-receiving region Z by magnetron sputtering, evaporation or solution method.

[0142] In some embodiments, to remove the part of the second laser shielding layer 132 located in the second region P, reference can be made to the description of removing the part of the first laser shielding layer 131 located in the first region N above, which will not be elaborated here.

[0143] Among them, the specific preparation method of the above-mentioned third electrode pattern 123 is not limited either. Similarly to the above-mentioned first electrode pattern 121, in addition to being prepared by laser irradiation process, the third electrode pattern 123 can also be prepared by a method combined with techniques such as screen printing, electroplating, laser transfer printing, and silver-coated silver, which will not be specifically limited here.

[0144] In some embodiments, such as Figure 4 and Figure 5As shown, before S302), preparing the third electrode pattern 123 by using a laser irradiation process, and after S301), forming the second laser shielding layer 132 on the second side 11b of the silicon-based substrate 11 and at least in the second region P, the preparation method further includes:

[0145] S300), forming a fourth electrode pattern 124 on the second side 11b of the silicon-based substrate 11 and in the non-light-receiving area;

[0146] S302), preparing the third electrode pattern 123 by using a laser irradiation process, including:

[0147] Performing laser irradiation treatment on the fourth electrode pattern 124 to prepare the third electrode pattern 123.

[0148] In these embodiments, the fourth electrode pattern 124 can be silver paste. After irradiating the fourth electrode pattern 124 by using the laser irradiation process, silver in the fourth electrode pattern 124 forms an ohmic contact with the second transparent conductive oxide layer 162 under ultra-high energy, or silver in the fourth electrode pattern 124 fuses with a part of the second laser shielding layer 132 located in the non-light-receiving area Z to form the third electrode pattern 123, both of which can improve the conductivity of the third electrode pattern 123 and its bonding property with the silicon-based substrate 11.

[0149] Second, some embodiments of the present application provide a solar cell prepared by the preparation method as described in the first aspect.

[0150] The light-receiving area of the solar cell is less irradiated by laser during the preparation process, which can reduce the laser damage to the silicon-based substrate, thereby improving the efficiency of the solar cell.

[0151] Third, some embodiments of the present application provide a photovoltaic module, which includes: a plurality of solar cells connected in series and / or in parallel;

[0152] At least one of the solar cells is the solar cell as described in the second aspect.

[0153] Since the photovoltaic module includes the solar cell provided by the above embodiments, it has the same beneficial effects as the solar cell described in the second aspect above, and will not be elaborated here.

[0154] Fourth, some embodiments of the present application provide a photovoltaic system, which includes the photovoltaic module as described in the third aspect.

[0155] Since the photovoltaic system includes the photovoltaic module provided by the above embodiments, it has the same beneficial effects as the photovoltaic module described in the third aspect above, and will not be elaborated here.

[0156] Photovoltaic systems can be applied in photovoltaic power stations, such as ground power stations, rooftop power stations, and water surface power stations, etc., and can also be applied to devices or apparatuses that generate electricity using solar energy, such as user solar power supplies, solar street lights, solar cars, solar buildings, and so on. Of course, it can be understood that the application scenarios of photovoltaic systems are not limited to this, that is to say, photovoltaic systems can be applied in all fields that require solar power generation. Taking a photovoltaic power generation system network as an example, a photovoltaic system may include a photovoltaic array, a busbar box, and an inverter. The photovoltaic array can be an array combination of multiple solar cells. For example, multiple solar cells can form multiple photovoltaic arrays. The photovoltaic arrays are connected to the busbar box, and the busbar box can converge the current generated by the photovoltaic arrays. After the converged current flows through the inverter and is converted into alternating current required by the mains power grid, it is connected to the mains network to achieve solar power supply.

[0157] In order to objectively evaluate the technical effects of the embodiments of the present application, the present application will be described in detail and exemplarily through the following embodiments and comparative examples.

[0158] In the following embodiments and comparative examples, all raw materials can be obtained through commercial purchases. And in order to maintain the reliability of the experiments, the raw materials used in the following embodiments and comparative examples have the same physical and chemical parameters or are prepared through the same treatment methods.

[0159] Example 1

[0160] The preparation method of the solar cell in Example 1 is as follows:

[0161] Step 1), clean and texture the N-type silicon substrate to obtain the textured N-type silicon substrate;

[0162] Step 2), prepare a first intrinsic amorphous silicon layer, a P-doped amorphous silicon layer, and a first TCO (Transparent Conductive Oxide) layer on the front surface of the textured N-type silicon substrate;

[0163] Step 3), use magnetron sputtering to prepare a copper metal layer on the first TCO layer in both the light-receiving area and the non-light-receiving area, and the thickness of the copper metal layer is 100 nm;

[0164] Step 4), use screen printing technology to prepare a conductive paste pattern on the front surface of the copper metal layer, and use laser-assisted sintering to prepare a front electrode pattern;

[0165] Step 5), dissolve and remove the part of the copper metal layer in the light-receiving area with a mixed solvent of sulfuric acid and hydrogen peroxide, where the mass concentration of sulfuric acid is 10% and the mass concentration of hydrogen peroxide is 3%;

[0166] Step 6): Prepare a second intrinsic amorphous silicon layer, a B-doped amorphous silicon layer, and a second TCO layer on the back surface of the N-type silicon substrate;

[0167] Step 7): Use magnetron sputtering to prepare a copper metal layer on the second TCO layer in both the light-receiving area and the non-light-receiving area, and the thickness of the copper metal layer is 30 nm;

[0168] Step 8): Use screen printing to prepare a conductive paste pattern on the back surface of the copper metal layer in step 7), and use laser-assisted sintering to prepare a back electrode pattern;

[0169] Step 9): Dissolve and remove the part of the copper metal layer obtained in step 7) located in the light-receiving area with a mixed solvent of sulfuric acid and hydrogen peroxide, wherein the mass concentration of sulfuric acid is 10% and the mass concentration of hydrogen peroxide is 3%.

[0170] Example 2

[0171] The preparation method of the solar cell in Example 2 is basically the same as that of the solar cell in Example 1, except that:

[0172] In step 3), a nickel metal layer is prepared on the first TCO layer in both the light-receiving area and the non-light-receiving area;

[0173] In step 5), dissolve and remove the part of the nickel metal layer located in the light-receiving area with nitric acid, wherein the mass concentration of nitric acid is 10%;

[0174] In step 7), a nickel metal layer is prepared on the second TCO layer in both the light-receiving area and the non-light-receiving area;

[0175] In step 9), dissolve and remove the part of the nickel metal layer obtained in step 7) located in the light-receiving area with nitric acid, wherein the mass concentration of nitric acid is 10%.

[0176] Example 3

[0177] The preparation method of the solar cell in Example 3 is basically the same as that of the solar cell in Example 1, except that:

[0178] In step 3), a tin metal layer is prepared on the first TCO layer in both the light-receiving area and the non-light-receiving area;

[0179] In step 5), dissolve and remove the part of the tin metal layer located in the light-receiving area with sulfuric acid, wherein the mass concentration of sulfuric acid is 10%;

[0180] In step 7), a tin metal layer is prepared on the second TCO layer in both the light-receiving area and the non-light-receiving area;

[0181] In step 9), the part of the tin metal layer obtained in step 7) located in the light-receiving area is removed by dissolving with sulfuric acid, wherein the mass concentration of the sulfuric acid is 10%.

[0182] Example 4

[0183] The preparation method of the solar cell in Example 4 is basically the same as that of the solar cell in Example 1, except that:

[0184] In step 3), a copper metal layer is formed only on the first TCO layer in the first region (the distance extending from the edge of the front electrode pattern away from the front electrode pattern is 0.1 mm) and the non-light-receiving area;

[0185] In step 7), a copper metal layer is formed only on the second TCO layer in the second region (the distance extending from the edge of the back electrode pattern away from the back electrode pattern is 0.1 mm) and the non-light-receiving area.

[0186] Example 5

[0187] The preparation method of the solar cell in Example 5 is basically the same as that of the solar cell in Example 2, except that:

[0188] In step 3), a nickel metal layer is formed only on the first TCO layer in the first region (the distance extending from the edge of the front electrode pattern away from the front electrode pattern is 0.1 mm) and the non-light-receiving area;

[0189] In step 7), a nickel metal layer is formed only on the second TCO layer in the second region (the distance extending from the edge of the back electrode pattern away from the back electrode pattern is 0.1 mm) and the non-light-receiving area.

[0190] Example 6

[0191] The preparation method of the solar cell in Example 6 is basically the same as that of the solar cell in Example 3, except that:

[0192] In step 3), a tin metal layer is formed only on the first TCO layer in the first region (the distance extending from the edge of the front electrode pattern away from the front electrode pattern is 0.1 mm) and the non-light-receiving area;

[0193] In step 7), a tin metal layer is formed only on the second TCO layer in the second region (the distance extending from the edge of the back electrode pattern away from the back electrode pattern is 0.1 mm) and the non-light-receiving area.

[0194] Comparative Example 1

[0195] The preparation method of the solar cell in Comparative Example 1 is basically the same as that in Example 1, except that:

[0196] Before steps 4) and 8), a copper metal layer is not prepared on the first TCO layer and the second TCO layer.

[0197] Test Example

[0198] Under the same conditions, the PCE of the solar cells provided in Examples 1 to 6 and Comparative Example 1, as well as the line resistance, series resistance (Rs), and welding pressure of the front electrode patterns in the solar cells, were tested. The specific test results are shown in Table 1 below:

[0199] Table 1

[0200]

[0201] As can be seen from Table 1, the photoelectric conversion efficiency of the solar cells provided in the embodiments of the present application has been greatly improved compared with Comparative Example 1, and the line resistance and series resistance of the front electrode patterns have been greatly reduced, while the welding tensile force has also been improved or remained the same to varying degrees with different materials of the metal layer. This shows that the preparation method of the solar cells provided in the embodiments of the present application has achieved the technical effects of reducing laser damage and improving photoelectric conversion efficiency.

[0202] The technical features of the above-described embodiments can be combined arbitrarily. For the sake of brevity of description, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, it should be considered as the scope described in this specification.

[0203] The above-described embodiments merely represent several implementation manners of the present application, and their descriptions are relatively specific and detailed, but they should not be construed as limiting the scope of the patent application. It should be noted that for those of ordinary skill in the art, without departing from the concept of the present application, several modifications and improvements can still be made, and these all belong to the protection scope of the present application. Therefore, the protection scope of the patent of the present application should be subject to the appended claims.

Claims

1. A method for preparing a solar cell, characterized in that, the solar cell has a light-receiving area and a non-light-receiving area, and the solar cell includes: a silicon-based bottom layer and a first electrode pattern disposed on a first side in the thickness direction of the silicon-based bottom layer, the first electrode pattern is located in the non-light-receiving area of the solar cell, and the first electrode pattern is prepared at least by a laser irradiation process; the preparation method includes: Before preparing the first electrode pattern by the laser irradiation process, a first laser shielding layer is formed on the first side of the silicon-based bottom layer and at least in a first area, the first area refers to the light-receiving area covered by extending a first distance from the edge of the first electrode pattern in a direction away from the first electrode pattern, the first distance is 0.1 mm to 0.5 mm, and the first laser shielding layer is used to shield at least the first area in the light-receiving area from laser irradiation; The material of the first laser shielding layer is a conductive material; Before preparing the first electrode pattern by the laser irradiation process, the first laser shielding layer is formed on the first side of the silicon-based bottom layer and located in the light-receiving area and the non-light-receiving area; And after preparing the first electrode pattern by the laser irradiation process, the part of the first laser shielding layer located in the light-receiving area is removed; Or, Before preparing the first electrode pattern by the laser irradiation process, by a patterning process, the first laser shielding layer is formed on the first side of the silicon-based bottom layer and located in the first area and the non-light-receiving area; And after preparing the first electrode pattern by the laser irradiation process, the part of the first laser shielding layer located in the first area is removed.

2. The preparation method according to claim 1, characterized in that, forming the first laser shielding layer on the first side of the silicon-based bottom layer and located in the light-receiving area and the non-light-receiving area includes: forming the first laser shielding layer on the first side of the silicon-based bottom layer and located in the light-receiving area and the non-light-receiving area by magnetron sputtering or evaporation.

3. The preparation method according to claim 1, characterized in that, by a patterning process, forming the first laser shielding layer on the first side of the silicon-based bottom layer and located in the first area and the non-light-receiving area includes: using a mask plate to shield the area other than the first area in the light-receiving area, and forming the first laser shielding layer on the first side of the silicon-based bottom layer and located in the first area and the non-light-receiving area by magnetron sputtering or evaporation.

4. The preparation method according to any one of claims 1 to 3, characterized in that, the material of the first laser shielding layer includes: one or more of copper, silver, aluminum, nickel, and tin.

5. The preparation method according to any one of claims 1 to 3, characterized in that, the thickness of the first laser shielding layer is 10 nm to 500 nm.

6. The preparation method according to any one of claims 1 to 3, characterized in that, Before preparing the first electrode pattern by using a laser irradiation process, after forming a first laser shielding layer on the first side of the silicon-based bottom layer and at least in a first region, the preparation method further includes: Forming a second electrode pattern on the first side of the silicon-based bottom layer and in the non-light-receiving region; Preparing the first electrode pattern by using a laser irradiation process, including: Performing laser irradiation treatment on the second electrode pattern to prepare the first electrode pattern.

7. The preparation method according to claim 1, wherein, the solar cell further includes: a third electrode pattern disposed on the second side in the thickness direction of the silicon-based bottom layer, the third electrode pattern being in the non-light-receiving region of the solar cell; the preparation method further includes: Before preparing the third electrode pattern by using a laser irradiation process, forming a second laser shielding layer on the second side of the silicon-based bottom layer and at least in a second region, the second region being a light-receiving region covered by extending a second distance of 0.1 mm to 0.5 mm in a direction away from the third electrode pattern from the edge of the third electrode pattern, the second laser shielding layer being used to shield at least the second region in the light-receiving region from laser irradiation; The material of the second laser shielding layer is a conductive material; Before preparing the third electrode pattern by using the laser irradiation process, forming the second laser shielding layer on the second side of the silicon-based bottom layer and in the light-receiving region and the non-light-receiving region; And after preparing the third electrode pattern by using the laser irradiation process, removing the portion of the second laser shielding layer in the light-receiving region; Or, Before preparing the third electrode pattern by using the laser irradiation process, using a patterning process to form the second laser shielding layer on the second side of the silicon-based bottom layer and in the second region and the non-light-receiving region; And after preparing the third electrode pattern by using the laser irradiation process, removing the portion of the second laser shielding layer in the second region.

8. The preparation method according to claim 7, wherein, Forming the second laser shielding layer on the second side of the silicon-based bottom layer and in the light-receiving region and the non-light-receiving region includes: Forming the second laser shielding layer on the second side of the silicon-based bottom layer and in the light-receiving region and the non-light-receiving region by using magnetron sputtering or evaporation.

9. The preparation method according to claim 7, wherein, Using a patterning process to form the second laser shielding layer on the second side of the silicon-based bottom layer and in the second region and the non-light-receiving region includes: Using a mask plate to shield the region in the light-receiving region other than the second region, and forming the second laser shielding layer on the second side of the silicon-based bottom layer and in the second region and the non-light-receiving region by using magnetron sputtering or evaporation.

10. The preparation method according to any one of claims 7 to 9, wherein, The material of the second laser shielding layer includes one or more of copper, silver, aluminum, nickel, and tin.

11. The manufacturing method according to any one of claims 7 to 9, characterized in that, the thickness of the second laser shielding layer is 10 nm to 500 nm.

12. The manufacturing method according to claim 7, characterized in that, before preparing the third electrode pattern by using a laser irradiation process, after forming the second laser shielding layer on the second side of the silicon-based bottom layer and at least in the second region, the manufacturing method further includes: forming a fourth electrode pattern on the second side of the silicon-based bottom layer and in the non-light-receiving region; preparing the third electrode pattern by using a laser irradiation process, including: performing laser irradiation treatment on the fourth electrode pattern to prepare the third electrode pattern.

13. A solar cell manufactured by the manufacturing method according to any one of claims 1 to 12.

14. A photovoltaic module, characterized in that, it includes: a plurality of serially and / or parallely connected solar cells; at least one of the solar cells is the solar cell according to claim 13.

15. A photovoltaic system, characterized in that, it includes the photovoltaic module according to claim 14.

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