Preparation method of solar cell and solar cell

Abstract

The invention provides a preparation method of a solar cell and the solar cell, and the method comprises the steps: providing a solar cell precursor which is provided with a first surface and a second surface which are opposite to each other; forming a seed layer on the local area of the first surface and / or the local area of the second surface, wherein the film layer to which the surface of the seed layer belongs is conductive; an insulating layer is formed on the surface where the seed layer is located, the insulating layer does not cover the seed layer or covers part of the seed layer, and the insulating layer is provided with an opening exposing at least part of the seed layer; and electroplating an electroplating layer on the seed layer exposed out of the opening. Another preparation method of the solar cell comprises the following steps: providing a solar cell precursor, wherein the solar cell precursor is provided with an antireflection layer; forming a metal-containing slurry on a local region of the antireflection layer; carrying out sintering treatment on the slurry to enable the slurry to burn through the antireflection layer, converting the slurry into a seed layer after sintering treatment, and forming electric connection between the seed layer and the doped silicon layer in the solar cell precursor; and plating a plating layer on the seed layer. The preparation method of the solar cell and the solar cell have the advantage of few process steps.

Description

Technical Field

[0001] The present application mainly relates to the field of photovoltaic technology, and in particular to a method for preparing a solar cell and a solar cell. Background Art

[0002] The grid line is one of the important components of solar cells. The methods for preparing the grid line include screen printing, electroplating, etc., but the above methods have the disadvantage of complicated process steps. Therefore, how to reduce the process steps for preparing solar cells is one of the research hotspots in this field. Summary of the invention

[0003] The technical problem to be solved by the present application is to provide a method for preparing a solar cell and a solar cell. The method for preparing a solar cell and the solar cell have the advantage of fewer process steps.

[0004] To solve the above technical problems, the present application provides a method for preparing a solar cell, comprising: providing a solar cell precursor, the solar cell precursor having a first surface and a second surface relative to each other; forming a seed layer on a local area of ​​the first surface and / or a local area of ​​the second surface, and the film layer to which the surface where the seed layer is located belongs is conductive; forming an insulating layer on the surface where the seed layer is located, the insulating layer not covering the seed layer or covering part of the seed layer, the insulating layer having an opening exposing at least part of the seed layer; and electroplating a plating layer on the seed layer exposed by the opening.

[0005] In one embodiment of the present application, the step of forming a seed layer on a local area of ​​the first surface and / or the second surface includes: directly printing a metal-containing slurry on the local area; and drying the slurry to transform the slurry into the seed layer.

[0006] In one embodiment of the present application, the width of the electroplating layer is less than, equal to, or greater than the width of the seed layer.

[0007] In one embodiment of the present application, the insulating layer includes insulating glue and / or hot melt wax.

[0008] In an embodiment of the present application, the depth of the opening of the insulating layer is 1 μm to 50 μm.

[0009] In an embodiment of the present application, the method for preparing a solar cell further includes: after electroplating the electroplating layer, removing the insulating layer.

[0010] In one embodiment of the present application, the electroplating layer includes a stacked first sublayer and a second sublayer. During the electroplating process of the electroplating layer, the first sublayer is electroplated first, and then after removing the insulating layer, the second sublayer is electroplated or chemically plated, wherein the second sublayer covers at least part of the first sublayer and / or the seed layer not covered by the first sublayer.

[0011] In one embodiment of the present application, the solar cell precursor includes a first transparent conductive layer and / or a second transparent conductive layer, the first surface is the surface of the first transparent conductive layer facing outward, and the second surface is the surface of the second transparent conductive layer facing outward.

[0012] In one embodiment of the present application, the method for preparing a solar cell also includes: forming an anti-reflection layer on the first surface and / or the second surface, the anti-reflection layer having an opening, the seed layer being located in the opening of the anti-reflection layer, and the insulating layer being in contact with a surface of the anti-reflection layer away from the first surface.

[0013] The present application also proposes another method for preparing a solar cell, comprising: providing a solar cell precursor, the solar cell precursor having an anti-reflection layer; forming a slurry containing a metal on a local area of ​​the anti-reflection layer; sintering the slurry so that the slurry burns through the anti-reflection layer, after the sintering treatment, the slurry is transformed into a seed layer, the seed layer forms an electrical connection with the doped silicon layer in the solar cell precursor; and electroplating a plating layer on the seed layer.

[0014] In an embodiment of the present application, the step of forming a seed layer on a local area of ​​the anti-reflection layer includes: directly printing the slurry on the local area.

[0015] In one embodiment of the present application, the electroplating layer includes a stacked first sublayer and a second sublayer. During the electroplating process of the electroplating layer, the first sublayer is electroplated first, and then the second sublayer is electroplated on the first sublayer, wherein the second sublayer covers at least part of the first sublayer and / or the seed layer not covered by the first sublayer.

[0016] On the other hand, the present application further provides a solar cell, comprising a plurality of grid lines, wherein the grid lines include a seed layer and an electroplating layer located on the seed layer, wherein the width of the electroplating layer is less than, equal to or greater than the width of the seed layer.

[0017] In one embodiment of the present application, the solar cell also includes: a first anti-reflection layer and / or a second anti-reflection layer, the multiple grid lines penetrate the first anti-reflection layer and / or the second anti-reflection layer, and form an electrical connection with the doped silicon layer in the solar cell, wherein, in the process of forming the seed layer, the seed layer burns through the anti-reflection layer in which it is located.

[0018] In an embodiment of the present application, the solar cell further includes: a first transparent conductive layer and / or a second transparent conductive layer, and the plurality of grid lines are located on the first transparent conductive layer and / or the second transparent conductive layer.

[0019] Compared with the prior art, this application has the following advantages:

[0020] (1) Compared with the technical solution of "first forming a seed layer on the entire surface and then removing part of the seed layer", the present application directly forms a seed layer on a local area, which can reduce the number of process steps.

[0021] (2) Compared with the technical solution of "first forming an insulating layer covering the entire surface and then removing the insulating layer at the seed layer", the technical solution of "directly forming a patterned insulating layer" of the present application does not need to form an insulating layer covering the entire surface, which can reduce the process steps. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] The accompanying drawings are included to provide a further understanding of the present application. They are included and constitute a part of the present application. The accompanying drawings illustrate embodiments of the present application and together with the present specification serve to explain the principles of the present application. In the accompanying drawings:

[0023] Figure 1 is a schematic flow chart of a method for preparing a solar cell in one embodiment of the present application;

[0024] Figures 2 to 6 is a schematic cross-sectional view of a solar cell in different steps of a method for preparing a solar cell in an embodiment of the present application;

[0025] Figure 7 and Figure 8 is a schematic cross-sectional view of a solar cell in different steps of a method for preparing a solar cell in another embodiment of the present application;

[0026] Fig. 9 and Fig.10 is a schematic cross-sectional view of a solar cell in different steps of a method for preparing a solar cell in an embodiment of the present application;

[0027] Fig.11 and Fig.12 is a cross-sectional schematic diagram of a solar cell in one embodiment of the present application;

[0028] Fig.13 and Fig.14 is a schematic cross-sectional view of a solar cell in different steps of a method for preparing a solar cell in an embodiment of the present application;

[0029] Fig.15is a cross-sectional schematic diagram of a solar cell in one embodiment of the present application;

[0030] Fig.16 is a schematic flow chart of a method for preparing a solar cell in one embodiment of the present application;

[0031] Figures 17 to 19 It is a schematic cross-sectional view of a solar cell in different steps of a method for preparing a solar cell in an embodiment of the present application. DETAILED DESCRIPTION

[0032] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the following is a brief introduction to the drawings required for the description of the embodiments. Obviously, the drawings described below are only some examples or embodiments of the present application. For ordinary technicians in this field, the present application can also be applied to other similar scenarios based on these drawings without creative work. Unless it is obvious from the language environment or otherwise explained, the same reference numerals in the figures represent the same structure or operation.

[0033] As shown in this application and claims, unless the context clearly indicates an exception, the words "a", "an", "an" and / or "the" do not refer to the singular and may also include the plural. Generally speaking, the terms "include" and "comprise" only indicate the inclusion of the steps and elements that have been clearly identified, and these steps and elements do not constitute an exclusive list. The method or device may also include other steps or elements.

[0034] Unless otherwise specifically stated, the relative arrangement, numerical expressions and numerical values ​​of the parts and steps set forth in these embodiments do not limit the scope of the present application. At the same time, it should be understood that, for ease of description, the sizes of the various parts shown in the accompanying drawings are not drawn according to the actual proportional relationship. The technology, method and equipment known to those of ordinary skill in the relevant field may not be discussed in detail, but in appropriate cases, the technology, method and equipment should be considered as a part of the authorization specification. In all examples shown and discussed here, any specific value should be interpreted as being merely exemplary, rather than as a limitation. Therefore, other examples of exemplary embodiments may have different values. It should be noted that similar reference numerals and letters represent similar items in the following drawings, so that once a certain item is defined in an accompanying drawing, it does not need to be further discussed in subsequent drawings.

[0035] In the description of the present application, it should be understood that the directions or positional relationships indicated by directional words such as "front, back, up, down, left, right", "lateral, vertical, perpendicular, horizontal" and "top, bottom" are usually based on the directions or positional relationships shown in the drawings, and are only for the convenience of describing the present application and simplifying the description. Unless otherwise specified, these directional words do not indicate or imply that the device or element referred to must have a specific direction or be constructed and operated in a specific direction, and therefore cannot be understood as limiting the scope of protection of the present application; the directional words "inside and outside" refer to the inside and outside relative to the contours of each component itself.

[0036] For ease of description, spatially relative terms such as "above", "above", "on the upper surface of", "above", etc. may be used here to describe the spatial positional relationship between a device or feature and other devices or features as shown in the figure. It should be understood that spatially relative terms are intended to include different orientations of the device in use or operation in addition to the orientation described in the figure. For example, if the device in the accompanying drawings is inverted, the device described as "above other devices or structures" or "above other devices or structures" will be positioned as "below other devices or structures" or "below other devices or structures". Thus, the exemplary term "above" can include both "above" and "below". The device can also be positioned in other different ways (rotated 90 degrees or in other orientations), and the spatially relative descriptions used here are interpreted accordingly.

[0037] In addition, it should be noted that the use of words such as "first" and "second" to define components is only for the convenience of distinguishing the corresponding components. If not otherwise stated, the above words have no special meaning and cannot be understood as limiting the scope of protection of this application. In addition, although the terms used in this application are selected from well-known and commonly used terms, some terms mentioned in the specification of this application may be selected by the applicant at his or her discretion, and their detailed meanings are explained in the relevant parts of the description of this article. In addition, it is required to understand this application not only by the actual terms used, but also by the meaning implied by each term.

[0038] Flowcharts are used in the present application to illustrate the operations performed by the system according to the embodiments of the present application. It should be understood that the preceding or following operations are not necessarily performed accurately in order. On the contrary, various steps may be processed in reverse order or simultaneously. At the same time, other operations may be added to these processes, or one or more operations may be removed from these processes.

[0039] Next, the preparation method of the solar cell and the solar cell of the present application are described through examples.

[0040] refer to Figure 1 As shown, the method for preparing a solar cell may include the following steps S110 to S140.

[0041] Step S110: providing a solar cell precursor, wherein the solar cell precursor has a first surface and a second surface opposite to each other;

[0042] Step S120: forming a seed layer on a local area of ​​the first surface and / or a local area of ​​the second surface, wherein the film layer to which the surface of the seed layer belongs is conductive;

[0043] Step S130: forming an insulating layer on the surface where the seed layer is located, wherein the insulating layer does not cover the seed layer or covers part of the seed layer, and the insulating layer has an opening exposing at least part of the seed layer;

[0044] Step S140: electroplating a plating layer on the seed layer exposed by the opening.

[0045] Next, steps S110 to S140 are described in detail.

[0046] refer to Figure 2 In step S110, a solar cell precursor 210 is provided, and the solar cell precursor 210 has a first surface 211 and a second surface 212 relative to each other. The solar cell precursor 210 refers to a solar cell that has not been metallized (i.e., grid lines have not been formed yet). The film layer to which the first surface 211 and / or the second surface 212 belongs can be conductive. For example, the first surface 211 can be the surface of a transparent conductive layer (Transparent Conductive Oxide, TCO) in the solar cell precursor 210, the surface of an N-type doped silicon material, or the surface of a P-type doped silicon material, and the second surface 212 can be the surface of a transparent conductive layer in the solar cell precursor 210, the surface of an N-type doped silicon material, or the surface of a P-type doped silicon material.

[0047] When the solar cell is working, the first surface 211 may face the sun or face away from the sun.

[0048] refer to Figure 2 and Figure 3 As shown, in step S120, a seed layer 220 is formed on a local area of ​​the first surface 211, and the film layer to which the surface (i.e., the first surface 211) where the seed layer 220 is located is conductive. Taking a solar cell intermediate having a transparent conductive layer as an example, "the film layer to which the surface where the seed layer 220 is located is conductive" is specifically described. The surface of the transparent conductive layer away from the silicon substrate is the first surface 211, and the seed layer 220 is formed on the transparent conductive layer, and the film layer (i.e., the transparent conductive layer) to which the first surface 211 where the seed layer 220 is located is conductive.

[0049] It should be noted that the seed layer 220 may be formed only on a local area of ​​the second surface 212, or the seed layer 220 may be formed on a local area of ​​the first surface 211 and a local area of ​​the second surface 212 at the same time. For the convenience of explanation, the present application is described below by taking "forming the seed layer 220 on a local area of ​​the first surface 211" as an example. The seed layer 220 may contain one or more of silver, copper, and nickel.

[0050] The width and thickness of the seed layer may be set as required. For example, the width of the seed layer may be set according to the width of the electroplated layer in step S140.

[0051] In one embodiment, the step of forming a seed layer on a local area of ​​the first surface includes:

[0052] Step S121: directly printing a slurry containing metal on a local area;

[0053] Step S122: drying the slurry to transform the slurry into a seed layer.

[0054] In addition to metals, the slurry may also contain organic matter, which volatilizes after drying.

[0055] Compared with the technical solution of "first forming a seed layer on the entire surface and then removing part of the seed layer", the present application directly forms the seed layer on a local area, which has the advantage of fewer process steps. In addition, it omits the step of etching the seed layer and reduces the generation of metal waste liquid.

[0056] refer to Figure 3 and Figure 4 As shown, in step S130, an insulating layer 230 is formed on the surface where the seed layer 220 is located, and the insulating layer 230 exposes at least a portion of the seed layer 220. When electroplating the electroplated layer, if the film layer where the seed layer 220 is located is conductive, for example, the seed layer 220 is formed on the transparent conductive layer, the electroplated layer will not be formed on the transparent conductive layer covered by the insulating layer.

[0057] exist Figure 3 and Figure 4 In the embodiment, the insulating layer 230 contacts the boundary of the seed layer 220 but does not cover the seed layer 220. The insulating layer 230 has an opening 231, and the opening 231 exposes the seed layer 220. Figure 4 In the figure, the insulating layer 230 has a first side wall 232 and a second side wall 233 relative to each other (the first side wall 232 and the second side wall 233 are also the side walls of the opening 231), the first side wall 232 contacts the left side boundary of the seed layer 220, the second side wall 233 contacts the right side boundary of the seed layer 220, and the insulating layer 230 does not cover the seed layer 220, or in other words, the projection of the insulating layer 230 in the vertical direction does not overlap with the seed layer 220.

[0058] refer to Figure 7 As shown, in Figure 7 In the embodiment, the insulating layer 230 covers the edge portion of the seed layer 220, or in other words, the projection of the insulating layer 230 in the vertical direction overlaps with the edge portion of the seed layer 220, and the opening 231 exposes part of the seed layer 220. The “edge portion” may account for less than 50% of the seed layer 220, for example, the “edge portion” may account for 5%, 15%, 25%, 35% or 45% of the seed layer 220. There is a risk that the metal in the electroplating layer will diffuse into the solar cell precursor 210, which will worsen the passivation effect on the solar cell. Figure 7 and Figure 8 In the embodiment, the electroplating layer 240 is formed on the seed layer 220 that is not covered by the insulating layer 230, and the electroplating layer 240 cannot be formed on the edge portion of the seed layer 220. This increases the distance for the metal in the electroplating layer 240 to diffuse into the solar cell precursor 210, thereby preventing the metal in the electroplating layer 240 from diffusing into the solar cell precursor 210.

[0059] refer to Fig. 9 As shown, in Fig. 9 In the embodiment of the present invention, the insulating layer 230 does not cover the seed layer 220 and is spaced a certain distance from the boundary of the seed layer 220 , and the opening 231 exposes the entire seed layer 220 .

[0060] In one embodiment, the insulating layer 230 includes insulating glue and / or hot melt wax.

[0061] In one embodiment, the depth of the opening 231 is any value within a range of 1 μm to 50 μm, for example, the depth of the opening 231 is 1 μm, 5 μm, 10 μm, 15 μm, 20 μm, 25 μm, 30 μm, 35 μm, 40 μm, 45 μm or 50 μm. It should be noted that when measuring the depth of the opening 231, the seed layer 220 is not considered.

[0062] refer to Figure 3 and Figure 4 As shown, compared with the technical solution of "first forming an insulating layer covering the entire first surface and then removing the insulating layer covering the seed layer", the present application "directly forming as shown in FIG. Figure 4 The technical solution of "patterned insulating layer" as shown can, on the one hand, save the process step of "removing the insulating layer covering the seed layer", and on the other hand, can also reduce the amount of insulating layer used.

[0063] refer to Figure 4 and Figure 5As shown, in step S140, a plating layer 240 is electroplated on the seed layer 220 exposed by the opening 231. The plating layer 240 may include one or more of copper, silver, and tin. The plating layer 240 may be a laminated structure. Specifically, a layer of metal copper may be electroplated first, and then a layer of metal silver may be electroplated on the metal copper, so as to form the plating layer 240 including a copper layer and a silver layer.

[0064] During the electroplating process of the electroplating layer 240, the opening 231 limits the width of the electroplating layer 240. For example, the width of the opening 231 can be set to be smaller, so that the electroplating layer 240 with a smaller width can be obtained, which can reduce the shielding of the electroplating layer 240 on the incident light. If the insulating layer 230 with the opening 231 is not provided, the width of the electroplating layer 240 will not be limited during the electroplating process, which will result in a larger width of the electroplating layer 240, and will further shield more incident light.

[0065] refer to Figure 5 and Figure 6 As shown, in one embodiment, the preparation method further includes: removing the insulating layer 230 after electroplating the electroplating layer 240 .

[0066] exist Figure 5 and Figure 6 In the example, the width of the seed layer 220 is w1, and the width of the electroplating layer 240 is w2. Figure 5 The insulating layer 230 in the embodiment contacts the boundary of the seed layer 220 and does not cover the seed layer 220, so the width w1 is equal to the width w2. The width w1 being equal to the width w2 can reduce the shielding of the incident light.

[0067] exist Figure 7 and Figure 8 In the embodiment, since the insulating layer 230 covers the edge portion of the seed layer 220, the electroplated plating layer 240 is formed on the seed layer 220 exposed by the opening 231, Figure 8 The width w1 in the lattice is greater than the width w2. The width w1 being greater than the width w2 can increase the distance that the metal in the electroplating layer 240 diffuses through the seed layer 220 to the solar cell precursor 210.

[0068] exist Fig. 9 and Fig.10 In the embodiment, a preset distance is provided between the boundary of the insulating layer 230 and the seed layer 220. During the electroplating process of the electroplating layer 240, the width of the electroplating layer 240 increases. After the electroplating is completed, the width w2 of the electroplating layer 240 is greater than the width w1 of the seed layer 220.

[0069] refer to Fig.15As shown, in one embodiment, the electroplating layer 240 includes a stacked first sublayer 241 and a second sublayer 242. During the electroplating process of the electroplating layer 240, the first sublayer 241 is electroplated first, and then after removing the insulating layer, the second sublayer 242 is electroplated or chemically plated, and the second sublayer 242 covers at least a portion of the first sublayer 241. If the first sublayer 241 does not cover the entire seed layer 220, the second sublayer 242 may also cover the uncovered seed layer 220.

[0070] refer to Fig.11 As shown, in one embodiment, the solar cell precursor 210 includes a first transparent conductive layer 213 and a second transparent conductive layer 214, the first surface 211 is the surface of the first transparent conductive layer 213 facing outward, and the second surface 212 is the surface of the second transparent conductive layer 214 facing outward. In some embodiments, the solar cell precursor 210 may not include the first transparent conductive layer 213 or the second transparent conductive layer 214. The metal-containing paste used for printing on the transparent conductive layer may be a low-temperature non-burn-through paste. The seed layer 220 and the electroplating layer 240 are formed on the first transparent conductive layer 213.

[0071] The transparent conductive layer can be a single-layer structure or a stacked-layer structure. For example, the transparent conductive layer can be a single-layer tin-doped indium oxide (ITO) film layer or a single-layer tin oxide (SnO) film layer. For another example, the transparent conductive layer can be a stacked-layer structure consisting of an ITO film layer and a SnO film layer. For another example, the transparent conductive layer can be a stacked-layer structure consisting of an ITO film layer, a SnO film layer and an ITO film layer.

[0072] refer to Fig.12 As shown, in one embodiment, the method for preparing a solar cell further includes forming a first anti-reflection layer 215 and a second anti-reflection layer 216 on the first surface 211 and the second surface 212 of the solar cell precursor 210, respectively. The first anti-reflection layer 215 and the second anti-reflection layer 216 are insulated, and the first anti-reflection layer 215 and the second anti-reflection layer 216 may include one or more of silicon nitride, silicon oxynitride, and silicon oxide. A seed layer 220 and an electroplating layer 240 are formed on the first surface 211, and the seed layer 220 penetrates the first anti-reflection layer 215 and contacts the first surface 211.

[0073] The anti-reflection layer may be a single-layer structure, for example, the anti-reflection layer is a SiN film layer, a SiON film layer, a SiO2 film layer or an Al2O3 film layer, etc., or may be a stacked structure composed of multiple film layers. It is understood that the anti-reflection layer may also be formed only on the first surface 211 or the second surface 212.

[0074] refer to Fig.14As shown, the first anti-reflection layer 215 has an opening 215a, the seed layer 220 is located in the opening 215a, the insulating layer 230 is located on the first surface 211, and the insulating layer 230 is in contact with the surface of the first anti-reflection layer 215 away from the first surface 211. Fig.14 The seed layer 220 in the reference Fig.13 As shown, a metal-containing paste 260 is printed on the first anti-reflection layer 215; then, the paste 260 is sintered, and the paste 260 burns through the first anti-reflection layer 215 and is transformed into a seed layer 220. After the seed layer 220 is formed, the insulating layer 230 is formed. The metal-containing paste 260 printed on the first anti-reflection layer can be a high-temperature burn-through type paste.

[0075] This application also proposes another method for preparing a solar cell, referring to Fig.16 As shown, Fig.16 The preparation method in the embodiment includes the following steps S310 to S340.

[0076] Step S310: providing a solar cell precursor, wherein the solar cell precursor has an anti-reflection layer;

[0077] Step S320: forming a slurry containing a metal on a local area of ​​the anti-reflection layer;

[0078] Step S330: sintering the slurry so that the slurry burns through the anti-reflection layer. After the sintering, the slurry is transformed into a seed layer, and the seed layer is electrically connected to the doped silicon layer in the solar cell precursor.

[0079] Step S340: electroplating a plating layer on the seed layer.

[0080] Next, steps S310 to S340 are described in detail.

[0081] refer to Fig.17 In step S310 , a solar cell precursor 310 is provided. The solar cell precursor 310 has a first anti-reflection layer 311 and a second anti-reflection layer 312 . The solar cell precursor 310 may not include the first anti-reflection layer 311 or the second anti-reflection layer 312 .

[0082] In step S320, a slurry 320 containing a metal is formed on a local area of ​​the first anti-reflection layer 311, or the slurry 320 may be formed only on a local area of ​​the second anti-reflection layer 312, or the slurry 320 may be formed on a local area of ​​the first anti-reflection layer 311 and a local area of ​​the second anti-reflection layer 312. The preparation method is described below by taking "forming the slurry 320 on the first anti-reflection layer 311" as an example. For other descriptions of the slurry, please refer to the relevant parts of the previous text, which will not be expanded here.

[0083] refer to Fig.17 and Fig.18 As shown, in step S330, the slurry 320 is sintered so that the slurry 320 burns through the first anti-reflection layer 311. After the sintering process, the slurry 320 is transformed into a seed layer 330, and the seed layer 330 contacts and forms an electrical connection with the doped silicon layer 340 in the solar cell precursor. The doped silicon layer 340 can be a doped polycrystalline silicon layer (e.g., N-type or P-type doped polycrystalline silicon), doped microcrystalline silicon (e.g., N-type or P-type doped microcrystalline silicon), or doped amorphous silicon (e.g., N-type or P-type doped amorphous silicon).

[0084] refer to Fig.18 and Fig.19 As shown, in step S340 , a plating layer 350 is electroplated on the seed layer 330 . The width of the plating layer 350 may be greater than the width of the seed layer 330 .

[0085] The method of forming the electroplating layer 350 in steps S310 to S340 does not require forming an insulating layer, which further simplifies the process steps of preparing the solar cell.

[0086] In one embodiment, the step of forming a seed layer on a local area of ​​the anti-reflection layer includes printing the paste 330 directly on the local area, rather than forming the paste covering the entire surface of the anti-reflection layer and then removing the paste except the local area.

[0087] refer to Fig.19 As shown, in one embodiment, the electroplating layer 350 includes a stacked first sublayer 351 and a second sublayer 352. During the electroplating process of the electroplating layer 350, the first sublayer 351 is electroplated first, and then the second sublayer 352 is electroplated or chemically plated on the first sublayer 351, and the second sublayer 352 covers at least a portion of the first sublayer 351.

[0088] For other details about the above preparation method, please refer to the relevant part above, which will not be elaborated here.

[0089] On the other hand, the present application also provides a solar cell, the solar cell includes a plurality of grid lines, and the plurality of grid lines can be arranged on the backlight surface of the solar cell, or on the light-receiving surface and the backlight surface of the solar cell. Figure 6 , Figure 8 and Fig.11 As shown, the gate line includes a seed layer 220 and an electroplating layer 240 located on the seed layer 220 , and the width of the electroplating layer 240 is smaller than, equal to, or larger than the width of the seed layer 220 .

[0090] refer to Fig.12As shown, in one embodiment, the solar cell further includes a first anti-reflection layer 215 and a second anti-reflection layer 216, and the grid line runs through the first anti-reflection layer 215 and forms an electrical connection with the doped silicon layer (not shown) in the solar cell. It can be understood that a grid line can also be provided on the side where the second anti-reflection layer 216 is located, and the grid line runs through the second anti-reflection layer 216. In the process of forming the seed layer 220, the seed layer 220 burns through the anti-reflection layer where it is located.

[0091] refer to Fig.11 As shown, in one embodiment, the solar cell further includes a first transparent conductive layer 213 and a second transparent conductive layer 214, and the gate line is located on the first transparent conductive layer 213, and the gate line is electrically connected to the first transparent conductive layer 213. It can be understood that the gate line can also be arranged on the second transparent conductive layer 214, and the gate line is electrically connected to the second transparent conductive layer 214.

[0092] For other descriptions about the solar cell of the present application, please refer to the relevant parts in the previous text, which will not be elaborated here.

[0093] The basic concepts have been described above. Obviously, for those skilled in the art, the above application disclosure is only an example and does not constitute a limitation of the present application. Although not explicitly stated herein, those skilled in the art may make various modifications, improvements and amendments to the present application. Such modifications, improvements and amendments are suggested in the present application, so such modifications, improvements and amendments still belong to the spirit and scope of the exemplary embodiments of the present application.

[0094] At the same time, the present application uses specific words to describe the embodiments of the present application. For example, "one embodiment", "an embodiment", and / or "some embodiments" refer to a certain feature, structure or characteristic related to at least one embodiment of the present application. Therefore, it should be emphasized and noted that "one embodiment" or "an embodiment" or "an alternative embodiment" mentioned twice or more in different positions in this specification does not necessarily refer to the same embodiment. In addition, some features, structures or characteristics in one or more embodiments of the present application can be appropriately combined.

[0095] Similarly, it should be noted that in order to simplify the description of the disclosure of this application and thus help understand one or more application embodiments, in the above description of the embodiments of this application, multiple features are sometimes merged into one embodiment, figure or description thereof. However, this disclosure method does not mean that the features required by the object of this application are more than the features mentioned in the claims. In fact, the features of the embodiments are less than all the features of the single embodiment disclosed above.

[0096] In some embodiments, numbers describing the number of components and attributes are used. It should be understood that such numbers used in the description of the embodiments are modified by the modifiers "about", "approximately" or "substantially" in some examples. Unless otherwise specified, "about", "approximately" or "substantially" indicate that the numbers are allowed to vary by ±20%. Accordingly, in some embodiments, the numerical parameters used in the specification and claims are approximate values, which may change according to the required features of individual embodiments. In some embodiments, the numerical parameters should take into account the specified significant digits and adopt the general method of retaining digits. Although the numerical domains and parameters used to confirm the breadth of their range in some embodiments of the present application are approximate values, in specific embodiments, the setting of such numerical values ​​is as accurate as possible within the feasible range.

[0097] Although the present application has been described with reference to the current specific embodiments, ordinary technicians in this technical field should recognize that the above embodiments are only used to illustrate the present application, and various equivalent changes or substitutions may be made without departing from the spirit of the present application. Therefore, as long as the changes and modifications to the above embodiments are within the essential spirit of the present application, they will fall within the scope of the claims of the present application.

Claims

1. A method for preparing a solar cell, characterized in that: include: Providing a solar cell precursor, the solar cell precursor having a first surface and a second surface opposite to each other; forming a seed layer on a local area of ​​the first surface and / or a local area of ​​the second surface, wherein the film layer to which the surface where the seed layer is located belongs is conductive; forming an insulating layer on the surface where the seed layer is located, wherein the insulating layer does not cover the seed layer or covers part of the seed layer, and the insulating layer has an opening exposing at least part of the seed layer; as well as An electroplating layer is electroplated on the seed layer exposed by the opening.

2. The method for preparing a solar cell according to claim 1, characterized in that: The step of forming a seed layer on a local area of ​​the first surface and / or the second surface comprises: Printing a paste containing a metal directly on the local area; The slurry is dried to transform the slurry into the seed layer.

3. The method for preparing a solar cell according to claim 1, wherein: The width of the electroplating layer is smaller than, equal to, or larger than the width of the seed layer.

4. The method for preparing a solar cell according to claim 1, wherein: The insulating layer includes insulating glue and / or hot melt wax.

5. The method for preparing a solar cell according to claim 1, wherein: The depth of the opening of the insulating layer is 1 μm to 50 μm.

6. The method for preparing a solar cell according to claim 1, wherein: Also includes: After electroplating the electroplating layer, the insulating layer is removed.

7. The method for preparing a solar cell according to claim 1, characterized in that: The electroplating layer includes a stacked first sublayer and a second sublayer. During the electroplating process of the electroplating layer, the first sublayer is electroplated first, and then after removing the insulating layer, the second sublayer is electroplated or chemically plated, wherein the second sublayer covers at least part of the first sublayer and / or the seed layer not covered by the first sublayer.

8. The method for preparing a solar cell according to claim 1, wherein: The solar cell precursor includes a first transparent conductive layer and / or a second transparent conductive layer, the first surface is a surface of the first transparent conductive layer facing outward, and the second surface is a surface of the second transparent conductive layer facing outward.

9. The method for preparing a solar cell according to claim 1, wherein: Also includes: An anti-reflection layer is formed on the first surface and / or the second surface, the anti-reflection layer has an opening, the seed layer is located in the opening of the anti-reflection layer, and the insulating layer is in contact with a surface of the anti-reflection layer away from the first surface.

10. A method for preparing a solar cell, characterized in that: include: Providing a solar cell precursor, wherein the solar cell precursor has an anti-reflection layer; forming a slurry containing a metal on a local area of ​​the anti-reflection layer; Sintering the slurry so that the slurry burns through the anti-reflection layer, and after the sintering, the slurry is transformed into a seed layer, and the seed layer is electrically connected to the doped silicon layer in the solar cell precursor; as well as A plating layer is electroplated on the seed layer.

11. The method for preparing a solar cell according to claim 10, characterized in that: The step of forming a seed layer on a local area of ​​the anti-reflection layer includes: printing the slurry directly on the local area.

12. The method for preparing a solar cell according to claim 10, characterized in that: The electroplating layer includes a stacked first sublayer and a second sublayer. During the electroplating process of the electroplating layer, the first sublayer is electroplated first, and then the second sublayer is electroplated or chemically plated on the first sublayer, wherein the second sublayer covers at least a portion of the first sublayer.

13. A solar cell, characterized in that: The invention comprises a plurality of grid lines, wherein the grid lines comprise a seed layer and an electroplating layer located on the seed layer, wherein the width of the electroplating layer is smaller than, equal to or larger than the width of the seed layer.

14. The solar cell according to claim 13, wherein: Also includes: A first anti-reflection layer and / or a second anti-reflection layer, the plurality of grid lines penetrate the first anti-reflection layer and / or the second anti-reflection layer and form an electrical connection with the doped silicon layer in the solar cell, wherein, in the process of forming the seed layer, the seed layer burns through the anti-reflection layer where it is located.

15. The solar cell according to claim 13, wherein: Also includes: A first transparent conductive layer and / or a second transparent conductive layer, and the plurality of gate lines are located on the first transparent conductive layer and / or the second transparent conductive layer.

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