CN118522820A - Electrode structure, preparation method thereof, solar cell and photovoltaic module - Google Patents

Abstract

The present invention provides an electrode structure and a preparation method thereof, a solar cell and a photovoltaic module, and relates to the field of photovoltaic technology. The method comprises: forming a laminated structure on a battery body; from away from the battery body to close to the battery body, the laminated structure comprises: a patterned layer, a whole layer of a main conductive metal layer and a whole layer of a first metal modification layer in sequence; the patterned layer is intermittently distributed on the main conductive metal layer, so that the main conductive metal layer is partially exposed; a first etching solution is used to wet-etch the exposed main conductive metal layer to form a patterned main conductive metal layer, and the first metal modification layer is partially exposed; a second etching solution is used to wet-etch the exposed first metal modification layer to form a patterned first metal modification layer, and the battery body is partially exposed. Two adjacent etching steps are not interrupted by non-etching steps, the cost is low, and the diffusion of metal ions into the battery body can be reduced.

Description

Electrode structure and preparation method thereof, solar cell and photovoltaic module

Technical Field

The present invention relates to the field of photovoltaic technology, and in particular to an electrode structure and a preparation method thereof, a solar cell and a photovoltaic module.

Background Art

Solar cells can convert solar energy into electrical energy. They use clean energy and therefore have broad application prospects. The electrode structure of solar cells is mainly used to conduct and collect carriers.

In the process of preparing the electrode of the solar cell, etching is inevitably performed. However, in the existing method of preparing the electrode of the solar cell, there are many etching steps, resulting in high cost.

Summary of the invention

The present invention provides an electrode structure and a preparation method thereof, a solar cell and a photovoltaic module, aiming to solve the problem that in the existing electrode preparation method, there are many etching steps, resulting in high costs.

A first aspect of the present invention provides a method for preparing an electrode structure of a solar cell, comprising:

A laminated structure is formed on the battery body; the laminated structure includes, in order from away from the battery body to close to the battery body: a patterned layer, a whole main conductive metal layer and a whole first metal modification layer; the patterned layer is intermittently distributed on the main conductive metal layer, so that the main conductive metal layer is partially exposed;

Using a first etching solution, wet-etching the exposed main conductive metal layer to form a patterned main conductive metal layer, and partially exposing the first metal modification layer;

The exposed first metal modification layer is wet-etched by using a second etching solution to form a patterned first metal modification layer, and the battery body is partially exposed.

In the embodiment of the present invention, the etching of the main conductive metal layer and the etching of the first metal modification layer are adjacent etching steps. There is no other non-etching step between the two adjacent etching steps, and the two adjacent etching steps are not interrupted by the non-etching step, so that only one etching device is needed to complete the preparation of the electrode structure, which can reduce the cost. For example, only one etching device or etcher is used, and the first etching solution and the second etching solution are set in different grooves to complete the preparation of the electrode structure. At the same time, most metal ions diffuse into the battery body, which will at least cause adverse effects such as recombination. Since the selected first etching solution has basically no etching effect on the first metal modification layer, the first metal modification layer below can basically maintain a complete structure during the wet etching of the main conductive metal layer, and the metal ions in the main conductive metal layer can be blocked or isolated during the etching process, and the metal ions in the main conductive metal layer can be avoided as much as possible from diffusing into the battery body during the etching process, which can reduce the effects of recombination. After etching, there is still a patterned first metal modification layer between the patterned main conductive metal layer and the battery body for isolation or blocking. In the subsequent use of the solar cell, the metal ions in the main conductive metal layer can still be prevented from diffusing into the battery body as much as possible, which can reduce the effects of recombination. Moreover, due to the above-mentioned isolation or blocking effect of the first metal modification layer, the main conductive metal layer has good stability. Moreover, the above two adjacent etching steps both use wet etching, which can reduce costs, improve reliability, and is suitable for mass production compared to other etching methods.

Optionally, forming a laminated structure on the battery body includes:

On the battery body, a first metal modification layer, a main conductive metal layer and an outer layer structure are sequentially formed in an entire layer;

At least one of laser etching and photolithography etching is used to remove part of the outer layer structure so that the entire main conductive layer is partially exposed to form the patterned layer.

Optionally, forming a laminated structure on the battery body includes:

On the battery body, sequentially forming a first metal modification layer and a main conductive metal layer;

The patterned layer is prepared on the entire main conductive metal layer by using at least one of inkjet printing, screen printing and gravure printing.

Optionally, the patterned layer includes: a patterned mask layer, and/or a patterned second metal modification layer, the patterned mask layer is farthest from the battery body; the material of the patterned mask layer includes: TCO, and/or tin; the material of the patterned second metal modification layer includes: at least one of nickel, titanium and silver.

Optionally, the battery body comprises: a TCO layer adjacent to the first metal modification layer and forming an entire layer;

The second etching solution is used to wet-etch the exposed first metal modification layer to form a patterned first metal modification layer, and the battery body is partially exposed, including:

The exposed first metal modification layer is etched with an acidic etching solution to form a patterned first metal modification layer, and the TCO layer is partially exposed. The acidic etching solution etches the exposed TCO layer to form a patterned TCO layer.

Optionally, the patterned layer includes: a patterned mask layer, the material of the patterned mask layer includes: TCO and/or tin; the patterned mask layer is farthest from the battery body; the acidic etching solution is used to etch the exposed first metal modification layer to form a patterned first metal modification layer, and the TCO layer is partially exposed, and the acidic etching solution is used to etch the exposed TCO layer to form a patterned TCO layer, including:

The acidic etching solution is used to etch the exposed first metal modification layer to form a patterned first metal modification layer, and the TCO layer is partially exposed. The acidic etching solution is used to etch the exposed TCO layer to form a patterned TCO layer. At the same time, the acidic etching solution etches away the patterned mask layer.

Optionally, the patterned layer only includes: a patterned mask layer; the second etching solution is used to wet-etch the exposed first metal modification layer to form a patterned first metal modification layer, and the battery body is partially exposed, including:

The second etching solution is used to etch the exposed first metal modification layer to form a patterned first metal modification layer, and the battery body is partially exposed, and the second etching solution etches away the patterned mask layer to expose the patterned main conductive metal layer;

A patterned second metal modification layer is obtained by electroplating on the patterned main conductive metal layer; the material of the patterned second metal modification layer includes at least one of nickel, titanium, silver and tin.

Optionally, the first etching solution includes: a neutral etching solution, or an alkaline etching solution;

The second etching solution includes: an acidic etching solution.

Optionally, the shape of the laser spot used for laser etching includes: square, circular; the size of the laser spot is 20 to 60 microns.

A second aspect of the present invention provides an electrode structure for a solar cell, comprising:

A patterned first metal modification layer is disposed adjacent to the battery body;

A patterned main conductive metal layer is located on a side of the patterned first metal modification layer away from the battery body;

Wherein, the material of the patterned main conductive metal layer includes: copper;

The patterned first metal modification layer includes: a tin layer; or, a tin layer adjacent to the patterned main conductive metal layer, and an aluminum layer between the tin layer and the battery body.

Optionally, the electrode structure further includes:

The patterned second metal modification layer is located on a side of the patterned main conductive metal layer away from the patterned first metal modification layer.

Optionally, the material of the patterned second metal modification layer includes at least one of nickel, titanium, silver and tin.

Optionally, the thickness of the patterned main conductive metal layer is greater than the thickness of the patterned second metal modification layer, and the thickness of the patterned main conductive metal layer is greater than the thickness of the patterned first metal modification layer.

Optionally, the patterned main conductive metal layer is a single-layer or multi-layer structure;

And/or, the patterned first metal modification layer is a single layer or multi-layer structure;

And/or, the patterned second metal modification layer is a single-layer or multi-layer structure.

Optionally, the patterned second metal modification layer has a thickness of 50 nm to 150 nm.

A third aspect of the present invention provides a solar cell, comprising:

A cell body, and an electrode structure located on at least one side of the cell body, such as any of the aforementioned solar cells.

Optionally, the battery body includes: a patterned TCO layer, which is arranged adjacent to the electrode structure.

A fourth aspect of the present invention provides a photovoltaic assembly, comprising: a plurality of any of the aforementioned solar cells.

The above-mentioned electrode structure, method for preparing the electrode structure, solar cell and photovoltaic module have the same or similar beneficial effects, and will not be described in detail here to avoid repetition as much as possible.

BRIEF DESCRIPTION OF THE DRAWINGS

In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings required for use in the description of the embodiments of the present invention will be briefly introduced below. Obviously, the accompanying drawings in the following description are only some embodiments of the present invention. For ordinary technicians in this field, other accompanying drawings can be obtained based on these accompanying drawings without paying creative labor.

1 to 4 are schematic diagrams showing steps for preparing an electrode structure of a solar cell according to an embodiment of the present invention;

5 to 7 are schematic diagrams showing steps for preparing another electrode structure of a solar cell according to an embodiment of the present invention;

8 to 11 are schematic diagrams showing steps for preparing another electrode structure of a solar cell in an embodiment of the present invention.

Description of the accompanying drawings:

1-battery body, 11-TCO layer, 21-patterning layer or outer layer structure, 22-main conductive metal layer, 23-first metal modification layer, 211-mask layer, 212-second metal modification layer.

DETAILED DESCRIPTION

The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

The inventors have found that in the existing method for preparing solar cell electrodes, there are many etching steps, and the main reason for the high cost is that non-etching steps are interspersed between some adjacent etching steps, interrupting the continuity of the etching steps. However, each discontinuous etching step usually requires different etching equipment, so that in the preparation process of the electrode, the etching steps require more etching equipment, resulting in higher costs.

The present invention provides a method for preparing an electrode structure of a solar cell. The solar cell can be distinguished from a material: a crystalline silicon solar cell, a perovskite solar cell, etc., and can be distinguished from a distribution position of the electrode structure: a double-sided solar cell, or a back contact solar cell, etc., and the type of the solar cell is not specifically limited. For example, the solar cell can be an HBC (back contact heterojunction solar cell). The solar cell may include: a battery body, and an electrode structure located on at least one side of the battery body. The battery body may include a base and an emitter, and the electrode structure is used to collect and conduct carriers in the battery body. The preparation method may include the following steps.

Step 101, forming a stacked structure on the battery body; from away from the battery body to close to the battery body, the stacked structure includes: a patterned layer, a whole layer of main conductive metal layer and a whole layer of first metal modification layer; the patterned layer is intermittently distributed on the main conductive metal layer, so that the main conductive metal layer is partially exposed.

Figures 1 to 4 show schematic diagrams of steps for preparing an electrode structure of a solar cell in an embodiment of the present invention. Figures 5 to 7 show schematic diagrams of steps for preparing another electrode structure of a solar cell in an embodiment of the present invention. Figures 8 to 11 show schematic diagrams of steps for preparing yet another electrode structure of a solar cell in an embodiment of the present invention.

Referring to FIG2 , a schematic diagram of a laminated structure is shown. In the figure, the laminated structure is located on the battery body 1. In the figure, the dotted line L shows the direction from away from the battery body 1 to close to the battery body 1. From away from the battery body 1 to close to the battery body 1, the laminated structure includes in sequence: a patterned layer 21, a whole layer of the main conductive metal layer 22 and a whole layer of the first metal modification layer 23. The patterned layer 21 is intermittently distributed on the main conductive metal layer 22, so that the main conductive metal layer 22 is partially exposed. The main conductive metal layer 22 here refers to the part of the electrode structure that is mainly used to collect and conduct carriers. The material of the main conductive metal layer 22 here can be a base metal with good conductivity and low cost.

It should be noted that the patterned layer 21 is distributed discontinuously on the main conductive metal layer 22 , and the size and specific shape of the discontinuous distribution are not limited.

Step 102: using a first etching solution, wet-etching the exposed main conductive metal layer to form a patterned main conductive metal layer, and partially exposing the first metal modification layer.

3, the first etching solution is used to wet-etch the exposed main conductive metal layer 22 to form a patterned main conductive metal layer 22, and partially expose the first metal modification layer 23. The composition of the first etching solution used here needs to be determined according to the materials of the main conductive metal layer 22 and the first metal modification layer 23, so as to be able to etch away the main conductive metal layer 22 while having substantially no etching effect on the first metal modification layer 23.

Step 103: using a second etching solution to wet-etch the exposed first metal modification layer to form a patterned first metal modification layer, and partially exposing the battery body.

The first etching solution and the second etching solution are different here. Referring to FIG. 4 , the second etching solution is used to wet-etch the exposed first metal modification layer 23 to form a patterned first metal modification layer 23, and partially expose the battery body 1. The composition of the second etching solution used here needs to be determined according to the materials of the main conductive metal layer 22 and the first metal modification layer 23, so as to be able to etch away the first metal modification layer 23 while having substantially no etching effect on the main conductive metal layer 22.

Compared with the prior art, in the process of preparing the electrode structure, the adjacent etching steps are interrupted, resulting in a technical problem of high etching cost. In the present invention, the etching of the main conductive metal layer 22 and the etching of the first metal modification layer 23 are adjacent etching steps. There is no other non-etching step between the two adjacent etching steps, and the two adjacent etching steps are not interrupted by the non-etching step. Therefore, only one etching device is needed to complete the preparation of the electrode structure, which can reduce the cost. For example, only one etching device or etcher is used, and the first etching solution and the second etching solution are set in different grooves to complete the preparation of the electrode structure. At the same time, most metal ions diffuse into the battery body, which will at least cause adverse effects such as recombination. Since the selected first etching solution has basically no etching effect on the first metal modification layer 23, the first metal modification layer 23 below can basically maintain a complete structure during the wet etching of the main conductive metal layer 22, and can block or isolate the metal ions in the main conductive metal layer 22 during the etching process, and avoid the metal ions in the main conductive metal layer 22 from diffusing into the battery body during the etching process as much as possible, which can reduce the effects of recombination. After etching, there is still a patterned first metal modification layer 23 between the patterned main conductive metal layer 22 and the battery body 1 to block or isolate. In the subsequent use of the solar cell, the metal ions in the main conductive metal layer 22 can still be avoided as much as possible from diffusing into the battery body 1, which can reduce the effects of recombination. In addition, due to the above-mentioned blocking or blocking effect of the first metal modification layer 23, the main conductive metal layer 22 has good stability. Moreover, the two adjacent etching steps mentioned above both adopt wet etching. Compared with other etching methods, wet etching can reduce costs, improve reliability, and is suitable for mass production.

Optionally, as shown in FIG. 1 , the aforementioned step 101 may include: on the battery body 1, sequentially forming a first metal modification layer 23, a main conductive metal layer 22, and a whole outer structure 21, and then, laser etching or photolithography may be used to remove part of the outer structure 21, so that the main conductive layer 22 of the whole layer is partially exposed to form the patterned layer 21, and both laser etching and photolithography etching have high etching precision and high etching efficiency. Here, the first metal modification layer 23, the main conductive metal layer 22, and the outer structure 21 of the whole layer may be formed by vacuum coating (such as PVD, etc.), electroplating, chemical plating, etc. For example, vacuum coating may be used to form the first metal modification layer 23, the main conductive metal layer 22, and the outer structure 21 of the whole layer. The thickness uniformity of the film formed by the vacuum coating method is good, and a thinner film structure can be obtained, which can further reduce the cost.

Optionally, the shape of the laser spot used in the laser etching here may include: one of square and circular, and the size of the laser spot here may be 20μm (micrometer) to 60μm, and the graphical size formed by the above laser spot is more appropriate, and the electrode structure formed has better performance. For example, the size of the laser spot may be 20μm, or 27μm, or 32μm, or 45μm, or 51μm, or 60μm. Optionally, the laser used in the laser etching may be a violet laser, which has good processing accuracy, etc.

Optionally, the aforementioned step 101 may include: forming a whole layer of the first metal modification layer 23 and a whole layer of the main conductive metal layer 22 on the battery body 1 in sequence, and then preparing a patterned layer 21 on the whole layer of the main conductive metal layer 22 by using at least one of the three methods of inkjet printing, screen printing, and gravure printing. The patterned layer 21 may be prepared in various forms. Here, the whole layer of the main conductive metal layer 22 and the whole layer of the first metal modification layer 23 may be formed by vacuum coating (such as PVD, etc.), electroplating, chemical plating, etc. For example, vacuum coating may be used to form a whole layer of the main conductive metal layer 22 and a whole layer of the first metal modification layer 23. The thickness uniformity of the film layer formed by the vacuum coating method is good, and a thinner film layer structure can be obtained, which can further reduce the cost.

Optionally, the patterned layer 21 may include: a patterned mask layer 211, and/or a patterned second metal modification layer 212, and the patterned mask layer 211 is farthest from the battery body. For example, in Figures 1 to 3, the patterned layer 21 includes: a patterned mask layer 211 and a patterned second metal modification layer 212, and the patterned mask layer 211 is farthest from the battery body. For another example, in Figures 5 to 7, the patterned layer 21 only includes: a patterned second metal modification layer 212. For another example, in Figures 8 to 10, the patterned layer 21 only includes: a patterned mask layer 211. The patterned layer 21 has various forms. The material of the patterned mask layer 211 includes: TCO (transparent conductive material), and/or tin. The mask layer of the above material is easy to be etched by laser etching, photolithography etching, etc., and has high processing accuracy, high processing efficiency, and good masking effect. The material of the patterned second metal modification layer 212 includes at least one of nickel, titanium, and silver. On the one hand, the above-mentioned material is easy to be etched by laser etching, photolithography etching, etc., and has high processing accuracy and high processing efficiency. Referring to Figure 4, after the patterned mask layer 211 is removed, the patterned second metal modification layer 212 is the outermost structure. On the other hand, the second metal modification layer 212 of the above-mentioned material has a large pull-off force and good welding performance during the subsequent string welding process of the solar cell to form a photovoltaic module, so that the long-term reliability of the photovoltaic module is better. Furthermore, the second metal modification layer 212 of the above-mentioned material has better environmental tolerance or better weather resistance, which can fully protect the patterned main conductive metal layer 22, improve its stability, and also improve the long-term reliability of the photovoltaic module.

It should be noted that a second metal modification layer 212 with a relatively thin thickness can be formed by vacuum coating or the like, for example, its thickness can be about 50 nm to 150 nm, and thus it is easy to be patterned by laser etching and photolithography, and the patterning has high precision and high efficiency. Even though silver is selected as the material of the second metal modification layer 212 here, the thickness of the second metal modification layer 212 is relatively thin, and it mainly plays a role in improving the long-term reliability of the photovoltaic module, and its cost is still relatively low compared to the all-silver electrode. The TCO mentioned in the full text may include: ITO, AZO, etc.

Optionally, referring to Figures 1 to 11, the battery body 1 may include: a TCO layer 11 that is adjacent to the first metal modification layer 23 and the entire layer, wherein the TCO layer 11 here can perform appropriate energy band matching on the electrode structure and the battery body, and can achieve low temperature deposition, etc. Referring to Figures 4 and 11, the aforementioned step 103 may include: using an acidic etching solution to etch the exposed first metal modification layer 23 to form a patterned first metal modification layer 23, and partially expose the TCO layer 11, and the acidic etching solution etches the exposed TCO layer 11 to form a patterned TCO layer 11, and the patterning of the TCO layer 11 and the patterning of the aforementioned first metal modification layer 23 are formed in one step, which saves process steps, improves production efficiency, and reduces production costs. The acidic etching solution here can etch away the aforementioned first metal modification layer 23 and TCO layer 11, but it is necessary to have no etching effect on the main conductive metal layer 22.

Optionally, referring to FIG. 3 or FIG. 10 , the patterned layer 21 may include: a patterned mask layer 211, the material of the patterned mask layer 211 includes: TCO, and/or tin, the mask layer of the above material is easy to be etched by laser etching, photolithography etching, etc., and has high processing accuracy, high processing efficiency, and good masking effect. The patterned mask layer 211 is farthest from the battery body 1. The aforementioned use of an acidic etching solution to etch the exposed first metal modification layer 23 to form a patterned first metal modification layer 23, and partially expose the TCO layer 11, and the acidic etching solution etches the exposed TCO layer 11 to form a patterned TCO layer 11, including: using the acidic etching solution to etch the exposed first metal modification layer 11 to form a patterned first metal modification layer 11, and partially expose the TCO layer 11, and the acidic etching solution etches the exposed TCO layer 11 is etched to form a patterned TCO layer 11. At the same time, the acidic etching solution etches the patterned mask layer 211, that is, the acidic etching solution removes the patterned mask layer 211 at one time, and the first metal modification layer 23 and the TCO layer 11 are both patterned and etched. For the patterning of the TCO layer 11, the patterning of the first metal modification layer 23 and the removal of the patterned mask layer 211 are formed in one step, which saves process steps, improves production efficiency, and reduces production costs. The acidic etching solution here can etch the aforementioned first metal modification layer 23, TCO layer 11 and the patterned mask layer 211, but it is necessary to have basically no etching effect on the main conductive metal layer 22. For example, the acidic etching solution here can be hydrochloric acid (HCl) or the like.

Optionally, referring to FIGS. 8 to 11, the patterned layer 21 only includes: a patterned mask layer 211, referring to FIGS. 10 and 11, the aforementioned step 103 may include: using the second etching solution to etch the exposed first metal modification layer 23 to form a patterned first metal modification layer 23, and partially expose the battery body 1, and the second etching solution etches away the patterned mask layer 211, so that the patterned main conductive metal layer 22 is exposed. The second etching solution can also remove the patterned mask layer 211, and can etch away the first metal modification layer 23, but has basically no etching effect on the main conductive metal layer 22. Next, referring to FIG. 4, a patterned second metal modification layer 212 is electroplated on the patterned main conductive metal layer 22, and the material of the patterned second metal modification layer 212 includes: at least one of nickel, titanium, silver, and tin. In this case, the patterned main conductive metal layer 22 is used as a seed layer for electroplating, and the second metal modification layer 212 of the above material is suitable for electroplating. Referring to FIG4 , the patterned second metal modification layer 212 is the outermost structure. On the other hand, the second metal modification layer 212 of the above material has a larger pull-off force and better welding performance during the subsequent string welding process of the solar cell to form a photovoltaic module, so that the long-term reliability of the photovoltaic module is better. Furthermore, the second metal modification layer 212 of the above material has better tolerance to the environment or weather resistance, which can fully protect the patterned main conductive metal layer 22, improve its stability, and improve the long-term reliability of the photovoltaic module.

It should be noted that, referring to Figures 8 to 11, the battery body 1 also includes: a TCO layer 11 that is adjacent to the first metal modification layer 23 and the entire layer. The second etching solution is used to etch the exposed first metal modification layer 23 to form a patterned first metal modification layer 23, and while removing the patterned mask layer 211, the second etching solution can also pattern the entire TCO layer 11 to form a patterned TCO layer, which is equivalent to merging multiple etching steps, with high production efficiency and low cost.

Optionally, the aforementioned first etching solution may include: a neutral etching solution, or an alkaline etching solution, and the second etching solution may include: an acidic etching solution, and further, the first metal modification layer 23 requires an acidic etching solution to be etched or removed, and the main conductive metal layer 22 may be etched or removed using a neutral etching solution or an alkaline etching solution. In the process of etching the main conductive metal layer 22, the neutral etching solution or the alkaline etching solution is basically unable to etch the first metal modification layer 23, and the first metal modification layer 23 can basically maintain a complete morphology, which can prevent the metal ions of the main conductive metal layer 22 from diffusing into the battery body 1 in the process of etching the main conductive metal layer 22. At the same time, in the process of etching the first metal modification layer 23, the acidic etching solution has basically no etching effect on the main conductive metal layer 22. In the case where the laminate structure includes a patterned mask layer 211 and the battery body includes a TCO layer 11, the patterned mask layer 211 can be removed by using an acidic etching solution, and the TCO layer 11 can be patterned and etched, which is equivalent to combining multiple etching steps, with high production efficiency and low cost. For example, the acidic etching solution here can be hydrochloric acid, the neutral etching solution here can include: ferric chloride solution (FeCl ₃ ), and the alkaline solution here can include: ammonia alkaline solution, etc.

The present invention also provides an electrode structure of a solar cell, as shown in FIG4 and FIG11, the electrode structure comprises: a patterned first metal modification layer 23, which is arranged adjacent to the battery body 1, and a patterned main conductive metal layer 22, which is located on a side of the patterned first metal modification layer 23 away from the battery body 1. In the electrode structure, the patterned first metal modification layer 23 can prevent the metal ions in the patterned main conductive metal layer 22 from diffusing into the battery body 1, and can also improve the stability of the main conductive metal layer 22.

Optionally, the material of the patterned main conductive metal layer 22 includes: copper, which has good conductivity, is not a precious metal, and has low cost. The patterned first metal modification layer 23 includes: a tin layer; or, a tin layer adjacent to the patterned main conductive metal layer 22, and an aluminum layer located between the tin layer and the battery body 1. On the one hand, the patterned first metal modification layer 23 of the above material can fully block or block the diffusion of Cu ions in the patterned main conductive metal layer 22 to the battery body 1, and the patterned first metal modification layer 23 of the above material has a small contact resistance with the adjacent battery body 1 and the patterned main conductive metal layer 22, which can reduce the contact resistance. For example, in the case where the battery body 1 includes a TCO layer 11 adjacent to the electrode structure, the patterned first metal modification layer 23 has a small contact resistance with the TCO layer 11 and the patterned main conductive metal layer 22, which can improve the problem of high contact resistance between the patterned main conductive metal layer 22 and the TCO layer 11. Moreover, the patterned main conductive metal layer 22 of the above material can be etched using a neutral etchant, such as FeCl ₃ , or an alkaline solution, such as an ammonia alkaline solution, while the patterned first metal modification layer 23 of the above material can be etched using an acidic etchant, such as hydrochloric acid, etc. The etching process of either of the two has a small impact on the etching of the other, and the diffusion of Cu ions in the patterned main conductive metal layer 22 to the battery body 1 during the etching process of the patterned main conductive metal layer 22 can be avoided as much as possible, and damage to the electrode structure can be avoided as much as possible.

Optionally, referring to Figure 4, the electrode structure may also include: a patterned second metal modification layer 212, located on the side of the patterned main conductive metal layer 22 away from the patterned first metal modification layer 11, and the patterned second metal modification layer 212 is closer to the outside, which can fully protect the patterned main conductive metal layer 22 and improve its stability.

Optionally, the material of the patterned second metal modification layer 212 includes at least one of nickel, titanium, silver, and tin. The patterned second metal modification layer 212 is the outermost structure. On the one hand, the second metal modification layer 212 of the above material has a large pull-off force and good welding performance during the subsequent string welding process of the solar cell to form a photovoltaic module, which makes the long-term reliability of the photovoltaic module better. On the other hand, the second metal modification layer 212 of the above material has better environmental tolerance or weather resistance, which can fully protect the patterned main conductive metal layer 22, improve its stability, and improve the long-term reliability of the photovoltaic module. Moreover, the second metal modification layer 212 of the above material is also easy to form a pattern.

Optionally, the thickness of the patterned main conductive metal layer 22 is greater than the thickness of the patterned second metal modification layer 212, and the thickness of the patterned main conductive metal layer 22 is greater than the thickness of the patterned first metal modification layer 23. The patterned first metal modification layer 23 mainly prevents the diffusion of metal ions in the patterned main conductive metal layer 22, reduces the contact resistance, and maintains the stability of the patterned main conductive metal layer 22. The patterned second metal modification layer 212 can improve the welding reliability and the long-term reliability of the photovoltaic module. In the electrode structure, the main carrier collection and conduction function is the patterned main conductive metal layer 22. The patterned main conductive metal layer 22 can be made of base metals, etc., which can reduce costs. For the patterned main conductive metal layer 22, the thickness difference between the patterned second metal modification layer 212 is not limited. For the thickness of the patterned main conductive metal layer 22, the thickness difference between the patterned first metal modification layer 23 is not specifically limited. There is no specific limitation on the thickness relationship between the patterned first metal modification layer 23 and the patterned second metal modification layer 212 .

Optionally, the patterned main conductive metal layer 22 is a single layer or multi-layer structure, and/or the patterned first metal modification layer 23 is a single layer or multi-layer structure, and/or the patterned second metal modification layer 212 is a single layer or multi-layer structure, and the electrode structure has various structural forms.

Optionally, the thickness of the patterned second metal modification layer 212 is 50nm to 150nm. The patterned second metal modification layer 212 of the above thickness can not only significantly improve the welding reliability and the long-term reliability of the photovoltaic module, but also is easy to prepare and has low cost. For example, the thickness of the patterned second metal modification layer 212 is 50nm, or 60nm, or 71nm, or 83nm, or 90nm, or 120nm, or 150nm.

The present invention also provides a solar cell, as shown in Figures 4 and 11, the solar cell includes: a battery body 1, and any of the aforementioned electrode structures located on at least one side of the battery body 1. Regarding the battery body, reference can be made to the aforementioned related records, and in order to avoid repetition as much as possible, they will not be repeated here.

Optionally, as shown in FIG. 4 and FIG. 11 , the battery body 1 includes: a patterned TCO layer 11 , which is disposed adjacent to the electrode structure. The TCO layer 11 may also refer to the aforementioned related records, and will not be described again here to avoid repetition as much as possible.

The present invention also provides a photovoltaic module, comprising: a plurality of any of the aforementioned solar cells. The photovoltaic module may also include packaging films located on opposite sides of the solar cell.

It should be noted that in the present application, the relevant parts of the electrode structure, the preparation method of the electrode structure, the solar cell and the photovoltaic module can be referenced to each other. In order to avoid repetition as much as possible, the relevant parts are abbreviated and have the same or similar beneficial effects.

The present application is further explained below in conjunction with specific embodiments.

Example 1

Referring to FIG1 , the battery body includes: a whole layer of TCO layer 11, a whole layer of first metal modification layer 23, a whole layer of main conductive metal layer 22 and a whole layer of outer structure 21 are sequentially formed on the TCO layer 11 by vacuum coating. Among them, the first metal modification layer 23 is a tin layer, and the main conductive metal layer 22 is a copper layer. The outer structure 21 includes: a second metal modification layer 212 adjacent to the main conductive metal layer 22, and a mask layer 211 away from the battery body 1. The material of the mask layer 211 is tin and/or TCO. The material of the second metal modification layer 212 is at least one of nickel, titanium and silver. The thickness of the second metal modification layer 212 is 80nm. The thickness of the first metal modification layer 23 is 100nm, and the thickness of the main conductive metal layer 22 is 500nm. The thickness of the mask layer 211 is 30nm to 100nm.

2 , an ultraviolet laser is used to perform laser etching on the entire mask layer 211 to form a patterned mask layer 211, so that the second metal modification layer 212 is partially exposed. Then, a laser is continuously used to perform laser etching on the exposed second metal modification layer 212 to form a patterned second metal modification layer 212, so that the main conductive metal layer 22 is partially exposed.

3 , FeCl ₃ or an ammonia alkaline solution is used to wet-etch the exposed main conductive metal layer 22 , so that the first metal modification layer 23 is partially exposed.

4 , a hydrochloric acid solution is used to remove the patterned mask layer 211 and etch the exposed first metal modification layer 23 to partially expose the TCO layer 11 . The hydrochloric acid solution continues to etch the exposed TCO layer 11 to form a patterned TCO layer 11 .

In Example 1, the electrode structure formed is shown in FIG4 , in which the main material is copper, and the cost is relatively low. In Example 1, the etching of the main conductive metal layer 22, the etching of the first metal modification layer 23, the removal of the patterned mask layer 211, and the patterning of the TCO layer 11 can all be performed in one etcher or etching equipment, with fewer etching steps, low production cost, and high production efficiency.

In Example 1, the second metal modification layer 212 of the above material, on the one hand, is easy to be etched by laser etching, photolithography etching, etc., and has high processing accuracy and high processing efficiency. On the other hand, the second metal modification layer 212 of the above material has a large pull-off force and good welding performance in the subsequent string welding process of the solar cell to form a photovoltaic module, so that the long-term reliability of the photovoltaic module is better. Moreover, the second metal modification layer 212 of the above material has better environmental tolerance or better weather resistance, which can fully protect the patterned main conductive metal layer 22, improve its stability, and also improve the long-term reliability of the photovoltaic module. In the process of etching the main conductive metal layer 22, FeCl ₃ or ammonia alkaline solution has basically no etching effect on the first metal modification layer 23, and the first metal modification layer 23 can basically maintain the complete morphology, and can avoid the diffusion of Cu ions into the battery body 1 during the etching process as much as possible. In the final structure formed, the first metal modification layer 23 can still prevent the diffusion of Cu ions into the battery body 1, thereby improving the stability of the main conductive metal layer 22. Moreover, the contact resistance between the first metal modification layer 23 and the patterned main conductive metal layer 22 and the contact resistance between the first metal modification layer 23 and the TCO layer 11 are both low, which can reduce the contact resistivity. At the same time, the first metal modification layer 23 can also prevent the oxygen in the TCO layer 11 from oxidizing the main conductive metal layer 22, which can further improve the stability of the main conductive metal layer 22.

Example 2

As shown in FIG5 , the battery body includes: a whole layer of TCO layer 11, a whole layer of first metal modification layer 23, a whole layer of main conductive metal layer 22 and a whole layer of outer structure 21 are sequentially formed on the TCO layer 11 by vacuum coating. Among them, the first metal modification layer 23 includes: a tin layer close to the main conductive metal layer 22, and an aluminum layer located between the tin layer and the TCO layer 11. The main conductive metal layer 22 is a copper layer. The outer structure 21 only includes: a second metal modification layer 212. The material of the second metal modification layer 212 is at least one of nickel, titanium and silver. The thickness of the second metal modification layer 212 is 80nm. The thickness of the first metal modification layer 23 is 100nm, and the thickness of the main conductive metal layer 22 is 500nm.

6 , an ultraviolet laser is used to perform laser etching on the entire second metal modification layer 212 to form a patterned second metal modification layer 212 , so that the main conductive metal layer 22 is partially exposed.

7 , FeCl ₃ or an ammonia alkaline solution is used to wet-etch the exposed main conductive metal layer 22 , so that the first metal modification layer 23 is partially exposed.

The exposed first metal modification layer 23 is etched with a hydrochloric acid solution to form a patterned first metal modification layer 23 , so that the TCO layer 11 is partially exposed. The hydrochloric acid solution continues to etch the exposed TCO layer 11 to form a patterned TCO layer 11 .

In Example 2, the electrode structure formed is shown in Figure 4. The main material in the electrode structure is copper, which has low cost. In Example 2, the etching of the main conductive metal layer 22, the etching of the first metal modification layer 23, and the patterning of the TCO layer 11 can all be performed in one etcher or etching equipment, with fewer etching steps, low production cost, and high production efficiency.

In Example 2, similar or identical beneficial effects are achieved as those in Example 1, and they will not be described again in detail to avoid repetition as much as possible.

Example 3

As shown in FIG8 , the battery body includes: a whole layer of TCO layer 11, and a whole layer of first metal modification layer 23, a whole layer of main conductive metal layer 22 and a whole layer of outer structure 21 are sequentially formed on the TCO layer 11 by vacuum coating. Among them, the first metal modification layer 23 includes: a tin layer. The main conductive metal layer 22 is a copper layer. The outer structure 21 only includes: a mask layer 211. The material of the mask layer 211 is tin and/or TCO. The thickness of the first metal modification layer 23 is 100nm, and the thickness of the main conductive metal layer 22 is 500nm. The thickness of the mask layer 211 is 30nm to 100nm.

9 , an ultraviolet laser is used to perform laser etching on the entire mask layer 211 to form a patterned mask layer 211 , so that the main conductive metal layer 22 is partially exposed.

10 , FeCl ₃ or an ammonia alkaline solution is used to wet-etch the exposed main conductive metal layer 22 to form a patterned main conductive metal layer 22 , and partially expose the first metal modification layer 23 .

11 , a hydrochloric acid solution is used to remove the patterned mask layer 211 so that the patterned main conductive metal layer 22 is exposed, and the exposed first metal modification layer 23 is etched so that the TCO layer 11 is partially exposed. The hydrochloric acid solution continues to etch the exposed TCO layer 11 to form a patterned TCO layer 11.

Then, the patterned main conductive metal layer 22 is used as a seed layer, and a second metal modification layer 212 is formed thereon by electroplating. The material of the second metal modification layer 212 is at least one of nickel, titanium, silver, and tin.

In Example 3, the electrode structure formed is shown in FIG4 , and the main material in the electrode structure is copper, which has low cost. In Example 3, the etching of the main conductive metal layer 22, the patterning of the TCO layer 11, and the removal of the patterned mask layer 211 can all be performed in one etcher or etching equipment, with fewer etching steps, low production cost, and high production efficiency.

In Example 3, similar or identical beneficial effects are achieved as those in Example 1, and they will not be described again in detail to avoid repetition as much as possible.

It should be noted that, for the method embodiments, for the sake of simplicity of description, they are all expressed as a series of action combinations, but those skilled in the art should be aware that the embodiments of the present application are not limited by the described order of actions, because according to the embodiments of the present application, certain steps can be performed in other orders or simultaneously. Secondly, those skilled in the art should also be aware that the embodiments described in the specification are all preferred embodiments, and the actions involved are not necessarily required by the embodiments of the present application.

It should be noted that, in this article, the terms "include", "comprises" or any other variations thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or device. In the absence of further restrictions, an element defined by the sentence "comprises a ..." does not exclude the existence of other identical elements in the process, method, article or device including the element.

The embodiments of the present invention are described above in conjunction with the accompanying drawings, but the present invention is not limited to the above-mentioned specific implementation methods. The above-mentioned specific implementation methods are merely illustrative and not restrictive. Under the enlightenment of the present invention, ordinary technicians in this field can also make many forms without departing from the scope of protection of the purpose of the present invention and the claims, which all fall within the protection of the present invention.

Claims (17)

1. A method for preparing an electrode structure of a solar cell, characterized by comprising: A laminated structure is formed on the battery body; the laminated structure includes, in order from away from the battery body to close to the battery body: a patterned layer, a whole main conductive metal layer and a whole first metal modification layer; the patterned layer is intermittently distributed on the main conductive metal layer, so that the main conductive metal layer is partially exposed; Using a first etching solution, wet-etching the exposed main conductive metal layer to form a patterned main conductive metal layer, and partially exposing the first metal modification layer; The exposed first metal modification layer is wet-etched by using a second etching solution to form a patterned first metal modification layer, and the battery body is partially exposed. 2. The preparation method according to claim 1, characterized in that the forming of the laminated structure on the battery body comprises: On the battery body, a first metal modification layer, a main conductive metal layer and an outer layer structure are sequentially formed in an entire layer; At least one of laser etching and photolithography etching is used to remove part of the outer layer structure so that the entire main conductive layer is partially exposed to form the patterned layer. 3. The preparation method according to claim 1, characterized in that the forming of the laminated structure on the battery body comprises: On the battery body, sequentially forming a first metal modification layer and a main conductive metal layer; The patterned layer is prepared on the entire main conductive metal layer by using at least one of inkjet printing, screen printing and gravure printing. 4. The preparation method according to any one of claims 1 to 3 is characterized in that the patterned layer comprises: a patterned mask layer, and/or a patterned second metal modification layer, the patterned mask layer is farthest from the battery body; the material of the patterned mask layer comprises: TCO, and/or tin; the material of the patterned second metal modification layer comprises: at least one of nickel, titanium, and silver. 5. The preparation method according to any one of claims 1 to 3, characterized in that the battery body comprises: a TCO layer adjacent to the first metal modification layer and the entire layer; The second etching solution is used to wet-etch the exposed first metal modification layer to form a patterned first metal modification layer, and the battery body is partially exposed, including: The exposed first metal modification layer is etched with an acidic etching solution to form a patterned first metal modification layer, and the TCO layer is partially exposed. The acidic etching solution etches the exposed TCO layer to form a patterned TCO layer. 6. The preparation method according to claim 5, characterized in that the patterned layer comprises: a patterned mask layer, the material of the patterned mask layer comprises: TCO, and/or tin; the patterned mask layer is farthest from the battery body; the acidic etching solution is used to etch the exposed first metal modification layer to form a patterned first metal modification layer, and the TCO layer is partially exposed, and the acidic etching solution is used to etch the exposed TCO layer to form a patterned TCO layer, comprising: The acidic etching solution is used to etch the exposed first metal modification layer to form a patterned first metal modification layer, and the TCO layer is partially exposed. The acidic etching solution is used to etch the exposed TCO layer to form a patterned TCO layer. At the same time, the acidic etching solution etches away the patterned mask layer. 7. The preparation method according to any one of claims 1 to 3, characterized in that the patterned layer only comprises: a patterned mask layer; the second etching solution is used to wet-etch the exposed first metal modification layer to form a patterned first metal modification layer, and the battery body is partially exposed, comprising: The second etching solution is used to etch the exposed first metal modification layer to form a patterned first metal modification layer, and the battery body is partially exposed, and the second etching solution etches away the patterned mask layer to expose the patterned main conductive metal layer; A patterned second metal modification layer is obtained by electroplating on the patterned main conductive metal layer; the material of the patterned second metal modification layer includes at least one of nickel, titanium, silver and tin. 8. The preparation method according to any one of claims 1 to 3, characterized in that the first etching solution comprises: a neutral etching solution, or an alkaline etching solution; The second etching solution includes: an acidic etching solution. 9. An electrode structure of a solar cell, characterized by comprising: A patterned first metal modification layer is disposed adjacent to the battery body; A patterned main conductive metal layer is located on a side of the patterned first metal modification layer away from the battery body; Wherein, the material of the patterned main conductive metal layer includes: copper; The patterned first metal modification layer includes: a tin layer; or, a tin layer adjacent to the patterned main conductive metal layer, and an aluminum layer between the tin layer and the battery body. 10. The electrode structure according to claim 9, further comprising: The patterned second metal modification layer is located on a side of the patterned main conductive metal layer away from the patterned first metal modification layer. 11 . The electrode structure according to claim 10 , wherein the material of the patterned second metal modification layer comprises at least one of nickel, titanium, silver and tin. 12. The electrode structure according to claim 10 is characterized in that the thickness of the patterned main conductive metal layer is greater than the thickness of the patterned second metal modification layer, and the thickness of the patterned main conductive metal layer is greater than the thickness of the patterned first metal modification layer. 13. The electrode structure according to claim 10, characterized in that the patterned main conductive metal layer is a single-layer or multi-layer structure; And/or, the patterned first metal modification layer is a single-layer or multi-layer structure; And/or, the patterned second metal modification layer is a single-layer or multi-layer structure. 14 . The electrode structure according to claim 10 , wherein the thickness of the patterned second metal modification layer is 50 nm to 150 nm. 15. A solar cell, comprising: A cell body, and an electrode structure for a solar cell according to any one of claims 9 to 14 located on at least one side of the cell body. 16 . The solar cell according to claim 15 , wherein the cell body comprises: a patterned TCO layer disposed adjacent to the electrode structure. 17. A photovoltaic module, comprising: a plurality of solar cells according to claim 15 or 16.