Non-contact solar cell electrode and preparation method thereof

Abstract

The invention discloses a non-contact solar cell electrode and a preparation method thereof. The preparation method of the non-contact solar cell electrode comprises the following steps: preparing a selective seed layer on a carrier film; the selective seed layer is imprinted on the bearing film to form a groove; then copper and tin metals are electroplated in the bearing film groove to prepare a metal electrode; thermally pressing the metal electrode on the solar cell; and finally, the bearing film on the metal electrode is removed, so that the electrode is exposed for electric conduction. According to the method, the solar cell electrode is prepared independently, then the proper electrode is matched according to the size and model of the cell, and the metal electrode is hot-pressed on the solar cell, so that the non-contact preparation of the electrode is realized, the waste of slurry can be effectively avoided, the damage to the solar cell is reduced, and the performance and reliability of the solar cell are improved.

Description

Technical Field

[0001] The present invention relates to the technical field of solar cells, and in particular to a contactless solar cell electrode and a preparation method thereof. Background Art

[0002] At present, the preparation methods of solar cell electrodes include screen printing and electroplating. Screen printing is to set a screen, apply slurry on the screen, and transfer the slurry through the mesh of the screen to the solar cell under the pressure of the scraper to form the required electrode pattern; however, the screen printing process will cause waste of slurry, and it is difficult to optimize the grid line shaping, the stability is poor, and it is difficult to ensure efficiency stability. Electroplating is a redox reaction that uses electrolytic reaction to reduce metal ions from the electrolyte and deposit them on the electrode surface. The workpiece is used as the cathode and the target material is used as the anode to immerse in the electrolyte. The metal ions diffuse and migrate to the cathode and are reduced to the atomic state and attached to the surface of the workpiece to form a film; however, when electroplating metal electrodes, the battery needs to be immersed in an electrolyte such as a copper sulfate solution, which will corrode the battery and cause damage. Summary of the invention

[0003] The purpose of the present invention is to design a method for preparing a contactless solar cell electrode in order to solve the above problems.

[0004] The present invention achieves the above-mentioned purpose through the following technical solutions: A method for preparing a contactless solar cell electrode comprises the following steps: S1, preparing a selective seed layer on a carrier film; S2, printing the selective seed layer on a carrier film; S3, electroplating metal on the carrier film to prepare a metal electrode; S4, hot pressing the metal electrode onto the solar cell; S5, removing the carrier film on the metal electrode.

[0005] The present invention further provides a contactless solar cell electrode, which is in the shape of an elliptical column and is obtained by the above-mentioned method for preparing the contactless solar cell electrode.

[0006] The beneficial effects of the present invention are: The method for preparing contactless solar cell electrodes is to first prepare a selective seed layer on a carrier film; then emboss the selective seed layer on the carrier film to form a groove; then electroplate copper and tin metals in the carrier film groove to prepare a metal electrode; then hot press the metal electrode onto the solar cell; finally, remove the carrier film on the metal electrode to expose the electrode for conductivity; that is, first prepare the solar cell electrode separately, then match the appropriate electrode according to the battery size model, and hot press the metal electrode onto the solar cell to achieve contactless preparation of the electrode, which can effectively avoid the waste of slurry and reduce damage to the solar cell, thereby improving the performance and reliability of the solar cell. BRIEF DESCRIPTION OF THE DRAWINGS

[0007] Figure 1 It is a schematic flow chart of the method for preparing the contactless solar cell electrode of the present invention; Figure 2 A schematic diagram of the steps of the method for preparing a contactless solar cell electrode of the present invention; Figure 3 A schematic diagram of the step of removing the carrier film in the method for preparing the contactless solar cell electrode of the present invention; In the figure: 1-carrier film, 2-metal electrode, 3-grid line spacing, 4-electrode width, 5-electrode radius, 6-stainless steel plate, 7-seed layer, 8-metal, 9-solar cell, 10-solar cell with carrier film, 11-ester soluble solution, 12-solar cell after removing the carrier film, 13-laser. DETAILED DESCRIPTION

[0008] In order to make the purpose, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings 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. Generally, the components of the embodiments of the present invention described and shown in the drawings here can be arranged and designed in various different configurations.

[0009] Therefore, the following detailed description of the embodiments of the present invention provided in the accompanying drawings is not intended to limit the scope of the invention claimed for protection, but merely represents selected embodiments of the present invention. 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.

[0010] It should be noted that similar reference numerals and letters denote similar items in the following drawings, and therefore, once an item is defined in one drawing, further definition and explanation thereof is not required in subsequent drawings.

[0011] In the description of the present invention, it should be understood that the terms "upper", "lower", "inside", "outside", "left", "right", etc. indicate directions or positional relationships based on the directions or positional relationships shown in the accompanying drawings, or are directions or positional relationships in which the product of the invention is usually placed when in use, or are directions or positional relationships commonly understood by those skilled in the art. These directions or positional relationships are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific direction, be constructed and operated in a specific direction, and therefore should not be understood as a limitation on the present invention.

[0012] Furthermore, the terms “first”, “second”, etc. are merely used for distinguishing descriptions and should not be understood as indicating or implying relative importance.

[0013] In the description of the present invention, it is also necessary to explain that, unless otherwise clearly specified and limited, the terms such as "setting" and "connection" should be understood in a broad sense. For example, "connection" can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or an indirect connection through an intermediate medium, or it can be the internal communication of two elements. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0014] The specific implementation modes of the present invention are described in detail below in conjunction with the accompanying drawings.

[0015] like Figure 1-3 As shown, the method for preparing a contactless solar cell electrode comprises the following steps: S1, preparing a selective seed layer 7 on a carrier film 1; S2, imprinting the selective seed layer 7 on the carrier film 1; S3, electroplating the metal 8 on the carrier film 1 to prepare the metal electrode 2; S4, hot pressing the metal electrode 2 onto the solar cell 9; S5, removing the carrier film 1 on the metal electrode 2.

[0016] In this embodiment, the carrier film 1 is a polymer ester-soluble material, which has good heat resistance, elasticity and transparency, and its transparency exceeds 95%. The carrier film 1 in this embodiment can be realized by polyester (PET), polycarbonate (PC), polyimide (PI) or polyurethane (PU), among which polyester is a PET film with high thermal stability, which not only has good transparency and elasticity, but also can maintain stability within a certain temperature range. However, the heat resistance of PET is limited, usually around about 120-150°C; polycarbonate has excellent transparency and good elasticity, and its high temperature resistance is relatively high. It can usually withstand temperatures of about 130-150°C, which is suitable for application scenarios requiring high transparency and certain elasticity; although polyimide is mainly known for its high temperature resistance, which can withstand temperatures exceeding 200°C, the modified PI film also has good transparency and elasticity, and its elasticity and transparency may be slightly inferior to PET and PC; the transparent polyurethane film has good elasticity and certain heat resistance, which can usually withstand temperatures of about 80-100°C, which is suitable for application scenarios in the medium temperature range. The carrier film 1 in this embodiment can be well combined with the velvet surface of the solar cell 9 without destroying the structure of the solar cell 9 itself.

[0017] In this embodiment, the metal 8 can be realized by using a metal 8 with low cost, good conductivity and low melting point, such as copper, tin, etc., so as to melt during hot pressing and form a good contact with the solar cell 9.

[0018] The preparation method of the contactless solar cell electrode of the present invention is to first prepare a selective seed layer 7 on a carrier film 1; then imprint the selective seed layer 7 on the carrier film 1 to form a groove; then electroplate copper and tin metals 8 in the groove of the carrier film 1 to prepare a metal electrode 2; then hot press the metal electrode 2 onto a solar cell 9; finally, remove the carrier film 1 on the metal electrode 2 to expose the metal electrode 2 for conductivity; that is, the solar cell electrode is prepared separately by laser transfer technology, and then the appropriate metal electrode 2 is matched according to the battery size model, and the metal electrode 2 is hot pressed onto the solar cell 9 to achieve contactless preparation of the metal electrode 2, which can effectively avoid waste of slurry and reduce damage to the solar cell 9, thereby improving the performance and reliability of the solar cell 9.

[0019] In one embodiment, the removal method in step S5 is: Penetrating the carrier film 1 on the metal electrode 2 with a laser 11; Alternatively, the carrier film 1 on the metal electrode 2 is melted with an ester-soluble solution 10 .

[0020] In this embodiment, there is a layer of carrier film 1 on the surface of the solar cell electrode prepared in step S4, and this layer of carrier film 1 makes the solar cell 9 unable to conduct electricity, so it is necessary to peel off this layer of carrier film 1 on the cell. In this embodiment, two methods can be used to peel off this layer of carrier film 1: the first method is to immerse the solar cell 9 in an ester-soluble solution 10 to dissolve the carrier film 1; the second method is to heat with a laser 11 to dissolve the carrier film 1, so that its metal electrode 2 is exposed to conduct electricity.

[0021] In one embodiment, the imprinting method in step S2 is: The carrier film 1 is fixed on a stainless steel plate 6 with a customized grid line spacing 3; The stainless steel plate 6 is used to stamp the carrier film 1 to form a groove of the solar cell electrode pattern.

[0022] In this embodiment, a stainless steel plate 6 customized according to the grid line spacing 3 is stamped on the carrier film 1 to form a groove of the solar cell electrode pattern, that is, a semi-cylindrical groove.

[0023] In one embodiment, the method for preparing the selective seed layer 7 in step S1 is: Covering the carrier film 1 with a mask plate having a customized battery grid line spacing 3; The selective seed layer 7 is prepared by laser transfer or physical vapor deposition.

[0024] In one embodiment, the metal electrode 2 is in the shape of an elliptical cylinder, and the width of the selective seed layer 7 is half of the elliptical circumference of the metal electrode 2 .

[0025] In this embodiment, the shape of the metal electrode 2 is an elliptical cylinder, which can make the contact area between the metal electrode 2 and the solar cell 9 smaller, so as to improve the utilization rate of the solar cell 9.

[0026] In practical applications, the cost of silver paste used in solar cells 9 exceeds 30% of the total cost. Therefore, this embodiment adopts laser transfer to prepare solar cell electrodes, which can reduce the use of silver paste, thereby reducing the manufacturing cost of solar cells 9. This embodiment uses laser transfer technology to first prepare solar cell electrodes separately, and then match the appropriate metal electrode 2 according to the size and model of the solar cell 9, and then hot press the metal electrode 2 onto the solar cell 9, thereby realizing contactless manufacturing of solar cell electrodes, thereby reducing slurry waste, better grid line shaping, and reducing damage to the solar cell 9 by the solution, so as to improve the performance and reliability of the solar cell 9.

[0027] In one embodiment, the metal 8 electroplating step in step S3 is: First, electroplate the metal 8 copper onto the carrier film 1; Then, the metal 8 is electroplated on the carrier film 1 .

[0028] The metal 8 in this embodiment can be selected from metals 8 with good conductivity and low melting point as needed, such as copper and tin, so that copper and tin can be electroplated in the grooves of the carrier film 1 at low temperature; it is also easy to melt during hot pressing to form good contact with the solar cell 9.

[0029] In one embodiment, the hot pressing temperature in step S4 is 80-200°C.

[0030] In this embodiment, the hot pressing temperature can be precisely controlled within a range of 80-200° C. to avoid damage to the solar cell 9 .

[0031] The preparation method of the contactless solar cell electrode of the present invention comprises five steps of sputtering a selective seed layer 7, stamping an electrode metal 8, preparing a metal electrode 2 by electroplating, hot pressing to combine the metal electrode 2 with a solar cell 9, and removing a carrier film 1 to expose the metal electrode 2; according to the preparation steps, a carrier film 1, a selective seed layer 7, a grid line spacing 3, an electrode width 4, a semi-cylindrical electrode radius 5, a stainless steel plate 6 customized according to the grid line spacing 3, a stamped selective seed layer 7, electroplating metal 8, a solar cell 9, an ester-soluble solution 10, and a laser 11 are sequentially arranged; the method of preparing an electrode by using laser transfer technology of the present invention has low cost and simple operation, can realize the function of fine printing, not only avoids the slurry problem of screen printing, but also can realize the electroplating of the metal electrode 2; the metal electrode 2 prepared by this method is an elliptical cylinder, has a smaller contact area with the solar cell 9, and can improve the utilization rate of the solar cell 9; and the metal electrode 2 prepared by this method has no contact with the solar cell 9, which is of great significance for reducing the damage to the solar cell 9 caused by the preparation process of the metal electrode 2 and reducing the manufacturing cost of the solar cell electrode.

[0032] The present invention further provides a contactless solar cell electrode. The contactless solar cell electrode is in the shape of an elliptical cylinder. The contactless solar cell electrode is obtained by the above-mentioned method for preparing the contactless solar cell electrode.

[0033] In the embodiment, the shape of the contactless solar cell electrode is an elliptical cylinder, which can reduce the contact area between the metal electrode 2 and the solar cell 9 to improve the utilization rate of the solar cell 9.

[0034] The above is only a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the technical principles of the present invention. These improvements and modifications should also be regarded as the scope of protection of the present invention.

Claims

1. A method for preparing a contactless solar cell electrode, characterized in that: The method for preparing the contactless solar cell electrode comprises the following steps: S1, preparing a selective seed layer on a carrier film; S2, printing the selective seed layer on a carrier film; S3, electroplating metal on the carrier film to prepare a metal electrode; S4, hot pressing the metal electrode onto the solar cell; S5, removing the carrier film on the metal electrode.

2. The method for preparing a contactless solar cell electrode according to claim 1, characterized in that: The removal method in step S5 is: Penetrating the carrier film on the metal electrode with a laser; Alternatively, the supporting film on the metal electrode is melted with an ester-soluble solution.

3. The method for preparing a contactless solar cell electrode according to claim 1, characterized in that: The imprinting method in step S2 is: The carrier film is fixed on a stainless steel plate with a customized grid line spacing; The stainless steel plate is used to stamp the grooves of the solar cell electrode pattern on the carrier film.

4. The method for preparing a contactless solar cell electrode according to claim 1, characterized in that: The method for preparing the selective seed layer in step S1 is: Covering the carrier film with a mask plate with customized battery grid line spacing; The selective seed layer is prepared by laser transfer or physical vapor deposition.

5. The method for preparing a contactless solar cell electrode according to claim 4, characterized in that: The metal electrode is in the shape of an elliptical cylinder, and the width of the selective seed layer is half of the circumference of the ellipse of the metal electrode.

6. The method for preparing a contactless solar cell electrode according to claim 1, characterized in that: The metal electroplating step in step S3 is: First, electroplating metallic copper on the carrier film; Then, metal tin is electroplated on the carrier film.

7. The method for preparing a contactless solar cell electrode according to claim 1, characterized in that: The hot pressing temperature in step S4 is 80-200°C.

8. A contactless solar cell electrode, characterized in that: The contactless solar cell electrode is in the shape of an elliptical cylinder, and the contactless solar cell electrode is obtained by the method for preparing the contactless solar cell electrode according to any one of claims 1 to 7.

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