Electrode slurry transfer plate body, preparation method of solar cell electrode and solar cell

Abstract

The invention provides an electrode slurry transfer plate body, a preparation method of a solar cell electrode and a solar cell. The electrode slurry transfer plate body is used for transferring slurry forming an electrode in a solar cell and comprises a substrate layer, the surface of the substrate layer is positively charged, the surface comprises a first surface and a second surface which are arranged back to back, and a plurality of grooves corresponding to electrode patterns are formed in the first surface of the substrate layer through a patterning process; the insulating coating is arranged on the first surface and at least covers the groove, the insulating coating has low surface energy and forms a low-energy surface opposite to the first surface, and the groove covered with the insulating coating is a groove to be filled. When the electrode slurry transfer plate body is used for preparing a solar cell electrode, the electrode width is reduced, the alignment degree is improved, high-quality laminated electrode arrangement is achieved, and the photoelectric conversion efficiency is improved.

Description

Technical Field

[0001] The present application relates to the technical field of solar cell preparation, and in particular to an electrode slurry transfer plate, a method for preparing solar cell electrodes, and a solar cell. Background Art

[0002] The existing technology for forming metal electrodes for solar cells is mostly implemented by screen printing. This method uses a screen corresponding to the electrode pattern to add electrode slurry, and then uses a printing head to squeeze the screen so that the slurry on the screen is placed on the surface of the silicon wafer and sintered at high temperature to form an electrode. In order to further improve the battery conversion efficiency, it is necessary to reduce the electrode shading rate, so the electrode width needs to be narrower and narrower to reduce shading. However, due to the characteristics of screen production, the existing screen printing technology is prone to line breakage and virtual printing when preparing narrow line widths, making it difficult to further narrow the metal electrode.

[0003] In addition, the stacking electrode method is also an effective means to improve the battery conversion efficiency. Using contact-type metal paste as the bottom electrode paste can improve the contact performance of the metal electrode and reduce the contact resistance; using metal paste with better conductivity as the top paste can reduce the transmission resistance and comprehensively improve FF. However, the existing screen printing technology requires multiple steps of printing to achieve the stacking of different pastes to form a stacked electrode. The paste is difficult to align during multiple printing processes, and the extrusion printing method is prone to deformation of the stacked electrode, which is not conducive to electrode shaping and affects the photoelectric conversion efficiency. It is difficult to achieve high-quality stacked electrode settings. Summary of the invention

[0004] The first aspect of the present application provides an electrode slurry transfer plate for transferring slurry for forming electrodes in solar cells, comprising:

[0005] A substrate layer, wherein the surface of the substrate layer is positively charged, and the surface includes a first surface and a second surface arranged in back-to-back relation, and a plurality of grooves corresponding to the electrode pattern are formed on the first surface of the substrate layer through a patterning process;

[0006] The insulating coating is disposed on the first surface and at least covers the groove. The insulating coating has low surface energy and forms a low-energy surface facing away from the first surface. The groove covered with the insulating coating is a groove to be filled.

[0007] In some optional embodiments of the first aspect of the present application, the base layer is made of a composite material with a positive charge on the surface, and the composite material includes at least one of diallyldimethylammonium chloride modified graphene and diallyldimethylammonium chloride modified cobalt-nickel alloy.

[0008] In some optional embodiments of the first aspect of the present application, the width of the groove to be filled is 3 μm to 12 μm.

[0009] In some optional embodiments of the first aspect of the present application, the insulating coating includes at least one of polyethylene and polypropylene.

[0010] A second aspect of the present application provides a method for preparing a solar cell electrode, comprising:

[0011] S10: filling metal slurry into the to-be-filled groove of the electrode slurry transfer plate of the first aspect of the present application, so that the electrode slurry transfer plate forms a first side surface exposed with the metal slurry and a second side surface facing away from the first side surface;

[0012] S20: an electric field applying device is arranged facing the second side surface, the first side surface is bonded to the surface to be metallized of the prefabricated silicon wafer, and at the same time, the electric field applying device is controlled to face the second side surface to generate a negative electric field layer, the negative electric field layer and the negative charges in the metal slurry are repelled by the same charges, and the metal slurry filled in the groove to be filled is bonded to the prefabricated silicon wafer;

[0013] S30: separating the electrode slurry transfer plate and the prefabricated silicon wafer, so that the metal slurry filled in the groove to be filled is separated from the electrode slurry transfer plate and remains on the surface to be metallized of the prefabricated silicon wafer;

[0014] S40: The metal slurry is sintered to form a metal electrode.

[0015] In some optional embodiments of the second aspect of the present application, in step S30, while separating the electrode slurry transfer plate and the prefabricated silicon wafer, the electric field applying device is kept facing the second side to generate a negative electric field layer.

[0016] In some optional embodiments of the second aspect of the present application, the electric field strength of the negative electric field layer is 20Mv / m to 50Mv / m.

[0017] In some optional embodiments of the second aspect of the present application, in steps S10 to S40, the first side surface is kept facing the ground, and the first side surface is opposite to the surface to be metallized.

[0018] In some optional embodiments of the second aspect of the present application, in step S10, at least two layers of metal pastes of different types are filled in each groove to be filled along the groove opening direction to form a laminated electrode.

[0019] A third aspect of the present application provides a solar cell, comprising:

[0020] A substrate having a P region and an N region formed thereon;

[0021] The electrode layer includes a plurality of electrodes arranged in the P region and the N region and used for collecting photogenerated carriers. The electrodes are prepared by the preparation method of the solar cell electrode of the second aspect of the present application.

[0022] Beneficial effects:

[0023] The first aspect of the present application provides an electrode slurry transfer plate, which includes a base layer and an insulating coating. The base layer forms an electrode pattern corresponding to the metal electrode of the solar cell on the first surface through a patterning process (such as corrosion or laser groove), avoiding the limitation of the metal electrode width by screen printing, and can reduce the width of the slot to be filled according to the actual shading needs, thereby reducing the width of the metal electrode more easily. The surface of the base layer is positively charged, which is conducive to attracting electrons in the metal slurry to move to the low-energy surface of the insulating coating during the metal slurry filling process, so that the negative charge is concentrated on the low-energy surface. Therefore, even if the surface energy of the insulating coating is low, the metal slurry can still be stored in the slot to be filled through the effect of charge attraction. Later, when the metal slurry is released from the slot to be filled to the side of the prefabricated silicon wafer to be metallized, the adhesion between the insulating coating with low surface energy and the metal slurry is much smaller than the adhesion between the prefabricated silicon wafer and the metal slurry, which helps the metal slurry to quickly detach from the slot to be filled and release to the prefabricated silicon wafer under the action of the electric field. Since the electrode slurry transfer plate has been graphically opened with a groove to be filled, the groove to be filled forms a limiting effect on the stacking of different slurries, avoiding deformation of the stacked electrodes caused by ordinary extrusion printing methods, eliminating multiple printing steps, and improving the alignment rate of the stacked electrodes on the prefabricated silicon wafer.

[0024] The electrode slurry transfer plate can shape and temporarily store the metal slurry according to the preset electrode pattern on the solar cell, which helps to efficiently fill and release the metal slurry, thereby improving the efficiency and accuracy of the metal electrode production of the solar cell, reducing the metal electrode shading rate, and increasing the photoelectric conversion efficiency.

[0025] The second aspect of the present application provides a method for preparing a solar cell electrode, which uses the electrode slurry transfer plate provided in the first aspect of the present application in combination with an external negative electric field to achieve temporary storage and release of metal slurry based on the principle of charge repulsion and charge attraction. The temporary storage of metal slurry can reduce the width of the metal slurry temporarily stored in the slot to be filled based on the graphical control of the electrode slurry transfer plate, avoiding displacement and deformation of the stacked metal slurry. In the process of releasing the metal slurry, due to avoiding the existence of obstacles between the metal slurry and the prefabricated silicon wafer due to the existence of the screen in the screen printing technology, a narrower metal slurry filling body can be formed to form a narrower electrode. And for the formation of stacked electrodes, multiple printing processes are avoided, the metal slurry has been stacked in the slot to be filled, and the alignment degree is higher during the release of the metal slurry, which can achieve multi-layer metal slurry stacking, reducing the shading effect of the electrodes in the solar cell on the solar cell.

[0026] The solar cell provided in the third aspect of the present application has a significantly narrowed electrode width, a low electrode shading rate, an improved photoelectric conversion efficiency, and an increased metal electrode alignment. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0028] Figure 1 It is a schematic diagram of the structure of the electrode slurry transfer plate body layer of an embodiment of the first aspect of the present application;

[0029] Figure 2 is a schematic diagram of the structure of the electrode slurry transfer plate body layer of another embodiment of the first aspect of the present application;

[0030] Figure 3 is a process schematic diagram of step S10 in the second aspect of the present application;

[0031] Figure 4 is a process schematic diagram of step S20 in the second aspect of the present application;

[0032] Figure 5 It is a process diagram of step S30 in the second aspect of the present application.

[0033] Description of reference numerals:

[0034] Electrode slurry transfer plate-1; first side-13; second side-14

[0035] Basal layer-11; Groove-111;

[0036] Insulating coatings - 12; Low energy surfaces - 121;

[0037] slots to be filled - 3;

[0038] Electric field applying device-2; layered conductor-21;

[0039] First metal slurry-a; second metal slurry-b;

[0040] The force exerted by the base layer on the metal slurry in step S10 is -F1;

[0041] The force exerted by the negative electric field layer on the metal paste in step S20 is -F2;

[0042] Prefabricated silicon wafer-4; surface to be metallized-41. DETAILED DESCRIPTION

[0043] The technical solution of the present application will be described clearly and completely below in conjunction with the accompanying drawings. Obviously, the described embodiments are part of the embodiments of the present application, rather than all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present application.

[0044] In the description of the present application, it should be noted that the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", etc., indicating the orientation or positional relationship, are based on the orientation or positional relationship shown in the drawings, and are only for the convenience of describing the present application and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as limiting the present application. In addition, the terms "first", "second", and "third" are used for descriptive purposes only, and cannot be understood as indicating or implying relative importance.

[0045] In the description of this application, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be indirectly connected through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in this application can be understood according to specific circumstances.

[0046] In addition, the technical features involved in the different embodiments of the present application described below can be combined with each other as long as they do not conflict with each other.

[0047] The first aspect of the present application provides an electrode slurry transfer plate for transferring slurry for forming electrodes in solar cells, comprising:

[0048] A substrate layer, the surface of the substrate layer is positively charged, and the surface includes a first surface and a second surface arranged in back-to-back relationship, and the substrate layer is provided with a plurality of grooves corresponding to the electrode pattern on the first surface through a patterning process;

[0049] The insulating coating is disposed on the first surface and at least covers the groove. The insulating coating has low surface energy and forms a low-energy surface facing away from the first surface. The groove covered with the insulating coating is a groove to be filled.

[0050] The first aspect of the present application provides an electrode slurry transfer plate, which includes a base layer and an insulating coating. The base layer forms an electrode pattern corresponding to the metal electrode of the solar cell on the first surface through a patterning process (such as corrosion or laser groove), avoiding the limitation of the metal electrode width by screen printing, and can reduce the width of the slot to be filled according to the actual shading needs, thereby reducing the width of the metal electrode more easily. The surface of the base layer is positively charged, which is conducive to attracting electrons in the metal slurry to move to the low-energy surface of the insulating coating during the metal slurry filling process, so that the negative charge is concentrated on the low-energy surface. Therefore, even if the surface energy of the insulating coating is low, the metal slurry can still be stored in the slot to be filled through the effect of charge attraction. Later, when the metal slurry is released from the slot to be filled to the side of the prefabricated silicon wafer to be metallized, the adhesion between the insulating coating with low surface energy and the metal slurry is much smaller than the adhesion between the prefabricated silicon wafer and the metal slurry, which helps the metal slurry to quickly detach from the slot to be filled and release to the prefabricated silicon wafer under the action of the electric field. Since the electrode slurry transfer plate has been graphically opened with a groove to be filled, the groove to be filled forms a limiting effect on the stacking of different slurries. The deformation of the stacked electrode caused by the ordinary extrusion printing method saves the steps of multiple printing and improves the alignment rate of the stacked electrode on the prefabricated silicon wafer.

[0051] The electrode slurry transfer plate can temporarily store the metal slurry in a shape according to the preset electrode pattern on the solar cell, which helps to efficiently fill and release the metal slurry, thereby improving the efficiency and accuracy of the metal electrode manufacturing of the solar cell, reducing the metal electrode shading rate, and increasing the photoelectric conversion efficiency.

[0052] like Figure 1 As shown, in some examples of the first aspect of the present application, the insulating coating 12 is disposed on the first surface and completely covers the first surface, that is, it covers both the grooves 111 and the plane connecting two adjacent grooves 111 .

[0053] like Figure 2 As shown, in some examples of the first aspect of the present application, the insulating coating 12 is disposed on the first surface and only covers the groove 111 .

[0054] In some optional embodiments of the first aspect of the present application, the base layer 11 is made of a composite material with a positive charge on the surface, and the composite material includes at least one of diallyldimethylammonium chloride modified graphene and diallyldimethylammonium chloride modified cobalt-nickel alloy.

[0055] In some optional embodiments of the first aspect of the present application, the width of the groove 3 to be filled is 3 μm to 12 μm.

[0056] In some optional embodiments of the first aspect of the present application, the insulating coating 12 includes at least one of polyethylene and polypropylene.

[0057] A second aspect of the present application provides a method for preparing a solar cell electrode, comprising:

[0058] like Figure 3 As shown, S10: fill the metal slurry into the to-be-filled groove 3 of the electrode slurry transfer plate body 1 as in the first aspect of the present application, and the electrode slurry transfer plate body 1 forms a first side surface 13 exposed with the metal slurry and a second side surface 14 facing away from the first side surface 13 .

[0059] In some optional embodiments of the second aspect of the present application, the electrode slurry transfer plate 1 is patterned on the base layer 11 by etching or laser grooving to form a groove 111 corresponding to the metal electrode pattern. The insulating coating 12 covers the groove 111 to form a groove to be filled 3. The width range of the groove 3 to be filled is 3μm to 12μm, which is much smaller than the 13 to 15μm commonly used in screen printing technology.

[0060] In some examples, an electric field applying device 2 is provided on the second side 14, but the electric field applying device 2 does not work and does not generate a negative electric field. The electric field applying device 2 includes a power source and a layered conductor 21 electrically connected to the power source, and when the layered conductor 21 is powered on, a negative electric field layer acting on the base layer 11 can be generated.

[0061] In some embodiments of the second aspect of the present application, in step S10, each to-be-filled groove 3 is filled with a metal slurry along the groove opening direction. In some examples, silver slurry is generally used.

[0062] In some embodiments of the second aspect of the present application, in step S10, each slot 3 to be filled is filled with at least two layers of metal pastes of different types along the slotting direction to form a laminated electrode. The metal pastes in the slot 3 to be filled include a first metal paste a and a second metal paste b.

[0063] In some examples, silver paste and copper paste are stacked to form a laminated electrode. Copper paste has low cost, but it is easy to diffuse at room temperature, resulting in large metal composites. Silver paste is used for the contact layer on the surface of the solar cell, and copper paste is stacked on the silver paste. Since the copper paste has average weldability, silver paste with good weldability is stacked on the copper paste. Since copper replaces part of the silver, the cost of the metal electrode is reduced without affecting the metal composite and the welding of the metal electrode. Figure 3 F1 is the force exerted by the base layer 11 on the metal slurry in step S10. The metal slurry is rich in negative charges. Since the base layer 11 carries positive charges, the negative charges in the metal slurry can be more attracted by the base layer 11 by utilizing the principle of opposite charges attracting each other. In addition, the binder is one of the main components in the metal slurry, so that the metal slurry adheres to the insulating coating 12 of the slot 3 to be filled without falling due to gravity, thereby achieving the filling of the metal slurry.

[0064] like Figure 4 As shown, S20: an electric field applying device 2 is arranged facing the second side surface 14, and the first side surface 13 is bonded to the surface 41 to be metallized of the prefabricated silicon wafer 4. At the same time, the electric field applying device 2 is controlled to face the second side surface 14 to generate a negative electric field layer. The negative electric field layer and the negative charges in the metal slurry repel each other due to their like charges, and the metal slurry filled in the groove 3 to be filled is bonded to the prefabricated silicon wafer 4.

[0065] In these embodiments, the negative charges in the negative electric field layer repel the negative charges of the metal paste in the groove to be filled 3, and the metal paste is bonded to the surface to be metallized 41 of the prefabricated silicon wafer 4 under the action of the electric field force of the negative electric field layer. Since the metal paste contains adhesive, it is easily bonded to the prefabricated silicon wafer 4 under the action of the electric field force. Figure 4 In step S20 of F2 , the negative electric field layer exerts a force on the metal paste, and the force is directed toward the prefabricated silicon wafer 4 , which makes it easy for the metal paste to adhere to the prefabricated silicon wafer 4 .

[0066] like Figure 5 As shown, S30: the electrode slurry transfer plate and the prefabricated silicon wafer 4 are separated, so that the metal slurry filled in the groove to be filled 3 is separated from the electrode slurry transfer plate body 1 and remains on the surface to be metallized 41 of the prefabricated silicon wafer 4.

[0067] In some embodiments of the second aspect of the present application, in step S30, while separating the electrode slurry transfer plate and the prefabricated silicon wafer 4, the electric field applying device 2 is kept facing the second side surface 14 to generate a negative electric field layer. In some examples, in steps S20 and S30, the electric field applying device 2 is always in operation, thereby forming a negative electric field layer facing the second side surface 14 of the electrode slurry transfer plate body 1, and the formation of the negative electric field layer applies a force toward the prefabricated silicon wafer 4 to the metal slurry in the groove to be filled 3, so that the metal slurry filled in the groove to be filled 3 is more likely to adhere to the prefabricated silicon wafer 4 and more likely to detach from the electrode slurry transfer plate body 1 and remain in the area of ​​the prefabricated silicon wafer 4 where the metal electrode is prepared.

[0068] Since the insulating coating 12 has a low-energy surface 121, the adhesion between the metal slurry in the groove 3 to be filled and the surface 41 to be metallized of the prefabricated silicon wafer 4 is much greater than the adhesion between the metal slurry and the insulating coating 12. Therefore, when the electrode slurry transfer plate and the prefabricated silicon wafer 4 are separated, the metal slurry is left on the prefabricated silicon wafer 4 from the groove 3 to be filled of the electrode slurry transfer plate body 1.

[0069] S40: The metal slurry is sintered to form a metal electrode.

[0070] In some embodiments of the second aspect of the present application, the metal electrode is formed by sintering at 600° C. to 900° C.

[0071] In some embodiments of the second aspect of the present application, the electric field strength of the negative electric field layer is 20Mv / m to 50Mv / m.

[0072] In some embodiments of the second aspect of the present application, in step S10 to step S40, the first side surface 13 is kept facing the ground, and the first side surface 13 is opposite to the surface to be metallized 41 of the prefabricated silicon wafer 4. In these embodiments, based on the attraction between the positively charged base layer 11 and the negatively charged metal slurry in the electrode slurry transfer plate 1 during the metal slurry filling process, the electrode slurry transfer plate 1 does not need to be turned back and forth during the metal slurry filling process and the process of releasing the metal slurry from the electrode slurry transfer plate 1 onto the prefabricated silicon wafer 4, and the first side surface 13 is kept facing the ground, which is conducive to shortening the process of preparing electrodes, reducing the steps required for production, and improving the efficiency of preparing electrodes by metallization of solar cells.

[0073] The second aspect of the present application provides a method for preparing a solar cell electrode, which uses the electrode slurry transfer plate 1 provided in the first aspect of the present application in combination with an external negative electric field to achieve temporary storage and release of metal slurry based on the principle of charge repulsion and charge attraction. The temporary storage of metal slurry can reduce the width of the metal slurry temporarily stored in the slot 3 to be filled based on the graphical control of the electrode slurry transfer plate 1, avoiding displacement and deformation of the stacked metal slurry. In the process of releasing the metal slurry, due to avoiding the existence of obstacles between the metal slurry and the prefabricated silicon wafer 4 due to the existence of the screen in the screen printing technology, a narrower metal slurry filling body can be formed to form a narrower electrode. And for the formation of stacked electrodes, multiple printing processes are avoided, the metal slurry has been stacked in the slot 3 to be filled, and the alignment degree is higher during the release of the metal slurry, which can achieve multi-layer metal slurry stacking, reducing the shading effect of the electrodes in the solar cell on the solar cell.

[0074] The method for preparing the solar cell electrode provided in the second aspect of the present application is applied to the preparation of the stacked electrode. Since the metal slurry is first stacked in the groove to be filled 3 and then transferred to the prefabricated silicon wafer 4, the alignment is higher, and the abnormal widening of the metal electrode caused by the improvement of the alignment is avoided, and the situation in which the non-silver metal slurry contacts the prefabricated silicon wafer 4 and causes the metal area to increase in composite size is avoided, and the setting of at least two or even more layers of stacked electrodes can be achieved. The stacked electrode may include a bottom metal slurry, a middle metal slurry and a top metal slurry. The bottom metal slurry (for example, silver slurry) has a low contact resistivity and has good contact and passivation properties. The middle metal slurry is, for example, copper slurry, which has low cost and does not contact the silicon wafer to avoid affecting metal composite. The top metal slurry (for example, silver slurry) has excellent welding performance and conductivity. In this example, the bottom layer of the slot 3 to be filled is first filled with silver paste, the middle layer is filled with copper paste, and then the silver paste is covered on the copper paste as the top layer paste, so that the amount of silver paste used in the overall electrode production is reduced, thereby saving costs, and the top layer is commonly used silver paste, which can ensure weldability.

[0075] A third aspect of the present application provides a solar cell, comprising:

[0076] A substrate having a P region and an N region formed thereon;

[0077] The electrode layer includes a plurality of electrodes arranged in the P region and the N region and used for collecting photogenerated carriers. The electrodes in the solar cell are prepared by the preparation method of the solar cell electrode in the second aspect of the present application.

[0078] The solar cell provided in the third aspect of the present application has a significantly narrowed electrode width, a low electrode shading rate, an improved photoelectric conversion efficiency, and an increased metal electrode alignment.

[0079] In some examples of the third aspect of the present application, the substrate is a silicon substrate. A P region may be formed on one of the light-receiving surface and the back side of the substrate, and an N region may be formed on one of the light-receiving surface and the back side of the substrate. Alternatively, alternating P regions and N regions are formed on the back side of the substrate. The silicon substrate may be an N-type silicon substrate or a P-type silicon substrate. When the silicon substrate is an N-type silicon substrate, an N-type doping structure of the same doping type as the substrate is formed in the N region, but the doping concentration is different. A P-type doping structure of the opposite doping type to the substrate is formed in the P region, and the main carriers of the P-type doping structure are holes, and the main carriers of the N-type doping structure are free electrons. When the silicon substrate is a P-type silicon substrate, an N-type doping structure of the opposite doping type to the substrate is formed in the N region, and a P-type doping structure of the same doping type as the substrate is formed in the P region, but the doping concentration is different.

[0080] The above is only a specific implementation of the present application, but the protection scope of the present application is not limited thereto. Any changes or substitutions that can be easily thought of by a person skilled in the art within the technical scope disclosed in the present application should be included in the protection scope of the present application. Therefore, the protection scope of the present application shall be based on the protection scope of the claims.

Claims

1. An electrode slurry transfer plate, characterized in that: The slurry used to transfer and form the electrodes in solar cells includes: A substrate layer, wherein the surface of the substrate layer is positively charged, the surface comprises a first surface and a second surface disposed in back-to-back relation, and the substrate layer is provided with a plurality of grooves corresponding to the electrode pattern on the first surface through a patterning process; The insulating coating is disposed on the first surface and at least covers the groove. The insulating coating has low surface energy and forms a low-energy surface facing away from the first surface. The groove covered with the insulating coating is a groove to be filled.

2. The electrode slurry transfer plate according to claim 1, characterized in that: The base layer is made of a composite material with a positive charge on the surface, and the composite material includes at least one of diallyldimethylammonium chloride modified graphene and diallyldimethylammonium chloride modified cobalt-nickel alloy.

3. The electrode slurry transfer plate according to claim 1, characterized in that: The width of the groove to be filled is 3 μm to 12 μm.

4. The electrode slurry transfer plate according to claim 1, characterized in that: The insulating coating includes at least one of polyethylene and polypropylene.

5. A method for preparing a solar cell electrode, characterized in that: include: S10: filling metal slurry into the to-be-filled groove of the electrode slurry transfer plate body according to any one of claims 1 to 4, so that the electrode slurry transfer plate body forms a first side surface exposed with the metal slurry and a second side surface facing away from the first side surface; S20: an electric field applying device is arranged facing the second side surface, the first side surface is bonded to the surface to be metallized of the prefabricated silicon wafer, and at the same time, the electric field applying device is controlled to generate a negative electric field layer facing the second side surface, the negative electric field layer and the negative charges in the metal slurry repel each other with the same charge, and the metal slurry filled in the groove to be filled is bonded to the prefabricated silicon wafer; S30: separating the electrode slurry transfer plate and the prefabricated silicon wafer, so that the metal slurry filled in the groove to be filled is separated from the electrode slurry transfer plate and remains on the surface to be metallized of the prefabricated silicon wafer; S40: The metal slurry is sintered to form a metal electrode.

6. The method for preparing a solar cell electrode according to claim 5, characterized in that: In the step S30, while separating the electrode slurry transfer plate and the prefabricated silicon wafer, the electric field applying device is kept facing the second side surface to generate a negative electric field layer.

7. The method for preparing a solar cell electrode according to claim 5 or 6, characterized in that: The electric field strength of the negative electric field layer is 20Mv / m to 50Mv / m.

8. The method for preparing a solar cell electrode according to claim 5, characterized in that: In the steps S10 to S40, the first side surface is kept facing the ground, and the first side surface is opposite to the surface to be metallized.

9. The method for preparing a solar cell electrode according to claim 5, characterized in that: In the step S10, each of the grooves to be filled is filled with at least two layers of metal pastes of different types along the groove opening direction to form a laminated electrode.

10. A solar cell, characterized in that: include: A substrate having a P region and an N region formed thereon; The electrode layer comprises a plurality of electrodes arranged in the P region and the N region and used for collecting photogenerated carriers, wherein the electrodes are prepared by the method for preparing a solar cell electrode according to any one of claims 5 to 9.

Images