A method for electroplating metal grid lines of a heterojunction solar cell

Abstract

The application discloses a plating method for metal grid lines of a heterojunction solar cell. After a silicon wafer is cleaned, scoured, amorphous silicon is deposited, a transparent conductive layer is deposited, a metal conductive layer is deposited, a mask is made on the metal conductive layer, exposure and development are performed to form a required electrode grid line pattern, movement is performed in a plating solution with a magnetic field to generate induced current, and the electrode grid line is formed by plating. Finally, the mask is removed, and the metal conductive layer except the electrode grid line is etched to manufacture a finished product. The plating method for the metal grid lines of the solar cell does not need a rectifier power supply and an anode and a cathode for plating, and greatly reduces the plating cost, thereby improving economic benefits.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of solar cell manufacturing, and is a low-cost solar cell manufacturing method. BACKGROUND

[0002] With the continuous development of solar cell technology, the photovoltaic industry has gradually upgraded from traditional solar cells, focusing on the development of new high-efficiency cells, and the typical representative is a heterojunction cell. The heterojunction cell has the advantages of simple structure, low process temperature, high conversion efficiency, good temperature coefficient, and the like. After adding the component efficiency technology, the degree of electric cost decreases sharply, and the cost performance advantage is more and more obvious.

[0003] However, with the continuous rise in the price of silver and other precious metals, the cost proportion of the heterojunction cell in the electrode grid line manufacturing is becoming higher and higher, which makes the new high-efficiency cell industry represented by the heterojunction cell have a lower competitiveness compared with the traditional solar cell industry, and is not conducive to the promotion of the heterojunction cell technology. SUMMARY

[0004] In view of the above problems, the present application provides a plating method for a metal grid line of a heterojunction solar cell, which replaces the current screen printing of low-temperature silver paste to manufacture an electrode grid line. The method mainly uses a magnetic field to promote the movement of metal ions in the plating solution, and at the same time, the wafer moves in the magnetic field to generate an induced current. The internal electrons flow to the surface and combine with the plating metal ions, and the plating metal is deposited on the wafer surface grid line area to form an electrode grid line. The method can greatly reduce the manufacturing cost of the heterojunction cell grid line.

[0005] The present application adopts the following technical solutions:

[0006] A plating method for a metal grid line of a heterojunction solar cell, after a silicon wafer is cleaned, textured, deposited with amorphous silicon, and deposited with a transparent conductive layer, a metal conductive layer is then deposited, a mask is then made on the metal conductive layer, exposure and development are then performed to form a required electrode grid line pattern, the wafer then moves in a plating solution with a magnetic field to generate an induced current, and the plating forms an electrode grid line. Finally, the mask is removed and the metal conductive layer except for the electrode grid line is etched away to manufacture a finished product cell.

[0007] Preferably, the metal conductive layer is a single film layer or a composite film layer of a nickel metal conductive layer or a cobalt metal conductive layer.

[0008] Preferably, the deposition method of the metal conductive layer is one of a PVD sputtering method, a PVD evaporation method, or a PVD ion plating method, and the deposition thickness of the metal conductive layer is 10-1000 nm.

[0009] Preferably, the magnetic field is formed by a combination of multiple magnets.

[0010] Preferably, the magnetic induction intensity of the magnetic field is 1-5T.

[0011] Preferably, the movement of the sheet in the electroplating solution with a magnetic field refers to the movement of the sheet in a state perpendicular to the direction of the magnetic field, that is, the metal conductive layer on the sheet cuts the magnetic field lines to generate an induced current.

[0012] Preferably, the electroplating solution is either a NiSO4 solution or a CoSO4 solution.

[0013] Preferably, the concentration of the electroplating solution is 50-400 g / L, and the electroplating time is 10-60 min.

[0014] Preferably, the etching of the conductive metal layer uses a sulfuric acid-hydrogen peroxide system or a nitric acid system.

[0015] Preferably, all of the above steps are double-sided processes.

[0016] By adopting the above technical solution, the beneficial effects of the present invention are:

[0017] This method replaces the current method of using low-temperature silver paste printed on screens to create electrode grid lines. It involves cleaning and texturing a silicon wafer, depositing amorphous silicon, depositing a transparent conductive layer, and then depositing a metal conductive layer. A mask is then fabricated on the metal conductive layer, exposed, and developed to form the desired electrode grid line pattern. The pattern is then moved through a magnetic plating solution to generate an induced current, electroplating the electrode grid lines. Finally, the mask is removed and the metal conductive layer (excluding the electrode grid lines) is etched away to produce the finished battery. This method is lower in cost and produces electrode grid lines with better conductivity. Attached Figure Description

[0018] Figure 1 This is a process flow diagram of the present invention. Detailed Implementation

[0019] To make the objectives, technical solutions, and advantages of the embodiments of the invention clearer, the technical solutions in the embodiments of the invention will be clearly and completely described below in conjunction with the embodiments of the invention. Obviously, the described embodiments are only some embodiments of the invention, not all embodiments. Based on the embodiments of the invention, those skilled in the art...

[0020] All other embodiments obtained by those skilled in the art without inventive effort are within the scope of protection of this invention.

[0021] like Figure 1 As shown, the present invention provides an electroplating method for electrode grid lines of a heterojunction solar cell, the method comprising the following steps.

[0022] Step 1: The silicon wafer is cleaned and texturized, then amorphous silicon is deposited, and a transparent conductive layer is deposited.

[0023] Step two, deposit a layer of metal conductive layer on the transparent conductive layer.

[0024] Step three, make a mask on the metal conductive layer, expose and develop to form the required electrode grid pattern.

[0025] Step four, the wafer moves in the electroplating solution with magnetic field, and the electrode grid is formed by electroplating.

[0026] Step five, remove the mask.

[0027] Step six, etch off the metal conductive layer except the electrode grid to make the finished battery.

[0028] Further, the silicon wafer is one of P-type silicon wafer or N-type silicon wafer, the size specification is one of M2, G1, M6, M10, G12, and the thickness is 100-180um.

[0029] Further, all the steps are double-sided process.

[0030] Further, after the silicon wafer is cleaned and textured, amorphous silicon is deposited, and the transparent conductive layer is deposited, a layer of metal conductive layer is deposited on the transparent conductive layer.

[0031] Further, the metal conductive layer is a single film layer or a composite film layer of nickel metal conductive layer or cobalt metal conductive layer.

[0032] Further, the deposition method of the metal conductive layer is one of PVD sputtering method, PVD evaporation method, and PVD ion plating method, and the deposition thickness is 10-1000nm.

[0033] Further, after the silicon wafer is deposited with the metal conductive layer, a mask is made, exposed and developed to form the required electrode grid pattern.

[0034] Further, the magnetic field is formed by a plurality of magnets, and the magnetic induction intensity is 1-5T.

[0035] Further, the wafer moves in the electroplating solution with magnetic field refers to the state that the wafer moves vertically to the direction of the magnetic field, that is, the metal conductive layer on the wafer cuts the magnetic induction lines to generate induced current.

[0036] Further, the electroplating solution is one of NiSO4 solution and CoSO4 solution.

[0037] Further, the concentration of the electroplating solution is 50-400g / L, and the electroplating time is 10-60min.

[0038] Further, after the electrode grid is made, the mask is removed and the metal conductive layer except the electrode grid is etched off.

[0039] Further, the etching of the metal conductive layer uses one of the etching solutions corresponding to the metal conductive layer, such as sulfuric acid-hydrogen peroxide system, nitric acid system, etc.

[0040] Example One

[0041] After 5 pieces of G1 silicon wafers are subjected to double-side cleaning, texturing, amorphous silicon deposition, transparent conductive layer deposition, etc., a 1000 nm thick Ni seed layer is deposited in PVD, a mask is made, then exposed and developed to form the required electrode grid line pattern; the wafer is moved in a NiSO4 electroplating solution with a magnetic induction intensity of about 1T formed by multiple magnets for 30 min, the concentration of the electroplating solution is about 300 g / L; after the electroplating is completed, the mask is removed, and the Ni seed layer in the area outside the grid line is etched by using sulfuric acid-hydrogen peroxide system etching liquid; the efficiency and the grid line height are as follows.

[0042]

[0043]

[0044] Example Two

[0045] After 5 pieces of G1 silicon wafers are subjected to double-side cleaning, texturing, amorphous silicon deposition, transparent conductive layer deposition, etc., a 1000 nm thick Ni seed layer is deposited in PVD, a mask is made, then exposed and developed to form the required electrode grid line pattern; the wafer is moved in a NiSO4 electroplating solution with a magnetic induction intensity of about 1T formed by multiple magnets for 50 min, the concentration of the electroplating solution is about 400 g / L; after the electroplating is completed, the mask is removed, and the Ni seed layer in the area outside the grid line is etched by using sulfuric acid-hydrogen peroxide system etching liquid; the efficiency and the grid line height are as follows.

[0046]

[0047]

[0048] Example Three

[0049] After 5 pieces of G1 silicon wafers are subjected to double-side cleaning, texturing, amorphous silicon deposition, transparent conductive layer deposition, etc., a 1000 nm thick Ni seed layer is deposited in PVD, a mask is made, then exposed and developed to form the required electrode grid line pattern; the wafer is moved in a NiSO4 electroplating solution with a magnetic induction intensity of about 1.5T formed by multiple magnets for 30 min, the concentration of the electroplating solution is about 400 g / L; after the electroplating is completed, the mask is removed, and the Ni seed layer in the area outside the grid line is etched by using sulfuric acid-hydrogen peroxide system etching liquid; the efficiency and the grid line height are as follows.

[0050]

[0051]

[0052] The above examples are only used to illustrate the technical solutions of the present application, but not to limit the present application; although the present application has been described in detail with reference to the foregoing examples, those ordinarily skilled in the art should understand: the technical solutions recorded in the foregoing examples can be modified, or some technical features can be replaced equivalently; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the spirit and scope of the technical solutions of the embodiments of the present application.

Claims

1. A method for electroplating metal grid lines of a heterojunction solar cell, characterized by: After the silicon wafer is cleaned, textured, deposited with amorphous silicon, deposited with a transparent conductive layer, and then deposited with a metal conductive layer, a mask is made on the metal conductive layer, and then exposed and developed to form the required electrode grid pattern; then the silicon wafer is moved in a magnetic field plating solution to generate induced current to form the electrode grid by plating; finally, the mask is removed and the metal conductive layer except the electrode grid is etched to produce the finished battery.

2. The plating method of metal grid lines for heterojunction solar cells according to claim 1, characterized in that: The metal conductive layer is a single film layer or a composite film layer of nickel metal conductive layer or cobalt metal conductive layer.

3. The plating method of metal grid lines for heterojunction solar cells according to claim 1, characterized in that: The deposition method of the metal conductive layer is one of PVD sputtering, PVD evaporation or PVD ion plating; the deposition thickness of the metal conductive layer is 10-1000 nm.

4. The plating method of metal grid lines for heterojunction solar cells according to claim 1, wherein: The magnetic field is formed by a plurality of magnets.

5. The plating method of metal grid lines for heterojunction solar cells according to claim 1, wherein: The magnetic field has a magnetic induction intensity of 1-5 T.

6. The plating method of metal grid lines for heterojunction solar cells according to claim 1, wherein: The movement of the silicon wafer in the magnetic field plating solution refers to the movement of the silicon wafer in a state perpendicular to the direction of the magnetic field, i.e. the metal conductive layer on the silicon wafer cuts the magnetic induction lines to generate induced current.

7. The plating method of metal grid lines for heterojunction solar cells according to claim 1, wherein: The plating solution is one of NiSO4 solution or CoSO4 solution.

8. The plating method of metal grid lines for heterojunction solar cells according to claim 1, wherein: The concentration of the plating solution is 50-400 g / L, and the plating time is 10-60 min.

9. The plating method of metal grid lines for heterojunction solar cells according to claim 1, wherein: The etching of the metal conductive layer uses sulfuric acid-hydrogen peroxide system or nitric acid system.

10. The plating method of metal grid lines for heterojunction solar cells according to claim 1, wherein: All the steps are double-sided processes.

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