Solar cell and preparation method of electrode thereof

Abstract

The invention relates to the technical field of solar cells, in particular to a solar cell and a preparation method of an electrode of the solar cell, and the preparation method of the electrode comprises the steps that an electrode pattern patch is arranged on a transparent conductive oxide layer of a cell piece, and the electrode pattern patch is provided with a groove; forming a grid line in the groove; and removing the electrode pattern patch, and leaving the grid line on the transparent conductive oxide layer. The preparation method of the electrode of the solar cell is simple and easy to operate, no metal ion waste liquid is generated, the cost is reduced, and the problem of environmental pollution is solved.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of solar cells, in particular to a solar cell and a preparation method of an electrode thereof. BACKGROUND

[0002] The grid line of a solar cell (for example, a heterojunction solar cell) is an important component, and the main function of the grid line is to collect and conduct photo-generated current.

[0003] The preparation process of the grid line provided by the related art is mainly a wet process, which includes: coating a pure copper film layer, forming a photosensitive adhesive film, exposing and printing the photosensitive adhesive (i.e., selectively exposing the photosensitive adhesive film to make a grid line pattern), pattern development (i.e., removing the exposed photosensitive adhesive with a chemical solution), insulating the edges (i.e., applying insulating adhesive to the edges of the solar cell to insulate the PN surface), electroplating to form a copper grid electrode, and removing the film and etching back (i.e., removing the residual photosensitive adhesive and the excess pure copper film layer between the grid line patterns).

[0004] The wet process described above produces a large amount of metal ion waste liquid, which is difficult to reduce production costs and is prone to pollution. SUMMARY

[0005] The present application aims to provide a solar cell and a preparation method of an electrode thereof, which is simple and easy to operate, does not produce metal ion waste liquid, is conducive to reducing costs, and improves environmental pollution problems.

[0006] The present application is implemented as follows:

[0007] In a first aspect, the present application provides a preparation method of an electrode of a solar cell, comprising:

[0008] arranging an electrode pattern patch on a transparent conductive oxide layer of a solar cell, the electrode pattern patch having a groove;

[0009] forming a grid line in the groove;

[0010] removing the electrode pattern patch and leaving the grid line on the transparent conductive oxide layer.

[0011] In an optional embodiment, the preparation method further comprises:

[0012] trimming to remove burrs on the outer surface of the grid line.

[0013] In an optional embodiment, the method of trimming to remove burrs on the outer surface of the grid line comprises:

[0014] removing the burrs with a laser.

[0015] In an optional embodiment, the wavelength of the laser is 325-400 nm, the pulse width of the laser is 10-15 ns, the power of the laser is 3-10 W, and the beam quality M 2 <1.2.

[0016] In an optional embodiment, the moving speed of the laser beam is 5-7 m / s.

[0017] In an optional embodiment, the preparation method further comprises:

[0018] A protective film is formed on the surface of the grid line.

[0019] In an optional embodiment, the protective film is a tin film.

[0020] In an optional embodiment, the preparation method further comprises: before the protective film is formed, pre-cleaning the grid line.

[0021] In an optional embodiment, the preparation method further comprises: after the protective film is formed, cleaning.

[0022] In an optional embodiment, the method for forming the grid line in the groove comprises: forming the grid line by physical vapor deposition.

[0023] In a second aspect, the present application further provides a preparation method of a solar cell, which comprises the preparation method of the electrode of the solar cell.

[0024] The preparation method of the electrode of the solar cell of the embodiments of the present application has the following beneficial effects: the preparation method of the electrode of the solar cell provided by the embodiments of the present application first sets an electrode pattern patch on the transparent conductive oxide layer of a cell sheet, then forms a grid line in the groove of the electrode pattern patch, and removes the electrode pattern patch after the grid line is formed, so that the grid line is prepared on the transparent conductive oxide layer. Since the preparation method of the present application does not need to coat a photosensitive glue on the transparent conductive oxide layer, the photosensitive glue after exposure no longer needs to be removed by using a medicine water, and thus metal ion waste liquid is not generated, the waste liquid no longer needs to be recovered and treated, which is beneficial to reduce the cost and improve the problem of environmental pollution by waste liquid. Meanwhile, the preparation method of the present application is simple and easy to operate.

[0025] The preparation method of the solar cell of the embodiments of the present application has all the beneficial effects of the preparation method of the electrode, for example: in the process of preparing the electrode, the photosensitive glue after exposure no longer needs to be removed by using a medicine water, and thus metal ion waste liquid is not generated, the waste liquid no longer needs to be recovered and treated, which is beneficial to reduce the cost and improve the problem of environmental pollution by waste liquid. Meanwhile, the preparation method of the present application is simple and easy to operate. BRIEF DESCRIPTION OF DRAWINGS

[0026] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the following will briefly introduce the drawings needed to be used in the embodiments. It should be understood that the following drawings only show some of the embodiments of the present application, and therefore should not be regarded as a limitation on the scope. For those skilled in the art, other related drawings can also be obtained without creative labor.

[0027] Figure 1 Preparation flowchart of the solar cell of the present disclosure;

[0028] Figure 2 Preparation flowchart of the solar cell of the embodiment 1 of the present application.

[0029] Main element symbol explanation: 010-solar cell; 100-substrate; 110-intrinsic oxidized amorphous silicon layer; 121-N-face doped film layer; 122-P-face doped film layer; 130-transparent conductive oxide layer; 140-electrode pattern patch; 150-grid line. DETAILED DESCRIPTION

[0030] In order to make the purpose, technical solutions and advantages of the embodiments of the present application more clear, the technical solutions in the embodiments of the present application will be clearly and completely described below. If the specific conditions are not specified in the embodiments, the conventional conditions or the conditions suggested by the manufacturers are adopted. If the reagents or instruments are not specified by the manufacturers, they are all conventional products that can be purchased in the market.

[0031] The preparation method of the solar cell provided by the related art comprises:

[0032] 1. Cleaning and texturing, preparing pyramid texture on the front and back surfaces of the substrate;

[0033] 2. PECVD process, preparing intrinsic oxidized amorphous silicon layer, and plating P / N face doped film layer;

[0034] 3. PVD process, preparing transparent conductive oxide layer (TCO layer) and pure copper film layer on the front and back surfaces;

[0035] 4. Coating, coating photosensitive adhesive film on the pure copper film layer;

[0036] 5. Exposure printing, selectively exposing the photosensitive adhesive film to make grid line pattern;

[0037] 6. Pattern development, removing the exposed photosensitive adhesive film with developer;

[0038] 7. Insulating edge coating, coating insulating adhesive on the side of the cell piece to isolate PN face;

[0039] 8. Copper grid electrode plating, copper grid electrode reaction forming;

[0040] 9. Removing the residual photoresist and the excess pure copper film between the grid lines;

[0041] 10. Tinning, forming a tin layer on the sidewall of the copper grid electrode through displacement reaction to prevent the copper grid electrode from being oxidized;

[0042] 11. Light injection, repairing the damage, and improving the battery efficiency;

[0043] 12. Testing and sorting, testing the electrical performance of the prepared battery to sort.

[0044] In the above process, the pattern development process is a wet process, which needs to use a chemical solution to remove the exposed photoresist film, thus a large amount of metal ion waste liquid is generated. In order to recover and treat the waste liquid, the cost is increased, and the environment is easily polluted.

[0045] In order to improve the above problems, the present disclosure provides a solar cell and a preparation method of an electrode thereof to improve the problems of cost increase and environmental pollution caused by waste liquid generation.

[0046] Please refer to Figure 1 The preparation method of the solar cell 010 provided by the present disclosure can be used to prepare a heterojunction solar cell 010, which comprises:

[0047] 1. Cleaning and texturing, preparing a pyramid texture on the front and back surfaces of a substrate 100 (for example, an N-type silicon substrate);

[0048] 2. PECVD process, preparing an intrinsic oxidized amorphous silicon layer 110 (including an I film layer on the front surface and an I film layer on the back surface), and a N-doped film layer 121 and a P-doped film layer 122;

[0049] 3. PVD process, preparing a transparent conductive oxide layer 130 (TCO layer) on the front and back surfaces;

[0050] 4. Pasting, pasting an electrode pattern 140 on the transparent conductive oxide layer 130 of the cell piece (the cell piece comprises the substrate 100 and the intrinsic oxidized amorphous silicon layer 110, the P / N-doped film layer 121 formed on the substrate 100), and the electrode pattern 140 has a groove, and the position of the groove corresponds to the position where the grid line 150 needs to be formed;

[0051] 5. Preparing a grid line 150, forming the grid line 150 in the groove of the pasting;

[0052] 6. Removing the pasting, removing the electrode pattern 140, and leaving the grid line 150 on the transparent conductive oxide layer 130, that is, making the grid line 150 on the transparent conductive oxide layer 130.

[0053] Since the preparation method of the present disclosure does not need to coat the photosensitive adhesive on the transparent conductive oxide layer 130, the exposed photosensitive adhesive no longer needs to be removed by using the chemical solution, thereby not producing metal ion waste liquid, and not needing to recover and treat the waste liquid, which is beneficial to reduce the cost and improve the problem of environmental pollution by waste liquid; at the same time, the preparation method of the present disclosure does not need to form a pure copper film layer on the transparent conductive oxide layer 130, which can reduce the process steps and ensure that the preparation method is simple and easy to operate.

[0054] It should be noted that the above patch refers to patching the transparent conductive oxide layer 130 on the front and back surfaces, so as to manufacture the gate lines 150 on the front and back surfaces, and after the gate lines 150 are formed, the patches on the front and back surfaces are removed together.

[0055] It should be understood that the preparation method of the electrode provided by the present disclosure can also be used to prepare electrodes of other types of solar cells 010, such as electrodes of TOPcon solar cells 010, etc., which are not limited here. It should be noted that when preparing other types of solar cells 010, other processes in addition to preparing the electrode can be adaptively adjusted.

[0056] Optionally, the transparent conductive oxide layer 130 on which the electrode pattern patch 140 is arranged can be completed by using an SMT (Surface Mount Technology) patch machine.

[0057] Optionally, the method for removing the electrode pattern patch 140 includes heating the patch and then taking the patch off the transparent conductive oxide layer 130, etc., which are not limited here.

[0058] Optionally, the above-mentioned gate line 150 refers to a copper gate line.

[0059] Optionally, the method for forming the gate line 150 in the groove of the electrode pattern patch 140 includes forming the gate line 150 by physical vapor deposition (PVD).

[0060] It should be noted that the process parameters of the above-mentioned physical vapor deposition are similar to those of the related art, which are not repeated here.

[0061] Of course, in other embodiments, the method for forming the gate line 150 in the groove of the electrode pattern patch 140 can also include electroplating, etc., which are not limited here.

[0062] Optionally, the method for preparing the electrode of the solar cell 010 of the present disclosure further comprises trimming the burrs on the outer surface of the grid lines 150. After removing the burrs, in addition to making the surface of the grid lines 150 more regular to form a good grid line 150 morphology, more importantly, it can reduce the adverse reflection, refraction and scattering of light caused by the burrs to ensure that the solar cell 010 receives more effective light and improves the photoelectric conversion efficiency of the prepared solar cell 010.

[0063] Optionally, the method for trimming the burrs on the outer surface of the grid lines 150 comprises removing the burrs with a laser. Using a laser to remove the burrs makes it easier to achieve point removal and improve the problem of adversely affecting the structure of the grid lines 150 itself, thereby ensuring good photoelectric conversion efficiency of the solar cell 010.

[0064] Optionally, the wavelength of the laser is 325-400 nm, for example: 325 nm, 355 nm, 400 nm, etc., which is not specifically limited here; the pulse width of the laser is 10-15 ns, for example: 10 ns, 11 ns, 12 ns, 13 ns, 14 ns, 15 ns, etc., which is not specifically limited here; the power of the laser is 3-10 W, for example: 3 W, 4 W, 5 W, 6 W, 7 W, 8 W, 9 W, 10 W, etc., which is not specifically limited here.

[0065] Under the above laser process, the burrs on the grid lines 150 can be efficiently and quickly removed, and the problem of adversely affecting the structure of the grid lines 150 itself caused by laser processing can be improved to ensure that the solar cell 010 has good photoelectric conversion efficiency. Among them, the beam quality M 2 of the laser is less than 1.2, and the M 2 factor of the laser beam is closer to 1, the beam quality is better, and the burrs can be reliably and efficiently removed.

[0066] Further, the moving speed of the laser beam is 5-7 m / s, for example: 5 m / s, 6 m / s, 7 m / s, etc., which is not specifically limited here.

[0067] It should be noted that when using a laser to remove the burrs on the surface of the grid lines 150, a CCD photographing imaging technology can be used to locate the position of the burrs so as to accurately remove the burrs with a laser.

[0068] Optionally, the method for preparing the electrode of the solar cell 010 further comprises: forming a protective film on the surface of the grid line 150; through the arrangement of the protective film, the problem that the grid line 150 is exposed to air for a long time, is easy to react with oxygen in the air, and forms an oxide film on the surface of the grid line 150, reducing the conductivity, can be improved; in particular, in the embodiment that the grid line 150 is a copper grid line, copper is easy to react with oxygen to form a copper oxide layer, which reduces the conductivity of the grid line 150 and causes the photoelectric conversion efficiency of the solar cell 010 to be reduced, and after the grid line 150 is prepared, the protective film is formed on the surface of the grid line 150 in time, which can improve the above-mentioned problems.

[0069] Optionally, the protective film is a tin film. The tin film can be prepared by a tin plating process, and a tin film is prepared on the surface of the grid line 150, which can effectively prevent the grid line 150 from being oxidized; wherein the tin plating process is similar to the related art, and will not be described here.

[0070] Optionally, the method for preparing the electrode of the solar cell 010 further comprises: pre-cleaning the grid line 150 before forming the protective film.

[0071] Optionally, the method for preparing the electrode of the solar cell 010 further comprises: cleaning after forming the protective film.

[0072] The pre-cleaning and cleaning processes can remove impurities and foreign matter generated in the process.

[0073] Optionally, the pre-cleaning and cleaning processes can use pure water as the cleaning agent, and the temperature of the cleaning agent is room temperature, for example, about 25°C; nitrogen can also be bubbled during pre-cleaning and cleaning.

[0074] Optionally, drying can be performed after cleaning, and the drying temperature is 80-90°C, for example, 80°C, 82°C, 85°C, 88°C, 90°C, etc.; wherein, during the drying process, fresh air can be continuously introduced into the drying tank to reduce ozone in the drying tank, and nitrogen can also be introduced.

[0075] It should be noted that during the drying and fresh air introduction process, impurities in the drying tank can be removed to reduce the residual impurities on the battery.

[0076] The application will be further described in detail below with reference to the embodiments.

[0077] Embodiment 1

[0078] Please refer to Figure 2 , the preparation process of embodiment 1 comprises:

[0079] 1. Cleaning and preparing a pyramidal surface on the front and back surfaces of the substrate;

[0080] 2. PECVD process, preparing intrinsic oxide amorphous silicon layer on the front and back surface, and depositing P / N surface doped film layer;

[0081] 3. PVD process, preparing transparent conductive oxide layer (TCO layer) on the front and back surface;

[0082] 4. Patch, setting electrode pattern patch on the transparent conductive oxide layer of the battery piece;

[0083] 5. Preparing grid line, forming grid line in the groove of the patch;

[0084] 6. Removing patch, removing the electrode pattern patch by laser, and leaving the grid line on the transparent conductive oxide layer;

[0085] 7. Trimming grid line, removing burrs on the surface of the grid line by laser; wherein the wavelength of the laser is 325nm, the pulse width of the laser is 15ns, the power of the laser is 3W, the beam quality M 2 of the laser is less than 1.2, and the moving speed of the beam is 7m / s;

[0086] 8. Tin and impurity cleaning, forming tin film on the surface of the grid line, and performing pre-cleaning and cleaning by water before and after forming the tin film, respectively;

[0087] 9. Light injection;

[0088] 10. Test sorting.

[0089] Example 2

[0090] The difference between example 2 and example 1 is that the laser process parameters are different; wherein the wavelength of the laser is 355nm, the pulse width of the laser is 12ns, the power of the laser is 5W, the beam quality M 2 of the laser is less than 1.2, and the moving speed of the beam is 5m / s.

[0091] Example 3

[0092] The difference between example 3 and example 1 is that the laser process parameters are different; wherein the wavelength of the laser is 400nm, the pulse width of the laser is 10ns, the power of the laser is 10W, the beam quality M 2 of the laser is less than 1.2, and the moving speed of the beam is 6m / s.

[0093] In summary, the solar cell 010 and the preparation method of the electrode thereof are simple and easy to operate, and no metal ion waste liquid is generated, which is conducive to reducing cost and improving environmental pollution problems.

[0094] The above merely describes the preferred embodiments of the present application, and is not used to limit the present application. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application shall be included in the protection scope of the present application.

Claims

1. A method for producing an electrode of a solar cell, characterized by, The preparation method comprises: providing an electrode pattern patch (140) on a transparent conductive oxide layer (130) of a battery piece, the electrode pattern patch (140) having a groove; forming a grid line (150) in the groove; removing the electrode pattern patch (140) and leaving the grid line (150) on the transparent conductive oxide layer (130).

2. The method for producing an electrode of a solar cell according to claim 1, wherein The preparation method further comprises: trimming burrs on the outer surface of the grid line (150).

3. The method for producing an electrode of a solar cell according to claim 2, wherein The method of trimming burrs on the outer surface of the grid line (150) comprises: removing the burrs by laser.

4. The method for producing an electrode of a solar cell according to claim 3, wherein The wavelength of the laser is 325-400 nm, the pulse width of the laser is 10-15 ns, the power of the laser is 3-10 W, the beam quality M 2 <1.

2.

5. The method of producing an electrode of a solar cell according to claim 4, wherein The moving speed of the light beam of the laser is 5-7 m / s.

6. The method of producing an electrode of a solar cell according to any one of claims 1 to 5, characterized in that, The preparation method further comprises: forming a protective film on the surface of the grid line (150).

7. The method of producing an electrode of a solar cell according to claim 6, wherein The protective film is a tin film.

8. The method of producing an electrode of a solar cell according to claim 6, wherein The preparation method further comprises: before forming the protective film, pre-cleaning the grid line (150); and / or, after forming the protective film, cleaning.

9. The method of producing an electrode of a solar cell according to any one of claims 1 to 5, characterized in that, The method of forming the grid line (150) in the groove comprises: forming the grid line (150) by physical vapor deposition.

10. A method of producing a solar cell, characterized by, The preparation method of an electrode of a solar cell as claimed in any one of claims 1-9. The preparation method of an electrode of a solar cell as claimed in any one of claims 1-9.

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