Copper-containing metal electrode solar cell, solar cell module and preparation method

Abstract

The invention discloses a copper-containing metal electrode solar cell, a solar cell module and a preparation method, and belongs to the technical field of solar cells, the copper-containing metal electrode solar cell comprises a silicon wafer, a first semiconductor layer, a second semiconductor layer, a conductive film layer, a copper-containing metal fine gate electrode and protective ink; a second semiconductor opening region is formed between the adjacent first semiconductor layers; an isolation groove is formed in the conductive film layer corresponding to the edge area of the second semiconductor opening area; the conductive film layer corresponding to each first semiconductor layer and each second semiconductor layer is provided with a copper-containing metal fine gate electrode; the protection ink covers the copper-containing metal fine gate electrode, and / or the protection ink covers the isolation groove; the refractive index of the protective ink is 1.4-2.2, and the average light transmittance of the protective ink at the wavelength of 300-1100 nm is larger than or equal to 80%. According to the invention, the long-term reliability of the module is improved, the technical requirements on packaging materials are reduced, and the product cost is effectively reduced.

Description

Technical Field

[0001] The present invention belongs to the technical field of solar cells, and particularly relates to a copper-containing metal electrode solar cell, a solar cell module and a preparation method thereof. Background Art

[0002] Silver paste for photovoltaic use is mainly used for making grid lines of photovoltaic cells, which affects the photoelectric conversion efficiency. The quality and conductivity of the silver paste directly affect the performance and quality of the cell wafers. With the development of the photovoltaic industry, in 2023, silver used for photovoltaic accounted for more than 16% of the total global silver demand, and silver for photovoltaic has become the largest disturbing item in the global silver demand side. In 2024, the demand for electronic-grade silver powder in the photovoltaic industry is expected to approach the level of 7,000 tons. Against the background of high silver prices, photovoltaic enterprises are accelerating the cost reduction of silver paste. Currently, the cost of silver paste accounts for more than 30% of the non-silicon material cost of photovoltaic cells.

[0003] To reduce the usage amount of silver, silver-coated copper pastes or even pure copper pastes have received extensive attention. Silver-coated copper pastes generally consist of conductive fillers and organic polymers. The conductive fillers are generally silver-coated copper powders or specially treated copper powders, which mainly play the role of conducting electrons and determine the conductivity of the grid lines. Organic polymers are mainly composed of various composite resins, solvents, curing agents and other additives. Resins such as epoxy resins and polyurethanes, after curing, serve as the molecular structure framework, connecting left and right and determining physical properties such as bonding strength. Solvents and additives are mainly used to adjust the viscosity and leveling property of the paste and determine the printability of the paste. The curing agent is mainly used to cure the collective bonding phase. Each raw material component is made into a uniform paste through high-speed stirring and three-roll grinding.

[0004] However, copper elements are very sensitive to water vapor or acids and bases. Water vapor will oxidize the copper in the silver-coated copper paste or copper paste to produce copper oxide, thereby reducing the conductivity of the grid lines. Copper ions are also prone to diffuse and penetrate on the cell wafers, forming deep-level recombination centers, thereby destroying the passivation effect and affecting the cell performance. Moreover, solar cell modules need to be used outdoors for a long time (generally required for 30 years), so there is a great risk in the outdoor reliability of copper-containing metal electrodes.

[0005] Currently, in order to reduce the influence of acids, bases and water vapor on silver-coated copper paste or copper paste cells, both the front and back sides of the module are encapsulated with glass with a low water vapor transmission rate and a large weight, and polymers with a high water vapor transmission rate and a low weight cannot be used for encapsulation. In addition, a layer of waterproof glue (such as butyl glue, silicone glue, etc.) needs to be added around the glass. At the same time, the encapsulation film of the module needs to select a film with as neutral a material as possible, thus increasing the encapsulation cost and difficulty of the module.

[0006] However, even if the above measures are taken for silver-coated copper paste or copper paste cells in the prior art, their performance in the DH reliability test of solar cells is still not good enough, and the long-term reliability of the module is insufficient.

[0007] It should be noted that this part of the content of the present invention only provides the background technology related to the present invention, and does not necessarily constitute the prior art or the well-known technology. Summary of the Invention

[0008] The present invention provides a copper-containing metal electrode solar cell, a solar cell module and a preparation method thereof, which at least solve the problem that in the prior art, after the battery is made into a module and used for a long time, water vapor, acid and alkali react with copper upon contact, copper is oxidized and migrates and diffuses, and the long-term reliability of the module is insufficient.

[0009] To achieve the above object, in a first aspect, the present invention provides a copper-containing metal electrode solar cell, including a silicon wafer, a first semiconductor layer, a second semiconductor layer, a conductive film layer, a copper-containing metal fine grid electrode and a protective ink; the silicon wafer has a back surface and a front surface; the first semiconductor layer and the second semiconductor layer are alternately arranged on the back surface of the silicon wafer, and a second semiconductor opening area is formed between adjacent first semiconductor layers; the conductive film layer is laid on the first semiconductor layer and the second semiconductor layer, and an isolation groove is formed in the conductive film layer corresponding to the edge area of the second semiconductor opening area; a copper-containing metal fine grid electrode is provided on the conductive film layer corresponding to each first semiconductor layer and the second semiconductor layer; the protective ink covers the copper-containing metal fine grid electrode, and / or the protective ink covers the isolation groove; wherein, the refractive index of the protective ink is 1.4 - 2.2, and the average light transmittance at a wavelength of 300 - 1100 nm is ≥ 80%.

[0010] Preferably, the thickness of the protective ink is 10 - 100 μm, and the width of the protective ink is not less than 60 μm; when the protective ink covers the copper-containing metal fine grid electrode, the thickness of the protective ink is more than 5 μm greater than the thickness of the copper-containing metal fine grid electrode, and the width of the protective ink is more than 10 μm greater than the width of the copper-containing metal fine grid electrode.

[0011] Preferably, the width of the isolation groove is 0.03 - 0.2 mm; when the protective ink covers the isolation groove, the width ratio of the protective ink to the isolation groove is (1 - 4):1.

[0012] Preferably, the protective ink includes the following components by mass percentage: matrix resin 50% - 80%, solvent 5% - 15%, and light transmittance enhancer 0.5% - 5%.

[0013] Preferably, the copper-containing metal electrode solar cell further comprises a first insulating ink and a second insulating ink; the first insulating ink is disposed on the conductive film layer corresponding to the first semiconductor layer and is spaced along the length direction of the first semiconductor layer, and covers the copper-containing metal fine grid electrode; the second insulating ink is disposed on the conductive film layer corresponding to the second semiconductor layer and is spaced along the length direction of the second semiconductor layer, and covers the copper-containing metal fine grid electrode; wherein, the first insulating ink and the second insulating ink are alternately arranged in a staggered manner along the length direction of the first semiconductor layer and the second semiconductor layer.

[0014] Preferably, the copper-containing metal electrode solar cell further comprises fine grid connection lines, and fine grid connection lines are respectively disposed on a plurality of first insulating inks spaced along the length direction of the first semiconductor layer and a plurality of second insulating inks spaced along the length direction of the second semiconductor layer, and the fine grid connection lines are perpendicular to the copper-containing metal fine grid electrodes; the fine grid connection lines are formed by curing silver-coated copper paste or copper paste, and the mass content of copper in the silver-coated copper paste is greater than 40%.

[0015] Preferably, a protective ink is disposed on the regions with a width W1 on both sides of the fine grid connection lines.

[0016] Preferably, no protective ink is disposed on the regions with a width W1 on both sides of the fine grid connection lines.

[0017] Preferably, the width W1 on both sides of the fine grid connection lines is 0.1 - 4 mm.

[0018] Preferably, the length of the copper-containing metal fine grid electrode without the protective ink accounts for less than 10% of the entire length of the copper-containing metal fine grid electrode.

[0019] Preferably, the length of the isolation groove without the protective ink accounts for less than 10% of the entire length of the isolation groove.

[0020] Preferably, the first semiconductor layer comprises a tunneling oxide layer and a doped polycrystalline layer, and the second semiconductor layer comprises an amorphous passivation layer and a doped amorphous layer.

[0021] Preferably, the copper-containing metal electrode solar cell further comprises a front passivation layer and an antireflection layer, and the front passivation layer and the antireflection layer are sequentially disposed on the front side of the silicon wafer.

[0022] On the other hand, the present invention also provides a preparation method for a copper-containing metal electrode solar cell, and the preparation method comprises the following steps: S101. Form an alternately arranged first semiconductor layer and second semiconductor layer on the back side of the silicon wafer, and form a second semiconductor opening region between adjacent first semiconductor layers; S102. Form a conductive film layer on the first semiconductor layer and the second semiconductor layer; S103. Etch an opening on the conductive film layer corresponding to the edge region of the second semiconductor opening region to form an isolation groove; S104. Form copper-containing metal fine grid electrodes on the conductive film layers corresponding to each first semiconductor layer and the second semiconductor layer; S105. Cover a protective ink on the copper-containing metal fine grid electrodes, and / or cover a protective ink on the isolation groove.

[0023] Preferably, S101 further includes: forming a front passivation layer and an anti-reflection layer on the front surface of the silicon wafer.

[0024] Preferably, between S104 and S105, it further includes: S106. Dispose the first insulating ink and the second insulating ink alternately and staggeredly on the corresponding conductive film layers along the length directions of the first semiconductor layer and the second semiconductor layer; dispose fine grid connection lines on each of the multiple first insulating inks disposed at intervals along the length direction of the first semiconductor layer and each of the multiple second insulating inks disposed at intervals along the length direction of the second semiconductor layer.

[0025] Preferably, S105 further includes disposing the first insulating ink and the second insulating ink alternately and staggeredly on the corresponding conductive film layers along the length directions of the first semiconductor layer and the second semiconductor layer; the first insulating ink, the second insulating ink and the protective ink are formed synchronously; then dispose fine grid connection lines on each of the multiple first insulating inks disposed at intervals along the length direction of the first semiconductor layer and each of the multiple second insulating inks disposed at intervals along the length direction of the second semiconductor layer.

[0026] On the other hand, the present invention also provides a copper-containing metal electrode solar cell module, including a plurality of copper-containing metal electrode solar cells, and the plurality of copper-containing metal electrode solar cells are connected by solder ribbons to form a battery string; the copper-containing metal electrode solar cell module further includes a backplane, a back adhesive film, a front adhesive film, and a front plate; wherein, the backplane, the back adhesive film, the battery string, the front adhesive film, and the front plate are laminated and laminated in sequence to form a copper-containing metal electrode solar cell module.

[0027] Preferably, the backplane and the front plate are independently glass or polymer plates.

[0028] On the other hand, the present invention also provides a preparation method for a copper-containing metal electrode solar cell module, and the preparation method includes the following steps: S201. Provide a plurality of copper-containing metal electrode solar cells; S202. Connect the plurality of copper-containing metal electrode solar cells with solder ribbons to form a battery string; S203. Lay the back adhesive film, the battery string formed in S202, the front adhesive film, and the front plate on the surface of the backplane in sequence; S204. Laminate the backplane, back adhesive film, battery string, front adhesive film, and front plate laid in S203 to form a copper metal electrode-containing solar cell module.

[0029] The beneficial effects of the present invention are as follows: 1. The present invention protects the copper metal fine grid electrode by using a protective ink, preventing water vapor, acids and alkalis from reacting with copper during the long-term use after the battery is made into a module, thereby avoiding the migration and diffusion of copper ions, improving the long-term reliability of the module, reducing the technical requirements for packaging materials, effectively reducing the product cost, and expanding the application scenarios of copper metal electrode-containing solar cells packaged into modules.

[0030] 2. The present invention also protects the isolation groove with a protective ink, avoiding the direct exposure of the insulating groove, reducing the environmental impact on the battery chip, such as humidity, dust, chemical substances, etc., and thus extending its service life.

[0031] 3. The protective ink provided by the present invention also has an antireflection effect, effectively improving the efficiency (double-sided rate) of the photovoltaic panel to receive and convert light energy from the front and back, significantly reducing the surface reflection loss of the battery chip, and enabling more light energy to be absorbed by the battery and converted into electrical energy. Description of the Drawings

[0032] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the following will briefly introduce the drawings required for use in the embodiments. It should be understood that the following drawings only show some embodiments of the present invention, and therefore should not be regarded as a limitation of the scope. For those of ordinary skill in the art, without creative efforts, other related drawings can also be obtained based on these drawings.

[0033] Figure 1 It is a cross-sectional schematic diagram of a copper metal electrode-containing solar cell provided by Embodiment 1 of the present invention; Figure 2 It is a plan schematic diagram of a copper metal electrode-containing solar cell provided by Embodiment 1 of the present invention; Figure 3 It is a plan schematic diagram of forming a first insulating ink, a second insulating ink, and a fine grid connection line on a copper metal electrode-containing solar cell provided by Embodiment 1 of the present invention; Figure 4 It is a cross-sectional schematic diagram of forming a protective ink on a copper metal electrode-containing solar cell provided by Embodiment 1 of the present invention; Figure 5 It is a plan schematic diagram of forming a protective ink on a copper metal electrode-containing solar cell provided by Embodiment 1 of the present invention; Figure 6Schematic plan view of connecting multiple copper-containing metal electrode solar cells with solder tapes to form a battery string provided in Embodiment 1 of the present invention; Figure 7 Schematic structural view of a copper-containing metal electrode solar cell module provided in Embodiment 1 of the present invention; Figure 8 Cross-sectional view of forming a protective ink on a copper-containing metal electrode solar cell provided in Embodiment 2 of the present invention; Figure 9 Cross-sectional view of forming a protective ink on a copper-containing metal electrode solar cell provided in Embodiment 3 of the present invention; Figure 10 Plan view of forming a protective ink on a copper-containing metal electrode solar cell provided in Embodiment 8 of the present invention; Figure 11 Plan view of forming a first insulating ink, a second insulating ink and a protective ink on a copper-containing metal electrode solar cell provided in Embodiment 11 of the present invention; Figure 12 Schematic structural view of a copper-containing metal electrode solar cell module provided in Comparative Example 1 of the present invention; Figure 13 Plan microscope view of a copper-containing metal electrode solar cell provided in Comparative Example 1 of the present invention; Figure 14 Plan microscope view of a copper-containing metal electrode solar cell provided in Embodiment 2 of the present invention; Figure 15 EL test image of a copper-containing metal electrode solar cell module DH1000 before testing provided in Embodiment 2 of the present invention; Figure 16 EL test image of a copper-containing metal electrode solar cell module DH1000 after testing provided in Embodiment 2 of the present invention; Figure 17 EL test image of a copper-containing metal electrode solar cell module DH1000 before testing provided in Comparative Example 1 of the present invention; Figure 18 EL test image of a copper-containing metal electrode solar cell module DH1000 after testing provided in Comparative Example 1 of the present invention; Figure 19 Cross-sectional view of forming a protective ink on a copper-containing metal electrode solar cell provided in Embodiment 14 of the present invention.

[0034] Explanation of reference numerals: 1. Silicon wafer; 2. Tunneling oxide layer; 3. Doped polycrystalline layer; 4. Amorphous passivation layer; 5. Doped amorphous layer; 6. Front passivation layer; 7. Anti-reflection layer; 8. Conductive film layer; 9. Copper-containing metal fine gate electrode; 10. Protective ink; 11. First insulating ink; 12. Second insulating ink; 13. Fine gate connection line; 100. Solar cell containing copper metal electrode; 200. Solder strip; 300. Back plate; 400. Back adhesive film; 500. Front adhesive film; 600. Front plate; 700. Waterproof adhesive. DETAILED DESCRIPTION

[0035] In the present invention, unless otherwise specified, directional words such as "upper, lower, left, right" are generally understood in conjunction with the directions shown in the drawings and actual applications.

[0036] In addition, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" and "second" may explicitly or implicitly include one or more of the features. In the description of the present invention, the meaning of "plurality" is two or more, unless otherwise clearly and specifically defined.

[0037] In the present invention, unless otherwise clearly specified and limited, a first feature being "above" or "below" a second feature may mean that the first and second features are in direct contact, or the first and second features are in indirect contact through an intermediate medium. Moreover, a first feature being "above", "above" or "above" a second feature may mean that the first feature is directly above or obliquely above the second feature, or simply means that the first feature is higher in level than the second feature. A first feature being "below", "below" or "below" a second feature may mean that the first feature is directly below or obliquely below the second feature, or simply means that the first feature is lower in level than the second feature.

[0038] The endpoints and any values ​​of the ranges disclosed herein are not limited to the precise ranges or values, and these ranges or values ​​should be understood to include values ​​close to these ranges or values. For numerical ranges, the endpoint values ​​of each range, the endpoint values ​​of each range and the individual point values, and the individual point values ​​can be combined with each other to obtain one or more new numerical ranges, which should be considered as specifically disclosed in this article. Among them, the terms "optional" and "optional" all mean that they may be included or not included (or may be present or not).

[0039] In a first aspect, the present invention provides a copper-containing metal electrode solar cell, comprising a silicon wafer, a first semiconductor layer, a second semiconductor layer, a conductive film layer, a copper-containing metal fine grid electrode, and a protective ink; the silicon wafer has a back surface and a front surface; the first semiconductor layer and the second semiconductor layer are alternately arranged on the back surface of the silicon wafer, and a second semiconductor opening area is formed between adjacent first semiconductor layers; the conductive film layer is laid on the first semiconductor layer and the second semiconductor layer, and an isolation groove is formed in the conductive film layer corresponding to the edge area of the second semiconductor opening area; a copper-containing metal fine grid electrode is arranged on the conductive film layer corresponding to each first semiconductor layer and the second semiconductor layer; the protective ink covers the copper-containing metal fine grid electrode, and / or the protective ink covers the isolation groove; wherein, the refractive index of the protective ink is 1.4 - 2.2, and the average light transmittance at a wavelength of 300 - 1100 nm is ≥ 80%.

[0040] It can be understood that the protective ink of the present invention can cover only the copper-containing metal fine grid electrode, or only the isolation groove, or cover both the copper-containing metal fine grid electrode and the isolation groove at the same time. On the premise of pursuing the protection effect, the protective ink preferably covers both the copper-containing metal fine grid electrode and the isolation groove at the same time.

[0041] It can be understood that although the present invention takes a hybrid passivated back contact cell as an example, the technical solution of the present invention is not limited to the type of solar cell, and can be a double-sided grid line cell or a back contact cell. The double-sided grid line cell can be an HJT (heterojunction cell), a Topcon (tunnel oxide passivated contact cell), a Perc (passivated emitter and rear contact cell), etc. The back contact cell can be a TBC cell (tunnel oxide passivated back contact cell), an HBC cell (heterojunction back contact cell), etc. The protective ink of the present invention can be arranged on the fine grid and / or isolation groove on the back surface of the back contact cell, or on the fine grid on the front and / or back surface of the double-sided grid line cell.

[0042] It can be understood that the conductive film layer is a transparent conductive film or a composite film layer composed of a transparent conductive film and a metal conductive film. The transparent conductive film is indium oxide doped with zinc, tin, tungsten, titanium or silicon, or can also be zinc oxide doped with aluminum, boron or gallium, etc. The metal conductive film is at least one of metal aluminum, metal copper, metal silver, nickel alloy, and titanium alloy.

[0043] It is understandable that the metal fine grid is formed by curing silver-coated copper paste or copper paste, and the mass content of copper in the silver-coated copper paste is greater than 40%. The silver-coated copper paste is composed of conductive fillers and organic polymers. The conductive fillers are silver-coated copper powder or specially treated copper powder, which mainly play the role of conducting electrons and determine the conductivity of the grid lines. The organic polymer is mainly composed of various composite resins, solvents, curing agents and other additives. Resins such as epoxy resin, polyurethane, etc., after curing, serve as the molecular structure framework, connecting left and right, and determining physical properties such as bonding strength. Solvents and additives mainly regulate the viscosity and leveling property of the paste and determine the printability of the paste. The curing agent mainly cures the collective bonding phase. Each raw material component is made into a uniform paste through high-speed stirring and three-roll grinding.

[0044] The refractive index of the protective ink is 1.4 - 2.2, preferably 1.55 - 2.0. By making the refractive index of the protective ink lie between that of the encapsulation material and the silicon-based semiconductor material, the present invention can gradually transition the refractive index of light in the multi-layer structure, significantly reducing the surface reflection loss of the battery cell, and enabling more light energy to be absorbed by the battery and converted into electrical energy, effectively improving the efficiency (double-sided rate) of the photovoltaic panel in receiving and converting light energy from the front and back sides.

[0045] The average transmittance of the protective ink at a wavelength of 300 - 1100 nm is ≥80%, preferably ≥85%. Traditional silicon-based batteries mainly absorb the 300 - 1100 nm band (visible light and near-infrared). The high transmittance of the protective ink in the present invention ensures that light can penetrate the protective layer and enter the battery interior, avoiding a decrease in the photoelectric conversion efficiency caused by absorption or scattering of the protective layer.

[0046] Preferably, the thickness of the protective ink is 10 - 100 μm, and the width of the protective ink is not less than 60 μm. The present invention reasonably controls the thickness and width of the protective ink, limiting the total volume (ink amount per unit area) of the protective ink within a reasonable range, ensuring that the protective ink has sufficient physical barrier capabilities to effectively block the penetration of water vapor, oxygen, and acid-base substances, while avoiding excessive ink from increasing the material cost.

[0047] When the protective ink covers the copper-containing metal fine grid electrode, the thickness of the protective ink is more than 5 μm greater than the thickness of the copper-containing metal fine grid electrode, and the width of the protective ink is more than 10 μm greater than the width of the copper-containing metal fine grid electrode. This application ensures that the protective ink completely covers the edge area of the electrode, avoiding copper oxidation caused by water vapor intrusion from the edge. When the protective ink covers the copper-containing metal fine grid electrode, the cross-sectional shape of the protective ink can be semi-circular, semi-elliptical, trapezoidal, etc.

[0048] Preferably, the width of the isolation groove is 0.03 - 0.2 mm; when the protective ink covers the isolation groove, the width ratio of the protective ink to the isolation groove is (1 - 4):1. The present invention controls the width of the isolation groove to ensure the electrical isolation effect between the first semiconductor layer and the second semiconductor layer. At the same time, when the protective ink covers the isolation groove, the width ratio of the protective ink to the isolation groove is controlled so that the protective ink fully fills the groove body, preventing the accumulation of residual pollutants or moisture in the groove.

[0049] It can be understood that the present invention does not limit the width of the protective ink. In the extreme case of pursuing the protection effect, the part of the conductive film layer except for the position of the fine grid connection line can be covered with the protective ink.

[0050] Preferably, the protective ink comprises the following components by mass percentage: matrix resin 50% - 80%, solvent 5% - 15%, and antireflection agent 0.5% - 5%. The matrix resin can be selected from one or a combination of butyl rubber resin, silicone resin, acrylic acid, and polyurethane. The above matrix resin can more easily obtain a protective ink that meets the refractive index and average light transmittance. The antireflection agent is preferably a silicone resin, such as methylphenyl silicone resin, epoxy-modified silicone resin, acrylic acid-modified silicone resin, etc. By selecting a suitable silicone resin and its content, the refractive index of the ink can be effectively adjusted to match that of the crystalline silicon cell, reducing interface reflection, improving light transmittance, and thus improving the bifaciality of the cell.

[0051] The solvent is selected from at least one of ketone, ester, or alcohol ether organic solvents, such as cyclohexanone, propylene glycol methyl ether acetate (PMA), diethylene glycol butyl ether acetate (DBA), etc.

[0052] It should be noted that, on the basis of not significantly changing the basic characteristics of the light transmittance and refractive index of the ink, other additives can also be selectively added according to the actual application scenario, which can include but are not limited to dispersants, antioxidants, leveling agents, curing accelerators, coupling agents, etc.

[0053] Preferably, the copper-containing metal electrode solar cell further comprises a first insulating ink and a second insulating ink; the first insulating ink is disposed on the conductive film layer corresponding to the first semiconductor layer and is spaced along the length direction of the first semiconductor layer, and covers the copper-containing metal fine grid electrode; the second insulating ink is disposed on the conductive film layer corresponding to the second semiconductor layer and is spaced along the length direction of the second semiconductor layer, and covers the copper-containing metal fine grid electrode; wherein, the first insulating ink and the second insulating ink are arranged in a staggered and alternating manner along the length direction of the first semiconductor layer and the second semiconductor layer.

[0054] It can be understood that both the first insulating ink and the second insulating ink are resin inks, and the resin is preferably acrylic resin.

[0055] Preferably, the copper-containing metal electrode solar cell further includes fine grid connection lines, and fine grid connection lines are respectively disposed on a plurality of first insulating inks spaced along the length direction of the first semiconductor layer and a plurality of second insulating inks spaced along the length direction of the second semiconductor layer. The fine grid connection lines are perpendicular to the copper-containing metal fine grid electrodes; the fine grid connection lines are formed by curing silver-coated copper paste or copper paste, and the mass content of copper in the silver-coated copper paste is greater than 40%.

[0056] Preferably, a protective ink is disposed or not disposed in a region with a width W1 on both sides of the fine grid connection line.

[0057] Preferably, the width W1 on both sides of the fine grid connection line is 0.1-4 mm.

[0058] It can be understood that when no protective ink is disposed in the region with a width W1 on both sides of the fine grid connection line (i.e., the protective ink gives way to the fine grid connection line), it is more convenient to fabricate connection solder tapes between multiple copper-containing metal electrode solar cells in a module. When a protective ink is disposed in the region with a width W1 on both sides of the fine grid connection line (i.e., the protective ink does not give way to the fine grid connection line), although the protection effect is better, when connecting the solder tape, poor contact may occur between the solder tape and the fine grid connection line.

[0059] Preferably, the length of the copper-containing metal fine grid electrode without the protective ink accounts for less than 10% of the entire length of the copper-containing metal fine grid electrode. The length of the isolation groove without the protective ink accounts for less than 10% of the entire length of the isolation groove. The above settings can ensure the protection effect of the protective ink.

[0060] Preferably, the first semiconductor layer includes a tunneling oxide layer and a doped polycrystalline layer, and the second semiconductor layer includes an amorphous passivation layer and a doped amorphous layer. The thicknesses and corresponding doping concentrations of the tunneling oxide layer or amorphous passivation layer, doped polycrystalline layer, and doped amorphous layer in the present invention can respectively refer to the ranges of the prior art and can all be used in the present invention. Exemplarily, the thickness of the tunneling oxide layer is 1-2 nm, and the thickness of the amorphous passivation layer is 3-10 nm; the thickness of the doped amorphous layer is 7-15 nm, and the effective doping concentration is 5e18 cm -3 -1e20 cm -3 , and the thickness of the doped polycrystalline layer is 30-250 nm, and the effective doping concentration is greater than 9e19 cm -3 .

[0061] Preferably, the copper-containing metal electrode solar cell further includes a front passivation layer and an antireflection layer, which are sequentially disposed on the front side of the silicon wafer. The types and thicknesses of the front passivation layer, the antireflection layer, and the mask layer of the present invention can be respectively referred to the prior art and can all be used in the present invention. Exemplarily, the front passivation layer is at least one of amorphous silicon, microcrystalline silicon, silicon oxide, and polycrystalline silicon, and the antireflection layer is a silicon dielectric layer, and the silicon dielectric layer is at least one of silicon nitride, silicon oxide, silicon oxynitride, and intrinsic amorphous silicon.

[0062] On the other hand, the present invention also provides a method for manufacturing a copper-containing metal electrode solar cell, and the manufacturing method includes the following steps: S101. Form an alternately arranged first semiconductor layer and a second semiconductor layer on the back side of the silicon wafer, and form a second semiconductor opening region between adjacent first semiconductor layers; S102. Form a conductive film layer on the first semiconductor layer and the second semiconductor layer; S103. Perform an etching opening on the conductive film layer corresponding to the edge region of the second semiconductor opening region to form an isolation groove; S104. Form a copper-containing metal fine grid electrode on the conductive film layer corresponding to each first semiconductor layer and the second semiconductor layer; S105. Cover a protective ink on the copper-containing metal fine grid electrode, and / or cover a protective ink on the isolation groove.

[0063] Preferably, S101 further includes: forming a front passivation layer and an antireflection layer on the front side of the silicon wafer.

[0064] Preferably, between S104 and S105, it further includes: S106. Dislocationally and alternately arrange a first insulating ink and a second insulating ink on the corresponding conductive film layer along the length directions of the first semiconductor layer and the second semiconductor layer; respectively arrange fine grid connection lines on a plurality of first insulating inks arranged at intervals along the length direction of the first semiconductor layer and a plurality of second insulating inks arranged at intervals along the length direction of the second semiconductor layer.

[0065] It can be understood that the first insulating ink, the second insulating ink, the protective ink, and the fine grid connection lines can be formed by printing or spraying processes.

[0066] Preferably, S105 further includes dislocationally and alternately arranging a first insulating ink and a second insulating ink on the corresponding conductive film layer along the length directions of the first semiconductor layer and the second semiconductor layer; the first insulating ink, the second insulating ink, and the protective ink are formed synchronously; then respectively arrange fine grid connection lines on a plurality of first insulating inks arranged at intervals along the length direction of the first semiconductor layer and a plurality of second insulating inks arranged at intervals along the length direction of the second semiconductor layer.

[0067] Understandably, when the first insulating ink, the second insulating ink, and the protective ink are formed simultaneously, the production efficiency is higher.

[0068] On the other hand, the present invention also provides a copper-containing metal electrode solar cell module, including a plurality of copper-containing metal electrode solar cells. The plurality of copper-containing metal electrode solar cells are connected by solder tapes to form a battery string; the copper-containing metal electrode solar cell module further includes a backsheet, a back adhesive film, a front adhesive film, and a front plate; wherein, the backsheet, the back adhesive film, the battery string, the front adhesive film, and the front plate are laminated and laminated in sequence to form a copper-containing metal electrode solar cell module.

[0069] Preferably, the backsheet and the front plate are each independently glass or a polymer plate.

[0070] Understandably, when the backsheet is a polymer plate, it can be polyvinyl fluoride (PVF), polyvinylidene fluoride (PVDF), polyethylene terephthalate (PET), etc.; when the front plate is a polymer plate, it can be ETFE (ethylene-tetrafluoroethylene copolymer), fluorocarbon resin, PVF (polyvinyl fluoride), and PVDF (polyvinylidene fluoride), etc.

[0071] On the other hand, the present invention also provides a method for preparing a copper-containing metal electrode solar cell module. The preparation method includes the following steps: S201. Provide a plurality of copper-containing metal electrode solar cells; S202. Connect the plurality of copper-containing metal electrode solar cells with solder tapes to form a battery string; S203. Sequentially lay a back adhesive film, the battery string formed in S202, a front adhesive film, and a front plate on the surface of the backsheet; S204. Laminate the backsheet, the back adhesive film, the battery string, the front adhesive film, and the front plate laid in S203 to form a copper-containing metal electrode solar cell module.

[0072] The embodiments of the present invention will be described in detail below. They are exemplary and are only used to explain the present invention and should not be construed as a limitation of the present invention.

[0073] Example 1 A method for preparing a copper-containing metal electrode solar cell. The preparation method includes the following steps: S101. As Figure 1 shown, a first semiconductor layer and a second semiconductor layer are alternately arranged on the back surface of the silicon wafer 1. A second semiconductor opening region is formed between adjacent first semiconductor layers. A front passivation layer 6 and an antireflection layer 7 are formed on the front surface of the silicon wafer 1; As Figure 1 shown, the first semiconductor layer includes a tunneling oxide layer 2 and a doped polycrystalline layer 3, and the second semiconductor layer includes an amorphous passivation layer 4 and a doped amorphous layer 5; S102, as Figure 1 shown, form a conductive film layer 8 on the first semiconductor layer and the second semiconductor layer; S103, as Figure 1 shown, etch an opening on the conductive film layer 8 corresponding to the edge region of the second semiconductor opening area to form an isolation groove; The width of the isolation groove is 60 μm; S104, as Figure 1 and Figure 2 shown, form copper-containing metal fine grid electrodes 9 on the conductive film layer 8 corresponding to each first semiconductor layer and second semiconductor layer; S106, as Figure 3 shown, alternately arrange the first insulating ink 11 and the second insulating ink 12 on the corresponding conductive film layer 8 along the length direction of the first semiconductor layer and the second semiconductor layer; respectively arrange fine grid connection lines 13 on a plurality of first insulating inks 11 arranged at intervals along the length direction of the first semiconductor layer and a plurality of second insulating inks 12 arranged at intervals along the length direction of the second semiconductor layer; S105, as Figure 4 and Figure 5 shown, cover a protective ink 10 on the copper-containing metal fine grid electrode 9 to obtain the copper-containing metal electrode solar cell 100; The refractive index of the protective ink 10 is 1.55 - 2.0, and the average light transmittance at a wavelength of 300 - 1100 nm is 90%; The thickness of the protective ink 10 is 50 μm, and the width is 200 μm; The protective ink 10 is composed of 80% matrix resin, 15% solvent, and 5% antireflection agent; No protective ink 10 is provided in the area with a width W1 on both sides of the fine grid connection line 13 (i.e., the protective ink 10 makes way for the fine grid connection line 13), and the width W1 on both sides of the fine grid connection line 13 is 2 mm.

[0074] A preparation method for manufacturing the obtained copper-containing metal electrode solar cell into a copper-containing metal electrode solar cell module, the preparation method includes the following steps: S201, as Figure 6 shown, provide a plurality of the above-mentioned copper-containing metal electrode solar cells 100; S202, as Figure 6 shown, connect a plurality of copper-containing metal electrode solar cells 100 with a solder tape 200 to form a battery string; S203, as Figure 7 shown, sequentially lay a back adhesive film 400, the battery string formed in S202, a front adhesive film 500, and a front plate 600 on the surface of the back plate 300; S204, asFigure 7 As shown, the backplane 300, back adhesive film 400, battery string, front adhesive film 500, and front plate 600 laid in S203 are laminated to form a copper metal electrode-containing solar cell module; Both the front plate 600 and the backplane 300 are made of glass.

[0075] Example 2 It is carried out with reference to the method of Example 1, except that, as Figure 8 shown, in S105, a protective ink 10 is covered on the isolation groove, and the protective ink 10 is not covered on the copper metal fine grid electrode 9.

[0076] Example 3 It is carried out with reference to the method of Example 1, except that, as Figure 9 shown, in S105, the protective ink 10 is simultaneously covered on both the isolation groove and the copper metal fine grid electrode 9.

[0077] Example 4 It is carried out with reference to the method of Example 1, except that the thickness of the protective ink 10 is 10 μm.

[0078] Example 5 It is carried out with reference to the method of Example 1, except that the thickness of the protective ink 10 is 100 μm.

[0079] Example 6 It is carried out with reference to the method of Example 1, except that the width of the protective ink 10 is 60 μm.

[0080] Example 7 It is carried out with reference to the method of Example 1, except that the width of the protective ink 10 is 300 μm.

[0081] Example 8 It is carried out with reference to the method of Example 1, except that, as Figure 10 shown, the protective ink 10 is provided in the area of the width W1 on both sides of the fine grid connection line 13 (that is, the protective ink 10 does not give way to the fine grid connection line 13).

[0082] Example 9 It is carried out with reference to the method of Example 1, except that the width W1 on both sides of the fine grid connection line 13 is 0.1 mm.

[0083] Example 10 It is carried out with reference to the method of Example 1, except that the width W1 on both sides of the fine grid connection line 13 is 4 mm.

[0084] Example 11 It is carried out with reference to the method of Example 1, except that, asFigure 11 As shown, without performing S106, the first insulating ink, the second insulating ink, and the protective ink are synchronously formed in S105.

[0085] Example 12 It is carried out according to the method of Example 1, except that the backplane 300 in S203 is a polymer plate.

[0086] Example 13 It is carried out according to the method of Example 1, except that both the front plate 600 and the backplane 300 in S203 are polymer plates.

[0087] Example 14 It is carried out according to the method of Example 2, except that, as Figure 19 shown, there is a second semiconductor opening region between adjacent first semiconductor layers. Both ends of the second semiconductor layer located in the second semiconductor opening region extend a preset distance toward the surfaces of the adjacent first semiconductor layers and overlap with them to form an overlapping region. There is a first semiconductor opening region on the first semiconductor layer. A conductive film layer is laid on the first semiconductor layer and the second semiconductor layer, and isolation grooves are provided at the positions of each overlapping region of the conductive film layer.

[0088] Comparative Example 1 As Figure 12 shown, a preparation method of a copper-containing metal electrode solar cell module includes the following steps: S101. Provide a plurality of copper-containing metal electrode solar cells 100 (different from Example 1 in that the protective ink 10 is not provided on the copper-containing metal electrode solar cells 100 in Comparative Example 1); S102. Connect a plurality of copper-containing metal electrode solar cells 100 with a solder strip 200 to form a battery string; S103. Sequentially lay a back adhesive film 400, the battery string formed in S102, a front adhesive film 500, and a front plate 600 on the surface of the backplane 300; there is also a waterproof adhesive 700 around between the backplane 300 and the front plate 600, and the waterproof adhesive 700 can be butyl rubber or silicone rubber; S104. Laminate the laminate laid in S103 to form a copper-containing metal electrode solar cell module; Both the front plate 600 and the backplane 300 are made of glass.

[0089] Test Example The batteries and battery modules obtained in the above examples and comparative examples were subjected to performance tests, and the results are shown in Table 1. The test method for DH1000 attenuation is to carry out a reliability test in an environment with a constant temperature of 85°C and a relative humidity of 85% for a duration of 1000 hours, and compare the difference ratio between the actual power output and the theoretical power output of the battery module.

[0090] Table 1

[0091] From the above results, it can be seen that, compared with the comparative example, adopting the embodiment scheme of the present invention and covering the protection ink on the electrode and the isolation groove will not significantly affect the battery performance, but can greatly improve the attenuation of the battery module in the DH1000 reliability test.

[0092] Furthermore, according to Embodiments 1-14, it can be known that adopting the preferred technical scheme of the present invention is more conducive to improving the battery performance and reliability.

[0093] Furthermore, as Figure 13 and Figure 14 shown, under microscopic observation, in Embodiment 2, the isolation groove is covered with a protection ink with a width of 200 μm.

[0094] As Figure 15 and Figure 16 shown, there is no obvious change in the EL test images of the battery module in Embodiment 2 before and after the DH1000 reliability test, and the reliability is excellent.

[0095] As Figure 17 and Figure 18 shown, obvious penetration and blackening phenomena appear at the edge in the EL test image of the battery module in Comparative Example 1 after the DH1000 reliability test, and the reliability is insufficient.

[0096] The preferred embodiments of the present invention have been described in detail above. However, the present invention is not limited thereto. Within the technical concept scope of the present invention, various simple modifications can be made to the technical scheme of the present invention, including any other suitable combination of each technical feature. These simple modifications and combinations should also be regarded as the content disclosed by the present invention and fall within the protection scope of the present invention.

Claims

1. A copper-containing metal electrode solar cell, characterized in that, Comprising: A silicon wafer having a back surface and a front surface; A first semiconductor layer and a second semiconductor layer, the first semiconductor layer and the second semiconductor layer are alternately arranged on the back surface of the silicon wafer, and a second semiconductor opening region is formed between adjacent first semiconductor layers; A conductive film layer, the conductive film layer is laid on the first semiconductor layer and the second semiconductor layer, and an isolation groove is formed in the conductive film layer corresponding to the edge region of the second semiconductor opening region; A copper-containing metal fine grid electrode, and the copper-containing metal fine grid electrode is provided on the conductive film layer corresponding to each of the first semiconductor layer and the second semiconductor layer; A protective ink, the protective ink covers the copper-containing metal fine grid electrode, and / or the protective ink covers the isolation groove; Wherein, the refractive index of the protective ink is 1.4 - 2.2, and the average light transmittance at a wavelength of 300 - 1100 nm is ≥ 80%; 2. The copper-containing metal electrode solar cell according to claim 1, wherein The thickness of the protective ink is 10 - 100 μm, and the width of the protective ink is not less than 60 μm; When the protective ink covers the copper-containing metal fine grid electrode, the thickness of the protective ink is more than 5 μm greater than the thickness of the copper-containing metal fine grid electrode, and the width of the protective ink is more than 10 μm greater than the width of the copper-containing metal fine grid electrode.

3. The copper-containing metal electrode solar cell according to claim 2, wherein The width of the isolation groove is 0.03 - 0.2 mm; When the protective ink covers the isolation groove, the width ratio of the protective ink to the isolation groove is (1 - 4):

1.

4. The copper-containing metal electrode solar cell according to claim 1, wherein The protective ink comprises the following components by mass percentage: matrix resin 50% - 80%, solvent 5% - 15%, and antireflection agent 0.5% - 5%.

5. The copper-containing metal electrode solar cell according to claim 1, characterized in that, The copper-containing metal electrode solar cell further comprises: A first insulating ink, the first insulating ink is provided on the conductive film layer corresponding to the first semiconductor layer and is arranged at intervals along the length direction of the first semiconductor layer, and covers the copper-containing metal fine grid electrode; A second insulating ink, the second insulating ink is provided on the conductive film layer corresponding to the second semiconductor layer and is arranged at intervals along the length direction of the second semiconductor layer, and covers the copper-containing metal fine grid electrode; Wherein, the first insulating ink and the second insulating ink are arranged alternately in a staggered manner along the length directions of the first semiconductor layer and the second semiconductor layer.

6. The copper-containing metal electrode solar cell according to claim 5, wherein, The copper-containing metal electrode solar cell further comprises: Fine grid connection lines, and the fine grid connection lines are respectively provided on a plurality of first insulating inks arranged at intervals along the length direction of the first semiconductor layer and a plurality of second insulating inks arranged at intervals along the length direction of the second semiconductor layer, and the fine grid connection lines are perpendicular to the copper-containing metal fine grid electrodes; The fine grid connection lines are formed by curing silver-coated copper paste or copper paste, and the mass content of copper in the silver-coated copper paste is greater than 40%.

7. The copper-containing metal electrode solar cell according to claim 6, wherein, The protective ink is provided in the region with a width W1 on both sides of the fine grid connection line.

8. The copper-containing metal electrode solar cell according to claim 6, wherein The protective ink is not provided in the region with a width W1 on both sides of the fine grid connection line.

9. The copper-containing metal electrode solar cell according to claim 7 or 8, wherein The width W1 on both sides of the fine grid connection line is 0.1 - 4 mm.

10. The copper-containing metal electrode solar cell according to claim 8, wherein The length of the copper-containing metal fine grid electrode without the protective ink accounts for within 10% of the length of the entire copper-containing metal fine grid electrode; and / or, The length of the isolation groove without the protective ink accounts for within 10% of the length of the entire isolation groove.

11. The copper-containing metal electrode solar cell according to claim 1, characterized in that, The first semiconductor layer includes a tunneling oxide layer and a doped polycrystalline layer, and the second semiconductor layer includes an amorphous passivation layer and a doped amorphous layer; and / or, The copper-containing metal electrode solar cell further includes: A front passivation layer and an antireflection layer, which are sequentially disposed on the front side of the silicon wafer.

12. A preparation method of a copper-containing metal electrode solar cell, characterized in that, The preparation method is used to prepare the copper-containing metal electrode solar cell according to any one of claims 1 to 11, and the preparation method includes the following steps: S101. Form an alternately arranged first semiconductor layer and second semiconductor layer on the back side of the silicon wafer, and form a second semiconductor opening region between adjacent first semiconductor layers; S102. Form a conductive film layer on the first semiconductor layer and the second semiconductor layer; S103. Etch an opening on the conductive film layer corresponding to the edge region of the second semiconductor opening region to form an isolation groove; S104. Form a copper-containing metal fine grid electrode on the conductive film layer corresponding to each first semiconductor layer and second semiconductor layer; S105. Cover the copper-containing metal fine grid electrode with a protective ink, and / or cover the isolation groove with a protective ink.

13. The preparation method of the copper-containing metal electrode solar cell according to claim 12, wherein S101 further includes: forming a front passivation layer and an antireflection layer on the front side of the silicon wafer.

14. The preparation method of the copper-containing metal electrode solar cell according to claim 12, wherein, Between S104 and S105, it further includes: S106. Dislocationally and alternately arrange a first insulating ink and a second insulating ink on the corresponding conductive film layer along the length directions of the first semiconductor layer and the second semiconductor layer; respectively arrange fine grid connection lines on a plurality of first insulating inks spaced along the length direction of the first semiconductor layer and a plurality of second insulating inks spaced along the length direction of the second semiconductor layer.

15. The preparation method of the copper-containing metal electrode solar cell according to claim 12, wherein, S105 further includes dislocationally and alternately arranging a first insulating ink and a second insulating ink on the corresponding conductive film layer along the length directions of the first semiconductor layer and the second semiconductor layer; the first insulating ink, the second insulating ink and the protective ink are formed synchronously; then respectively arrange fine grid connection lines on a plurality of first insulating inks spaced along the length direction of the first semiconductor layer and a plurality of second insulating inks spaced along the length direction of the second semiconductor layer.

16. A copper-containing metal electrode solar cell module, characterized in that, Including a plurality of copper-containing metal electrode solar cells according to any one of claims 1 to 11, and the plurality of copper-containing metal electrode solar cells are connected by solder tapes to form a battery string; The copper-containing metal electrode solar cell module further includes a backplane, a back adhesive film, a front adhesive film, and a front plate; Wherein, the backplane, the back adhesive film, the battery string, the front adhesive film, and the front plate are sequentially laminated and laminated to form the copper-containing metal electrode solar cell module.

17. The copper-containing metal electrode solar cell module according to claim 16, wherein The backplane and the front plate are each independently a glass or polymer plate.

18. A method for preparing a copper-containing metal electrode solar cell module, characterized in that, The preparation method is used to prepare the copper-containing metal electrode solar cell module according to claim 16, and the preparation method includes the following steps: S201. Provide a plurality of copper-containing metal electrode solar cells as described in any one of claims 1 to 11; S202. Connect a plurality of the copper-containing metal electrode solar cells with solder strips to form a battery string; S203. Sequentially lay a back adhesive film, the battery string formed in S202, a front adhesive film, and a front plate on the surface of the back plate; S204. Laminate the back plate, back adhesive film, battery string, front adhesive film, and front plate laid in S203 to form a copper-containing metal electrode solar cell module.

Images