Solar cell with titanium layer and metal wire current lead-out structure and manufacturing

Abstract

The application belongs to the technical field of solar cells, and particularly relates to a solar cell with a titanium layer and a metal wire current lead-out structure and a manufacturing method thereof, and comprises the following steps: S1, providing a cell piece comprising a semiconductor region and a conductive film layer arranged outside the semiconductor region, and providing a polymer film with a plurality of parallel metal wires arranged on the surface; S2, printing titanium hydride paste outside the semiconductor region and the conductive film layer of the cell piece, and then performing heating to make the titanium hydride paste semi-solidified or physically gelled; S3, parallelly adhering the metal wires of the polymer film to the titanium hydride paste and contact connecting; and S4, then performing heat treatment. The application can form a current lead-out structure with a titanium layer and a metal wire as an electrode to replace fine grids and cancel main grids, and does not need to use silver paste material electrodes; meanwhile, the application has better conductivity and stability, and can effectively improve the conversion efficiency and reliability of the cell.

Description

Technical Field

[0001] This invention belongs to the field of solar cell technology, specifically relating to a solar cell with a titanium layer and a metal line current-conducting structure and its manufacturing process. Background Technology

[0002] In the field of solar cell manufacturing, traditional techniques typically use silver paste as the electrode material, employing a grid structure of fine grids and main grids to collect and extract current. While these methods can meet the functional requirements of solar cells to some extent, they also have some significant disadvantages:

[0003] First, traditional silver paste materials are relatively expensive, which directly increases the overall manufacturing cost of solar cells. As silver is a precious metal, its price fluctuations significantly impact the cost of solar cells, limiting the potential for price reductions.

[0004] Secondly, the use of fine grids and main grids in traditional technical solutions complicates the manufacturing process of solar cells, increases the number of steps and time in the production process, thereby increasing manufacturing costs and reducing production efficiency.

[0005] Furthermore, due to the high resistivity of silver paste, traditional current-derivation structures result in significant energy loss during cell operation, affecting cell conversion efficiency.

[0006] In addition, the silver paste used in traditional technical solutions is prone to oxidation in harsh environments such as high temperature and high humidity, which reduces the reliability and stability of the solar cells and affects their service life.

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

[0008] The purpose of this invention is to overcome the shortcomings of existing technologies, such as the high cost and complex manufacturing process of traditional solar cells using silver paste as electrode materials for the fine grid and main grid, the high resistivity of traditional silver paste affecting the photoelectric conversion efficiency of the cell, and the easy oxidation of silver paste leading to a decrease in the reliability and stability of the cell. This invention provides a solar cell with a titanium layer and metal wire current-guiding structure and its manufacturing process. This structure can form a current-guiding structure with a titanium layer and metal wires as electrodes to replace the fine grid, eliminating the need for the main grid and the use of silver paste electrodes. This reduces the amount of silver paste used, lowers material costs, simplifies the manufacturing process, and improves production efficiency. Simultaneously, it has better conductivity and stability, effectively improving the cell's conversion efficiency and reliability.

[0009] To achieve the above objectives, in a first aspect, the present invention provides a method for manufacturing a solar cell having a titanium layer and a metal line current-conducting structure, comprising the following steps:

[0010] S1. A battery cell including a semiconductor region and a conductive film layer disposed outside the semiconductor region is provided, and a polymer film with several parallel metal lines disposed on its surface is provided.

[0011] S2. Print titanium hydrogen slurry on the semiconductor region and its conductive film layer of the battery cell, and then heat it to semi-cur or physically gel the titanium hydrogen slurry.

[0012] S3. The metal wires of the polymer film are bonded to the titanium hydride slurry in parallel and made in contact.

[0013] S4. Then, heat treatment is performed to form a current-conducting structure with a titanium layer and metal wires as an electrode; the heat treatment temperature is 380-700℃.

[0014] In some preferred embodiments of the present invention, the metal in the metal wire is a non-silver metal.

[0015] In some preferred embodiments of the present invention, the metal in the metal wire is selected from at least one of copper, aluminum, nickel, tin, bismuth and their corresponding alloys, and / or the diameter of the metal wire is 0.02-0.05 mm.

[0016] In some preferred embodiments of the present invention, the spacing between two adjacent metal lines is 0.5-1 mm, and the spacing between two adjacent metal lines corresponds to the same spacing between two adjacent semiconductor regions on the battery cell.

[0017] In some preferred embodiments of the present invention, the thickness of the polymer film is 0.05-0.1 mm, and / or the polymer film is selected from at least one of polyimide, polyethylene terephthalate, polyvinyl chloride, polyvinylidene fluoride, and ethylene-tetrafluoroethylene copolymer.

[0018] In some preferred embodiments of the present invention, the printing thickness of the titanium hydride paste is 0.01-0.02 mm, and / or the viscosity of the titanium hydride paste is between 5000 and 10000 centipoise.

[0019] In some preferred embodiments of the present invention, the solid content in the titanium hydride slurry is 50%-70%, and the fineness of the titanium hydride slurry is controlled to be below 10µm.

[0020] In some preferred embodiments of the present invention, the titanium hydrogenation slurry contains TiH2 powder and the mass content of TiH2 powder is 40%-80%.

[0021] In some preferred embodiments of the present invention, the titanium hydrogen slurry contains TiH2 powder, binder, solvent, and additives, which may be added as needed.

[0022] More preferably, the binder has a mass content of 5%-10% in the titanium hydrogenation slurry, and the additive has a mass content of 0-3% in the titanium hydrogenation slurry.

[0023] More preferably, the particle size of the TiH2 powder is 1-10µm.

[0024] In some preferred embodiments of the present invention, the binder is selected from ethyl cellulose and / or acrylic resin.

[0025] Preferably, the solvent in this invention is selected from terpineol and / or butylcarbidol.

[0026] In some preferred embodiments of the present invention, the additives include plasticizers and dispersants. The plasticizer has a mass content of 1%-2% in the titanium hydrogenation slurry, and the dispersant has a mass content of 0.5%-1% in the titanium hydrogenation slurry. The plasticizer is dibutyl phthalate, and the dispersant is polyethylene glycol.

[0027] In some preferred embodiments of the present invention, the titanium hydride slurry is prepared by the following steps:

[0028] The binder is added to the solvent for the first stirring, then the additives are introduced as needed for the second stirring, and then TiH2 powder is introduced for the third stirring.

[0029] The conditions for the first stirring include: stirring at room temperature to 50°C, stirring speed of 300-500 r / min, and stirring time of 30-60 min;

[0030] The conditions for the second stirring include: a stirring speed of 200-300 r / min and a stirring time of 15-30 min;

[0031] The third stirring conditions include: a stirring speed of 100-200 r / min and a stirring time of 3-5 h.

[0032] In some preferred embodiments of the present invention, the manufacturing method further includes the following processes:

[0033] In process 1, S2, screen printing is used, and the mesh count of the screen used for screen printing is 300-500.

[0034] In process 2, the heating conditions in S2 include: temperature of 50-180℃ and time of 60-240min;

[0035] In process 3, S2, the printing conditions include: printing pressure of 0.2 - 0.5 MPa and printing speed of 50 - 100 mm / s;

[0036] The heat treatment conditions in process 4, S4 include: a heating rate of 5-10℃ / min, and a heating time of 30-60min to reach the heat treatment temperature;

[0037] Process 5, S4, also includes the following heat treatment process: cooling after heat treatment, with a cooling rate of 3-5℃ / min.

[0038] In some preferred embodiments of the present invention, the battery cell is a back contact battery, and the semiconductor region includes a first semiconductor region and a second semiconductor region, wherein one of the first semiconductor region and the second semiconductor region is N-type and the other is P-type.

[0039] In a second aspect, the present invention provides a solar cell having a titanium layer and a metal line current-guiding structure, which is manufactured by the solar cell manufacturing method having a titanium layer and a metal line current-guiding structure described in the first aspect.

[0040] Thirdly, the present invention also provides a solar cell with a titanium layer and a metal wire current-discharging structure, comprising a cell, the back side of which includes a semiconductor region and a conductive film layer disposed outside the semiconductor region, and further comprising a titanium layer and a metal wire layer disposed sequentially outside the semiconductor region and the conductive film layer; wherein the titanium layer and the metal wire layer serve as the current-discharging structure, and the metal wire layer comprises a plurality of parallel patterned metal wires, the metal wires being disposed corresponding to the regions of the semiconductor region. This solar cell has the same structure and performance as the solar cell with a titanium layer and a metal wire current-discharging structure described in the second aspect.

[0041] Preferably, the thickness of the titanium layer in this invention is 0.01-0.02 mm.

[0042] In some preferred embodiments of the present invention, the solar cell has at least one of the following structures:

[0043] Structure 1: The metal in the metal wire is selected from at least one of copper, aluminum, nickel, tin, bismuth and their corresponding alloys;

[0044] Structure 2: The diameter of the metal wire is 0.02-0.05mm;

[0045] Structure 3: The titanium layer covers the entire outer surface of the semiconductor region and its conductive film layer;

[0046] Structure 4: The titanium layer is made of metallic titanium or a titanium alloy.

[0047] Fourthly, the present invention also provides a battery assembly comprising a solar cell having a titanium layer and a metal line current-conducting structure as described in the second aspect, or a solar cell having a titanium layer and a metal line current-conducting structure as described in the third aspect.

[0048] Beneficial effects:

[0049] This invention, through the aforementioned technical solution, particularly the process of first printing titanium hydrogen paste on a conductive film layer outside the semiconductor region, then heating it to semi-cur or physically gel it, followed by bonding a polymer film with metal wires, and subsequent heat treatment steps, can form a current-conducting structure with a titanium layer and metal wires as an electrode to replace the fine grid, eliminating the need for a main grid and silver paste electrodes, thus reducing the amount of silver paste used. This not only lowers material costs but also simplifies the manufacturing process and improves production efficiency. Furthermore, the metal wires of this invention can be made of non-silver materials (such as Cu, Al, etc.), exhibiting better conductivity and stability, effectively improving battery conversion efficiency and reliability. In this process, heating causes the titanium hydride slurry to semi-solidify or physically gel, facilitating the initial solidification of titanium and promoting the subsequent formation of a dense titanium layer to improve conductivity. Combined with a heat treatment step, the organic compounds in the titanium hydride slurry decompose, and TiH2 decomposes, releasing hydrogen gas and converting it into Ti. Simultaneously, the polymer film decomposes, forming a metal composite interface and alloy structure—the titanium layer—which conducts current between the semiconductor region and the metal, creating a solar cell structure with a titanium layer and metal wires for current conduction. This replaces the traditional fine grid and main grid, ensuring good conductivity while reducing silver paste usage and preventing leakage from the conductive region, thus improving the cell conversion efficiency and reliability of the solar cell. Furthermore, the titanium hydride slurry used in this invention is environmentally friendly, reducing harmful emissions during production and aligning with the trend of green manufacturing. This invention is also applicable to various metal wire materials, including non-silver materials, increasing the flexibility of material selection and allowing for rapid adjustments to the product structure based on market demand. Detailed Implementation

[0050] In this invention, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this invention, "a plurality of" means two or more, unless otherwise explicitly specified.

[0051] In this invention, unless otherwise explicitly specified and limited, "above" or "below" the second feature can mean that the first feature is in direct contact with the second feature, or that the first feature is in indirect contact with the second feature through an intermediate medium. Furthermore, "above," "over," and "on top" of the second feature can mean that the first feature is directly above or diagonally above the second feature, or simply that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature can mean that the first feature is directly below or diagonally below the second feature, or simply that the first feature is at a lower horizontal level than the second feature.

[0052] 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. For numerical ranges, the endpoint values ​​of the ranges, the endpoint values ​​of the ranges and individual point values, and individual point values ​​can be combined with each other to obtain one or more new numerical ranges, which should be considered as specifically disclosed herein. The terms "optional" and "discretionary" mean that they may or may not be included (or may or may not be present).

[0053] In this invention, the area closer to the silicon wafer is considered the inside, and the area farther from the silicon wafer is considered the outside.

[0054] This invention provides a method for manufacturing a solar cell having a titanium layer and a metal line current-conducting structure, comprising the following steps:

[0055] S1. A battery cell including a semiconductor region and a conductive film layer disposed outside the semiconductor region is provided, and a polymer film with several parallel metal lines disposed on its surface is provided.

[0056] S2. Print titanium hydrogen slurry on the semiconductor region and its conductive film layer of the battery cell, and then heat it to semi-cur or physically gel the titanium hydrogen slurry.

[0057] S3. The metal wires of the polymer film are bonded to the titanium hydride slurry in parallel and made in contact.

[0058] S4. Then, heat treatment is performed to form a current-conducting structure with a titanium layer and metal wires as an electrode; the heat treatment temperature is 380-700℃.

[0059] The heat treatment temperature is 380-700℃, for example, it can be 380℃, 385℃, 390℃, 395℃, 400℃, 410℃, 420℃, 430℃, 440℃, 450℃, 460℃, 470℃, 480℃, 490℃, 500℃, 510℃, 520℃, 530℃, 540℃, 550℃, 560℃, 570℃, 580℃, 590℃, 600℃, 610℃, 620℃, 630℃, 640℃, 650℃, 660℃, 670℃, 680℃, 690℃, 700℃, etc., and any range between these values; for example, 380-600℃ is preferred.

[0060] Preferably, the heat treatment time is 30-60 min, for example, it can be 30 min, 35 min, 40 min, 45 min, 50 min, 55 min, 60 min, etc., or any range between these values; for example, it can be preferably 40-60 min.

[0061] In some preferred embodiments of the present invention, the heat treatment conditions in S4 include: a heating rate of 5-10°C / min, and the duration of heating to the heat treatment temperature, i.e., the heat treatment time.

[0062] In some preferred embodiments of the present invention, the heat treatment process in S4 further includes: cooling after heat treatment, with a cooling rate of 3-5°C / min.

[0063] The metal in the metal wire of this invention can be silver or a non-silver material, preferably a non-silver material. In some preferred embodiments of this invention, the metal in the metal wire is a non-silver metal. The current-conducting structure formed by the metal wire and a thin layer of titanium replaces the fine gate, eliminating the need for a main gate. Even if the metal in the metal wire can contain silver, the amount of silver used is significantly reduced, lowering material costs.

[0064] In some preferred embodiments of the present invention, the metal in the metal wire is selected from at least one of copper, aluminum, nickel, tin, bismuth, and their corresponding alloys. Using these metals provides better conductivity and stability, further improving battery conversion efficiency and reliability. It is understood that copper, aluminum, nickel, tin, bismuth, and their corresponding alloys refer to alloys formed by combining copper, aluminum, nickel, tin, bismuth, or two or more metals.

[0065] Preferably, the diameter of the metal wire in this invention is 0.02-0.05 mm, for example, it can be 0.02 mm, 0.025 mm, 0.03 mm, 0.035 mm, 0.04 mm, 0.045 mm, 0.05 mm, or any value within this range. This invention uses a suitable small-diameter metal wire, which is more conducive to patterned screen printing and simplifies the process.

[0066] In some preferred embodiments of the present invention, the spacing between two adjacent metal wires is 0.5-1 mm. The present invention uses several parallel metal wires with appropriate spacing, which facilitates alignment between upper and lower layers and subsequent processing, while ensuring excellent electrical conductivity.

[0067] The battery cell provided in this invention, comprising a semiconductor region and a conductive film layer disposed outside the semiconductor region, can be a back-contact battery, such as a heterojunction passivated back-contact battery or a combined passivated back-contact battery, or it can be a bifacial battery. The specific passivation structure and film layer of the semiconductor region can refer to existing technologies and can all be used in this invention. It is understood that the titanium hydride slurry of this invention is disposed in the corresponding electrode area of ​​the corresponding battery cell.

[0068] In some preferred embodiments of the present invention, the battery cell is a back contact battery, and the semiconductor region includes a first semiconductor region and a second semiconductor region, wherein one of the first semiconductor region and the second semiconductor region is N-type and the other is P-type.

[0069] Preferably, the spacing between two adjacent metal lines corresponds to the spacing between two adjacent semiconductor regions on the battery cell.

[0070] In some preferred embodiments of the present invention, the thickness of the polymer film is 0.05-0.1 mm. The present invention uses a suitablely thin polymer film, which facilitates removal after metal bonding.

[0071] Preferably, the polymer film of the present invention is selected from at least one of polyimide (PI), polyethylene terephthalate (PET), polyvinyl chloride (PVC), polyvinylidene fluoride (PVDF), and ethylene-tetrafluoroethylene copolymer (ETFE).

[0072] During the S4 heat treatment process of this invention (the heat treatment temperature is 380-700℃), the polymer film decomposes.

[0073] In some preferred embodiments of the present invention, the printing thickness of the titanium hydride paste is 0.01-0.02 mm, for example, it can be 0.010 mm, 0.011 mm, 0.012 mm, 0.013 mm, 0.014 mm, 0.015 mm, 0.016 mm, 0.017 mm, 0.018 mm, 0.019 mm, 0.020 mm, etc., or any value within any range. Using a titanium hydride paste of suitable thickness is more conducive to the conduction of current through the upper and lower parts, reduces resistance, and has good adhesion.

[0074] Preferably, the viscosity of the titanium hydride paste in this invention is between 5000 and 10000 centipoise. Using a titanium hydride paste with a suitable viscosity is more conducive to screen printing.

[0075] In some preferred embodiments of the present invention, the solid content in the titanium hydride slurry is between 50% and 70%, for example, it can be 50%, 52%, 55%, 57%, 60%, 62%, 65%, 67%, 68%, 69%, 70%, etc., or any value between these points, for example, it can be more preferably 50% to 68%. Using a titanium hydride slurry with a suitable solid content is more conducive to forming an effective current conduction channel, while also having good adhesion.

[0076] Preferably, the fineness of the titanium hydride paste is controlled below 10µm. Using titanium hydride paste with suitable fineness is more conducive to screen printing extremely fine lines.

[0077] In this invention, fineness refers to the particle size of solid particles in the slurry.

[0078] In some preferred embodiments of the present invention, the titanium hydride slurry contains TiH2 powder, and the mass content of TiH2 powder is 40%-80%, for example, it can be 40%, 42%, 44%, 45%, 47%, 50%, 52%, 55%, 57%, 60%, 62%, 65%, 67%, 68%, 69%, 70%, 72%, 75%, 77%, 78%, 80%, etc., and any range between these values, for example, more preferably 40%-65%. Using a titanium hydride slurry with an appropriate content of TiH2 powder is more conducive to forming an effective current conduction channel, and also has good adhesion.

[0079] The TiH2 powder described in this invention is a high-purity powder, preferably with a purity of over 99% by mass.

[0080] More preferably, the particle size of the TiH2 powder is 1-10µm.

[0081] In some preferred embodiments of the present invention, the titanium hydrogenation slurry contains TiH2 powder, a binder, a solvent, and additives, which may be added if necessary. The addition of additives may or may not be added, depending on actual requirements.

[0082] More preferably, the binder content in the titanium hydrogenation slurry is 5%-10% by mass.

[0083] In some preferred embodiments of the present invention, the binder is selected from ethyl cellulose and / or acrylic resin.

[0084] In some preferred embodiments of the present invention, the solvent is selected from terpineol and / or butylcarbitol. The viscosity of the titanium hydride slurry can be adjusted by changing the amount of solvent used in the present invention.

[0085] Preferably, the solvent accounts for 40%-50% of the mass of the titanium hydrogenation slurry.

[0086] More preferably, the additive content in the titanium hydrogenation slurry is 0-3% by mass, more preferably 0.5%-3%.

[0087] In some preferred embodiments of the present invention, the additives include plasticizers and dispersants.

[0088] More preferably, the plasticizer content in the titanium hydride slurry is 1%-2% by mass, and the dispersant content in the titanium hydride slurry is 0.5%-1% by mass. This preferred method is more conducive to the uniformity of the titanium hydride slurry.

[0089] In some preferred embodiments of the present invention, the plasticizer is dibutyl phthalate.

[0090] In some preferred embodiments of the present invention, the dispersant is polyethylene glycol.

[0091] In some preferred embodiments of the present invention, the titanium hydride slurry is prepared by the following steps: adding a binder to a solvent and stirring for the first time, then introducing additives as needed and stirring for the second time, and then introducing TiH2 powder and stirring for the third time. This preferred approach facilitates the full dissolution and dispersion of the components in the titanium hydride slurry, thereby improving the uniformity of the resistivity of the metallic titanium after hydrogen release.

[0092] In some preferred embodiments of the present invention, the conditions for the first stirring include: stirring at room temperature to 50°C, stirring speed of 300-500 r / min, and stirring time of 30-60 min.

[0093] In some preferred embodiments of the present invention, the conditions for the second stirring include: a stirring speed of 200-300 r / min and a stirring time of 15-30 min.

[0094] In some preferred embodiments of the present invention, the conditions for the third stirring include: a stirring speed of 100-200 r / min and a stirring time of 3-5 h.

[0095] In some preferred embodiments of the present invention, in S2, the printing is performed using screen printing.

[0096] More preferably, the screen used for screen printing has a mesh count of 300-500.

[0097] More preferably, the heating conditions include: a temperature of 50-180°C and a time of 60-240 min.

[0098] In some preferred embodiments of the present invention, in S2, the printing conditions include: a printing pressure of 0.2-0.5 MPa and a printing speed of 50-100 mm / s.

[0099] Secondly, this invention provides a solar cell with a titanium layer and a metal wire current-guiding structure, which is manufactured by the solar cell manufacturing method with a titanium layer and a metal wire current-guiding structure described in the first aspect. The solar cell of this invention has a current-guiding structure with a titanium layer and metal wires as the electrode instead of a fine grid, and eliminates the main grid. This eliminates the need for silver paste electrodes, reducing the amount of silver paste used, lowering material costs, simplifying the manufacturing process, and improving production efficiency. Simultaneously, it exhibits better conductivity and stability, effectively improving cell conversion efficiency and reliability.

[0100] Thirdly, the present invention also provides a solar cell with a titanium layer and a metal wire current-discharging structure, comprising a cell, the back side of which includes a semiconductor region and a conductive film layer disposed outside the semiconductor region, and further comprising a titanium layer and a metal wire layer disposed sequentially outside the semiconductor region and the conductive film layer; wherein the titanium layer and the metal wire layer serve as the current-discharging structure, and the metal wire layer comprises a plurality of parallel patterned metal wires, the metal wires being disposed corresponding to the regions of the semiconductor region. This solar cell has the same structure and performance as the solar cell with a titanium layer and a metal wire current-discharging structure described in the second aspect.

[0101] Preferably, the thickness of the titanium layer in this invention is 0.01-0.02 mm. The thickness of the titanium layer is basically the same as the printing thickness of the titanium hydride slurry during preparation. This is because, although dehydrogenation and polymer film decomposition occur during heat treatment, the TiH2 particles are "fixed" into a linear structure by the polymer film during the curing stage. Therefore, the original linear outline of the printing can still be maintained after high-temperature heat treatment (only slight volume expansion may occur due to the formation of pores, with an expansion rate of <5% and minimal impact on thickness).

[0102] In some preferred embodiments of the present invention, the metal in the metal wire is selected from at least one of copper, aluminum, nickel, tin, bismuth and their corresponding alloys.

[0103] In some preferred embodiments of the present invention, the diameter of the metal wire is 0.02-0.05 mm.

[0104] In some preferred embodiments of the present invention, the titanium layer covers the outer surface of the semiconductor region and its conductive film layer as a whole.

[0105] In some preferred embodiments of the present invention, the titanium layer is made of metallic titanium or a titanium alloy.

[0106] Fourthly, the present invention also provides a battery assembly comprising a solar cell having a titanium layer and a metal line current-conducting structure as described in the second aspect, or a solar cell having a titanium layer and a metal line current-conducting structure as described in the third aspect.

[0107] The embodiments of the present invention described below are exemplary and are only used to explain the present invention, and should not be construed as limiting the present invention.

[0108] Example 1

[0109] A solar cell having a titanium layer and a metal wire current-conducting structure is manufactured by the following steps:

[0110] S1. A battery cell including a semiconductor region and a conductive film layer disposed outside the semiconductor region is provided. The battery cell is a back contact battery. The semiconductor region includes a first semiconductor region and a second semiconductor region. One of the first semiconductor region and the second semiconductor region is N-type and the other is P-type.

[0111] It provides a polymer film with several parallel metal lines on its surface; the metal in the metal lines is copper, and the diameter of the metal lines is 0.03 mm; the spacing between two adjacent metal lines is 0.8 mm, which corresponds to the spacing between two adjacent semiconductor regions on the solar cell; the thickness of the polymer film is 0.08 mm, and the polymer film is made of polyimide.

[0112] S2. Print titanium hydride paste outside the semiconductor region of the solar cell. The printing is carried out by screen printing process, with a screen mesh of 400 mesh, a printing pressure of 0.3 MPa, and a printing speed of 80 mm / s. The printing thickness of the titanium hydride paste is 0.015 mm. Then, heat the titanium hydride paste to semi-cur or physically gel it. The heating conditions are: temperature of 100℃ and time of 60 min.

[0113] The titanium hydride slurry, by mass percentage, contains TiH2 powder, 8% binder (ethyl cellulose), 45% solvent (terpineol), and additives (specifically 1.5% dibutyl phthalate (DBP) and 0.8% polyethylene glycol (PEG)), with the balance being TiH2 powder (using TiH2 powder with an average particle size of 5µm and a purity of 99.5%). The preparation method of the titanium hydride slurry is as follows: The binder is added to the solvent for the first stirring at 40°C, a stirring speed of 400 r / min, and a stirring time of 45 min, to ensure the binder is fully dissolved in the solvent and forms a homogeneous solution. Then, the additives are introduced for the second stirring at a stirring speed of 250 r / min and a stirring time of 20 min, to ensure the additives are fully mixed. Finally, TiH2 powder is introduced for the third stirring at a stirring speed of 150 r / min and a stirring time of 4 h, until the TiH2 powder is uniformly dispersed in the slurry. The viscosity of the titanium hydride slurry was adjusted to 8000 centipoise by adjusting the amount of terpineol, the solid content in the titanium hydride slurry was 60 wt%, and the fineness of the titanium hydride slurry was controlled to be below 8 µm.

[0114] S3. The metal wires of the polymer film are bonded to the titanium hydride slurry in parallel and made in contact.

[0115] S4. Then, heat treatment is performed to decompose the polymer film and form a thin titanium layer, thus forming a current-conducting structure with a titanium layer and metal wires as an electrode. The heat treatment temperature is 450℃, the heating rate is 8℃ / min, and the time to reach the heat treatment temperature is 45min. After heat treatment, the temperature is lowered at a rate of 4℃ / min. The thickness of the titanium layer is 0.015mm.

[0116] Example 2

[0117] The procedure was carried out in accordance with Example 1, except that the printing thickness of the titanium hydride paste was 0.02 mm. The corresponding thickness of the resulting titanium layer was 0.02 mm.

[0118] Example 3

[0119] The experiment was conducted in accordance with Example 1, except that the mass content of TiH2 powder in the titanium hydrogenation slurry was 70%, the content of other components except solvent remained unchanged, and the amount of solvent was adjusted to replenish the total amount to 100%; the solid content in the titanium hydrogenation slurry was 70%.

[0120] Example 4

[0121] The procedure was carried out in accordance with Example 1, except that the heat treatment time was 30 minutes.

[0122] Example 5

[0123] The process was carried out in accordance with Example 1, except that the heat treatment temperature was 650°C.

[0124] Comparative Example 1

[0125] The process was carried out in accordance with Example 1, except that the heat treatment temperature was 350°C. The resulting titanium layer thickness was 0.015 mm.

[0126] Test case

[0127] The performance of the solar cells obtained in the above embodiments and comparative examples was tested, and the results are shown in Table 1. The resistivity was measured using the four-probe method on the titanium layer and metal wire layer in the solar cell as current-derived structures. The contact resistance was measured using the TLM method on the solar cell.

[0128] Table 1

[0129]

[0130] The results above show that, compared with the comparative example, the embodiment of the present invention does not require the use of silver paste electrode material, reducing the amount of silver paste used, which not only reduces material costs but also simplifies the manufacturing process and improves production efficiency; at the same time, it has better conductivity, which can effectively improve battery conversion efficiency, thus making the battery more stable and reliable.

[0131] Furthermore, as can be seen from Examples 1 and 2-5, the preferred scheme of the present invention is more conducive to obtaining better conductivity and battery conversion efficiency.

[0132] The preferred embodiments of the present invention have been described in detail above; however, the present invention is not limited thereto. Within the scope of the inventive concept, various simple modifications can be made to the technical solutions of the present invention, including combinations of various technical features in any other suitable manner. These simple modifications and combinations should also be considered as the content disclosed in the present invention and are all within the protection scope of the present invention.

Claims

1. A method of manufacturing a solar cell having a titanium layer and a metal wire current lead-out structure, characterized by, Includes the following steps: S1. Provide a battery cell including a semiconductor region and a conductive film layer disposed outside the semiconductor region, and provide a polymer film with several parallel metal lines disposed on the surface, wherein the spacing between two adjacent metal lines is 0.5-1mm, the spacing between two adjacent metal lines corresponds to the same spacing between two adjacent semiconductor regions on the battery cell, and the metal in the metal lines is a non-silver metal. S2. Print titanium hydrogen slurry on the semiconductor region and its conductive film layer of the battery cell, and then heat it to semi-cur or physically gel the titanium hydrogen slurry. S3. The metal wires of the polymer film are bonded to the titanium hydride slurry in parallel and made in contact. S4. Then, heat treatment is performed to form a current-conducting structure with a titanium layer and metal wires as an electrode. The heat treatment temperature is 380-700℃.

2. The method of manufacturing a solar cell having a titanium layer and a metal wire current lead-out structure according to claim 1, wherein The metal in the wire is selected from at least one of copper, aluminum, nickel, tin, bismuth and their corresponding alloys.

3. The method of claim 1, wherein the method further comprises: The diameter of the metal wire is 0.02-0.05mm.

4. The method of claim 1, wherein the method further comprises: The thickness of the polymer film is 0.05-0.1 mm, and / or the polymer film is selected from at least one of polyimide, polyethylene terephthalate, polyvinyl chloride, polyvinylidene fluoride, and ethylene-tetrafluoroethylene copolymer.

5. The method of claim 1, wherein the method further comprises: The printing thickness of the titanium hydride paste is 0.01-0.02 mm, and / or the viscosity of the titanium hydride paste is between 5000 and 10000 centipoise.

6. The method of claim 1, wherein the method further comprises: The solid content in the titanium hydride slurry is 50%-70%, and the fineness of the titanium hydride slurry is controlled below 10µm. And / or, the titanium hydrogenation slurry contains TiH2 powder and the mass content of TiH2 powder is 40%-80%.

7. The method for manufacturing a solar cell with a titanium layer and a metal line current-conducting structure according to claim 1, claim 5, or claim 6, characterized in that, The titanium hydride slurry contains TiH2 powder, binder, solvent, and additives including plasticizers and dispersants. The binder has a mass content of 5%-10% in the titanium hydrogenation slurry, the additive has a mass content of 0-3% in the titanium hydrogenation slurry, and / or the TiH2 powder has a particle size of 1-10µm.

8. The method for manufacturing a solar cell with a titanium layer and a metal line current-conducting structure according to claim 7, characterized in that, The binder is selected from ethyl cellulose and / or acrylic resin, and the solvent is selected from terpineol and / or butyl carbitol; And / or, The plasticizer in the titanium hydrogenation slurry has a mass content of 1%-2%, and the dispersant has a mass content of 0.5%-1%. The plasticizer is dibutyl phthalate, and the dispersant is polyethylene glycol.

9. The method for manufacturing a solar cell with a titanium layer and a metal line current-conducting structure according to claim 7, characterized in that, Titanium hydride slurry is prepared through the following steps: The binder is added to the solvent for the first stirring, then the additive is introduced for the second stirring, and then TiH2 powder is introduced for the third stirring. The conditions for the first stirring include: stirring at room temperature to 50°C, stirring speed of 300-500 r / min, and stirring time of 30-60 min; The conditions for the second stirring include: a stirring speed of 200-300 r / min and a stirring time of 15-30 min; The third stirring conditions include: a stirring speed of 100-200 r / min and a stirring time of 3-5 h.

10. The method of claim 1, wherein the method further comprises: The manufacturing method also includes the following processes: In process 1, S2, screen printing is used, and the mesh count of the screen used for screen printing is 300-500. In process 2, the heating conditions in S2 include: temperature of 50-180℃ and time of 60-240min; In process 3, S2, the printing conditions include: printing pressure of 0.2 - 0.5 MPa and printing speed of 50 - 100 mm / s; The heat treatment conditions in process 4, S4 include: a heating rate of 5-10℃ / min, and a heating time of 30-60min to reach the heat treatment temperature; Process 5, S4, also includes the following heat treatment process: cooling after heat treatment, with a cooling rate of 3-5℃ / min.

11. The method of claim 1, wherein the method further comprises: The battery cell is a back-contact battery. The semiconductor region includes a first semiconductor region and a second semiconductor region. One of the first semiconductor region and the second semiconductor region is N-type and the other is P-type.

12. A solar cell having a titanium layer and a metal line current lead-out structure, characterized by, It is manufactured by the solar cell manufacturing method having a titanium layer and a metal line current-conducting structure as described in any one of claims 1-11.

13. A solar cell having a titanium layer and a metal line current-conducting structure, comprising a cell, wherein the back side of the cell includes a semiconductor region and a conductive film layer disposed outside the semiconductor region, characterized in that, It also includes a titanium layer and a metal wire layer sequentially disposed outside the semiconductor region and its conductive film layer; wherein, the titanium layer and the metal wire layer serve as current conduction structures, the metal wire layer contains several parallel patterned metal wires, the metal wires are disposed corresponding to the regions of the semiconductor region, the spacing between two adjacent metal wires is 0.5-1mm, the spacing between two adjacent metal wires corresponds to the spacing between two adjacent semiconductor regions on the solar cell, and the metal in the metal wires is a non-silver metal; the thickness of the titanium layer is 0.01-0.02mm.

14. The solar cell having a titanium layer and a metal wire current lead-out structure according to claim 13, characterized by, Solar cells have at least one of the following structures: Structure 1: The metal in the metal wire is selected from at least one of copper, aluminum, nickel, tin, bismuth and their corresponding alloys; Structure 2: The diameter of the metal wire is 0.02-0.05mm; Structure 3: The titanium layer covers the entire outer surface of the semiconductor region and its conductive film layer; Structure 4: The titanium layer is made of metallic titanium or a titanium alloy.

15. A battery assembly characterized by, This includes solar cells with a titanium layer and a metal line current-delivering structure as described in claim 12, or solar cells with a titanium layer and a metal line current-delivering structure as described in claim 13 or 14.

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