Patent Application
20250143007
The present disclosure relates to the field of photovoltaic technologies, and in particular, to a method for preparing a solar cell, a solar cell, and a solar cell module.
Generally, electrodes of solar cells need to meet three requirements: high carrier collection efficiency, low preparation costs, and good reliability.
In the related art, there are mainly two methods for preparing an electrode of a solar cell: screen printing and laser transfer printing. The screen printing process is mature, but requires the use of precious metal silver in the electrode material, resulting in high costs. The laser transfer printing is a technology of irradiating a local region of a light-transmitting film layer with laser after a silver paste is formed on the light-transmitting film layer and dried, so that an irradiated part of the silver paste is separated from the light-transmitting film layer and falls on a region on which an electrode is to be formed in a solar cell body, to form the electrode. In the laser transfer printing, the light-transmitting film layer cannot be reused, and there are silver paste residues on the light-transmitting film layer, resulting in high costs. In addition, it is difficult to match the light-transmitting film layer with the laser process. For example, during matching of the light-transmitting film layer with the laser process, because the solvent evaporation capability, adhesion between the paste and a carrier plate, and the like vary with the composition of the silver paste, laser parameters need to be adjusted a plurality of times to adapt to the silver paste, to achieve good matching between the silver paste and laser power. This leads to high difficulty and low production efficiency of the laser transfer printing process.
The present disclosure provides a method for preparing a solar cell, a solar cell, and a solar cell module, to resolve a problem that an electrode of the solar cell has high preparation costs.
According to a first aspect of the present disclosure, a method for preparing a solar cell is provided, including:
In the present disclosure, the second conductive pattern is prepared on the imprint template, instead of being prepared on the solar cell body, and a process of preparing the second conductive pattern has little or substantially no effect on the solar cell body. In addition, the foregoing four electrical connection manners feature a low bonding temperature and high bonding strength. The low bonding temperature can reduce a heat effect on the solar cell body, thereby having little effect on photoelectric conversion efficiency of the solar cell. The high bonding strength can make the electrode of the solar cell have good reliability. Compared with screen printing, in the present disclosure, materials of the second conductive pattern and the first conductive film layer or the first conductive pattern can be welded, bonded, electroplated or chemically plated, or eutectically bonded, and are not limited to a silver paste. Therefore, costs can be appropriately reduced. Compared with laser transfer printing, in the present disclosure, the second conductive pattern and the first conductive part are electrically connected together, the process is mature, and there is no need to adjust parameters of laser a plurality of times. Therefore, process difficulty is relatively low, so that production efficiency can be appropriately improved.
Optionally, before the electrical connection, the method further includes:
Optionally, the bonding part includes a conductive adhesive film layer or a conductive adhesive pattern; and after the first conductive part and the second conductive pattern are bonded together through the conductive adhesive film layer, and after the removing the imprint template, the method further includes: removing the conductive adhesive film layer outside a region on which the electrode is to be formed, to form the conductive adhesive pattern.
Optionally, before the bonding, the method further includes:
Optionally, before the bonding, the method further includes:
Optionally, after the aligning the second conductive pattern with a first conductive part, and before the electrically connecting the second conductive pattern to the first conductive part, the preparation method further includes: prefixing the second conductive pattern and the first conductive part through a plurality of curing patterns.
Optionally, before the welding, the method further includes:
Optionally, before the welding or the eutectic bonding, the method further includes:
the diffusion control pattern is used for controlling a thickness of an alloy formed in the welding or the eutectic bonding of a material of the first conductive part and a material of the second conductive pattern.
Optionally, before the forming a first conductive pattern or a first conductive film layer on a solar cell body, the method further includes:
Optionally, the imprint template includes a first groove; and the forming a second conductive pattern on an imprint template includes:
Optionally, the imprint template includes a substrate, the first groove is arranged on the substrate, and the imprint template further includes a first boss arranged on the substrate and located at an edge of the first groove; and the forming the second conductive pattern in the first groove of the imprint template includes:
Optionally, in a direction from a notch of the first groove to a groove bottom of the first groove, an area of a cross section of the first groove gradually decreases, where the cross section is perpendicular to a lamination direction of the first conductive part and the second conductive pattern.
Optionally, the imprint template includes a substrate and a second boss arranged on the substrate; and the forming a second conductive pattern on an imprint template includes:
Optionally, a surface of the second boss away from the substrate is a plane; or
Optionally, the bonding part includes a conductive adhesive pattern; the imprint template includes a third groove; the forming a second conductive pattern on an imprint template includes:
Optionally, the forming a second conductive pattern on an imprint template includes:
Optionally, the second conductive pattern is a metal wire.
Optionally, the imprint template includes a substrate, and the forming a second conductive pattern on an imprint template includes:
Optionally, before the forming a second conductive pattern on an imprint template, the method further includes:
Optionally, in an extension direction of the second conductive pattern, a length of the second conductive pattern is greater than a length of the first conductive pattern; and/or
According to a second aspect of the present disclosure, a solar cell is provided, including:
Optionally, the first conductive pattern is closer to the solar cell body than the second conductive pattern is; and
Optionally, a shape of a longitudinal section of the second conductive pattern or a partial region of the second conductive pattern away from the solar cell body is a triangle, a trapezoid, or a shape formed by an arc and a line segment connecting two endpoints of the arc, where a length of the line segment is less than or equal to a diameter of a circle corresponding to the arc; and the longitudinal section is parallel to a lamination direction of the solar cell body and the first conductive pattern.
Optionally, the solar cell further includes a bonding pattern arranged between the first conductive pattern and the solar cell body, where the bonding pattern is used for improving bonding force between the first conductive pattern and the solar cell body.
Optionally, in the lamination direction of the solar cell body and the first conductive pattern, the second conductive pattern includes a seed layer pattern and a plating pattern that are laminated, where the plating pattern is closer to the solar cell body than the seed layer pattern is, and the plating pattern wraps the seed layer pattern.
Optionally, in the lamination direction of the solar cell body and the first conductive pattern, the second conductive pattern is formed by at least two second conductive sub-patterns that are laminated.
Optionally, the second conductive pattern and the first conductive pattern are eutectically bonded or welded together; and
Optionally, the second conductive pattern and the first conductive pattern are welded together; and
Optionally, the solar cell further includes a plurality of curing adhesive patterns arranged a side of the first conductive pattern and the second conductive pattern away from the solar cell body.
Optionally, in an extension direction of the second conductive pattern, a length of the second conductive pattern is greater than a length of the first conductive pattern; and/or in a width direction of the second conductive pattern, a width of the second conductive pattern is greater than a width of the first conductive pattern.
Optionally, the second conductive pattern is a metal wire.
According to a third aspect of the present disclosure, a method for preparing a solar cell is provided, including:
Optionally, before the aligning the second conductive pattern with a region on which an electrode is to be formed in a solar cell body, and electrically connecting the second conductive pattern to the region on which the electrode is to be formed in the solar cell body, the method further includes:
Optionally, the bonding part includes a conductive adhesive film layer or a conductive adhesive pattern; and after the second conductive pattern is bonded to the region on which the electrode is to be formed in the solar cell body through the conductive adhesive film layer, and after the removing the imprint template, the method further includes: removing the conductive adhesive film layer outside a region on which the electrode is to be formed, to form the conductive adhesive pattern.
Optionally, before the bonding, the method further includes:
Optionally, a material of the conductive adhesive pattern is an aluminum paste, and the conductive adhesive pattern is in contact with a silicon substrate of the solar cell body; and
Optionally, a material of the second conductive pattern is aluminum, and the second conductive pattern is in contact with a silicon substrate of the solar cell body; and
Optionally, before the welding or the eutectic bonding, the method further includes:
Optionally, the imprint template includes a first groove; and the forming a second conductive pattern on an imprint template includes:
Optionally, the imprint template includes a substrate, the first groove is arranged on the substrate, and the imprint template further includes a first boss arranged on the substrate and located at an edge of the first groove; and the forming the second conductive pattern in the first groove of the imprint template includes:
Optionally, in a direction from a notch of the first groove to a groove bottom of the first groove, an area of a cross section of the first groove gradually decreases, where the cross section is perpendicular to a lamination direction of the second conductive pattern and the solar cell body.
Optionally, the imprint template includes a substrate and a second boss located on the substrate; and the forming a second conductive pattern on an imprint template includes:
Optionally, a surface of the second boss away from the substrate is a plane; or a side of the second boss away from the substrate includes a second groove, where the second conductive pattern is flush with a notch of the second groove, or protrudes from the second groove.
Optionally, the bonding part includes a conductive adhesive pattern; the imprint template includes a third groove; the forming a second conductive pattern on an imprint template includes:
Optionally, the forming a second conductive pattern on an imprint template includes:
Optionally, the imprint template includes a substrate, and the forming a second conductive pattern on an imprint template includes:
Optionally, before the forming a second conductive pattern on an imprint template, the method further includes:
According to a fourth aspect of the present disclosure, a solar cell is provided, including:
Optionally, in a direction away from the solar cell body, an area of a cross section of the second conductive pattern or a partial region of the second conductive pattern away from the solar cell body gradually decreases, where the cross section is perpendicular to a lamination direction of the solar cell body and the second conductive pattern.
Optionally, a shape of a longitudinal section of the second conductive pattern or a partial region of the second conductive pattern away from the solar cell body is a triangle, a trapezoid, or a shape formed by an arc and a line segment connecting two endpoints of the arc, where a length of the line segment is less than or equal to a diameter of a circle corresponding to the arc; and the longitudinal section is parallel to a lamination direction of the solar cell body and the second conductive pattern.
Optionally, the second conductive pattern is welded or eutectically bonded to the solar cell body; and
Optionally, in the lamination direction of the solar cell body and the second conductive pattern, the second conductive pattern includes a seed layer pattern and a plating pattern that are laminated, where the plating pattern is closer to the solar cell body than the seed layer pattern is, and the plating pattern wraps the seed layer pattern.
Optionally, in the lamination direction of the solar cell body and the second conductive pattern, the second conductive pattern is formed by at least two second conductive sub-patterns that are laminated.
Optionally, the second conductive pattern is a metal wire.
According to a fifth aspect of the present disclosure, a solar cell module is provided, including a first encapsulation adhesive film, a solar cell string, and a second encapsulation adhesive film that are sequentially laminated, where the solar cell string is formed by a plurality of solar cells sequentially connected in series; and each of the solar cells is a solar cell according to any one of the foregoing descriptions.
Optionally, two adjacent solar cells in the solar cell string overlap each other, and second conductive patterns of the two adjacent solar cells are electrically connected together through a conductive structure.
Optionally, the solar cell includes a collector gate line, where the collector gate line is used for collecting carriers; the collector gate line includes a first conductive pattern and a second conductive pattern that are sequentially laminated, or the collector gate line includes a second conductive pattern; and an extension direction of the collector gate line is parallel to a direction in which the plurality of solar cells in the solar cell string are sequentially connected in series.
The foregoing descriptions are merely an overview of the technical solutions in this application. In order that technical means of this application can be understood more clearly so that the technical solutions can be implemented according to content of the descriptions, and in order that the foregoing and other objectives, features, and advantages of this application can be understood more clearly, specific implementations of this application are described below.
To describe technical solutions in embodiments of this application or the related art more clearly, the following briefly introduces accompanying drawings required for describing the embodiments or the related art. Apparently, the accompanying drawings in the following descriptions show some of the embodiments of this application, and a person of ordinary skill in the art still derives other drawings from these accompanying drawings without creative efforts.
To make the objectives, technical solutions, and advantages of the embodiments of this application clearer, the following clearly and completely describes the technical solutions in the embodiments of this application with reference to the accompanying drawings in the embodiments of this application. Apparently, the described embodiments are some rather than all of the embodiments of this application. All other embodiments obtained by a person of ordinary skill in the art based on the embodiments of this application without creative efforts shall fall within the protection scope of this application.
Referring to
An embodiment of the present disclosure further provides a solar cell. The solar cell may be applied to the foregoing solar cell module, and specifically, the solar cell is applied to the foregoing solar cell string. A type of the solar cell is not limited in the present disclosure. The solar cell may be, for example, a hetero-junction with intrinsic thin-layer (HJT) solar cell, a silicon heterjunction (SHJ) solar cell, an interdigital back contact (IBC) solar cell, a tunnel oxide passivated contact (TOPcon) solar cell, or a passivated emitter and back cell (PERC).
As shown in
In the solar cell, the positive electrode and the negative electrode may be located on a same side of the solar cell body, or may be separately arranged on two opposite sides of the solar cell body. Any one of the positive electrode or the negative electrode may include only a collector gate line, or may include a collector gate line and a bus gate line, where the collector gate line is used for collecting carriers, for example, electrons or holes, and the bus gate line is used for collecting currents on the collector gate line. It should be noted that, when any one of the positive electrode or the negative electrode includes only the collector gate line, in some examples, an extension direction of the collector gate line is parallel to a direction in which the plurality of solar cells in the solar cell string are sequentially connected in series
The following provides a plurality of embodiments to describe a structure of a solar cell and a method for preparing a solar cell.
Embodiment 1 provides a solar cell. Referring to
When the solar cell provided in Embodiment 1 is used in a solar cell string, in some examples, two adjacent solar cells in the solar cell string overlap each other, and second conductive patterns 104 of the two adjacent solar cells are electrically connected together through a conductive structure. The conductive structure herein may be a conductive solder strip or a conductive adhesive. When solar cells provided in the following other embodiments are used in a solar cell string, the method may also be used in a connection of two adjacent solar cells in the solar cell string.
For example, for a double-sided solar cell, an electrode may be located on a light receiving side or a back side of a solar cell body. For a back contact solar cell, an electrode may be located on a back side of a solar cell body. It may be understood that, a part of the solar cell body in contact with the first conductive pattern herein can conduct electricity. For example, the part of the solar cell body in contact with the first conductive pattern may be a TCO; or the part of the solar cell body in contact with the first conductive pattern may be a doped layer. For another example, if a passivation layer is formed on a surface of the solar cell body, the part of the solar cell body in contact with the first conductive pattern herein is a layer that is exposed after the passivation layer is grooved and that can conduct electricity.
The first conductive pattern 321 and the second conductive pattern 104 are welded together. The welding process is simple and mature, and mass production is easy to be implemented. In addition, the welding features a low bonding temperature and high bonding strength. The low bonding temperature can reduce a heat effect on the solar cell body, thereby having little effect on photoelectric conversion efficiency of the solar cell. The high bonding strength can make the electrode of the solar cell have good reliability. In addition, during the welding, the materials of the second conductive pattern 104 and the first conductive pattern 321 can be welded, are not limited to a silver paste, and have more material selections; and compared with the silver paste, selecting copper, tin, or the like can appropriately reduce costs. In addition, the silver paste is granular, resulting in little contact between silver particles; and the silver paste includes an organic component, and the organic component also affects the contact between the silver particles. In this way, an electrode made of a silver paste has high resistivity and poor conductivity performance. However, in this embodiment of the present disclosure, a material of the electrode may not be granular (for example, a silver paste), and the material of the electrode may be, for example, silver, copper, tin, or an alloy thereof, so that the electrode has good conductivity performance. In addition, because the second conductive pattern 104 may not be prepared on the solar cell body, a process of preparing the second conductive pattern has little or substantially no effect on the solar cell body, and mass production is easy to be implemented. Therefore, preparation costs can be reduced.
It should be noted that, the materials of the first conductive pattern 321 and the second conductive pattern 104 may be materials that can be welded, and the materials of the first conductive pattern 321 and the second conductive pattern 104 are not specifically limited.
It should be noted that, a difference between
Optionally, the first conductive pattern 321 and the second conductive pattern 104 each may be made of a low-temperature conductive material, so that the heat effect of the welding on the solar cell body can be reduced. For example, the first conductive pattern 321 and the second conductive pattern 104 may be made of at least one of the following eight low-temperature conductive materials: A first low-temperature conductive material has a melting point of 98° C. and has the following components in percentage by mass: Bismuth (Bi): 50%, lead (Pb): 25%, and tin (Sn): 25%. A second low-temperature conductive material has a melting point of 74° C. and has the following components in percentage by mass: Bismuth (Bi): 42.5%, lead (Pb): 37.7%, tin (Sn): 11.3%, and cadmium (Cd): 8.5%. A third low-temperature conductive material has a melting point of 70° C. and has the following components in percentage by mass: Bismuth (Bi): 50%, lead (Pb): 26.7%, tin (Sn): 13.3%, and cadmium (Cd): 10%. A fourth low-temperature conductive material has a melting point of 62° C. and has the following components in percentage by mass: Bismuth (Bi): 32.5%, tin (Sn): 16.5%, and indium (In): 51%. A fifth low-temperature conductive material has a melting point of 58° C. and has the following components in percentage by mass: Bismuth (Bi): 49%, lead (Pb): 18%, tin (Sn): 12%, and indium (In): 21%. A sixth low-temperature conductive material has a melting point of 47.2° C. and has the following components in percentage by mass: Bismuth (Bi): 44.7%, lead (Pb): 22.6%, tin (Sn): 8.3%, indium (In): 19.1%, and cadmium (Cd): 5.3%. A seventh low-temperature conductive material has a melting point of 41.5° C. and has the following components in percentage by mass: Bismuth (Bi): 40.3%, lead (Pb): 22.2%, tin (Sn): 10.7%, indium (In): 17.7%, cadmium (Cd): 8.1%, and thallium (TI): 1.1%. An eighth low-temperature conductive material has a melting point of 30.0° C. and has the following component in percentage by mass: gallium (Ga): 100%.
Optionally, referring to
Referring to
Optionally, a shape of a longitudinal section of the second conductive pattern 104 or a partial region of the second conductive pattern 104 away from the solar cell body is a triangle, a trapezoid, or a shape formed by an arc and a line segment connecting two endpoints of the arc, where a length of the line segment is less than or equal to a diameter of a circle corresponding to the arc; and the longitudinal section is parallel to a lamination direction of the first conductive pattern 321 and the second conductive pattern 104, or the longitudinal section is parallel to a lamination direction of the solar cell body and the first conductive pattern 321. It should be noted that, if the length of the line segment is equal to the diameter of the circle corresponding to the arc, the shape of the longitudinal section of the second conductive pattern 104 or the partial region of the second conductive pattern 104 away from the solar cell body is a semicircle, and a shape of the second conductive pattern 104 or the partial region of the second conductive pattern 104 away from the solar cell body is a semi-cylinder. If the length of the line segment is less than the diameter of the circle corresponding to the arc, the arc is an inferior arc of the circle corresponding to the arc.
For example, in
Optionally, referring to
Optionally, a thickness of the bonding pattern 311 may range from 1 nm to 50 nm; and a thickness direction is parallel to the lamination direction of the first conductive pattern 321 and the second conductive pattern 104, or the thickness direction is parallel to the lamination direction of the solar cell body and the first conductive pattern 321. When the thickness of the bonding pattern 311 is within the range, the effect of improving the bonding force between the first conductive pattern 321 and the solar cell body is good, and costs are low. For example, the bonding pattern 311 may be a titanium bonding pattern of 10 nm.
In some examples, the thickness of the bonding pattern 311 may be, for example, 1 nm, 10 nm, 20 nm, 30 nm, 40 nm, or 50 nm. Compared with
Optionally, the solar cell may further include a diffusion control pattern (not shown in the figure) located between the first conductive pattern 321 and the second conductive pattern 104, where the diffusion control pattern is used for controlling a thickness of an alloy formed in the welding of the second conductive pattern 104 and the first conductive pattern 321, to obtain an ideal interface alloy region. Specifically, the diffusion control pattern located between the first conductive pattern 321 and the second conductive pattern 104 can slow down atomic diffusion speeds of both the first conductive pattern 321 and the second conductive pattern 104 during the welding, so that a thickness of the alloy formed at various positions of a welding interface is relatively uniform, and the thickness of the alloy formed during the welding is not excessively thick, so that bonding force between the first conductive pattern 321 and the second conductive pattern 104 can be improved. In addition, the diffusion control pattern located between the first conductive pattern 321 and the second conductive pattern 104 can also improve infiltration of the first conductive pattern 321 and infiltration of the second conductive pattern 104, so that fewer bubbles are formed during bonding of the first conductive pattern 321 and the second conductive pattern 104, and the first conductive pattern 321 and the second conductive pattern 104 are bonded more tightly, thereby further improving the bonding force between the first conductive pattern 321 and the second conductive pattern 104. In addition, the diffusion control pattern located between the first conductive pattern 321 and the second conductive pattern 104 can also prevent the atomic diffusion speeds of both the first conductive pattern 321 and the second conductive pattern 104 to a certain extent when the solar cell is heated or cooled after the welding, to prevent the alloy from continuously thickening. A material of the diffusion control pattern is not specifically limited. For example, the material of the diffusion control pattern may be graphene, and may be single-layer graphene or multi-layer graphene. A shape of the diffusion control pattern may be the same as or similar to the shapes of the first conductive pattern 321 and the second conductive pattern 104.
It should be noted that, if both a flux pattern and the diffusion control pattern exist between the first conductive pattern 321 and the second conductive pattern 104, the diffusion control pattern is located between the flux pattern and the first conductive pattern 321, or the diffusion control pattern is located between the flux pattern and the second conductive pattern 104. For example, the structure of the electrode may be as follows: The first conductive pattern 321, the diffusion control pattern, the flux pattern, and the second conductive pattern 104 are sequentially laminated, and the diffusion control pattern is located between the flux pattern and the first conductive pattern 321. In this case, the diffusion control pattern can control the thickness of the alloy formed in the welding of the second conductive pattern 104 and the first conductive pattern 321, and can also control a thickness of an alloy formed in welding of the flux pattern and the second conductive pattern 104. For example, for the foregoing example, during the welding, the flux pattern and the second conductive pattern 104 also need to be welded, and the diffusion control pattern can also control the thickness of the alloy formed in the welding of the flux pattern and the second conductive pattern 104.
Optionally, a thickness of the second conductive pattern 104 ranges from 5 μm to 50 μm, and/or a thickness of the first conductive pattern 321 ranges from 10 nm to 100 nm; and a thickness direction is parallel to the lamination direction of the first conductive pattern 321 and the second conductive pattern 104. The thickness of the second conductive pattern 104 and the thickness of the first conductive pattern 321 are within the ranges, so that the electrode has a good carrier collection effect. It should be noted that, the thickness direction involved in this specification is the definition.
For example, the thickness of the second conductive pattern 104 may be 5 μm, 10 μm, 20 μm, 30 μm, 40 μm, or 50 μm. For example, the thickness of the first conductive pattern 321 may be 10 nm, 20 nm, 30 nm, 40 nm, 50 nm, 60 nm, 70 nm, 80 nm, 90 nm, or 100 nm.
Optionally, referring to
Optionally, in a direction parallel to the lamination direction of the solar cell body and the first conductive pattern 321, the second conductive pattern 104 includes a seed layer pattern and a plating pattern that are laminated, where the plating pattern is closer to the solar cell body than the seed layer pattern is, and the plating pattern wraps the seed layer pattern. To be specific, the plating pattern is located between the seed layer pattern and the solar cell body, and the plating pattern is formed on a side of the seed layer pattern close to the solar cell body through electroplating or chemical plating. Therefore, the plating pattern wraps the side of the seed layer pattern close to the solar cell body. There is an interface between the plating pattern and the seed layer pattern, and the second conductive pattern 104 is formed in flexible and diverse manners. The electroplating is to plate a material of the plating pattern on the seed layer pattern by using the principle of electrolysis. The chemical plating is to reduce metal ions in a chemical plating solution to a metal by using an appropriate reducing agent without an applied current, and deposit the metal onto the seed layer pattern. A process parameter such as a temperature of the electroplating or the chemical plating is not specifically limited, and is suitable for forming the plating pattern. A specific manner of the chemical plating is not limited. For example, the chemical plating may be lithium plating.
Optionally, a material of the second conductive sub-pattern 1041 farthest away from the first conductive pattern 321 in the second conductive pattern 104 may include tin. The second conductive sub-pattern 1041 farthest away from the first conductive pattern 321 in the second conductive pattern 104 is also a part of the electrode farthest away from the solar cell body, and a material of the part includes tin. This can avoid oxidation of the remaining second conductive sub-patterns in the second conductive pattern 104. In addition, a melting point of tin is low, and during welding of a solder strip and the electrode, a welding temperature can be low due to the low melting point of tin. This helps reduce the welding temperature of the electrode in a process of forming a solar cell module, to reduce a heat effect on the solar cell or the solar cell module. A material of a second conductive sub-pattern closest to the first conductive pattern 321 in the second conductive pattern 104 may be tin or a tin alloy. For example, in the solar cell shown in
It should be noted that, the tin alloy herein may be a copper-tin alloy, a lead-tin alloy, or the like.
Optionally, the solar cell may further include a flux pattern (not shown in the figure) located between the first conductive pattern 321 and the second conductive pattern 104. There is the flux pattern between the first conductive pattern 321 and the second conductive pattern 104, and flux usually includes tin. During the welding of the solder strip and the electrode, the welding temperature can be low due to the low melting point of tin, so that the heat effect on the solar cell or the solar cell module can be reduced. In addition, after the flux comes into contact with the first conductive pattern 321 and the second conductive pattern 104, impurities on a surface of the first conductive pattern 321 and a surface of the second conductive pattern 104 can be appropriately adsorbed. The flux is usually volatile, and volatilized flux can carry out some of the impurities. Therefore, the welding effect is good.
In some embodiments, for a first conductive pattern between any second conductive pattern and the solar cell body, the first conductive pattern may continuously extend, or the first conductive pattern may include a plurality of discontinuously distributed parts in an extension direction of the second conductive pattern. For other embodiments except Embodiment 1, in some examples, the method may also be used.
In some embodiments, in an extension direction of the second conductive pattern, a length of the second conductive pattern is greater than a length of the first conductive pattern. For example, in the extension direction of the second conductive pattern, two endpoints of the first conductive pattern are located between two endpoints of the second conductive pattern. For another example, in the extension direction of the second conductive pattern, one endpoint of the first conductive pattern is located between the two endpoints of the second conductive pattern. For other embodiments except Embodiment 1, in some examples, the method may also be used.
In some embodiments, in a width direction of the second conductive pattern, a width of the second conductive pattern is greater than a width of the first conductive pattern. For example, in the width direction of the second conductive pattern, two endpoints of the first conductive pattern are located between two endpoints of the second conductive pattern. For another example, in the width direction of the second conductive pattern, one endpoint of the first conductive pattern is located between the two endpoints of the second conductive pattern. For other embodiments except Embodiment 1, in some examples, the method may also be used.
In some embodiments, the solar cell further includes a plurality of curing adhesive patterns arranged on a side of the first conductive pattern and the second conductive pattern away from the solar cell body. A material of each of the curing adhesive patterns herein may be a heat curing material, an ultraviolet (UV) curing material, or an infrared curing material. For other embodiments except Embodiment 1, in some examples, the method may also be used.
Embodiment 1 further provides a method for preparing a solar cell, which can be used to prepare the solar cell in Embodiment 1.
A manner of forming the first conductive pattern on the solar cell body may include: forming the first conductive pattern on a region on which an electrode is to be arranged in the solar cell body through screen printing, deposition, electroplating, or the like; or forming the entire first conductive film layer on the solar cell body in the foregoing manner, and patterning the first conductive film layer, to form the first conductive pattern. For example, a first conductive film layer 321 may be formed through vacuum deposition such as vacuum sputtering deposition. If the entire first conductive film layer 321 is formed, a mask layer may be arranged on the first conductive film layer 321, and the mask layer is patterned, to form the first conductive pattern 321 through wet etching. Alternatively, the first conductive film layer 321 may be patterned by using laser, to form the first conductive pattern 321. This is not specifically limited in the embodiments.
Optionally, the forming a first conductive pattern or a first conductive film layer on a solar cell body may include: laying a metal foil on the solar cell body, to form the first conductive film layer; and patterning the metal foil, to form the first conductive pattern. The patterning manner is not specifically limited. A material of the metal foil is the same as a material of the first conductive pattern or the first conductive film layer.
Optionally, after the laying a metal foil on the solar cell body, the method may include: pressing the metal foil, to bond the metal foil to the solar cell body. Specifically, if the solar cell body has a pyramid shape, a gap between the metal foil and the solar cell body may be relatively large. The metal foil and the solar cell body are well bonded through the pressing. This facilitates aligning and welding, and improves reliability of the electrode. The pressing manner is not specifically limited. For example, pressing may be performed by using a roller. After the pressing, a surface of the metal foil may be further cleaned, to reduce pollution of a pressing substance on the surface of the metal foil, and the like. This is not specifically limited in the embodiments of the present disclosure.
It should be noted that, in this embodiment of this application, the imprint template may be a rigid template or a flexible template.
In some examples, the forming a second conductive pattern 104 on an imprint template includes: first, in
In some other examples, the forming a second conductive pattern 104 on an imprint template includes: first, in
A manner of forming the second conductive pattern 104 on the imprint template may include: electroplating, deposition, or the like. The second conductive pattern 104 is formed on the imprint template, instead of being prepared on the solar cell body, and a process of preparing the second conductive pattern 104 has little or substantially no effect on the solar cell body, so that the effect on the solar cell body can be reduced, and mass production is easy to be implemented.
The second conductive pattern 104 is aligned with the first conductive pattern 321. The aligning herein may be that a first projection of the second conductive pattern 104 on the solar cell body and a second projection of the first conductive pattern 321 on the solar cell body have an overlapping region. An area of the overlapping region is not specifically limited. For example, an area of the first projection may be equal to an area of the second projection, and the area of the overlapping region may be smaller than the area of the first projection; or the area of the first projection may be equal to the area of the second projection, and the area of the overlapping region may be equal to the area of the first projection; or the area of the second projection may be larger than the area of the first projection, and the first projection may completely fall within the second projection. It should be noted that, aligning involved in this specification is the same as or similar to the definition of the aligning herein. In some embodiments, a projection of the second conductive pattern on the solar cell body covers a projection of the first conductive pattern on the solar cell body. In some other embodiments, the projection of the second conductive pattern on the solar cell body partially overlaps the projection of the first conductive pattern on the solar cell body.
In some examples, after aligning the second conductive pattern with a first conductive part, and before the welding the second conductive pattern and the first conductive part together, the preparation method further includes: prefixing the second conductive pattern and the first conductive part through a plurality of curing patterns. For example, prefixing the second conductive pattern and the first conductive part can include fixing the second conductive pattern and the first conductive part using curing patterns (e.g., made of light curing adhesive, or a heat curing adhesive), before electrically connecting the second conductive pattern and the first conductive part (e.g., through bonding, welding, electroplating or chemical plating, or eutectically bonding). In this way, positions of the second conductive pattern and the first conductive part cannot be moved before and when the second conductive pattern and the first conductive part are welded together, so that the electrical connection between the second conductive pattern and the first conductive part can be formed with better precision and efficiency.
After the first conductive pattern 321 is aligned with the second conductive pattern 104, the second conductive pattern 104 and the first conductive pattern 321 are welded together, so that welding transfer of the second conductive pattern 104 located on the imprint template to the first conductive film layer 321 or the first conductive pattern 321 on the solar cell body is implemented. Compared with screen printing, in the present disclosure, materials of the second conductive pattern and the first conductive film layer or the first conductive pattern can be welded, and are not limited to a silver paste. Therefore, costs can be appropriately reduced. Compared with laser transfer printing, in the present disclosure, the second conductive pattern and the first conductive pattern can be welded together, or the second conductive pattern and the region on which the electrode is to be formed in the first conductive film layer can be welded together. The welding process is mature, and process difficulty is relatively low, so that production efficiency can be appropriately improved. Compared with electroplating, in the present disclosure, the second conductive pattern and the first conductive pattern can be welded together, or the second conductive pattern and the region on which the electrode is to be formed in the first conductive film layer can be welded together. In this way, there is no process problem such as winding plating for the solar cell body, the yield and the reliability are good, and mass production is easy to be implemented.
That the second conductive pattern 104 is aligned with the region on which the electrode is to be formed in the first conductive film layer 321 is similar to that the second conductive pattern 104 is aligned with the first conductive pattern 321. Reference may be made to the foregoing related descriptions, and the same or similar beneficial effects can be achieved. To avoid repetition, details are not described herein again.
For that the second conductive pattern 104 and the region on which the electrode is to be formed in the first conductive film layer 321 are welded together, reference may also be made to the foregoing related descriptions in which the second conductive pattern 104 and the first conductive pattern 321 are welded together, and the same or similar beneficial effects can be achieved. To avoid repetition, details are not described herein again.
The welding transfer of the second conductive pattern 104 located on the imprint template to the first conductive film layer 321 or the first conductive pattern 321 on the solar cell body is implemented, so that the electrode of the solar cell is substantially formed. Then, the imprint template is removed. The imprint template may be removed by using mechanical external force or the like. The manner of removing the imprint template is not specifically limited in the embodiments of the present disclosure. Removing the imprint template mainly relies on that bonding force between the second conductive pattern 104 and the imprint template is less than welding force between the second conductive pattern 104 and the first conductive film layer 321 or the first conductive pattern 321, to remove the imprint template. Optionally, a coating or the like for making the second conductive pattern 104 easy to be separated from the imprint template may be coated between the imprint template and the second conductive pattern 104, thereby further facilitating removing the imprint template. For example, tin or a tin alloy is provided between the imprint template and the second conductive pattern 104. Tin or the tin alloy has a low melting point, so that the imprint template can be easily removed by heating.
It should be noted that, after the imprint template is removed, second conductive pattern residues on the imprint template may be further cleaned by using an acid solution or an alkali solution, so that the imprint template can be reused, thereby further reducing costs. Specifically, whether the imprint template is cleaned by using the acid solution or the imprint template is cleaned by using the alkali solution needs to be determined according to the material of the second conductive pattern. This is not specifically limited in the embodiments.
The first conductive film layer 321 is entirely arranged on the solar cell body, and the first conductive film layer 321 outside the region of the electrode may be removed by using a removal solution corresponding to the material of the first conductive film layer 321, to form the first conductive pattern, thereby avoiding a problem such as a short circuit.
It should be noted that, a concentration and/or removal time of the removal solution may be controlled, to control precision of forming the first conductive pattern, to obtain the first conductive pattern with an appropriate shape. This is not specifically limited in the embodiments.
Optionally, before Step A3, the method may further include: annealing the imprint template on which the second conductive pattern 104 has been formed, to cause the second conductive pattern 104 to recrystallize, to eliminate a stress. The annealing is performed on the second conductive pattern 104 on the imprint template, instead of being performed after the second conductive pattern 104 is transferred to the solar cell body. In this case, the annealing has no heat effect on the solar cell body, thereby having no adverse effect on the photoelectric conversion efficiency of the solar cell.
Optionally, an annealing temperature ranges from 200° C. to 700° C., and annealing time ranges from 0.5 min to 2 min. When the annealing is performed within the temperature range, the stress of the second conductive pattern 104 located on the imprint template is completely relieved, and energy is saved. For example, the annealing temperature is 200° C., and the annealing time is 30 s. For another example, the annealing temperature is 700° C., and the annealing time is 2 min. For another example, the annealing temperature is 400° C., and the annealing time is 60 s. For another example, the annealing temperature is 700° C., and the annealing time is 45 s.
Optionally, an annealing temperature ranges from 500° C. to 700° C., and annealing time is 1 min. At the annealing temperature and the annealing time, a relief degree of the stress of the second conductive pattern 104 located on the imprint template and energy saving are well balanced.
The annealing manner may be infrared heating, ultrasonic heating, resistance heating, or the like. This is not specifically limited in the embodiments of the present disclosure.
Optionally, before the welding, the method may further include: forming a flux pattern on the second conductive pattern; and/or forming a flux pattern on the first conductive part, that is, the first conductive pattern or the region on which the electrode is to be formed in the first conductive film layer, to improve a welding effect. The flux pattern may be formed through coating, deposition, or the like. This is not specifically limited in the embodiments.
Optionally, before the welding, the method may further include: forming a diffusion control pattern on the first conductive part, that is, the first conductive pattern or the region on which the electrode is to be formed in the first conductive film layer; and/or forming a diffusion control pattern on the second conductive pattern, where the diffusion control pattern is used for controlling a thickness of an alloy formed in the welding of the second conductive pattern and the first conductive pattern, to obtain an ideal welded alloy region. For a material, a structure, and the like of the diffusion control pattern, reference may be made to the foregoing descriptions, and the same or similar beneficial effects can be achieved. To avoid repetition, details are not described herein again. A manner of forming the diffusion control pattern may be deposition, coating, or the like.
Optionally, before the forming a first conductive pattern or a first conductive film layer on the solar cell body, the method may further include: forming a bonding pattern or a bonding film layer on the solar cell body, where the bonding pattern or the bonding film layer is used for improving bonding force between the first conductive pattern and the solar cell body; and the forming a first conductive pattern may include: forming the first conductive pattern on the bonding pattern or the bonding film layer. Forming the bonding film layer herein means forming the entire bonding film layer on the solar cell body. After the entire bonding film layer is patterned, the bonding pattern is obtained. A manner of forming the bonding pattern may also include: first, forming the entire bonding film layer on the solar cell body through screen printing, electroplating, deposition, or the like; and then forming a mask on the bonding film layer, patterning the mask, and then performing wet etching, to obtain the bonding pattern; or patterning the bonding film layer by using laser, to obtain the bonding pattern. This is not specifically limited in the embodiments. For a material and the like of the bonding pattern, reference may be made to the foregoing descriptions, and the same or similar beneficial effects can be achieved. To avoid repetition, details are not described herein again.
For example, referring to
For example, the first groove 103 is provided inward on a partial region of a surface of a substrate 101, to form the imprint template. Referring to
The hard substrate or the flexible substrate herein only needs to have a specific support degree, and both a thickness and a material of the substrate are not specifically limited. Materials of the conductive substance and the non-conductive substance are also not specifically limited. For example, the hard substrate may be ceramic with a thickness of 5 nm. An aluminum layer may be deposited on the ceramic of 5 nm. For example, the aluminum layer of 20 μm is formed through sputtering or evaporation. Then, the aluminum layer is oxidized, so that a part of the thickness of the aluminum layer away from the ceramic is oxidized into aluminum oxide, and a remaining aluminum layer close to the ceramic is not oxidized. Thicknesses of the oxidized aluminum layer and the non-oxidized aluminum layer are not specifically limited herein. For example, the thickness of the oxidized aluminum may be 10 μm, and the thickness of the non-oxidized aluminum layer is 10 μm. Then, the groove may be etched by using laser, so that a part of aluminum oxide is removed until the aluminum layer is exposed. During the electroplating, aluminum oxide is not electroplated, and only the aluminum layer at the groove bottom of the first groove 103 is electroplated.
Optionally, referring to
It should be noted that, the second conductive pattern is not formed on the surface of the first boss 102 away from the substrate 101, so that a waste can be reduced, and a current loss can be reduced. More specifically, if the second conductive pattern is formed on the surface of the first boss 102 away from the substrate 101, a projection of the part of the second conductive pattern on a surface of the substrate 101 close to the first boss 102 does not coincide with a projection of the second conductive pattern located in the first groove 103 and in the region defined by the first boss 102 on the surface of the substrate 101 close to the first boss 102, and carriers collected on the part need to be transported in a direction parallel to the width of the notch of the first groove 103 to be exported. A transport path of the carriers is long, resulting in a specific current loss. Therefore, in some examples, the second conductive pattern is not formed on the surface of the first boss 102 away from the substrate 101 and the first groove 103. In this way, a current loss can be reduced, and a waste of the material of the second conductive pattern can be reduced. An implementation in which the second conductive pattern is not formed on the surface of the first boss 102 away from the substrate 101 may be as follows: In a process of depositing the second conductive pattern, the second conductive pattern is also deposited on the surface of the first boss 102 away from the substrate 101, then a mask is arranged, the mask is patterned, and the second conductive pattern formed on the surface of the first boss 102 away from the substrate 101 is removed through wet etching. Alternatively, in a process of depositing the second conductive pattern, the second conductive pattern is also deposited on the surface of the first boss 102 away from the substrate 101, and the second conductive pattern formed on the surface of the first boss 102 away from the substrate 101 is removed through laser etching. Alternatively, the region defined by two sides of the first boss 102 is configured as a conductive surface, and the surface of the first boss 102 away from the substrate 101 is configured as a non-conductive surface. In a specific implementation, a conductive substance may be selected as a part of the first boss 102 close to the substrate 101. Then, a non-conductive substance is arranged on the part of the first boss 102 close to the substrate 101 through deposition, coating, or the like. Then, the non-conductive substance in the region defined by the two sides of the first boss 102 is etched, so that the region defined by the two sides of the first boss 102 is a conductive surface, and the surface of the first boss 102 away from the substrate 101 is a non-conductive surface. During electroplating, the second conductive pattern can be electroplated on the region defined by the two sides of the first boss 102, which is a conductive surface and serves as a cathode, and the second conductive pattern cannot be electroplated on the surface of the first boss 102 away from the substrate 101.
It should be noted that, the first boss 102 and the substrate 101 may be integrally formed, or the first boss 102 and the substrate 101 are separately manufactured; and then the first boss 102 and the substrate 101 are fixedly connected together by using an adhesive layer or the like. This is not specifically limited in the embodiments.
Optionally, referring to
The second conductive film layer 104 herein may be a metal foil, and Step A3 may include: laying the metal foil on the side of the imprint template on which the second boss 202 is formed, where a part of the metal foil located on the second boss 202 is the second conductive pattern 104. A part of the metal foil located outside the second boss 202 may be adsorbed on the substrate 101 through lamination, or the like, to avoid displacement of the metal foil. For example, pressing may be performed by using a roller. After the pressing, a surface of the metal foil may be further cleaned, to reduce pollution of a pressing substance on the surface of the metal foil, and the like. This is not specifically limited in the embodiments of the present disclosure. Similarly, the part of the metal foil located outside the second boss 202 is adsorbed on the substrate 101. In this way, after the second conductive pattern 104 is aligned with the first conductive pattern 321 or the region on which the electrode is to be arranged in the first conductive film layer 321, it can be ensured that only the part of the second conductive film layer 104 located on the second boss 202 is in contact with the first conductive pattern 321, to facilitate aligning the second conductive pattern 104 with the first conductive pattern 321; and the part of the second conductive film layer 104 located on the substrate 101 is not in contact with the first conductive pattern 321 or the region on which the electrode is to be arranged in the first conductive film layer 321, so that pollution on the first conductive film layer 321 or the solar cell body can be reduced. In this case, the part of the metal foil located on the second boss 202 and the part of the metal foil located outside the second boss 202 may not be disconnected before the welding, and may be disconnected after the welding. A material of the metal foil herein may be the same as the material of the second conductive pattern 104 described above. To avoid repetition, details are not described herein again. For example, the metal foil may be a copper foil.
Small burrs or the like may be provided on a surface of the second boss 202 away from the substrate 101. The small burrs or the like may hang the metal foil, so that the second conductive pattern is not prone to positional deviation or the like during aligning and welding between the second conductive pattern and the first conductive pattern or the region on which the electrode is to be arranged in the first conductive film layer. The material of the metal foil herein is the same as or similar to the material of the second conductive pattern described above. For example, the metal foil may be a copper foil.
Optionally, referring to
Alternatively, optionally, referring to
Optionally, the imprint template may include a substrate, and Step A2 may include: laying a metal foil on the substrate, and patterning the metal foil, to form the second conductive pattern. In other words, the metal foil is entirely laid on the substrate, and then the metal foil is patterned through laser etching or the like, to form the second conductive pattern. A material or the like of the metal foil may also be the same as the material of the second conductive pattern 104 or the second conductive film layer 104 described above. To avoid repetition, details are not described herein again.
Optionally, before Step A2, the method may further include: providing a plurality of metal foil patterns; the imprint template may include a plurality of adsorption regions; and Step A2 may include: at least aligning one of the adsorption regions with one of the metal foil patterns, and adsorbing the metal foil pattern on the adsorption region, to form the second conductive pattern on the imprint template. For example, the imprint template may include the substrate and a plurality of adsorption regions arranged on the substrate at intervals. At least one of the adsorption regions is aligned with one of the metal foil patterns, and the metal foil pattern is adsorbed on the adsorption region, to form the second conductive pattern on the substrate. The adsorption region herein may be located on a local region on a surface of the substrate. Alternatively, for example, a boss is provided on the substrate, adsorption regions are provided on the boss, at least one of the adsorption regions on the boss is aligned with one of metal foil patterns, and the metal foil pattern is adsorbed on the adsorption region, to form the second conductive pattern on the boss of the substrate. For the aligning herein, reference may be made to the definition of the aligning described above. To avoid repetition, details are not described herein again.
For example, the substrate may be a hollow structure, and a vacuum adsorption component, a magnet, or the like may be locally arranged in the hollow structure of the substrate. The metal foil pattern is absorbed by using the vacuum adsorption component, the magnet, or the like. A specific absorption manner is not specifically limited in the embodiments of the present disclosure.
Optionally, referring to
The metal wire may be arranged in the first groove 103 or the second groove 2021 of the imprint template, so that the metal wire can be stuck. After the metal wire is stuck, the metal wire is flush with the notches of the first groove 103 and the second groove 2021, or the metal wire protrudes from the notches of the first groove 103 and the second groove 2021, to form the second conductive pattern on the imprint template.
It should be noted that, if an entire metal foil is laid on the solar cell body, after welding, due to a high welding temperature during the welding, the metal foil may be partially damaged at a welding boundary, and the like. Therefore, a manner of removing the metal foil outside the region of the electrode may include: blowing the part away by airflow, sticking the part away by using a viscous material, or the like. This is not specifically limited in the embodiments.
For example, referring to
Only parts different from those of the solar cell and the method for preparing a solar cell provided in Embodiment 1 are described in Embodiment 2. For other same parts, reference may be made to the solar cell and the method for preparing a solar cell in Embodiment 1.
Embodiment 2 provides another solar cell. The solar cell includes a solar cell body, and a positive electrode and a negative electrode arranged on the solar cell body, where a structure of the positive electrode and a structure of the negative electrode may be the same or may be different. An electrode (for the electrode, reference may be made to the descriptions in Embodiment 1, and details are not described herein again) of the solar cell includes a second conductive pattern laminated on the solar cell body, where the second conductive pattern is welded to the solar cell body.
For an effect that the second conductive pattern is welded to the solar cell body, reference may be made to the descriptions in Embodiment 1, and details are not described herein again.
It should be noted that, the material of the second conductive pattern may be a material that can be welded to the solar cell body. The material of the second conductive pattern is not specifically limited. For example, the material of the second conductive pattern may include nickel or aluminum. For example, the material of the second conductive pattern may be singular nickel or a nickel alloy, or the material of the second conductive pattern may be aluminum. The material of the second conductive pattern can be welded to the solar cell body at a temperature of about 800° C. to 900° C. The welding process is simple and mature, and mass production is easy to be implemented. In addition, the bonding temperature of about 800° C. to 900° C. can reduce the heat effect on the solar cell body. In addition, the high bonding strength of the welding can make the electrode of the solar cell have the good reliability.
In addition, compared with screen printing, the second conductive pattern can be welded to the solar cell body, and is not limited to a silver paste. Therefore, costs can be appropriately reduced. In addition, compared with laser transfer printing, in the present disclosure, the second conductive pattern and the solar cell body are welded together. The welding process is mature, and process difficulty is relatively low, so that production efficiency can be appropriately improved. Compared with electroplating, in the present disclosure, the second conductive pattern and the solar cell body can be welded together. In this way, there is no process problem such as winding plating for the solar cell body, the yield and the reliability are good, and mass production is easy to be implemented.
Optionally, in a direction parallel to a lamination direction of the solar cell body and a first conductive pattern 321, the second conductive pattern 104 includes a seed layer pattern and a plating pattern that are laminated, where the plating pattern is closer to the solar cell body than the seed layer pattern is, and the plating pattern wraps the seed layer pattern. For the descriptions herein, reference may be correspondingly made to the related descriptions in Embodiment 1, and the same or similar beneficial effects can be achieved. To avoid repetition, details are not described herein again.
Optionally, for a shape, a thickness, the structure, and the like of the second conductive pattern in Embodiment 2, reference may be correspondingly made to the related descriptions in Embodiment 1, and the same or similar beneficial effects can be achieved. To avoid repetition, details are not described herein again.
Optionally, the solar cell may further include a diffusion control pattern located between the second conductive pattern and the solar cell body, where the diffusion control pattern is used for controlling a thickness of an alloy formed in the welding of the second conductive pattern and the solar cell body, to obtain an ideal interface alloy region, and avoid a possible effect on the solar cell body during the welding. For a material, a structure, and the like of the diffusion control pattern, reference may be made to the related descriptions in Embodiment 1, and the same or similar beneficial effects can be achieved. To avoid repetition, details are not described herein again.
Embodiment 2 further provides a method for preparing a solar cell, which can be used to prepare the solar cell in Embodiment 2.
For Step S1, reference may be made to the related descriptions in Embodiment 1, and the same or similar beneficial effects can be achieved. To avoid repetition, details are not described herein again.
For the aligning in Step S2, reference may also be made to the related descriptions in Embodiment 1. To avoid repetition, details are not described herein again. In Step S2, the second conductive pattern is transferred to the solar cell body.
For Step S3, reference may be made to the related descriptions in Embodiment 1, and the same or similar beneficial effects can be achieved. To avoid repetition, details are not described herein again.
Optionally, before the welding, the method may further include: annealing the imprint template on which the second conductive pattern has been formed, to cause the second conductive pattern to recrystallize, to eliminate a stress. For an annealing temperature, annealing time, an annealing manner, and the like, reference may be correspondingly made to the related descriptions in Embodiment 1, and the same or similar beneficial effects can be achieved. To avoid repetition, details are not described herein again.
Optionally, before the welding, the method may further include: forming a diffusion control pattern on the second conductive pattern; and/or forming a diffusion control pattern on the region on which the electrode is to be formed in the solar cell body, where the diffusion control pattern is used for controlling a thickness of an alloy formed in the welding of the second conductive pattern and the region on which the electrode is to be formed in the solar cell body, to obtain an ideal welded alloy region. For a material, a structure, a forming manner, and the like of the diffusion control pattern, reference may be correspondingly made to the related descriptions in Embodiment 1, and the same or similar beneficial effects can be achieved. To avoid repetition, details are not described herein again.
Optionally, referring to
Optionally, referring to
Optionally, referring to
Optionally, referring to
Optionally, a surface of the second boss 202 away from the substrate 101 is a plane; or optionally, a side of the second boss 202 away from the substrate 101 includes a second groove 2021, where the second conductive pattern 104 is flush with a notch of the second groove 2021, or protrudes from the second groove 2021. For the descriptions herein, reference may be correspondingly made to the related descriptions in Embodiment 1, and the same or similar beneficial effects can be achieved. To avoid repetition, details are not described herein again.
Optionally, referring to
Optionally, before Step S1, the method may further include: providing a plurality of metal foil patterns; the imprint template may include a plurality of adsorption regions; and Step S1 may include: at least aligning one of the adsorption regions with one of the metal foil patterns, and adsorbing the metal foil pattern on the adsorption region, to form the second conductive pattern on the imprint template. For example, the imprint template may include the substrate and a plurality of adsorption regions arranged on the substrate at intervals. Step S1 may include: at least aligning one of the adsorption regions with one of the metal foil patterns, and adsorbing the metal foil pattern on the adsorption region, to form the second conductive pattern on the substrate. Alternatively, for example, a boss is provided on the substrate, adsorption regions are provided on the boss, at least one of the adsorption regions on the boss is aligned with one of metal foil patterns, and the metal foil pattern is adsorbed on the adsorption region, to form the second conductive pattern on the boss of the substrate. For the descriptions herein, reference may be correspondingly made to the related descriptions in Embodiment 1, and the same or similar beneficial effects can be achieved. To avoid repetition, details are not described herein again.
Optionally, referring to
Optionally, referring to
Optionally, Step S1 may include: forming at least two aluminum conductive sub-patterns laminated on the imprint template. In the process of aligning the second conductive pattern 104 with the region on which the electrode is to be formed in the solar cell body, an aluminum conductive sub-pattern located on a side of the second conductive pattern 104 away from the imprint template is in direct contact with the silicon substrate 305. Therefore, in the process in which the part of aluminum in the second conductive pattern 104 made of aluminum diffuses into the silicon substrate 305, the aluminum conductive sub-pattern located on the side of the second conductive pattern 104 away from the imprint template preferentially diffuses into the silicon substrate 305. Under a specific welding heat, a remaining aluminum conductive sub-pattern may partially diffuse into the silicon substrate 305 or may not diffuse into the silicon substrate 305. In other words, during the diffusion, the aluminum conductive sub-pattern located on the side of the second conductive pattern 104 away from the imprint template is equivalent to appropriately protecting the remaining aluminum conductive sub-pattern, so that the remaining aluminum conductive sub-pattern has little diffusion, so that a shape of the remaining aluminum conductive sub-pattern has little deformation. The remaining aluminum conductive sub-pattern is used as the electrode, which can ensure precision of the formed electrode.
For example, referring to
The present disclosure is further described below with reference to a more detailed embodiment.
As shown in
In
Only parts different from those of the solar cell and the method for preparing a solar cell provided in Embodiment 1 are described in Embodiment 3. For other same parts, reference may be made to the solar cell and the method for preparing a solar cell in Embodiment 1.
Embodiment 3 provides a solar cell. Referring to
The first conductive pattern 321 and the second conductive pattern 104 are bonded together through the conductive adhesive pattern 313. The bonding process is simple and mature, and mass production is easy to be implemented. In addition, the bonding features a low bonding temperature and high bonding strength. The low bonding temperature can reduce a heat effect on the solar cell body, thereby having little effect on photoelectric conversion efficiency of the solar cell. The high bonding strength can make the electrode of the solar cell have good reliability. In addition, during the bonding, materials of the second conductive pattern 104 and the first conductive pattern 321 can conduct electricity, are not limited to a silver paste, and have more material selections; and compared with the silver paste, selecting copper, tin, conductive resin, or the like can appropriately reduce costs. In addition, the conductive adhesive pattern 313 can have bonding performance and conductivity performance, and has more material selections; and compared with the silver paste, selecting conductive resin or the like can appropriately reduce costs. In addition, because a material of the electrode in this embodiment of the present disclosure may not be granular (for example, a silver paste), a process of preparing the second conductive pattern has little or substantially no effect on the solar cell body, and mass production is easy to be implemented. Therefore, preparation costs can be reduced. For the descriptions herein, reference is made to Embodiment 1. To avoid repetition, details are not described again.
It should be noted that, the materials of the first conductive pattern 321 and the second conductive pattern 104 may be materials that can conduct electricity, and the materials of the first conductive pattern 321 and the second conductive pattern 104 are not specifically limited. The conductive adhesive pattern 313 can have the bonding performance and the conductivity performance, and a material of the conductive adhesive pattern 313 is also not specifically limited. For example, the first conductive pattern 321 and the second conductive pattern 104 each may be made of a metal material. For example, the material of the conductive adhesive pattern 313 may include a silver paste. Alternatively, for example, at least one of the first conductive pattern 321, the second conductive pattern 104, or the conductive adhesive pattern 313 may be made of an organic conductive material or the like. Compared with the metal material, the organic conductive material may further reduce a weight of the solar cell, thereby reducing a weight of a solar cell module. When being applied to a photovoltaic rooftop, a lightweight solar cell module can appropriately reduce mechanical requirements on a building rooftop.
It should be noted that, a difference between
Optionally, the conductive adhesive pattern 313 may have good bonding performance at a normal temperature or a low temperature. The first conductive pattern 321 and the second conductive pattern 104 can be firmly bonded at the normal temperature or the low temperature, so that a heat effect of the bonding on the solar cell body can be reduced. For example, the material of the conductive adhesive pattern 313 may be selected from a conductive adhesive including graphite, which has reliable bonding performance and excellent conductivity performance at about 150° C. The bonding process may be accompanied by a curing reaction or sintering. The curing reaction herein may include heat curing or light curing.
Optionally, referring to
Optionally, a shape of a longitudinal section of the second conductive pattern 104 or a partial region of the second conductive pattern 104 away from the solar cell body is a triangle, a trapezoid, or a shape formed by an arc and a line segment connecting two endpoints of the arc, where a length of the line segment is less than or equal to a diameter of a circle corresponding to the arc; and the longitudinal section is parallel to a lamination direction of the conductive adhesive pattern 313 and the second conductive pattern 104. For the longitudinal section herein, reference may be correspondingly made to the related descriptions in Embodiment 1, and the same or similar beneficial effects can be achieved. To avoid repetition, details are not described herein again.
Optionally, the electrode of the solar cell further includes a bonding pattern located between the first conductive pattern 321 and the solar cell body. For a material, a thickness, and the like of the bonding pattern, reference may be correspondingly made to the related descriptions in Embodiment 1, and the same or similar beneficial effects can be achieved. To avoid repetition, details are not described herein again.
It should be noted that, a thickness of the conductive adhesive pattern 313 is not specifically limited, provided that the second conductive pattern 104 and the first conductive pattern 321 can be firmly bonded and costs can be reduced. For example, the thickness of the conductive adhesive pattern 313 may be 5 nm. If the silver paste is selected for the conductive adhesive pattern 313, because the thickness of the conductive adhesive pattern 313 is significantly smaller than a thickness of the electrode, costs of the conductive adhesive pattern 313 are relatively low, and costs of a solar cell formed accordingly are still relatively low.
Optionally, for the materials, shapes, thicknesses, structures, and the like of the first conductive pattern 321 and the second conductive pattern in Embodiment 3, reference may be correspondingly made to the related descriptions in Embodiment 1, and the same or similar beneficial effects can be achieved. To avoid repetition, details are not described herein again.
Optionally, referring to
Optionally, a material of the second conductive sub-pattern 1041 farthest away from the first conductive pattern 321 in the second conductive pattern 104 may include tin. For an advantage, a component, and the like of tin herein, reference may be correspondingly made to the related descriptions in Embodiment 1, and the same or similar beneficial effects can be achieved. To avoid repetition, details are not described herein again.
Optionally, in a direction parallel to the lamination direction of the solar cell body and the first conductive pattern 321, the second conductive pattern 104 includes a seed layer pattern and a plating pattern that are laminated, where the plating pattern is closer to the solar cell body than the seed layer pattern is, and the plating pattern wraps the seed layer pattern. For the descriptions herein, reference may be correspondingly made to the related descriptions in Embodiment 1, and the same or similar beneficial effects can be achieved. To avoid repetition, details are not described herein again.
Embodiment 3 further provides a method for preparing a solar cell, which can be used to prepare the solar cell in Embodiment 3.
For Step B1, reference may be correspondingly made to the related descriptions in Embodiment 1, and the same or similar beneficial effects can be achieved. To avoid repetition, details are not described herein again.
Optionally, the forming a first conductive pattern or a first conductive film layer on a solar cell body may include: laying a metal foil on the solar cell body, to form the first conductive film layer. For the part, reference may be correspondingly made to the related descriptions in Embodiment 1, and the same or similar beneficial effects can be achieved. To avoid repetition, details are not described herein again.
Optionally, after the laying a metal foil on the solar cell body, the method may include: pressing the metal foil, to bond the metal foil to the solar cell body. For the part, reference may be correspondingly made to the related descriptions in Embodiment 1, and the same or similar beneficial effects can be achieved. To avoid repetition, details are not described herein again.
For Step B2, reference may be correspondingly made to the related descriptions in Embodiment 1, and the same or similar beneficial effects can be achieved. To avoid repetition, details are not described herein again.
For that a second conductive pattern 104 is aligned with the first conductive part, reference may be correspondingly made to the related descriptions in Embodiment 1, and the same or similar beneficial effects can be achieved. To avoid repetition, details are not described herein again.
After the first conductive part is aligned with the second conductive pattern 104, the second conductive pattern 104 and the first conductive part are bonded together through a conductive adhesive film layer 313 or a conductive adhesive pattern 313, so that bonding transfer of the second conductive pattern 104 located on the imprint template to the first conductive film layer 321 or a first conductive pattern 321 on the solar cell body is implemented. For the beneficial effects of the bonding, reference may be made to the beneficial effects of the welding in Embodiment 1, and details are not described herein again.
The bonding transfer of the second conductive pattern 104 located on the imprint template to the first conductive film layer 321 or the first conductive pattern 321 on the solar cell body is implemented, so that the electrode of the solar cell is substantially formed. Then, the imprint template is removed. Removing the imprint template mainly relies on that bonding force between the second conductive pattern 104 and the imprint template is less than bonding force between the second conductive pattern 104 and the conductive adhesive film layer 313 or the conductive adhesive pattern 313, to remove the imprint template. For a manner of removing the imprint template and the like, reference may be correspondingly made to the related descriptions in Embodiment 1, and the same or similar beneficial effects can be achieved. To avoid repetition, details are not described herein again.
For Step B5, reference may be correspondingly made to the related descriptions in Embodiment 1, and the same or similar beneficial effects can be achieved. To avoid repetition, details are not described herein again.
Optionally, the bonding part may include a conductive adhesive film layer 313 or a conductive adhesive pattern 313. When the first conductive part and the second conductive pattern 104 are bonded together through the conductive adhesive film layer 313, after the removing the imprint template, the method may further include: removing the conductive adhesive film layer 313 outside a region on which the electrode is to be formed, to form the conductive adhesive pattern 313. The conductive adhesive film layer 313 is entirely arranged on the solar cell body or the second conductive pattern 104, and the conductive adhesive film layer 313 outside the region of the electrode may be removed by using a removal solution corresponding to the material of the conductive adhesive film layer 313, to form the conductive adhesive pattern 313, thereby avoiding a problem such as a short circuit.
It should be noted that, a concentration and/or removal time of the removal solution may be controlled, to control precision of forming the conductive adhesive pattern 313, to obtain the conductive adhesive pattern 313 with an appropriate shape. This is not specifically limited in the embodiments.
Optionally, before Step B3, the method may further include: annealing the imprint template on which the second conductive pattern 104 has been formed. For an annealing manner, an annealing temperature, and the like in Embodiment 3, reference may be correspondingly made to the related descriptions in Embodiment 1, and the same or similar beneficial effects can be achieved. To avoid repetition, details are not described herein again.
Optionally, before the bonding, the method may further include: forming the bonding part, that is, the conductive adhesive pattern or the conductive adhesive film layer, on the second conductive pattern. A manner of forming the conductive adhesive pattern or the conductive adhesive film layer on the second conductive pattern of the imprint template may include: screen printing, coating, or the like. The conductive adhesive pattern or the conductive adhesive film layer is formed on the second conductive pattern of the imprint template, instead of being prepared on the solar cell body, and a process of preparing the conductive adhesive pattern or the conductive adhesive film layer has little or substantially no effect on the solar cell body, so that the effect on the solar cell body can be reduced, and mass production is easy to be implemented. It should be noted that, if the entire conductive adhesive film layer is formed on the second conductive pattern of the imprint template, a mask layer may be arranged on the entire conductive adhesive film layer, and the mask layer is patterned, to form the conductive adhesive pattern is formed through wet etching. Alternatively, the entire conductive adhesive film layer may be patterned by using laser, to form the conductive adhesive pattern. This is not specifically limited in the embodiments.
In Step B3, the aligning the second conductive pattern with a first conductive part includes: aligning the first conductive part with the conductive adhesive pattern or the region on which the electrode is to be formed in the conductive adhesive film layer. For the definition of the aligning, reference is made to the foregoing related descriptions. To avoid repetition, details are not described herein again.
Optionally, before the bonding, the method may further include: forming the bonding part, that is, the conductive adhesive pattern 313 or the conductive adhesive film layer 313, on one of the first conductive pattern 321, the region on which the electrode is to be formed in the first conductive film layer 321, or the first conductive film layer 321. For example, referring to
Optionally, before the forming a first conductive pattern or a first conductive film layer on the solar cell body, the method may further include: forming a bonding pattern or a bonding film layer on the solar cell body. For a function, a material, a forming manner, and the like of the bonding pattern or the bonding film layer, reference may be correspondingly made to the related descriptions in Embodiment 1, and the same or similar beneficial effects can be achieved. To avoid repetition, details are not described herein again.
Optionally, referring to
For example, the first groove 103 is provided inward on a partial region of a surface of a substrate 101, to form the imprint template. Referring to
For a forming manner, a structure, and a size of the first groove 103, a material of the substrate, and the like, reference may be correspondingly made to the related descriptions in Embodiment 1, and the same or similar beneficial effects can be achieved. To avoid repetition, details are not described herein again.
Optionally, referring to
It should be noted that, for an advantage of not forming the second conductive pattern on the surface of the first boss 102 away from the substrate 101, a method of preparing the first boss 102, and the like, reference may be made to the related descriptions in Embodiment 1, and the same or similar beneficial effects can be achieved. To avoid repetition, details are not described herein again.
Optionally, referring to
Optionally, optionally, referring to
Optionally, referring to
The second conductive film layer 104 herein may be a metal foil, and Step B2 may include: laying the metal foil on the side of the imprint template on which the second boss 202 is formed, where a part of the metal foil located on the second boss 202 is the second conductive pattern 104. A part of the metal foil located outside the second boss 202 may be adsorbed on the substrate 101 through lamination, or the like, to avoid displacement of the metal foil. The part of the metal foil located outside the second boss 202 is absorbed on the substrate 101. In this way, if the conductive adhesive film layer or the conductive adhesive pattern is formed on the first conductive pattern 321 or the region on which the electrode is to be arranged in the first conductive film layer 321, after the second conductive pattern 104 is aligned with the conductive adhesive film layer or the region on which the electrode is to be arranged in the conductive adhesive pattern, it can be ensured that only the part of the second conductive film layer 104 located on the second boss 202 is in contact with the conductive adhesive film layer or the conductive adhesive pattern, to facilitate aligning the second conductive pattern 104 with the conductive adhesive film layer or the conductive adhesive pattern; and the part of the second conductive film layer 104 located on the substrate 101 is not in contact with the conductive adhesive film layer or the region on which the electrode is to be arranged in the conductive adhesive pattern, so that pollution on the conductive adhesive film layer or the conductive adhesive pattern, the first conductive film layer 321, or the solar cell body can be reduced. In this case, the part of the metal foil located on the second boss 202 and the part of the metal foil located outside the second boss 202 may not be disconnected before the bonding, and may be disconnected after the bonding. For a material, an arrangement manner, and the like of the metal foil herein, reference may be made to Embodiment 1. To avoid repetition, details are not described again. Small burrs or the like may be provided on a surface of the second boss 202 away from the substrate 101. The small burrs or the like may hang the metal foil, so that the second conductive pattern is not prone to positional deviation or the like in a process of bonding the second conductive pattern to the first conductive pattern or the region on which the electrode is to be arranged in the first conductive film layer. A material of the metal foil herein is the same as or similar to the material of the second conductive pattern described above. For example, the metal foil may be a copper foil.
Optionally, referring to
Optionally, the imprint template may include a substrate, and Step B2 may include: laying a metal foil on the substrate, and patterning the metal foil, to form the second conductive pattern. For laying of the metal foil, patterning of the metal foil, and the like, reference may be correspondingly made to the related descriptions in Embodiment 1, and the same or similar beneficial effects can be achieved. To avoid repetition, details are not described herein again.
Optionally, before Step B2, the method may further include: providing a plurality of metal foil patterns; the imprint template may include a plurality of adsorption regions; and Step B2 may include: at least aligning one of the adsorption regions with one of the metal foil patterns, and adsorbing the metal foil pattern on the adsorption region, to form the second conductive pattern on the imprint template. For providing of a metal foil, the aligning of the metal foil pattern, the absorption of the metal foil, and the like, reference may be correspondingly made to the related descriptions in Embodiment 1, and the same or similar beneficial effects can be achieved. To avoid repetition, details are not described herein again.
Optionally, the second conductive pattern 104 may also be a metal wire. A shape, a size, and the like of the metal wire are all not specifically limited. For example, a wire diameter of the metal wire may range from 10 μm to 50 μm, and a length of the metal wire may range from 10 μm to 1000 μm. A material of the metal wire may be the same as the material of the second conductive pattern described above, and details are not described herein again. For example, the material of the metal wire may be copper or aluminum.
Optionally, a surface of the metal wire may be further coated with a coating. For a material, a thickness, and the like of the coating, reference may be correspondingly made to the related descriptions in Embodiment 1, and the same or similar beneficial effects can be achieved. To avoid repetition, details are not described herein again.
The metal wire may be arranged in the first groove 103 or the second groove 2021 of the imprint template, so that the metal wire can be stuck. After the metal wire is stuck, the metal wire is flush with the notches of the first groove 103 and the second groove 2021, or the metal wire protrudes from the notches of the first groove 103 and the second groove 2021, to form the second conductive pattern on the imprint template.
Only parts different from those of the solar cell and the method for preparing a solar cell provided in Embodiment 1 are described in Embodiment 4. For other same parts, reference may be made to the solar cell and the method for preparing a solar cell in Embodiment 1.
It should be noted that, the material of the second conductive pattern may be a material that can conduct electricity and can be bonded through the conductive adhesive pattern 313. The material of the second conductive pattern is not specifically limited. For example, the material of the second conductive pattern may include nickel, aluminum, or another metal material. For example, the material of the second conductive pattern may be singular nickel or a nickel alloy, or the material of the second conductive pattern may be aluminum. Alternatively, the material of the second conductive pattern may include an organic conductive material, for example, conductive resin. For the material of the second conductive pattern, reference may be made to the related descriptions in Embodiment 1. To avoid repetition, details are not described herein again. For example, the material of the second conductive pattern and the solar cell body can be bonded together at a normal temperature or a low temperature through the conductive adhesive pattern 313. The bonding process is simple and mature, and mass production is easy to be implemented. In addition, the low bonding temperature can reduce the heat effect on the solar cell body. In addition, the high bonding strength of the bonding can make the electrode of the solar cell have the good reliability.
In addition, compared with screen printing, the second conductive pattern 104 can be bonded through the conductive adhesive pattern 313, and is not limited to the silver paste. Therefore, costs can be appropriately reduced. The conductive adhesive pattern 313 can have conductivity performance and bonding performance, and is not limited to the silver paste. Therefore, the costs can be appropriately reduced. In addition, compared with laser transfer printing, in the present disclosure, the second conductive pattern 104 and the solar cell body are bonded together through the conductive adhesive pattern 313. The bonding process is mature, and process difficulty is relatively low, so that production efficiency can be appropriately improved. Compared with electroplating, in the present disclosure, the second conductive pattern 104 and the solar cell body can be bonded together through the conductive adhesive pattern 313. In this way, there is no process problem such as winding plating for the solar cell body, the yield and the reliability are good, and mass production is easy to be implemented.
Optionally, in a direction parallel to a lamination direction of the solar cell body and a first conductive pattern 321, the second conductive pattern 104 includes a seed layer pattern and a plating pattern that are laminated, where the plating pattern is closer to the solar cell body than the seed layer pattern is, and the plating pattern wraps the seed layer pattern. For the descriptions herein, reference may be correspondingly made to the related descriptions in Embodiment 1, and the same or similar beneficial effects can be achieved. To avoid repetition, details are not described herein again.
Optionally, for a shape, a thickness, the structure, and the like of the second conductive pattern in Embodiment 4, reference may be correspondingly made to the related descriptions in Embodiment 3, and the same or similar beneficial effects can be achieved. To avoid repetition, details are not described herein again.
Optionally, referring to
Embodiment 4 further provides a method for preparing a solar cell, which can be used to prepare the solar cell in Embodiment 4.
For Step C1, reference may be made to the related descriptions in Embodiment 3, and the same or similar beneficial effects can be achieved. To avoid repetition, details are not described herein again.
For the aligning, the conductive material, the adhesive, and the like in Step C2, reference may also be made to the related descriptions in Embodiment 3. To avoid repetition, details are not described herein again. In Step C2, the second conductive pattern is transferred to the solar cell body.
For Step C3, reference may be made to the related descriptions in Embodiment 3, and the same or similar beneficial effects can be achieved. To avoid repetition, details are not described herein again.
Optionally, the bonding part includes a conductive adhesive film layer or a conductive adhesive pattern; and after the second conductive pattern is bonded to the region on which the electrode is to be formed in the solar cell body through the conductive adhesive film layer, and after the removing the imprint template, the method may further include: removing the conductive adhesive film layer outside a region on which the electrode is to be formed, to form the conductive adhesive pattern. For the step, reference may be made to the related descriptions in Embodiment 3, and the same or similar beneficial effects can be achieved. To avoid repetition, details are not described herein again.
Optionally, before the bonding, the method may further include: annealing the imprint template on which the second conductive pattern has been formed, to cause the second conductive pattern to recrystallize, to eliminate a stress. For an annealing temperature, annealing time, an annealing manner, and the like, reference may be correspondingly made to the related descriptions in Embodiment 3, and the same or similar beneficial effects can be achieved. To avoid repetition, details are not described herein again.
Optionally, before the bonding, the method may further include: forming the conductive adhesive pattern or the conductive adhesive film layer on the second conductive pattern. For a manner of forming the conductive adhesive pattern or the conductive adhesive film layer, reference may be made to the related descriptions in Embodiment 1. To avoid repetition, details are not described herein again. In Step C2, the aligning the second conductive pattern with a region on which an electrode is to be formed in a solar cell body may include: aligning the region on which the electrode is to be formed in the solar cell body with the conductive adhesive pattern or the region on which the electrode is to be formed in the conductive adhesive film layer; or For the aligning herein, reference may be made to the related descriptions in Embodiment 3, and the same or similar beneficial effects can be achieved. To avoid repetition, details are not described herein again.
Optionally, before the bonding, the method may further include: forming the conductive adhesive pattern or the conductive adhesive film layer on one of the region on which the electrode is to be formed in the solar cell body or the solar cell body. In Step C2, the aligning the second conductive pattern with a region on which an electrode is to be formed in a solar cell body includes: aligning the second conductive pattern with the conductive adhesive pattern or the region on which the electrode is to be formed in the conductive adhesive film layer. For the descriptions herein, reference may also be made to the related descriptions in Embodiment 3, and the same or similar beneficial effects can be achieved. To avoid repetition, details are not described herein again.
Optionally, referring to
Optionally, referring to
Optionally, referring to
Optionally, referring to
Optionally, a surface of the second boss 202 away from the substrate 101 is a plane; or optionally, a side of the second boss 202 away from the substrate 101 includes a second groove 2021, where the second conductive pattern 104 is flush with a notch of the second groove 201, or protrudes from the second groove 2021. For the descriptions herein, reference may be correspondingly made to the related descriptions in Embodiment 3, and the same or similar beneficial effects can be achieved. To avoid repetition, details are not described herein again.
Optionally, referring to
Optionally, the imprint template includes a substrate 101, and Step C1 may include: laying a metal foil on the substrate, and patterning the metal foil, to form the second conductive pattern. For the descriptions herein, reference may be correspondingly made to the related descriptions in Embodiment 3, and the same or similar beneficial effects can be achieved. To avoid repetition, details are not described herein again.
Optionally, before Step C1, the method may further include: providing a plurality of metal foil patterns; the imprint template may include a plurality of adsorption regions; and Step C1 may include: at least aligning one of the adsorption regions with one of the metal foil patterns, and adsorbing the metal foil pattern on the adsorption region, to form the second conductive pattern on the imprint template. For example, the imprint template may include the substrate and a plurality of adsorption regions arranged on the substrate at intervals. Step C1 may include: at least aligning one of the adsorption regions with one of the metal foil patterns, and adsorbing the metal foil pattern on the adsorption region, to form the second conductive pattern on the substrate. Alternatively, for example, a boss is provided on the substrate, adsorption regions are provided on the boss, at least one of the adsorption regions on the boss is aligned with one of metal foil patterns, and the metal foil pattern is adsorbed on the adsorption region, to form the second conductive pattern on the boss of the substrate. For the descriptions herein, reference may be correspondingly made to the related descriptions in Embodiment 3, and the same or similar beneficial effects can be achieved. To avoid repetition, details are not described herein again.
Optionally, referring to
Optionally, referring to
Optionally, the forming the conductive adhesive pattern 313 may include: forming at least two conductive adhesive sub-patterns that are laminated, where a material of each of the conductive adhesive sub-patterns is an aluminum paste. During the sintering, an aluminum paste conductive adhesive sub-pattern closest to the silicon substrate 305 preferentially diffuses into the silicon substrate 305. Under a specific sintering heat, a remaining aluminum paste conductive adhesive sub-pattern may partially diffuse into the silicon substrate 305 or may not diffuse into the silicon substrate 305. In other words, during the diffusion, the aluminum paste conductive adhesive sub-pattern close to the silicon substrate 305 is equivalent to appropriately protecting the remaining aluminum paste conductive adhesive sub-pattern, so that the remaining aluminum paste conductive adhesive sub-pattern has little diffusion, so that a shape of the remaining aluminum paste conductive adhesive sub-pattern has little deformation. The remaining aluminum paste conductive adhesive sub-pattern is used as a part of the electrode, which can ensure precision of the formed electrode.
Optionally, referring to
The present disclosure is further described below with reference to a more detailed embodiment.
As shown in
In
Only parts different from those of the solar cell and the method for preparing a solar cell provided in Embodiment 1 are described in Embodiment 5. For other same parts, reference may be made to the solar cell and the method for preparing a solar cell in Embodiment 1.
Embodiment 5 provides a solar cell. Referring to
For the solar cell body herein, reference may be made to the related descriptions in Embodiment 1, and the same or similar beneficial effects can be achieved. To avoid repetition, details are not described herein again.
The first conductive pattern 321 and the second conductive pattern 104 are connected together through the third conductive pattern 313 formed through electroplating or chemical plating. The electroplating or chemical plating process is simple and mature, and mass production is easy to be implemented. In addition, the electroplating or the chemical plating features a low bonding temperature and high bonding strength. The low bonding temperature can reduce a heat effect on the solar cell body, thereby having little effect on photoelectric conversion efficiency of the solar cell. The high bonding strength can make the electrode of the solar cell have good reliability. Materials of the second conductive pattern 104 and the first conductive pattern 321 can conduct electricity, are not limited to a silver paste, and have more material selections; and compared with the silver paste, selecting copper, tin, or the like can appropriately reduce costs. In addition, a material of the third conductive pattern 313 can conduct electricity, is not limited to the silver paste, and has more material selections; and compared with the silver paste, selecting copper, tin, or the like can appropriately reduce costs. In addition, the silver paste is granular, resulting in little contact between silver particles; and the silver paste includes an organic component, and the organic component also affects the contact between the silver particles. In this way, an electrode made of a silver paste has high resistivity and poor conductivity performance. However, in this embodiment of the present disclosure, a material of the electrode may not be granular (for example, a silver paste), and the material of the electrode may be, for example, silver, copper, tin, or an alloy thereof, so that the electrode has good conductivity performance. In addition, because the second conductive pattern 104 may not be prepared on the solar cell body, a process of preparing the second conductive pattern has little or substantially no effect on the solar cell body, and mass production is easy to be implemented. Therefore, preparation costs can be reduced.
It should be noted that, the materials of the first conductive pattern 321, the third conductive pattern 313, and the second conductive pattern 104 may be materials that can conduct electricity, and the materials of the first conductive pattern 321, the third conductive pattern 313, and the second conductive pattern 104 are not specifically limited.
Optionally, referring to
Optionally, a shape of a longitudinal section of the second conductive pattern 104 or a partial region of the second conductive pattern 104 away from the solar cell body is a triangle, a trapezoid, or a shape formed by an arc and a line segment connecting two endpoints of the arc, where a length of the line segment is less than or equal to a diameter of a circle corresponding to the arc; and the longitudinal section is parallel to a lamination direction of the third conductive pattern 313 and the second conductive pattern 104. For the longitudinal section and the like, reference may be correspondingly made to the related descriptions in Embodiment 1, and the same or similar beneficial effects can be achieved. To avoid repetition, details are not described herein again.
Optionally, for the materials, shapes, thicknesses, structures, and the like of the first conductive pattern 321 and the second conductive pattern in Embodiment 5, reference may be correspondingly made to the related descriptions in Embodiment 1, and the same or similar beneficial effects can be achieved. To avoid repetition, details are not described herein again.
Optionally, referring to
Optionally, a material of a second conductive sub-pattern 1041 farthest away from the third conductive pattern 313 in the second conductive pattern 104 may include tin. For an advantage, a component, and the like of tin herein, reference may be correspondingly made to the related descriptions in Embodiment 1, and the same or similar beneficial effects can be achieved. To avoid repetition, details are not described herein again.
Optionally, in a direction parallel to the lamination direction of the solar cell body and the first conductive pattern 321, the second conductive pattern 104 includes a seed layer pattern and a plating pattern that are laminated, where the plating pattern is closer to the solar cell body than the seed layer pattern is, and the plating pattern wraps the seed layer pattern. For the descriptions herein, reference may be correspondingly made to the related descriptions in Embodiment 1, and the same or similar beneficial effects can be achieved. To avoid repetition, details are not described herein again.
Embodiment 5 further provides a method for preparing a solar cell, which can be used to prepare the solar cell in Embodiment 5.
For Step D1, reference may be correspondingly made to the related descriptions in Embodiment 1, and the same or similar beneficial effects can be achieved. To avoid repetition, details are not described herein again.
Optionally, the forming a first conductive pattern or a first conductive film layer on a solar cell body may include: laying a metal foil on the solar cell body, to form the first conductive film layer. For the part, reference may be correspondingly made to the related descriptions in Embodiment 1, and the same or similar beneficial effects can be achieved. To avoid repetition, details are not described herein again.
Optionally, after the laying a metal foil on the solar cell body, the method may include: pressing the metal foil, to bond the metal foil to the solar cell body. For the part, reference may be correspondingly made to the related descriptions in Embodiment 1, and the same or similar beneficial effects can be achieved. To avoid repetition, details are not described herein again.
For Step D2, reference may be correspondingly made to the related descriptions in Embodiment 1, and the same or similar beneficial effects can be achieved. To avoid repetition, details are not described herein again.
For that a second conductive pattern 104 is aligned with the first conductive part, reference may be correspondingly made to the related descriptions in Embodiment 1, and the same or similar beneficial effects can be achieved. To avoid repetition, details are not described herein again.
After the first conductive part is aligned with the second conductive pattern 104, the second conductive pattern 104 and the first conductive part are connected together through a third conductive pattern 313 formed through electroplating or chemical plating, so that after the imprint template is removed, the second conductive pattern 104 located on the imprint template is transferred to a first conductive film layer 321 or a first conductive pattern 321 on the solar cell body. The electroplating or chemical plating process is mature, and process difficulty is relatively low, so that production efficiency can be appropriately improved.
The electroplating is to plate the material of the third conductive pattern on a surface of the second conductive pattern close to the first conductive pattern by using the principle of electrolysis, and plate the material of the third conductive pattern on a surface of the first conductive pattern close to the second conductive pattern by using the principle of electrolysis. The chemical plating is to reduce metal ions in a chemical plating solution to a metal by using an appropriate reducing agent without an external current, deposit the metal onto a surface of the second conductive pattern close to the first conductive pattern, and deposit the metal onto a surface of the first conductive pattern close to the second conductive pattern. A process parameter such as a temperature of the electroplating or the chemical plating is not specifically limited, and is suitable for forming the third conductive pattern. A specific manner of the chemical plating is not limited. For example, the chemical plating may be lithium plating.
It should be noted that, if a pyramid textured structure is formed in the first conductive pattern 321 or the region on which the electrode is to be formed in the first conductive film layer, the third conductive pattern or a third conductive film layer 321 is filled in the textured structure during the electroplating or chemical plating of the third conductive pattern.
For Step D4, reference may be correspondingly made to the related descriptions in Embodiment 1, and the same or similar beneficial effects can be achieved. To avoid repetition, details are not described herein again.
For Step D5, reference may be correspondingly made to the related descriptions in Embodiment 1, and the same or similar beneficial effects can be achieved. To avoid repetition, details are not described herein again.
Optionally, before Step D3, the method may further include: annealing the imprint template on which the second conductive pattern 104 has been formed. For an annealing manner, an annealing temperature, and the like in Embodiment 3, reference may be correspondingly made to the related descriptions in Embodiment 1, and the same or similar beneficial effects can be achieved. To avoid repetition, details are not described herein again.
Optionally, before the forming a first conductive pattern or a first conductive film layer on the solar cell body, the method may further include: forming a bonding pattern 311 or a bonding film layer 311 on the solar cell body. For a function, a material, a forming manner, and the like of the bonding pattern 311 or the bonding film layer 311, reference may be correspondingly made to the related descriptions in Embodiment 1, and the same or similar beneficial effects can be achieved. To avoid repetition, details are not described herein again.
Optionally, referring to
For a forming manner, a structure, and a size of the first groove 103, a material of the substrate, and the like, reference may be correspondingly made to the related descriptions in Embodiment 1, and the same or similar beneficial effects can be achieved. To avoid repetition, details are not described herein again.
Optionally, referring to
It should be noted that, for an advantage of not forming the second conductive pattern on the surface of the first boss 102 away from the substrate 101, a method of preparing the first boss 102, and the like, reference may be made to the related descriptions in Embodiment 1, and the same or similar beneficial effects can be achieved. To avoid repetition, details are not described herein again.
Optionally, referring to
Optionally, optionally, referring to
The second conductive film layer 104 herein may be a metal foil, and Step D2 may include: laying the metal foil on the side of the imprint template on which the second boss 202 is formed, where a part of the metal foil located on the second boss 202 is the second conductive pattern 104. A part of the metal foil located outside the second boss 202 is absorbed on the substrate 101. In this way, after the second conductive pattern 104 is aligned with the first conductive pattern 321 or the region on which the electrode is to be arranged in the first conductive film layer 321, it can be ensured that only the part of the metal foil located on the second boss 202 is closer to the first conductive pattern 321, the third conductive pattern can only be formed between the second conductive pattern 104 and the region on which the electrode is to be arranged in the first conductive film layer 321 through electroplating or chemical plating, and the third conductive pattern is substantially not formed on a remaining part of the imprint template through electroplating or chemical plating. In this way, the imprint template cannot be polluted, and a material used for electroplating or chemical plating can be reduced. For the descriptions herein, reference may be made to Embodiment 1. To avoid repetition, details are not described again.
Small burrs or the like may be provided on a surface of the second boss 202 away from the substrate 101. The small burrs or the like may hang the metal foil, so that the second conductive pattern is not prone to positional deviation or the like in the process of aligning the second conductive pattern with the first conductive pattern or the region on which the electrode is to be arranged in the first conductive film layer and forming the third conductive pattern through electroplating or chemical plating. A material of the metal foil herein is the same as or similar to the material of the second conductive pattern described above.
Optionally, referring to
Optionally, referring to
Optionally, the imprint template may include a substrate, and Step D2 may include: laying a metal foil on the substrate, and patterning the metal foil, to form the second conductive pattern. For laying of the metal foil, patterning of the metal foil, and the like, reference may be correspondingly made to the related descriptions in Embodiment 1, and the same or similar beneficial effects can be achieved. To avoid repetition, details are not described herein again.
Optionally, before Step D2, the method may further include: providing a plurality of metal foil patterns; the imprint template may include a plurality of adsorption regions; and Step D2 may include: at least aligning one of the adsorption regions with one of the metal foil patterns, and adsorbing the metal foil pattern on the adsorption region, to form the second conductive pattern on the imprint template. For providing of a metal foil, the aligning of the metal foil pattern, the absorption of the metal foil, and the like, reference may be correspondingly made to the related descriptions in Embodiment 1, and the same or similar beneficial effects can be achieved. To avoid repetition, details are not described herein again.
Optionally, the second conductive pattern 104 may also be a metal wire. Optionally, a surface of the metal wire may be further coated with a coating. For a shape and a size of the metal wire, a thickness and a material of the coating, an arrangement manner of the metal wire, and the like, reference may be correspondingly made to the related descriptions in Embodiment 1, and the same or similar beneficial effects can be achieved. To avoid repetition, details are not described herein again.
Only parts different from those of the solar cell and the method for preparing a solar cell provided in Embodiment 1 are described in Embodiment 6. For other same parts, reference may be made to the solar cell and the method for preparing a solar cell in Embodiment 1.
Embodiment 6 provides another solar cell. The solar cell includes a solar cell body, and a positive electrode and a negative electrode arranged on the solar cell body, where a structure of the positive electrode and a structure of the negative electrode may be the same or may be different. Referring to
For distribution of the grain size of the third conductive pattern, and the like, reference may be made to the related descriptions in Embodiment 5. Details are not described herein again.
Referring to
It should be noted that, a material of the second conductive pattern and the third conductive pattern can conduct electricity. The materials of the second conductive pattern and the third conductive pattern are not specifically limited. For example, the materials of the second conductive pattern and the third conductive pattern may include metals such as nickel and aluminum. For example, the material of the second conductive pattern may be singular nickel or a nickel alloy, or the material of the second conductive pattern may be aluminum.
In addition, compared with screen printing, the second conductive pattern and the third conductive pattern can conduct electricity, and are not limited to the silver paste. Therefore, costs can be appropriately reduced. In addition, compared with laser transfer printing, in the present disclosure, the second conductive pattern and the solar cell body are connected together through the third conductive pattern formed through electroplating or chemical plating. The electroplating or chemical plating process is mature, and process difficulty is relatively low, so that production efficiency can be appropriately improved.
Optionally, for a shape, a thickness, the material, a structure, and the like of the second conductive pattern, and a shape, a thickness, the material, a structure, and the like of the third conductive pattern in Embodiment 6, reference may be correspondingly made to the related descriptions in Embodiment 5, and the same or similar beneficial effects can be achieved. To avoid repetition, details are not described herein again.
Optionally, in a direction parallel to a lamination direction of the solar cell body and a first conductive pattern 321, the second conductive pattern 104 includes a seed layer pattern and a plating pattern that are laminated, where the plating pattern is closer to the solar cell body than the seed layer pattern is, and the plating pattern wraps the seed layer pattern. For the descriptions herein, reference may be correspondingly made to the related descriptions in Embodiment 1, and the same or similar beneficial effects can be achieved. To avoid repetition, details are not described herein again.
Embodiment 6 further provides a method for preparing a solar cell, which can be used to prepare the solar cell in Embodiment 2.
For Step E1, reference may be made to the related descriptions in Embodiment 5, and the same or similar beneficial effects can be achieved. To avoid repetition, details are not described herein again.
For the aligning in Step E2, reference may also be made to the related descriptions in Embodiment 5. To avoid repetition, details are not described herein again. In Step E2, the second conductive pattern is transferred to the solar cell body.
For Step E3, reference may be made to the related descriptions in Embodiment 5, and the same or similar beneficial effects can be achieved. To avoid repetition, details are not described herein again.
Optionally, before the electroplating or the chemical plating, the method may further include: annealing the imprint template on which the second conductive pattern has been formed, to cause the second conductive pattern to recrystallize, to eliminate a stress. For an annealing temperature, annealing time, an annealing manner, and the like, reference may be correspondingly made to the related descriptions in Embodiment 5, and the same or similar beneficial effects can be achieved. To avoid repetition, details are not described herein again.
Optionally, referring to
Optionally, referring to
Optionally, referring to
Optionally, referring to
Optionally, a surface of the second boss 202 away from the substrate 101 is a plane; or optionally, a side of the second boss 202 away from the substrate 101 includes a second groove 2021, where the second conductive pattern 104 is flush with a notch of the second groove 2021, or protrudes from the second groove 2021. For the descriptions herein, reference may be correspondingly made to the related descriptions in Embodiment 5, and the same or similar beneficial effects can be achieved. To avoid repetition, details are not described herein again.
Optionally, referring to
Optionally, the imprint template includes a substrate 101, and Step E1 may include: laying a metal foil on the substrate, and patterning the metal foil, to form the second conductive pattern. For the descriptions herein, reference may be correspondingly made to the related descriptions in Embodiment 5, and the same or similar beneficial effects can be achieved. To avoid repetition, details are not described herein again.
Optionally, before Step E1, the method may further include: providing a plurality of metal foil patterns; the imprint template may include a plurality of adsorption regions; and Step E1 may include: at least aligning one of the adsorption regions with one of the metal foil patterns, and adsorbing the metal foil pattern on the adsorption region, to form the second conductive pattern on the imprint template. For the descriptions herein, reference may be correspondingly made to the related descriptions in Embodiment 5, and the same or similar beneficial effects can be achieved. To avoid repetition, details are not described herein again.
The present disclosure is further described below with reference to a more detailed embodiment.
As shown in
In
Only parts different from those of the solar cell and the method for preparing a solar cell provided in Embodiment 1 are described in Embodiment 7. For other same parts, reference may be made to the solar cell and the method for preparing a solar cell in Embodiment 1.
Embodiment 7 provides a solar cell. Referring to
For a position of the electrode, the solar cell body, and the like, reference may be made to the related descriptions in Embodiment 1, and the same or similar beneficial effects can be achieved. To avoid repetition, details are not described herein again.
The first conductive pattern 321 and the second conductive pattern 104 are eutectically bonded together. The eutectic bonding process is simple and mature, and mass production is easy to be implemented. In addition, the eutectic bonding features a low bonding temperature and high bonding strength. The low bonding temperature can reduce a heat effect on the solar cell body, thereby having little effect on photoelectric conversion efficiency of the solar cell. The high bonding strength can make the electrode of the solar cell have good reliability. In addition, during the eutectic bonding, materials of the second conductive pattern 104 and the first conductive pattern 321 can be eutectically bonded, are not limited to a silver paste, and have more material selections; and compared with the silver paste, selecting copper, tin, or the like can appropriately reduce costs. In addition, the silver paste is granular, resulting in little contact between silver particles; and the silver paste includes an organic component, and the organic component also affects the contact between the silver particles. In this way, an electrode made of a silver paste has high resistivity and poor conductivity performance. However, in this embodiment of the present disclosure, a material of the electrode may not be granular (for example, a silver paste), and the material of the electrode may be, for example, silver, copper, tin, or an alloy thereof, so that the electrode has good conductivity performance. In addition, because the second conductive pattern 104 may not be prepared on the solar cell body, a process of preparing the second conductive pattern has little or substantially no effect on the solar cell body, and mass production is easy to be implemented. Therefore, preparation costs can be reduced.
It should be noted that, the materials of the first conductive pattern 321 and the second conductive pattern 104 may be materials that can be eutectically bonded, and the materials of the first conductive pattern 321 or the first conductive film layer 321 and the second conductive pattern 104 are not specifically limited. For example, the materials of the first conductive pattern 321 or the first conductive film layer 321 and the second conductive pattern 104 may be selected from materials whose temperatures during the eutectic bonding are less than or equal to 400° C., so that the heat effect of the eutectic bonding on the solar cell body can be reduced. For example, the materials of the first conductive pattern 321 or the first conductive film layer 321 and the second conductive pattern 104 may be selected from materials whose temperatures during the eutectic bonding are less than or equal to 200° C.
Optionally, the first conductive pattern 321 and the second conductive pattern 104 each may be made of a low-temperature conductive material, so that the heat effect of the eutectic bonding on the solar cell body can be reduced. For the materials of the first conductive pattern 321 and the second conductive pattern 104, reference may be made to the related descriptions in Embodiment 1, and the same or similar beneficial effects can be achieved. To avoid repetition, details are not described herein again.
Optionally, the materials of the first conductive pattern 321 or the first conductive film layer 321 and the second conductive pattern 104 may be selected from one of the following material pairs. If the first conductive pattern 321 or the first conductive film layer 321 is selected from one material in one of the following material pairs, the second conductive pattern 104 is selected from the other material in the one of the following material pairs. The material pairs may include: a material pair of copper (Cu) and copper (Cu), a material pair of copper (Cu) and tin (Sn), a material pair of gold (Au) and indium (In), and a material pair of gold (Au) and germanium (Ge). The material pairs are prone to eutectic bonding at a temperature less than or equal to 400° C., and in this case, the eutectic bonding is stronger. For example, the material pair of copper (Cu) and copper (Cu) can achieve good eutectic bonding at a temperature of 150° C. to 200° C. The material pair of copper (Cu) and tin (Sn) can achieve good eutectic bonding at a temperature of 231° C. The material pair of gold (Au) and indium (In) can achieve good eutectic bonding at a temperature of 156° C. The material pair of gold (Au) and germanium (Ge) can achieve good eutectic bonding at a temperature of 361° C.
Optionally, referring to
Optionally, a shape of a longitudinal section of the second conductive pattern 104 or a partial region of the second conductive pattern 104 away from the solar cell body is a triangle, a trapezoid, or a shape formed by an arc and a line segment connecting two endpoints of the arc, where a length of the line segment is less than or equal to a diameter of a circle corresponding to the arc; and the longitudinal section is parallel to a lamination direction of the first conductive pattern 321 and the second conductive pattern 104. For the longitudinal section herein, reference may be correspondingly made to the related descriptions in Embodiment 1, and the same or similar beneficial effects can be achieved. To avoid repetition, details are not described herein again.
Optionally, referring to
Optionally, the solar cell may further include a diffusion control pattern (not shown in the figure) located between the first conductive pattern 321 and the second conductive pattern 104, where the diffusion control pattern is used for controlling a thickness of an alloy formed in the eutectic bonding of the second conductive pattern 104 and the first conductive pattern 321, to obtain an ideal interface alloy region. Specifically, the diffusion control pattern located between the first conductive pattern 321 and the second conductive pattern 104 can slow down atomic diffusion speeds of both the first conductive pattern 321 and the second conductive pattern 104 during the eutectic bonding, so that a thickness of the alloy formed at various positions of a eutectic bonding interface is relatively uniform, and the thickness of the alloy formed during the eutectic bonding is not excessively thick, so that bonding force between the first conductive pattern 321 and the second conductive pattern 104 can be improved. In addition, the diffusion control pattern located between the first conductive pattern 321 and the second conductive pattern 104 can also improve infiltration of the first conductive pattern 321 and infiltration of the second conductive pattern 104, so that fewer bubbles are formed during bonding of the first conductive pattern 321 and the second conductive pattern 104, and the first conductive pattern 321 and the second conductive pattern 104 are bonded more tightly, thereby further improving the bonding force between the first conductive pattern 321 and the second conductive pattern 104. In addition, the diffusion control pattern located between the first conductive pattern 321 and the second conductive pattern 104 can also prevent the atomic diffusion speeds of both the first conductive pattern 321 and the second conductive pattern 104 to a certain extent when the solar cell is heated or cooled after the eutectic bonding, to prevent the alloy from continuously thickening. A material of the diffusion control pattern is not specifically limited. For example, the material of the diffusion control pattern may be graphene, and may be single-layer graphene or multi-layer graphene. A shape of the diffusion control pattern may be the same as or similar to the shapes of the first conductive pattern 321 and the second conductive pattern 104.
Optionally, for the materials, shapes, thicknesses, structures, and the like of the first conductive pattern 321 and the second conductive pattern in Embodiment 7, reference may be correspondingly made to the related descriptions in Embodiment 1, and the same or similar beneficial effects can be achieved. To avoid repetition, details are not described herein again.
Optionally, referring to
Optionally, a material of the second conductive sub-pattern 1041 farthest away from the first conductive pattern 321 in the second conductive pattern 104 may include tin. For an advantage, a component, and the like of tin herein, reference may be correspondingly made to the related descriptions in Embodiment 1, and the same or similar beneficial effects can be achieved. To avoid repetition, details are not described herein again.
Optionally, in a direction parallel to a lamination direction of the solar cell body and a first conductive pattern 321, the second conductive pattern 104 includes a seed layer pattern and a plating pattern that are laminated, where the plating pattern is closer to the solar cell body than the seed layer pattern is, and the plating pattern wraps the seed layer pattern. For the descriptions herein, reference may be correspondingly made to the related descriptions in Embodiment 1, and the same or similar beneficial effects can be achieved. To avoid repetition, details are not described herein again.
Embodiment 7 further provides a method for preparing a solar cell, which can be used to prepare the solar cell in Embodiment 1.
For Step F1, reference may be correspondingly made to the related descriptions in Embodiment 1, and the same or similar beneficial effects can be achieved. To avoid repetition, details are not described herein again.
Optionally, the forming a first conductive pattern or a first conductive film layer on a solar cell body may include: laying a metal foil on the solar cell body, to form the first conductive film layer. For the part, reference may be correspondingly made to the related descriptions in Embodiment 1, and the same or similar beneficial effects can be achieved. To avoid repetition, details are not described herein again.
Optionally, after the laying a metal foil on the solar cell body, the method may include: pressing the metal foil, to bond the metal foil to the solar cell body. For the part, reference may be correspondingly made to the related descriptions in Embodiment 1, and the same or similar beneficial effects can be achieved. To avoid repetition, details are not described herein again.
For Step F2, reference may be correspondingly made to the related descriptions in Embodiment 1, and the same or similar beneficial effects can be achieved. To avoid repetition, details are not described herein again.
For that a second conductive pattern 104 is aligned with the first conductive part, reference may be correspondingly made to the related descriptions in Embodiment 1, and the same or similar beneficial effects can be achieved. To avoid repetition, details are not described herein again.
After the first conductive pattern 321 is aligned with the second conductive pattern 104, the second conductive pattern 104 and the first conductive pattern 321 are eutectically bonded together, so that eutectic bonding transfer of the second conductive pattern 104 located on the imprint template to the first conductive film layer 321 or the first conductive pattern 321 on the solar cell body is implemented. Compared with laser transfer printing, in the present disclosure, the second conductive pattern and the first conductive pattern can be eutectically bonded together, or the second conductive pattern and the region on which the electrode is to be formed in the first conductive film layer can be eutectically bonded together. The eutectic bonding process is mature, and process difficulty is relatively low, so that production efficiency can be appropriately improved. Compared with electroplating, in the present disclosure, the second conductive pattern and the first conductive pattern can be eutectically bonded together, or the second conductive pattern and the region on which the electrode is to be formed in the first conductive film layer can be eutectically bonded together. In this way, there is no process problem such as winding plating for the solar cell body, the yield and the reliability are good, and mass production is easy to be implemented.
Referring to
For Step F4, reference may be correspondingly made to the related descriptions in Embodiment 1, and the same or similar beneficial effects can be achieved. To avoid repetition, details are not described herein again.
The eutectic bonding transfer of the second conductive pattern 104 located on the imprint template to the first conductive film layer 321 or the first conductive pattern 321 on the solar cell body is implemented, so that the electrode of the solar cell is substantially formed. Then, the imprint template is removed. The imprint template may be removed by using mechanical external force or the like. The manner of removing the imprint template is not specifically limited in the embodiments of the present disclosure. Removing the imprint template mainly relies on that bonding force between the second conductive pattern 104 and the imprint template is less than eutectic bonding force between the second conductive pattern 104 and the first conductive film layer 321 or the first conductive pattern 321, to remove the imprint template. Optionally, a coating or the like for making the second conductive pattern 104 easy to be separated from the imprint template may be coated between the imprint template and the second conductive pattern 104, thereby further facilitating removing the imprint template. For example, tin or a tin alloy is provided between the imprint template and the second conductive pattern 104. Tin or the tin alloy has a low melting point, so that the imprint template can be easily removed.
For Step F5, reference may be correspondingly made to the related descriptions in Embodiment 1, and the same or similar beneficial effects can be achieved. To avoid repetition, details are not described herein again.
Optionally, before Step F3, the method may further include: annealing the imprint template on which the second conductive pattern 104 has been formed. For an annealing manner, an annealing temperature, and the like in Embodiment 3, reference may be correspondingly made to the related descriptions in Embodiment 1, and the same or similar beneficial effects can be achieved. To avoid repetition, details are not described herein again.
Optionally, before the eutectic bonding, the method may further include: forming a diffusion control pattern on the first conductive pattern or the region on which the electrode is to be formed in the first conductive film layer; and/or forming a diffusion control pattern on the second conductive pattern, where the diffusion control pattern is used for controlling a thickness of an alloy formed in the eutectic bonding of the second conductive pattern and the first conductive pattern, to obtain an ideal eutectically-bonded alloy region. For a material, a structure, and the like of the diffusion control pattern, reference may be made to the foregoing descriptions, and the same or similar beneficial effects can be achieved. To avoid repetition, details are not described herein again. A manner of forming the diffusion control pattern may be deposition, coating, or the like.
Optionally, before the forming a first conductive pattern or a first conductive film layer on the solar cell body, the method may further include: forming a bonding pattern or a bonding film layer on the solar cell body. For a function, a material, a forming manner, and the like of the bonding pattern or the bonding film layer, reference may be correspondingly made to the related descriptions in Embodiment 1, and the same or similar beneficial effects can be achieved. To avoid repetition, details are not described herein again.
Optionally, referring to
Optionally, referring to
It should be noted that, the second conductive pattern is not formed on the surface of the first boss 102 away from the substrate 101, so that a waste can be reduced, and a current loss can be reduced. More specifically, if the second conductive pattern is formed on the surface of the first boss 102 away from the substrate 101, a projection of the part of the second conductive pattern on a surface of the substrate 101 close to the first boss 102 does not coincide with a projection of the second conductive pattern located in the first groove 103 and in the region defined by the first boss 102 on the surface of the substrate 101 close to the first boss 102, and carriers collected on the part need to be transported in a direction parallel to the width of the notch of the first groove 103 to be exported. A transport path of the carriers is long, resulting in a specific current loss. Therefore, in some examples, the second conductive pattern is not formed on the surface of the first boss 102 away from the substrate 101. In this way, a current loss can be reduced, and a waste of the material of the second conductive pattern can be reduced. An implementation in which the second conductive pattern is not formed on the surface of the first boss 102 away from the substrate 101 may be as follows: In a process of depositing the second conductive pattern, the second conductive pattern is also deposited on the surface of the first boss 102 away from the substrate 101, then a mask is arranged, the mask is patterned, and the second conductive pattern formed on the surface of the first boss 102 away from the substrate 101 is removed through wet etching. Alternatively, in a process of depositing the second conductive pattern, the second conductive pattern is also deposited on the surface of the first boss 102 away from the substrate 101, and the second conductive pattern formed on the surface of the first boss 102 away from the substrate 101 is removed through laser etching. Alternatively, the region defined by two sides of the first boss 102 is configured as a conductive surface, and the surface of the first boss 102 away from the substrate 101 is configured as a non-conductive surface. In a specific implementation, a conductive substance may be selected as a part of the first boss 102 close to the substrate 101. Then, a non-conductive substance is arranged on the part of the first boss 102 close to the substrate 101 through deposition, coating, or the like. Then, the non-conductive substance in the region defined by the two sides of the first boss 102 is etched, so that the region defined by the two sides of the first boss 102 is a conductive surface, and the surface of the first boss 102 away from the substrate 101 is a non-conductive surface. During electroplating, the second conductive pattern can be electroplated on the region defined by the two sides of the first boss 102, which is a conductive surface and serves as a cathode, and the second conductive pattern cannot be electroplated on the surface of the first boss 102 away from the substrate 101.
It should be noted that, the first boss 102 and the substrate 101 may be integrally formed, or the first boss 102 and the substrate 101 are separately manufactured; and then the first boss 102 and the substrate 101 are fixedly connected together by using an adhesive layer or the like. This is not specifically limited in the embodiments.
Optionally, referring to
Optionally, referring to
Optionally, referring to
The second conductive film layer 104 herein may be a metal foil, and Step F2 may include: laying the metal foil on the side of the imprint template on which the second boss 202 is formed, where a part of the metal foil located on the second boss 202 is the second conductive pattern 104. A part of the metal foil located outside the second boss 202 may be adsorbed on the substrate 101 through lamination, or the like, to avoid displacement of the metal foil. For the descriptions herein, reference may also be made to the related descriptions in Embodiment 1, and the same or similar beneficial effects can be achieved. To avoid repetition, details are not described herein again.
For fixing between the second boss 202 and the metal foil, and the like, reference may be made to the related descriptions in Embodiment 1, and the same or similar beneficial effects can be achieved. To avoid repetition, details are not described herein again.
Optionally, referring to
Optionally, the imprint template may include a substrate, and Step F2 may include: laying a metal foil on the substrate, and patterning the metal foil, to form the second conductive pattern. For the descriptions herein, reference may also be made to the related descriptions in Embodiment 1, and the same or similar beneficial effects can be achieved. To avoid repetition, details are not described herein again.
Optionally, before Step F2, the method may further include: providing a plurality of metal foil patterns; the imprint template may include a plurality of adsorption regions; and Step F2 may include: at least aligning one of the adsorption regions with one of the metal foil patterns, and adsorbing the metal foil pattern on the adsorption region, to form the second conductive pattern on the imprint template. For the descriptions herein, reference may also be made to the related descriptions in Embodiment 1, and the same or similar beneficial effects can be achieved. To avoid repetition, details are not described herein again.
Optionally, the second conductive pattern 104 may also be a metal wire. Optionally, a surface of the metal wire may be further coated with a coating 1045. For the descriptions herein, reference may also be made to the related descriptions in Embodiment 1, and the same or similar beneficial effects can be achieved. To avoid repetition, details are not described herein again.
It should be noted that, if an entire metal foil is laid on the solar cell body, due to a high eutectic bonding temperature during eutectic bonding, the metal foil may be partially damaged at a eutectic bonding boundary, and the like. Therefore, after the eutectic bonding, a manner of removing the metal foil outside the region of the electrode may include: blowing the part away by airflow, sticking the part away by using a viscous material, or the like. This is not specifically limited in the embodiments.
Only parts different from those of the solar cell and the method for preparing a solar cell provided in Embodiment 1 are described in Embodiment 8. For other same parts, reference may be made to the solar cell and the method for preparing a solar cell in Embodiment 1.
Embodiment 8 provides another solar cell. The solar cell includes a solar cell body, and a positive electrode and a negative electrode arranged on the solar cell body, where a structure of the positive electrode and a structure of the negative electrode may be the same or may be different. An electrode (for the electrode, reference may be made to the descriptions in Embodiment 1, and details are not described herein again) of the solar cell includes a second conductive pattern laminated on the solar cell body, where the second conductive pattern is eutectically bonded to the solar cell body.
For the solar cell body, reference is made to the related descriptions in Embodiment 1. To avoid repetition, details are not described herein again. For example, the solar cell body herein may be a silicon substrate. If a passivation layer or the like is further arranged on the solar cell body, the passivation layer may be grooved, so that the silicon substrate is exposed.
The second conductive pattern is eutectically bonded to the solar cell body. For the beneficial effects of the eutectic bonding process, reference may be made to Embodiment 1 or 7, and details are not described herein again.
It should be noted that, the material of the second conductive pattern may be a material that can be eutectically bonded to the solar cell body. The material of the second conductive pattern is not specifically limited. For example, the material of the second conductive pattern may include nickel, aluminum, or gold. For example, the material of the second conductive pattern may be singular nickel or a nickel alloy, or the material of the second conductive pattern may be aluminum, or the material of the second conductive pattern may be gold. The material of the second conductive pattern can be eutectically bonded to the solar cell body at a temperature of about 800° C. to 900° C. or lower. The eutectic bonding process is simple and mature, and mass production is easy to be implemented. In addition, the bonding temperature of about 800° C. to 900° C. or lower can reduce the heat effect on the solar cell body. The high bonding strength of the eutectic bonding can make the electrode of the solar cell have good reliability. For example, the material of the second conductive pattern may be gold, and good eutectic bonding can be achieved between gold and silicon in the solar cell body at a temperature of 370° C.
Optionally, for a shape, a thickness, the structure, and the like of the second conductive pattern in Embodiment 8, reference may be correspondingly made to the related descriptions in Embodiment 1, and the same or similar beneficial effects can be achieved. To avoid repetition, details are not described herein again.
Optionally, the solar cell may further include a diffusion control pattern located between the second conductive pattern and the solar cell body, where the diffusion control pattern is used for controlling a thickness of an alloy formed in the eutectic bonding of the second conductive pattern and the solar cell body, to obtain an ideal interface alloy region, and avoid a possible effect on the solar cell body during the eutectic bonding. For a material, a structure, and the like of the diffusion control pattern, reference may be made to the related descriptions in Embodiment 7, and the same or similar beneficial effects can be achieved. To avoid repetition, details are not described herein again.
Optionally, in a direction parallel to a lamination direction of the solar cell body and a first conductive pattern 321, the second conductive pattern 104 includes a seed layer pattern and a plating pattern that are laminated, where the plating pattern is closer to the solar cell body than the seed layer pattern is, and the plating pattern wraps the seed layer pattern. For the descriptions herein, reference may be correspondingly made to the related descriptions in Embodiment 1, and the same or similar beneficial effects can be achieved. To avoid repetition, details are not described herein again.
Embodiment 8 further provides a method for preparing a solar cell, which can be used to prepare the solar cell in Embodiment 8.
For Step G1, reference may be made to the related descriptions in Embodiment 7, and the same or similar beneficial effects can be achieved. To avoid repetition, details are not described herein again.
For the aligning in Step G2, reference may also be made to the related descriptions in Embodiment 7. To avoid repetition, details are not described herein again. In Step G2, the second conductive pattern is transferred to the solar cell body.
For Step G3, reference may be made to the related descriptions in Embodiment 7, and the same or similar beneficial effects can be achieved. To avoid repetition, details are not described herein again.
Optionally, before the eutectic bonding, the method may further include: annealing the imprint template on which the second conductive pattern has been formed, to cause the second conductive pattern to recrystallize, to eliminate a stress. For an annealing temperature, annealing time, an annealing manner, and the like, reference may be correspondingly made to the related descriptions in Embodiment 7, and the same or similar beneficial effects can be achieved. To avoid repetition, details are not described herein again.
Optionally, before the eutectic bonding, the method may further include: forming a diffusion control pattern on the second conductive pattern; and/or forming a diffusion control pattern on the region on which the electrode is to be formed in the solar cell body, where the diffusion control pattern is used for controlling a thickness of an alloy formed in the eutectic bonding of the second conductive pattern and the region on which the electrode is to be formed in the solar cell body, to obtain an ideal eutectically-bonded alloy region. For a material, a structure, a forming manner, and the like of the diffusion control pattern, reference may be correspondingly made to the related descriptions in Embodiment 7, and the same or similar beneficial effects can be achieved. To avoid repetition, details are not described herein again.
Optionally, referring to
Optionally, referring to
Optionally, referring to
Optionally, referring to
Optionally, a surface of the second boss 202 away from the substrate 101 is a plane; or optionally, a side of the second boss 202 away from the substrate 101 includes a second groove 2021, where the second conductive pattern 104 is flush with a notch of the second groove 2021, or protrudes from the second groove 2021. For the descriptions herein, reference may be correspondingly made to the related descriptions in Embodiment 7, and the same or similar beneficial effects can be achieved. To avoid repetition, details are not described herein again.
Optionally, referring to
Optionally, the imprint template includes a substrate 101, and Step G1 may include: laying a metal foil on the substrate, and patterning the metal foil, to form the second conductive pattern. For the descriptions herein, reference may be correspondingly made to the related descriptions in Embodiment 7, and the same or similar beneficial effects can be achieved. To avoid repetition, details are not described herein again.
Optionally, before Step G1, the method may further include: providing a plurality of metal foil patterns; the imprint template may include a plurality of adsorption regions; and Step G1 may include: at least aligning one of the adsorption regions with one of the metal foil patterns, and adsorbing the metal foil pattern on the adsorption region, to form the second conductive pattern on the imprint template. For the descriptions herein, reference may be correspondingly made to the related descriptions in Embodiment 7, and the same or similar beneficial effects can be achieved. To avoid repetition, details are not described herein again.
Optionally, referring to
Optionally, referring to
Optionally, Step G1 may include: forming at least two aluminum conductive sub-patterns laminated on the imprint template. In the process of aligning the second conductive pattern 104 with the region on which the electrode is to be formed in the solar cell body, an aluminum conductive sub-pattern located on a side of the second conductive pattern 104 away from the imprint template is in direct contact with the silicon substrate 305. Therefore, in the process in which the part of aluminum in the second conductive pattern 104 made of aluminum diffuses into the silicon substrate 305, the aluminum conductive sub-pattern located on the side of the second conductive pattern 104 away from the imprint template preferentially diffuses into the silicon substrate 305. Under a specific eutectic bonding heat, a remaining aluminum conductive sub-pattern may partially diffuse into the silicon substrate 305 or may not diffuse into the silicon substrate 305. In other words, during the diffusion, the aluminum conductive sub-pattern located on the side of the second conductive pattern 104 away from the imprint template is equivalent to appropriately protecting the remaining aluminum conductive sub-pattern, so that the remaining aluminum conductive sub-pattern has little diffusion, so that a shape of the remaining aluminum conductive sub-pattern has little deformation. The remaining aluminum conductive sub-pattern is used as the electrode, which can ensure precision of the formed electrode.
For example, referring to
The present disclosure is further described below with reference to a more detailed embodiment.
As shown in
In
It should be noted that, in Embodiment 1 to Embodiment 8, for a solar cell, a method for preparing a solar cell, and a solar cell module in a same embodiment and between embodiments, reference may be made to each other, and the same or similar beneficial effects can be achieved.
It should be noted that, for ease of description, the method embodiments are stated as a combination of a series of actions. However, a person skilled in the art is to know that the embodiments of this application are not limited to the described action sequence, because according to this embodiment of this application, some steps may be performed in another sequence or simultaneously. In addition, a person skilled in the art is also to learn that the embodiments described in this specification are all exemplary embodiments, and the actions involved are not necessarily required by the embodiments of this application.
It should be noted that, the term “include”, “comprise”, or any other variation thereof in this specification is intended to cover a non-exclusive inclusion, which specifies the presence of stated processes, methods, objects, or apparatuses, but does not preclude the presence or addition of one or more other processes, methods, objects, or apparatuses. Without more limitations, elements defined by the sentence “including one . . . ” does not exclude that there are still other same elements in the processes, methods, objects, or apparatuses. In the present disclosure, the term “or” is used to refer to a nonexclusive or, such that “A or B” includes “A but not B,” “B but not A,” and “A and B,” unless otherwise indicated.
The embodiments of the present disclosure are described above with reference to the accompanying drawings. However, the present disclosure is not limited to the foregoing specific implementations. The foregoing specific implementations are illustrative instead of limitative. Enlightened by the present disclosure, a person of ordinary skill in the art can make many forms without departing from the idea of the present disclosure and the scope of protection of the claims. All of the forms fall within the protection of the present disclosure.
The foregoing described apparatus embodiments are merely examples. The units described as separate parts may or may not be physically separate, and the parts displayed as units may or may not be physical units, may be located in one position, or may be distributed on a plurality of network units. Some or all of the modules may be selected according to actual needs to achieve the objectives of the solutions of the embodiments. A person of ordinary skill in the art may understand and implement the method without any creative effort.
“One embodiment”, “Embodiment”, or “one or more embodiments” mentioned in this specification mean that particular features, structures, or characteristics described with reference to the embodiments may be included in at least one embodiment of this application. In addition, the word example of “in an embodiment” herein does not necessarily all refer to a same embodiment.
In this specification provided herein, numerous specific details are described. However, it may be understood that, the embodiments of this application may be practiced without these specific details. In some instances, well-known methods, structures, and technologies are not shown in detail, so that understanding of this specification is not obscured.
Finally, it should be noted that, the foregoing embodiments are merely used for describing the technical solutions of this application, but are not intended to limit this application. Although this application is described in detail with reference to the foregoing embodiments, it should be understood that a person of ordinary skill in the art may still make modifications to the technical solutions described in the foregoing embodiments or make equivalent replacements to some technical features thereof, without departing from the spirit and scope of the technical solutions of the embodiments of this application.
In this specification provided herein, numerous specific details are described. However, it may be understood that, the embodiments of this application may be practiced without these specific details. In some instances, well-known methods, structures, and technologies are not shown in detail, so that understanding of this specification is not obscured.
| Number | Date | Country | Kind |
|---|---|---|---|
| 202210795202.4 | Jul 2022 | CN | national |
| 202210795204.3 | Jul 2022 | CN | national |
| 202210795205.8 | Jul 2022 | CN | national |
| 202210796261.3 | Jul 2022 | CN | national |
This application is a continuation-in-part of International Application No. PCT/CN2023/106350, filed on Jul. 7, 2023, which claims priority to Chinese Patent Application Nos. 202210796261.3, 202210795204.3, 202210795205.8 and 202210795202.4, all filed on Jul. 7, 2022. The disclosures of the aforementioned applications are hereby incorporated by reference in their entireties.
| Number | Date | Country | |
|---|---|---|---|
| Parent | PCT/CN2023/106350 | Jul 2023 | WO |
| Child | 19010659 | US |
