Solar cell and preparation method thereof, photovoltaic module, tracing method and system

Abstract

The invention provides a solar cell and a preparation method thereof, a photovoltaic module, and a tracing method and system, which can be applied to the technical field of semiconductors. The solar cell comprises at least one group of graphical marks, each group of graphical marks comprises a plurality of graphical sub-marks, the graphical marks have first features, the first features are used for distinguishing the plurality of graphical sub-marks, and different graphical sub-marks represent that the solar cell has different first production information; each graphical sub-mark has at least one second feature, each second feature represents a piece of second production information, and different values of the same second feature represent that the corresponding second production information is different.

Description

Technical Field

[0001] This disclosure relates to the photovoltaic field, specifically to a solar cell and its preparation method, a photovoltaic module, a traceability method and system. Background Technology

[0002] In the production of solar cells, accurate traceability of the production information for each cell is crucial for quality control, process optimization, and anomaly analysis. However, existing solutions mainly rely on batch management or simple surface marking, which cannot accurately trace the production information of each solar cell. Summary of the Invention

[0003] In view of the above problems, this disclosure provides solar cells and their preparation methods, photovoltaic modules, traceability methods and systems.

[0004] According to a first aspect of this disclosure, a solar cell is provided, the solar cell having at least one set of graphic markings, each set of graphic markings including a plurality of graphic sub-markers, the graphic markings having a first feature for distinguishing the plurality of graphic sub-markers, different graphic sub-markers representing different first production information of the solar cell; each graphic sub-marker having at least one second feature, each second feature representing a second production information, different values ​​of the same second feature representing different corresponding second production information; wherein the second feature is different from the first feature.

[0005] According to embodiments of this disclosure, the first feature includes at least one of the following: the arrangement direction of the plurality of graphic sub-markers; the spacing setting mode between adjacent graphic sub-markers; and the positional distribution of the plurality of graphic sub-markers on the surface of the solar cell.

[0006] According to embodiments of this disclosure, the first production information indicates the type of process the solar cell has undergone; and / or, the second production information indicates at least one of the following when the solar cell performs the process: machine used, production time, material batch number, and process version.

[0007] According to an embodiment of this disclosure, when there are multiple graphic markers, each of the multiple graphic markers includes at least one third feature. Different values ​​of the same third feature indicate that the solar cell has different third production information. The third feature is different from both the first feature and the second feature.

[0008] According to embodiments of this disclosure, the third production information indicates the process group through which the solar cell has undergone.

[0009] According to an embodiment of this disclosure, the solar cell includes multiple busbar structures, and the multiple graphic sub-markers are respectively disposed between two adjacent busbar structures.

[0010] According to embodiments of this disclosure, the second feature includes at least one of shape and size; and / or, the third feature includes at least one of color, shape, position, and height.

[0011] According to embodiments of this disclosure, the graphical marker is at least one of the first production information, the second production information, and the third production information extracted by a designated device.

[0012] According to embodiments of this disclosure, the graphical sub-marker may be linear, square, irregular, curved, elliptical, or polygonal.

[0013] According to embodiments of this disclosure, the solar cell also has visually visible markings;

[0014] The visually visible marker is set in a designated area, which is an area associated with the semiconductor junction type of the solar cell. The visually visible marker is used to determine the semiconductor junction type corresponding to the currently located designated area.

[0015] According to embodiments of this disclosure, the visually visible marker includes at least one of the graphical markers or at least one of the graphical sub-markers.

[0016] According to embodiments of this disclosure, the projection of the visually visible mark on the surface of the solar cell overlaps with or is completely separated from the projection portion of any of the graphic marks or any of the graphic sub-marks.

[0017] A second aspect of this disclosure provides a method for manufacturing a solar cell, the method comprising: whenever a process is completed in the solar cell, acquiring first production information and second production information associated with the process; in response to detecting that the current process is a predefined node process, forming the first production information and second production information associated with the target process on the solar cell in the form of graphical markers, obtaining at least one set of graphical markers, wherein the target process includes all processes between adjacent node processes; wherein each set of graphical markers includes multiple graphical sub-markers, the graphical markers having a first feature, the first feature being used to distinguish the multiple graphical sub-markers, different graphical sub-markers representing different first production information of the solar cell; each graphical sub-marker having at least one second feature, each second feature representing a second production information, different values ​​of the same second feature representing different corresponding second production information; the second feature being different from the first feature.

[0018] According to an embodiment of this disclosure, the method further includes: storing the first production information and the second production information in a flower basket chip, the flower basket chip being disposed on a flower basket loaded with the solar cell.

[0019] According to an embodiment of this disclosure, the process includes grid line printing, and the method further includes: printing a visually visible mark in a designated area before the grid line printing, the designated area being an area associated with the semiconductor junction type of the solar cell, the visually visible mark being used to determine the semiconductor junction type corresponding to the currently located designated area.

[0020] A third aspect of this disclosure provides a photovoltaic module comprising a solar cell according to the first aspect and an encapsulation layer covering the surface of the solar cell.

[0021] A fourth aspect of this disclosure provides a method for tracing production information of a solar cell, applied to a solar cell as described in the first aspect. The method includes: acquiring an optical image of at least one set of graphic markings formed on the surface of a target solar cell; parsing the optical image to identify a first feature commonly presented by multiple graphic sub-markers in each set of graphic markings, and determining first production information corresponding to the solar cell based on a pre-stored mapping relationship between the first feature and first production information; parsing the optical image to measure the value of at least one second feature possessed by each graphic sub-marker, and determining at least one second production information corresponding to the solar cell based on a pre-stored mapping relationship between the second feature value and second production information; wherein the first feature and the second feature are different.

[0022] According to an embodiment of this disclosure, the method further includes: when multiple graphic marks are present on the surface of the solar cell, identifying at least one third feature commonly presented by the multiple graphic marks; determining the third production information corresponding to the solar cell based on a pre-stored third feature-third production information mapping relationship; wherein the third feature is different from both the first feature and the second feature.

[0023] According to embodiments of this disclosure, the method further includes: associating the first production information and the second production information with the electrical performance data of the solar cell.

[0024] The fifth aspect of this disclosure provides a traceability system for solar cell production information, used to implement the traceability method described in the fourth aspect. The system includes: an image acquisition module configured to image the surface of a target solar cell to obtain an optical image of at least one set of graphic markings; an image processing and decoding module communicatively connected to the image acquisition module, configured to: analyze the optical image, identify a first feature commonly presented by multiple graphic sub-markers in each set of graphic markings, and determine corresponding first production information according to a pre-stored mapping relationship between the first feature and first production information; and analyze the optical image, measure the value of at least one second feature possessed by each graphic sub-marker, and determine corresponding at least one second production information according to a pre-stored mapping relationship between the second feature value and second production information; and a data fusion and storage module communicatively connected to the image processing and decoding module, configured to encapsulate and store the decoded first and second production information. Attached Figure Description

[0025] The foregoing contents, as well as other objects, features, and advantages of this disclosure, will become clearer from the following description of embodiments with reference to the accompanying drawings, in which:

[0026] Figure 1 A schematic diagram of a solar cell according to an embodiment of the present disclosure is shown.

[0027] Figure 2 A schematic diagram illustrating the structure of another solar cell according to an embodiment of the present disclosure is shown.

[0028] Figure 3 A schematic diagram illustrating graphical sub-markers between bus structures according to embodiments of the present disclosure is shown.

[0029] Figure 4 A schematic diagram illustrating visually visible markings on a solar cell according to an embodiment of the present disclosure is shown.

[0030] Figure 5 A flowchart illustrating a method for fabricating a solar cell according to an embodiment of the present disclosure is shown schematically.

[0031] Figure 6 A graphical representation of the symbol transformation relationship according to an embodiment of the present disclosure is illustrated schematically;

[0032] Figure 7 A schematic diagram illustrating the process flow according to an embodiment of the present disclosure is shown.

[0033] Figure 8 This illustration schematically shows a diagram of graphic symbolization based on flower basket information according to an embodiment of the present disclosure;

[0034] Figure 9A flowchart illustrating a method for tracing solar cell production information according to an embodiment of the present disclosure is shown schematically.

[0035] Figure 10 A block diagram of a traceability system for solar cell production information according to an embodiment of the present disclosure is shown schematically.

[0036] Figure 11 An RFID recording rule diagram according to an embodiment of the present disclosure is illustrated schematically;

[0037] Figure 12 A schematic diagram of a solar cell coding scheme according to an embodiment of the present disclosure is shown.

[0038] Figure 13 A schematic diagram of a solar cell with visually visible markings and a flower basket according to an embodiment of the present disclosure is shown.

[0039] Figure 14 A partial schematic diagram of a solar cell with visually visible markings according to an embodiment of the present disclosure is shown schematically.

[0040] Figure 15 The illustration shows a schematic diagram of a solar cell with visually visible markings according to an embodiment of the present disclosure before screen printing. Detailed Implementation

[0041] The embodiments of the present disclosure will now be described with reference to the accompanying drawings. However, it should be understood that these descriptions are exemplary only and are not intended to limit the scope of the disclosure. In the following detailed description, numerous specific details are set forth to provide a thorough understanding of the embodiments of the present disclosure for ease of explanation. However, it will be apparent that one or more embodiments may be practiced without these specific details. Furthermore, descriptions of well-known structures and techniques are omitted in the following description to avoid unnecessarily obscuring the concepts of the present disclosure.

[0042] The terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit this disclosure. The terms “comprising,” “including,” etc., as used herein indicate the presence of the stated features, steps, operations, and / or components, but do not exclude the presence or addition of one or more other features, steps, operations, or components.

[0043] All terms used herein (including technical and scientific terms) have the meanings commonly understood by those skilled in the art, unless otherwise defined. It should be noted that the terms used herein are to be interpreted in a manner consistent with the context of this specification, and not in an idealized or overly rigid way.

[0044] When using expressions such as "at least one of A, B and C", they should generally be interpreted in accordance with the meaning that is commonly understood by those skilled in the art (e.g., "a system having at least one of A, B and C" should include, but is not limited to, a system having A alone, a system having B alone, a system having C alone, a system having A and B, a system having A and C, a system having B and C, and / or a system having A, B and C, etc.).

[0045] Figure 1 A schematic diagram of a solar cell according to an embodiment of the present disclosure is shown.

[0046] like Figure 1 As shown, the solar cell according to this embodiment has at least one set of graphic markers A. Each set of graphic markers A may include multiple graphic sub-markers. Graphic marker A may have a first feature, which is used to distinguish multiple graphic sub-markers. Different graphic sub-markers represent that the solar cell has different first production information. Each graphic sub-marker has at least one second feature, and each second feature represents a second production information. Different values ​​of the same second feature represent different corresponding second production information. The second feature is different from the first feature.

[0047] According to embodiments of this disclosure, the graphic mark A and the graphic sub-mark can be blind marks. A blind mark is a mark that is not intended to be directly and easily identified and interpreted by the human eye, but can be detected and read with the aid of specific tools, detection equipment, or algorithms. By using blind mark solar cells, it is possible to achieve concealed storage of information without affecting the product's appearance and performance, for example, for anti-counterfeiting, traceability, and precision production management.

[0048] According to embodiments of this disclosure, the graphic mark A and the graphic sub-mark can be fabricated in non-functional areas of the battery without affecting the photoelectric conversion efficiency. For example, they can be located on the back of the battery, in non-main grid areas on the front of the battery, or at the edge of the battery. For instance, the non-main grid area on the front of the battery can be... Figure 2 The diagram shows the dividing area Q between the main grids, the area between the outermost main grid and the edge of the battery, etc.

[0049] According to embodiments of this disclosure, graphic marker A can refer to a set of markers as a single information unit. A solar cell may have one or more such sets of markers to distinguish different information modules. For example, one set of graphic marker A is used to trace the diffusion process, and another set of graphic marker A is used to trace the coating process.

[0050] According to embodiments of this disclosure, graphical sub-markers can be the basic units constituting each group of graphical marks A. These graphical sub-markers can be specific, discrete physical structures arranged according to certain rules. For example, a complete graphical mark A can be an array composed of multiple points, lines, or basic geometric shapes.

[0051] According to embodiments of this disclosure, the first feature may refer to a macroscopic or holistic geometric attribute within the entire graphical mark A, used to establish differences among multiple graphical sub-markers, thereby carrying different information. When the first features exhibited by the graphical sub-markers are different, the first production information they represent is also different. This establishes a mapping relationship between feature differences and information differences.

[0052] According to embodiments of this disclosure, the second feature can refer to the microscopic geometric or physical properties possessed by each independent graphical sub-tag that can be used to encode information. Different values ​​of the same second feature can refer to specific parameter differences of the same type of second feature. When the values ​​of the same second feature are different, it can characterize the corresponding second production information as different, thereby establishing a mapping relationship between changes in a single feature parameter and changes in a single information item.

[0053] According to embodiments of this disclosure, the difference between the second feature and the first feature can refer to the fact that the physical dimensions upon which the first and second features depend are different. For example, the first feature is the spacing pattern between graphical sub-tags, and the second feature is the shape of a single graphical sub-tag. This ensures that information can be read and parsed hierarchically and independently, avoiding mutual interference and greatly increasing the capacity and flexibility of information encoding.

[0054] According to embodiments of this application, by setting a graphical marker A with hierarchical features such as a first feature and a second feature, production information can be directly and permanently stored on the battery, enabling high-capacity, high-reliability cell-level traceability. The first feature is used for macroscopic differentiation among groups of graphical sub-markers, carrying higher-level production information; the second feature is used for microscopic encoding on individual graphical sub-markers, carrying more specific production parameters. The difference in the dimensions of the two features ensures that the information encoding does not interfere with each other, making it easy to detect and parse, and providing an effective technical means for the refined production and full life cycle management of solar cells.

[0055] The first feature and the first production information are illustrated below. Those skilled in the art should understand that these embodiments are merely examples and are not intended to limit the scope of protection of this application.

[0056] According to embodiments of this disclosure, the first feature may include the arrangement direction of a plurality of patterned sub-markers. The arrangement direction may refer to the angular characteristics exhibited by the main axis or overall orientation of the entire array composed of the plurality of patterned sub-markers. This direction may be defined relative to a fixed reference frame (such as the edge of a solar cell, the main grid line, or the crystal orientation of crystalline silicon).

[0057] For example, the arrangement direction of multiple graphical sub-markers can be angular encoding relative to the battery edge, angular encoding relative to the main grid line, equal spacing pattern, arithmetic sequence spacing pattern, and non-periodic pattern based on a specific function, etc.

[0058] According to embodiments of this disclosure, the first production information can represent the process category that the solar cell has undergone. When a specific type of defect or performance problem occurs in the solar cell, the faulty process category can be located through the first production information, enabling traceability at the production line level. For example, the process category may include texturing, diffusion, etching, coating, screen printing, and sintering.

[0059] In one example, the orientation of multiple graphical sub-tags can be angularly encoded relative to the edge of the cell. A set of graphical sub-tags is arranged in a virtual straight line. The angle θ between this line and the bottom edge of the solar cell defines its orientation. Different angles θ map to different initial production information.

[0060] For example, when θ=0°, it indicates that the battery has undergone a texturing process; when θ=45°, it indicates that the battery has undergone a diffusion process; when θ=90°, it indicates that the battery has undergone a passivation coating process.

[0061] In some implementations, after capturing the first feature using detection equipment such as an optical camera, the angle of the straight line can be quickly detected using a simple image processing algorithm (such as Hough transform), thereby decoding the corresponding process information.

[0062] In one example, the arrangement direction of multiple patterned sub-markers can be angularly encoded relative to the main grid lines. In a cell with a bus structure, the reference frame can be selected as the main grid lines of the solar cell. The arrangement direction of the patterned sub-markers can be parallel to, perpendicular to, or at a specific angle to the main grid lines.

[0063] For example, an arrangement parallel to the main grid lines can characterize the coating process on the front side, while an arrangement perpendicular to the main grid lines can characterize the coating process on the back side.

[0064] In one example, the arrangement direction of multiple graphical sub-tags can be a curve or the direction of a complex pattern. The arrangement direction is not limited to a straight line, but can also extend to the overall direction of a curve or complex pattern.

[0065] For example, sub-markers can be arranged along an arc or a wavy line. The location of the center of curvature of the arc or the direction of propagation of the wavy line can serve as distinguishing directional features.

[0066] According to embodiments of this disclosure, the first feature may include a spacing setting pattern between adjacent graphical sub-markers. The spacing setting pattern may refer to the rule governing the variation of the distance between the center points of adjacent graphical sub-markers.

[0067] In one example, the spacing between adjacent patterned sub-markers can be set to an equal spacing mode. The spacing between all adjacent sub-markers remains constant. Different fixed spacing values ​​can represent different initial production information; for example, when P=50μm, it indicates that the battery has undergone an alkaline texturing process. When P=100μm, it indicates that the battery has undergone an acid etching process. When P=150μm, it indicates that the battery has undergone a PSG (phosphosilicate glass) removal process.

[0068] In one example, the spacing pattern between adjacent graphical sub-markers can be an arithmetic progression spacing pattern. The spacing between sub-markers follows an arithmetic progression. For example, the spacing between the first and second sub-markers is P, the spacing between the second and third is P+d, the spacing between the third and fourth is P+2d, and so on. The value of the tolerance d, or the initial spacing P, can be used to encode information. For example, when the tolerance d is positive (increasing spacing), it indicates that the cell has undergone a front-side atomic layer deposition (ALD) coating process. When the tolerance d is negative (decreasing spacing), it indicates that the cell has undergone a back-side ALD coating process. When the tolerance d = 0 (degenerates to equal spacing), it indicates that the cell has undergone a physical vapor deposition (PVD) coating process.

[0069] In one example, the spacing between adjacent graphical sub-markers can be a binary-encoded density pattern. A dense spacing is defined as binary "1", and a sparse spacing as binary "0". A binary number can be directly encoded using a sequence of alternating dense and sparse spacing. For example, the sequence "dense, sparse, dense, dense" can represent the binary number "1011", which corresponds to the laser grooving process.

[0070] In one example, the spacing pattern between adjacent graphical sub-markers can be an aperiodic pattern based on a specific function. The spacing can vary according to a predefined mathematical function, such as the Fibonacci sequence or a sequence of prime numbers. This complex pattern offers enhanced anti-counterfeiting features and can be used to differentiate between different customers or product lines.

[0071] According to embodiments of this disclosure, the first feature may include the positional distribution of multiple patterned sub-markers on the surface of the solar cell. The positional distribution may refer to the macroscopic area occupied by the entire patterned mark A on the solar cell surface; for example, the relative relationship between the center position or coverage area of ​​patterned mark A and a specific functional area of ​​the cell.

[0072] In one example, the distribution of multiple graphical sub-markers on the surface of the solar cell can be relative to the center of the cell. Graphical mark A can be set in different preset areas on the surface of the solar cell.

[0073] For example, when the marker cluster is distributed across the non-main grid area on the front (light-receiving) side of the cell, it indicates that the cell has undergone a front anti-reflection coating deposition process. When multiple patterned sub-markers are distributed across the back side of the cell, it indicates that the cell has undergone a back passivation film deposition process. When multiple patterned sub-markers are distributed across the chamfered edge area of ​​the cell, it indicates that the cell has undergone an edge isolation process.

[0074] In one example, the distribution of multiple graphical sub-markers on the surface of a solar cell can be relative to the functional structure. The position of graphical mark A can be defined relative to the cell's main grid. This distribution associates the mark positions with the cell's electrical structure, providing an additional dimension of information.

[0075] For example, if multiple patterned sub-markers are located in the area between the two outermost main grids, it indicates that the battery has undergone the main grid printing process. When multiple patterned sub-markers span across the main grid lines and the areas on both sides, it indicates that the battery has undergone overall testing and sorting processes.

[0076] According to embodiments of this disclosure, by establishing a clear mapping relationship between the specific forms of the three first features—arrangement direction, spacing setting mode, and position distribution—and the process categories that the solar cell undergoes, process information can be encoded using the macroscopic geometric properties of the graphics, thereby achieving efficient and accurate production traceability.

[0077] The second feature and the second production information are illustrated below. Those skilled in the art should understand that these embodiments are merely examples and are not intended to limit the scope of protection of this application.

[0078] According to embodiments of this disclosure, the second feature may include at least one of shape and size.

[0079] Shape can refer to the geometric outline of a graphical representation on a plane. Examples include basic geometric shapes, directional shapes, and anisotropic shapes.

[0080] For example, basic geometric shapes can be circles, squares, triangles, ellipses, crosses, etc. Different shapes can be directly mapped to different discrete states.

[0081] For example, directional shapes can be rectangles, isosceles triangles, or other shapes with obvious directionality, and the direction of their major axis or vertex angle can also be used as a variable in the encoding.

[0082] For example, irregular shapes can be specifically designed to represent more complex codes or serve as anti-counterfeiting features.

[0083] Size can refer to a macroscopic physical measure of a graphical sub-tag. For example, linear size, area, and size variation patterns.

[0084] For example, a linear dimension can be the diameter of a circular sub-marker, the side length of a square sub-marker, or the line width or length of a linear sub-marker.

[0085] For example, the area can be the projected area of ​​the sub-mark on the plane.

[0086] For example, the pattern of size change can be a continuously changing gradient, such as increasing linearly from one end to the other, or it can be multiple discrete, quantifiable levels.

[0087] According to embodiments of this disclosure, the second production information may represent at least one of the following: the machine used in the solar cell implementation process, the production time, the material batch number, and the process version.

[0088] The term "machine" can refer to the identification of production equipment that performs a specific process, such as diffusion furnace number, PECVD (plasma-enhanced chemical vapor deposition) equipment cavity number, laser sintering machine ID, etc.

[0089] Production time can refer to the precise point in time or time period during which the process is performed, accurate to the second-level timestamp, or expressed as a shift.

[0090] Material batch number can refer to the batch code of the main raw materials or auxiliary materials used in this process, such as silicon wafer batch number, front silver paste LotNumber, silicon nitride target batch number, etc.

[0091] Process version can refer to the version number of a specific process formula used in a particular process, such as the version of the diffusion temperature profile, the formula version of the etching solution concentration, the design version of the film thickness, etc.

[0092] According to embodiments of this application, the second feature of each patterned sub-marker can be used to encode second production information, i.e., the specific parameters used when performing the process. In a battery with a busbar structure, the reference frame can be selected as the main grid line of the solar cell. The shape, size, and other second features of the patterned sub-marker can be used to characterize the machine used, production time, material batch number, and process version.

[0093] For example, the second feature is shape, used to represent the machine used. When a process is completed, the shape of the graphical sub-marker can be mapped to the specific machine number used. For example, a circular sub-marker can represent that the process is completed by machine number 1, while a square sub-marker can represent that the process is completed by machine number 2. If there are more machines, other shapes such as triangles or ellipses can be used for differentiation.

[0094] For example, the second feature is size, used to characterize the machine used. When completing a process, the size of the graphical sub-marker can be mapped to the specific machine number used. For example, a rectangular sub-marker with a linewidth of 10 μm can characterize that the process was completed in diffusion furnace number 1, while a rectangular sub-marker with a linewidth of 15 μm can characterize that the process was completed in diffusion furnace number 2.

[0095] For example, the second feature is size, used to characterize production time. Upon completion of a process, the size of the graphical sub-marker can be mapped to production time information. For instance, in a laser etching process, the depth of the sub-marker can be used to encode the hour information of production. A depth of 5 μm can characterize the production time as the 5th working hour of the day, while a depth of 8 μm can characterize the production time as the 8th working hour of the day.

[0096] For example, the second feature is shape, used to characterize the material batch number. Upon completion of the process, the shape of the graphical sub-marker can be mapped to the material batch number used. For instance, in a PECVD process, a circular sub-marker can indicate that silane gas from supplier A is used, while a square sub-marker can indicate that silane gas from supplier B is used.

[0097] For example, the second feature is size, used to characterize the process version. Upon completion of a process step, the size of the graphical sub-marker can be mapped to a specific process formulation version. For instance, in the sintering process, the diameter of the sub-marker can be used to encode the process version. A diameter of 20 μm indicates that a standard sintering process curve is being used, while a diameter of 25 μm indicates that an optimized high-temperature rapid sintering process curve is being used.

[0098] According to embodiments of this disclosure, by establishing a clear mapping relationship between the second features such as the shape and size of the graphical sub-marker and the second production information such as the machine used during the implementation of the process, the production time, the material batch number, and the process version, it is possible to achieve refined and piece-level traceability of key parameters in the production process.

[0099] Figure 3 A schematic diagram of graphical sub-markers between bus structures according to embodiments of the present disclosure is shown.

[0100] like Figure 3As shown, in this embodiment, multiple patterned sub-markers can be individually disposed between two adjacent busbar structures. This ensures that the patterning process does not damage the busbar structure, thereby guaranteeing the conductivity and reliability of the solar cell.

[0101] Multiple graphical sub-markers are set one by one between two adjacent busbars, which can be done by linear array distribution, staggered array distribution, or composite distribution combined with sub-gates.

[0102] For example, multiple patterned sub-markers, each positioned between two adjacent busbars, can be arranged in a linear array. The surface of the solar cell has multiple parallel busbars. In the region between two adjacent busbars (i.e., the grid gap region), a series of patterned sub-markers are positioned. These patterned sub-markers can be arranged in a straight line within each gap region, and the direction of this line can be parallel to the busbar. In this case, the arrangement direction of the patterned sub-markers (first feature) is parallel to the direction of the main grid. The spacing pattern (first feature) of the sub-markers can be the same or different in different gap regions to encode different information.

[0103] For example, multiple graphical sub-markers, each positioned between two adjacent busbars, can be arranged in a staggered array. In the region between adjacent busbars, the graphical sub-markers are arranged in a staggered manner. For instance, in the first gap region, the sub-markers are arranged in a straight line; in the second gap region, the sub-markers are arranged in another straight line, offset horizontally from the first line by a certain distance.

[0104] This staggered positional distribution (the first feature) can serve as a basis for distinguishing different marker groups. For example, all odd-numbered gap regions use one staggered phase, while all even-numbered gap regions use another staggered phase.

[0105] For example, multiple patterned sub-markers, each positioned between two adjacent busbars, can be arranged in a composite distribution combined with sub-grids. Fine grid lines intersecting perpendicularly to the busbars also exist on the battery surface. Patterned sub-markers can be positioned within a tiny grid enclosed by adjacent busbars and adjacent fine grid lines. In this case, the precise positional distribution (first feature) of the patterned sub-markers can be defined by their grid coordinates. For example, a sub-marker located between the second and third main grids from the left, and between the fifth and sixth fine grids from the bottom, can have its position itself carrying encoded information.

[0106] According to the embodiments of this application, by limiting the graphical sub-marks between adjacent bus structures, it not only perfectly integrates into the existing structure of the battery and avoids negative impacts on its electrical performance, but also utilizes the regular areas naturally formed by the bus structures to provide great convenience and flexibility for the arrangement of marks, the encoding and decoding of information.

[0107] According to an embodiment of this disclosure, when there are multiple graphic markers A, each of the multiple graphic markers A includes at least one third feature. Different values ​​of the same third feature indicate that the solar cell has different third production information, and the third feature is different from both the first feature and the second feature.

[0108] The third characteristic can refer to the overall physical or chemical properties that distinguish these groups of marks from each other when multiple independent graphic marks A are present on the battery surface. For example, the third characteristic includes at least one of color, shape, location, and height.

[0109] Third production information can refer to production data that is at a higher level or in a different dimension than the first and second production information, characterized by a third feature. For example, third production information represents the process group that a solar cell has undergone.

[0110] In one example, the third feature could be the overall color of multiple graphic markers A. For instance, graphic marker A in blue indicates that the third production information is process group A, such as a pretreatment stage including texturing, diffusion, and etching. Graphic marker A in red indicates that the third production information is process group B, such as a functionalization stage including coating, printing, and sintering.

[0111] In this embodiment, the operator can quickly perform initial sorting of the battery's production stage based solely on color (the third feature). Then, the operator further reads the first and second features under the specific color markings to obtain more detailed process and machine information.

[0112] In one example, the third feature can be the overall outline shape of multiple graphic markers A. Different graphic markers A can be made to form different geometric shapes by controlling the laser scanning path or the photolithographic mask pattern. This can be used for rapid identification and sorting of multiple products in co-production, avoiding product confusion.

[0113] For example, a graphic marker A has a circular shape, indicating that the third production information is from a PERC battery production line. Another marker has a square shape, indicating that the third production information is from a TOPCon battery production line.

[0114] In one example, the third feature could be the relative positional arrangement of multiple graphical markers A on the battery surface. For instance, a marker appearing only in the top left corner indicates the third production information is at the standard efficiency level. A marker appearing in both the top left and bottom right corners indicates the third production information is at the high efficiency level. A marker appearing in all four corners indicates the third production information is a customer-customized version.

[0115] In one example, the third feature could be the height of a graphical marker A relative to the battery surface. For example, a marker indicating a deep pit (e.g., depth > 5 μm) represents the third production information that the battery was produced in factory one. A marker indicating a shallow pit (e.g., depth < 2 μm) represents the third production information that the battery was produced in factory two.

[0116] The above graphical marker A and graphical sub-markers can be blind marks, requiring the use of specific tools, detection equipment, or algorithms to read at least one of the first, second, and third production information. The following combines... Figure 4 The present invention will illustrate the visually visible mark B on the solar cell of an embodiment of the present disclosure. The visually visible mark B refers to a mark that can be directly observed and distinguished by the operator's normal vision without the need for specific tools or testing equipment.

[0117] Figure 4 A schematic diagram of a visually visible marking on a solar cell according to an embodiment of the present disclosure is shown.

[0118] like Figure 4 As shown, the solar cell in this embodiment also has visually visible markings. These markings can be achieved through screen printing of characters or symbols, laser marking to create visible scratches or discolored areas, inkjet printing, etc.

[0119] For example, the visually visible mark B can be a specific color, symbol, barcode, or a surface discoloration area caused by laser.

[0120] A visually visible mark B is placed in a designated area. This designated area is associated with the semiconductor junction type of the solar cell. The semiconductor junction type can refer to the polarity of the PN junction. Accordingly, the associated area can refer to the N-type semiconductor region (N-region) or the P-type semiconductor region (P-region) of the PN junction. The visually visible mark B is intentionally and selectively placed on one of these two polarity regions as a clear visual indicator.

[0121] For example, a mark can be made on the top edge of a solar cell using a laser. This top edge is the designated area. The operational specification is defined as follows: when the mark is located on the top edge, this edge is an N-type surface (or corresponds to the front electrode printing area). Conversely, if there is no mark or the mark is on the bottom edge of the other side, it corresponds to a P-type surface.

[0122] For example, the four corners of a solar cell can be numbered A, B, C, and D using corner markings. The rule is: when the visually visible mark B appears at corner A, it indicates a PNP structure cell; when it appears at corner B, it indicates an NPN structure cell. In this case, the corner region where the mark is located is the designated area, and its position is associated with the junction type.

[0123] For example, the markings are not necessarily only at the very edge, but the position of the markings relative to the edge is fixed. For example, the definition rule is: if the visual marking is within 10mm of the top edge of the battery, it means that the front silver paste needs to be printed on that edge; if it is within 10mm of the bottom edge of the battery, it means that the back silver paste needs to be printed on that edge.

[0124] According to embodiments of this disclosure, the graphical marker A used for fine-grained traceability and the visually visible marker B used for rapid orientation identification can also be physically combined into one entity.

[0125] The visually visible mark B can itself be at least one graphic mark A. Through process control, such as laser enhancement and subsequent cleaning of the graphic mark A in a two-stage process, the graphic mark A, which may have been subtle, becomes clearly visible to the naked eye on the final product.

[0126] For example, a set of square dot matrixes (graphical marker A) consisting of multiple sub-markers used to encode machine information can also be used as a visually visible marker B indicating direction, due to its sufficiently large size or strong contrast. In this case, the marker has both precise traceability and rapid identification functions.

[0127] The visually visible marker B can itself be at least one graphical sub-marker. For example, in a complex coded array consisting of dozens of tiny graphical sub-markers, one or more key sub-markers, such as those located at the four corners, can be made larger, darker, or made more prominent by filling them with ink. These enhanced sub-markers serve as the visually visible marker B for orientation identification, while the entire array is used for information tracing.

[0128] According to embodiments of this disclosure, when the visually visible mark B is not at least one graphic mark A or at least one graphic sub-mark, the visually visible mark B and the graphic mark A used for traceability can also have various spatial relationships. For example, the projection of the visually visible mark B onto the surface of the solar cell may overlap with or be completely separated from the projection of any graphic mark A or any graphic sub-mark.

[0129] In one example, the projection of the visually visible mark B onto the solar cell surface overlaps with the projection of any graphic mark A or any graphic sub-mark. This saves valuable space on the cell surface and is suitable for high-efficiency cell designs with extremely low dead area requirements.

[0130] For example, a screen-printed solid circle for orientation identification (visually visible mark B) has a printed area that precisely covers a laser-etched micro-dot matrix for traceability (graphical mark A). The operator sees the circle, while the detection equipment can "see through" the ink and read the laser dot matrix underneath using penetrating infrared light or a special imaging angle.

[0131] For example, the visually visible mark B is a triangular silkscreen pattern, and the central area of ​​the triangle is precisely the distribution area of ​​a set of graphic sub-markers.

[0132] In one example, the projection of the visually visible marker B onto the solar cell surface is completely separate from the projections of any graphic marker A or any graphic sub-marker. The visually visible marker B facilitates quick location, while the graphic marker A focuses on information storage. The visually visible marker B (such as a large circle for orientation identification) and the graphic marker A for traceability (such as a tiny QR code for encoding information) are located in two non-overlapping areas on the cell surface. Functional zoning is clear and they do not interfere with each other.

[0133] Figure 5 A flowchart illustrating a method for fabricating a solar cell according to an embodiment of the present disclosure is shown schematically.

[0134] like Figure 5 As shown, the method for fabricating a solar cell in this embodiment includes operations S510 to S520.

[0135] In operation S510, whenever a solar cell completes a process, first production information and second production information associated with the process are acquired.

[0136] According to embodiments of this disclosure, the process can be performed in real time at the exit of each process equipment (such as diffusion furnace, PECVD, laser equipment, etc.) on the production line. Data is automatically captured by the equipment's own sensors and manufacturing execution system (MES).

[0137] In operation S520, in response to detecting that the current process is a predefined node process, the first production information and the second production information associated with the target process are formed on the solar cell in the form of graphical markers A, to obtain at least one set of graphical markers A. The target process includes all processes between adjacent node processes.

[0138] Each group of graphic markers A includes multiple graphic sub-markers. Graphic marker A has a first feature, which is used to distinguish multiple graphic sub-markers. Different graphic sub-markers represent that the solar cells have different first production information. Each graphic sub-marker has at least one second feature, and each second feature represents a second production information. Different values ​​of the same second feature represent different corresponding second production information. The second feature is different from the first feature.

[0139] According to embodiments of this disclosure, a node process can refer to a process after the manufacturing process that is suitable for physical marking and poses no risk to battery performance.

[0140] According to embodiments of this disclosure, a target process can refer to the set of all processes experienced from the previous node process to the current node process. For example, if node processes are patterning one and patterning two, the target process may include all cleaning, coating, and other processes between patterning one and patterning two.

[0141] According to embodiments of this disclosure, the graphic mark A can be formed by printing a blind mark. Specifically, a laser of a specific wavelength is used to perform micron-level etching on a specific area of ​​the battery (such as a non-functional area on the back surface) to form a graphic mark A that is difficult to observe directly with the naked eye but can be identified by a dedicated automated optical inspection device.

[0142] According to an embodiment of this disclosure, the method further includes: storing first production information and second production information in a flower basket chip, the flower basket chip being disposed on a flower basket loaded with solar cells.

[0143] In one specific implementation, whenever a solar cell completes a process, its production information is not only prepared for subsequent graphical marker A, but also written into the basket chip (i.e., RFID chip) of the basket containing that cell via an RFID reader. The basket chip acts as a mobile database, recording the complete path information (i.e., all process codes, machine numbers, entry and exit times, etc.) experienced by all solar cells within the basket. In subsequent testing and sorting processes, the graphical marker A on the solar cell is identified by automatic optical detection on the back, while the testing machine reads the corresponding detailed process data from the basket chip. Finally, the abbreviation represented by the graphical marker A is associated with the detailed process data in the basket chip and stored together in the final test data file, achieving precise traceability.

[0144] According to embodiments of this disclosure, precise traceability at the wafer level for cleanroom processes is achieved through a dual data link of graphical marker A and basket chip, solving the challenges of traditional labeling in cleanroom environments. Graphical marker A avoids marking critical functional areas of the battery, ensuring that the battery's electrical performance remains unaffected. The batch marking strategy for node processes, compared to marking each process individually, improves production efficiency and reduces the impact of laser processing on production line cycle time. The basket chip, acting as auxiliary storage, carries a massive amount of process parameters and cross-verifies with the simple graphical marker A on the solar cell, forming a complete data closed loop.

[0145] Figure 6 A graphical representation of the symbol transformation relationship according to an embodiment of the present disclosure is illustrated schematically.

[0146] like Figure 6 As shown, the position represents the spatial coordinates of the graphical marker A in a certain direction. For example, it could be a long strip of area reserved on a solar cell, which is divided into 9 (or more) specific positions, each of which can be set between grid lines.

[0147] A process can represent the various steps in a production flow (process 1 through process 9). Each process generates data that needs to be recorded.

[0148] Numerical values ​​can represent the characteristic values ​​obtained after transforming the production information corresponding to each process. In this example, the characteristic values ​​are quantized as integers from 1 to 9.

[0149] According to embodiments of this disclosure, the value of a process can be plotted in space with its corresponding position as the x-axis and the value itself as the y-axis (or height), forming a marker point. For example, if the value of process 1 is 1, then a marker with a height (or Y-coordinate) of 1 is formed at position 1. If the value of process 2 is 3, then a marker with a height of 3 is formed at position 2. And so on, ultimately the data of all 9 processes together constitute a graphical sequence with 9 marker points of different heights.

[0150] Figure 7 A process flow diagram according to an embodiment of the present disclosure is illustrated schematically. Figure 8 The illustration shows a schematic diagram of graphic symbolization based on flower basket information according to an embodiment of the present disclosure.

[0151] like Figure 7 and 8As shown, the first process group includes processes 1, 2, and 3. The node process is process 4. Process 4 itself is a production step and is also defined as the first marker trigger node. The second process group includes processes 5, 6, and 7. The node process is process 8, which is the second marker trigger node. The third process group includes process 9.

[0152] When a silicon wafer flows through a predefined node process (such as process 4 or process 8), a special mark, namely graphical mark A, is applied. This graphical mark A locates or represents not only the information of the current node process itself, but also the set of information of all processes preceding it in the process group. Specifically, the graphical mark A applied in process 4 encapsulates the production information of processes 1 / 2 / 3. The graphical mark A applied in process 8 encapsulates the production information of processes 5 / 6 / 7.

[0153] In the final testing process, special markings from previous processes can be captured. By reading the two graphical markings A formed on the solar cell in processes 4 and 8, the complete production history from process 1 to process 7 can be obtained. Combined with the information from process 9, full-process traceability can be achieved.

[0154] Figure 9 A flowchart illustrating a method for tracing solar cell production information according to an embodiment of this disclosure is shown schematically.

[0155] like Figure 9 As shown, the method for tracing solar cell production information in this embodiment includes operations S910 to S920.

[0156] In operation S910, an optical image of at least one set of graphic markings formed on the surface of the target solar cell is acquired.

[0157] According to embodiments of this disclosure, optical images can be acquired at offline inspection stations or online key nodes where battery production information needs to be obtained.

[0158] For example, in the final testing and sorting stage (EL / IV testing), before or simultaneously with the final electrical performance testing and sorting of solar cells after all manufacturing processes are completed, high-resolution images containing complete graphic marking areas are captured using industrial cameras or dedicated automated optical inspection equipment. This allows for the linking of final performance data (efficiency, power, etc.) with production process information, enabling in-depth analysis of key process factors affecting performance.

[0159] For example, in the quality sampling inspection stage after key processes. After critical processes such as diffusion, coating, and sintering, sampling inspection stations can be set up to acquire and decode images of solar cells leaving this process. This allows for real-time monitoring of the process stability and equipment status, enabling rapid problem localization, such as identifying latent defects in solar cells produced by specific machines within a specific time period.

[0160] For example, in the analysis of customer complaints or quality incidents. When a component supplier or end customer reports a quality issue, the battery cells can be disassembled from the problematic component, and images of the battery cells themselves can be directly obtained. This allows for reverse tracing to accurately pinpoint the production batch, machine used, process parameters, and even the operating team of the problematic battery cell, providing raw data for root cause analysis.

[0161] In operation S920, the optical image is analyzed, the first feature presented by multiple graphic sub-markers in each group of graphic marks is identified, and the first production information corresponding to the solar cell is determined according to the pre-stored mapping relationship between the first feature and the first production information.

[0162] According to embodiments of this disclosure, identifying the first feature may refer to extracting the macroscopic geometric properties of the graphical markers through an algorithm. For example, calculating the direction angle of the fitted line for all graphical sub-markers as the first feature, or analyzing the spatial distribution pattern of the sub-markers.

[0163] According to embodiments of this disclosure, the pre-stored mapping relationship can refer to a decoding table stored in a local or cloud database. For example, looking up the table reveals that a direction angle of 0 degrees corresponds to the first production information: the texturing process; and a direction angle of 45 degrees corresponds to the diffusion process.

[0164] In operation S930, the optical image is analyzed, the value of at least one second feature of each patterned sub-marker is measured, and at least one second production information corresponding to the solar cell is determined according to the pre-stored mapping relationship between the second feature value and the second production information.

[0165] According to embodiments of this disclosure, measuring the value of the second feature may refer to a quantitative analysis of the microscopic geometric parameters of each individual sub-marker. For example, precisely measuring the line width, diameter, or area of ​​each sub-marker.

[0166] According to embodiments of this disclosure, the pre-stored mapping relationship can be another set of decoding tables. For example, by looking up the table, it is found that a line width of 10μm corresponds to the second production information: machine A; and a line width of 12μm corresponds to machine B.

[0167] According to embodiments of this disclosure, the first feature is different from the second feature, which can ensure that macroscopic information and microscopic information do not interfere with each other during decoding and can be extracted in parallel or sequentially independently.

[0168] According to embodiments of this disclosure, when multiple graphic marks exist on the surface of a solar cell, at least one third feature commonly presented by the multiple graphic marks can be identified; based on a pre-stored mapping relationship between the third feature and third production information, the third production information corresponding to the solar cell can be determined; wherein the third feature is different from both the first feature and the second feature.

[0169] In one scenario, multiple graphic markings could represent a solar cell undergoing several independent, recordable critical process stages, with each stage marking a set of graphic markings at different locations on the cell or at different times within the same location. For example, the first set of markings might be formed after the "texturing-diffusion" stage, and the second set after the "coating-laser" stage.

[0170] According to embodiments of this disclosure, the third feature is the abstraction of the global relationships between multiple graphical tags. Its identification does not rely on the details of graphical sub-tags within a single graphical tag, but rather focuses on the attributes exhibited by the multiple graphical tags as a whole.

[0171] For example, relative positional layout characteristics. Identify the distribution pattern of multiple marker groups on the surface of the solar cell, such as an L-shaped arrangement, a diagonal arrangement, etc.

[0172] For example, the topological relationship characteristics between groups. Analyze the spatial relationships between different marker groups, such as azimuth angles and distance ratios.

[0173] For example, global visual attributes. Under specific imaging conditions, such as different wavelength light sources, different groups of markers may exhibit different overall colors or average grayscale differences.

[0174] According to embodiments of this disclosure, the third production information mapped by the third feature can represent a more macroscopic and generalized level than the first and second production information. For example, it could be a production line or factory identifier, a product series or technology route identifier, a production batch or customer code, etc.

[0175] According to embodiments of this disclosure, first production information and second production information can be associated with the electrical performance data of solar cells.

[0176] According to embodiments of this disclosure, electrical performance data can refer to a set of core parameters characterizing the photoelectric conversion capability and quality of a solar cell, obtained through standard testing methods. Examples include current-voltage characteristic data such as photoelectric conversion efficiency, open-circuit voltage, short-circuit current, maximum power point power, and fill factor; spectral response data; parallel and series resistance; electroluminescence or photoluminescence image analysis data, etc.

[0177] According to embodiments of this disclosure, when an abnormal efficiency distribution is detected in a batch of cells, inefficient solar cells can be quickly identified through associated data records, and their specific production path can be directly traced back. For example, it can be discovered that they all originated from cells produced on a specific machine after a certain maintenance cycle, or that they all used a specific batch of paste. This significantly shortens the problem-solving time. When customers report that the module's power degradation is too rapid, the cells in the module can be disassembled, their graphical markings read, production information traced, and compared with the historical average degradation data of that cell model. This provides strong objective evidence for determining responsibility.

[0178] Figure 10 A block diagram of a traceability system for solar cell production information according to an embodiment of the present disclosure is shown schematically.

[0179] like Figure 10 As shown, the traceability system for solar cell production information in this embodiment can be integrated into the automated optical inspection station in the testing and sorting section of the production line. This automated optical inspection station can be equipped with a dedicated image acquisition lens, a light source, and a processing unit that runs the traceability method disclosed herein. The traceability system may include an image acquisition module 1010, an image acquisition module 1020, and a data fusion and storage module 1030.

[0180] The image acquisition module 1010 is configured to image the surface of a target solar cell to obtain an optical image of at least one set of graphic markings. In one embodiment, the image acquisition module 1010 may be used to perform the operation S910 described above, which will not be repeated here.

[0181] The image processing and decoding module 1020, which is communicatively connected to the image acquisition module, is configured to: analyze the optical image, identify the first feature commonly presented by multiple graphic sub-markers in each group of graphic marks, and determine the corresponding first production information according to the pre-stored mapping relationship between the first feature and the first production information; and analyze the optical image, measure the value of at least one second feature possessed by each graphic sub-marker, and determine the corresponding at least one second production information according to the pre-stored mapping relationship between the second feature value and the second production information. In one embodiment, the image processing and decoding module 1020 can be used to perform the operation S920 described above, which will not be repeated here.

[0182] The data fusion and storage module 1030 is communicatively connected to the image processing and decoding module, and is configured to encapsulate and store the decoded first production information and second production information. In one embodiment, the data fusion and storage module 1030 can be used to perform the operation S930 described above, which will not be repeated here.

[0183] Understandably, any details not covered above can be found in this disclosure. Figures 1-5The method for tracing solar cell production information provided by this disclosure is illustrated in the description of the embodiments shown, and will not be repeated here.

[0184] According to embodiments of this application, any plurality of modules in the image acquisition module 1010, image acquisition module 1020, and data fusion and storage module 1030 can be combined into one module, or any one of these modules can be split into multiple modules. Alternatively, at least part of the functionality of one or more of these modules can be combined with at least part of the functionality of other modules and implemented in one module. According to embodiments of this application, at least one of the image acquisition module 1010, image acquisition module 1020, and data fusion and storage module 1030 can be at least partially implemented as hardware circuitry, such as a field-programmable gate array (FPGA), a programmable logic array (PLA), a system-on-a-chip, a system-on-a-substrate, a system-on-package, an application-specific integrated circuit (ASIC), or implemented in hardware or firmware by any other reasonable means of integrating or packaging the circuitry, or implemented in software, hardware, or firmware, or in any suitable combination of any of these three implementation methods. Alternatively, at least one of the image acquisition module 1010, image acquisition module 1020, and data fusion and storage module 1030 may be at least partially implemented as a computer program module, which can perform corresponding functions when the computer program module is run.

[0185] Figure 11 An RFID recording rule diagram according to an embodiment of the present disclosure is illustrated schematically. Figure 12 A schematic diagram of a solar cell coding scheme according to an embodiment of the present disclosure is shown.

[0186] like Figure 11-12 As shown, in the testing and sorting stage, the traceability method of this embodiment can automatically read and decode the graphic mark A through an integrated automatic optical inspection device, thereby achieving accurate traceability of production information.

[0187] In specific areas of a solar cell (such as the back surface), graphic markings are implemented using marking lines of a specific shape. This marking line system employs multi-dimensional features for composite encoding:

[0188] Color Feature: Under specific spectral imaging by automated optical inspection equipment, the marker lines exhibit two distinguishable types, defined as blue and black. This color feature serves as the primary feature, used to differentiate different dimensions or streams of information.

[0189] Location feature: The marker lines are located within a specific grid divided by the main grid on the back surface of the solar cell. The cell surface is predefined horizontally into 17 discrete coded locations (01 to 17 from left to right). This location feature serves as another first or third feature to identify the category or affiliation of the information.

[0190] Length feature: The physical length of the marking line is quantified into four standard sizes: 1mm, 2mm, 3mm, and 4mm. This length feature serves as a secondary feature to characterize specific data values.

[0191] An automated optical inspection device images the solar cell and performs the following steps:

[0192] Feature recognition: Identify all marker lines in the image that meet the shape requirements, and record their color, precise center position (mapped to one of 17 preset encoding positions), and quantized length value respectively.

[0193] Information pairing: On the same solar cell, the identified information can be grouped and paired by color. Specifically, the following two sets of data can be identified and recorded simultaneously: Blue marker line information: position code, length value; Black marker line information: position code, length value. If a marker line of a certain color is not identified, its corresponding data is recorded as 00,00.

[0194] Data Transmission and Storage: The automated optical inspection equipment transmits the identified blue-position-length and black-position-length data pairs to the test sorting machine in real time via a communication interface. The test sorting machine correlates this data with detailed process data read from the flower basket RFID chip and the battery's IV performance data, and stores them together in the final test database file.

[0195] Figure 13 A schematic diagram of a solar cell with a visually visible mark B, according to an embodiment of the present disclosure, is shown. Figure 14 A partial schematic diagram of a solar cell with visually visible markings according to an embodiment of the present disclosure is shown. Figure 15 The illustration shows a schematic diagram of a solar cell with visually visible markings according to an embodiment of the present disclosure before screen printing.

[0196] According to an embodiment of this disclosure, the process may include grid line printing. Before grid line printing, a visually visible mark B may be printed in a designated area. The designated area is an area associated with the semiconductor junction type of the solar cell. The visually visible mark B is used to determine the semiconductor junction type corresponding to the currently located designated area.

[0197] For example, the laser-editable feature of the patterning process allows two laser marking points to be edited on the top edge of the silicon wafer. These laser markings can then be used to identify the top and bottom edges (i.e., the P-type semiconductor edge and the N-type semiconductor edge). After the patterning process, the orientation of the silicon wafer within the basket of materials is marked. Figure 13 As shown. After the silicon wafer undergoes the second cleaning process, the areas where the laser works are removed, slightly reducing the visual visibility. When the silicon wafer reaches the second patterning process, a laser is used to enhance the marking ability at this point. After the third cleaning process, the laser-marked areas become more prominent, allowing the naked eye to discern the orientation of the solar cell, as shown. Figure 14 As shown.

[0198] For example, after the solar cell is transferred to the screen printing process, the first printing screen can be combined with a camera positioning system to print screen markings on the patterned marking areas on the surface of the solar cell, such as... Figure 15 As shown in the image, this pattern is a visually visible representation used for rapid differentiation and identification of the N / P area direction in the screen printing process.

[0199] Among them, grid line printing can be screen-printed grid lines, seed layer printing of electroplated grid lines, inkjet printing, laser transfer, etc.

[0200] Those skilled in the art will understand that the features described in the various embodiments and / or claims of this disclosure can be combined or combined in various ways, even if such combinations or combinations are not explicitly described in this disclosure. In particular, the features described in the various embodiments and / or claims of this disclosure can be combined or combined in various ways without departing from the spirit and teachings of this disclosure. All such combinations and / or combinations fall within the scope of this disclosure.

[0201] The embodiments of this disclosure have been described above. However, these embodiments are for illustrative purposes only and are not intended to limit the scope of this disclosure. Although various embodiments have been described above, this does not mean that the measures in the various embodiments cannot be used advantageously in combination. The scope of this disclosure is defined by the appended claims and their equivalents. Various substitutions and modifications can be made by those skilled in the art without departing from the scope of this disclosure, and all such substitutions and modifications should fall within the scope of this disclosure.

Claims

1. A solar cell having at least one set of graphic markings, each set of graphic markings including multiple graphic sub-markers, the graphic markings having a first feature, the first feature being used to distinguish the multiple graphic sub-markers, different graphic sub-markers representing that the solar cell has different first production information; Each of the graphical sub-tags has at least one second feature, and each second feature represents a second production information. Different values ​​of the same second feature indicate that the corresponding second production information is different. in, The second feature is different from the first feature.

2. The solar cell according to claim 1, wherein, The first feature includes at least one of the following: The arrangement direction of the plurality of graphical sub-markers; The spacing setting mode between adjacent graphical sub-markers; The multiple graphic sub-markers are distributed on the surface of the solar cell.

3. The solar cell according to claim 1, wherein, The first production information indicates the type of process the solar cell has undergone; and / or, The second production information indicates at least one of the following when the solar cell performs the process: machine used, production time, material batch number, and process version.

4. The solar cell according to claim 1, wherein, When there are multiple graphical markers, each of the multiple graphical markers includes at least one third feature. Different values ​​of the same third feature indicate that the solar cell has different third production information. The third feature is different from both the first feature and the second feature.

5. The solar cell according to claim 4, wherein, The third production information indicates the process group through which the solar cell has undergone.

6. The solar cell according to claim 1, wherein, The solar cell includes multiple busbar structures, and the multiple graphic sub-markers are respectively set between two adjacent busbar structures.

7. The solar cell according to claim 4, wherein, The second feature includes at least one of shape and size; and / or, The third feature includes at least one of color, shape, position, and height.

8. The solar cell according to claim 4, wherein, The graphical marker is at least one of the first production information, the second production information, and the third production information extracted by a specified device.

9. The solar cell according to claim 1, wherein, The graphical sub-markers can be linear, square, irregular, curved, elliptical, or polygonal.

10. The solar cell according to any one of claims 1 to 9, wherein, The solar cell also has visually visible markings; The visually visible marker is set in a designated area, which is an area associated with the semiconductor junction type of the solar cell. The visually visible marker is used to determine the semiconductor junction type corresponding to the currently located designated area.

11. The solar cell according to claim 10, wherein, The visually visible marker includes at least one of the graphical markers or at least one of the graphical sub-markers.

12. The solar cell according to claim 10, wherein, The projection of the visually visible mark on the surface of the solar cell overlaps with or is completely separated from the projection portion of any of the graphic marks or any of the graphic sub-marks.

13. A method for preparing a solar cell, the method comprising: Whenever a process is completed for a solar cell, first production information and second production information associated with that process are acquired. In response to detecting that the current process is a predefined node process, the first production information and the second production information associated with the target process are formed on the solar cell in the form of graphical markers to obtain at least one set of graphical markers. The target process includes all processes between adjacent node processes. Each group of graphical markers includes multiple graphical sub-markers. Each graphical marker has a first feature, which is used to distinguish the multiple graphical sub-markers. Different graphical sub-markers indicate that the solar cell has different first production information. Each graphical sub-marker has at least one second feature, and each second feature represents a second production information. Different values ​​of the same second feature indicate that the corresponding second production information is different. The second feature is different from the first feature.

14. The method for preparing a solar cell according to claim 13, wherein, The method further includes: The first production information and the second production information are stored in a flower basket chip, which is disposed on a flower basket containing the solar cell.

15. The method for preparing a solar cell according to claim 13, wherein, The process includes grid line printing, and the method further includes: Before the grid lines are printed, visually visible markings are printed in designated areas, which are regions associated with the semiconductor junction type of the solar cell. The visually visible markings are used to determine the semiconductor junction type corresponding to the currently located designated area.

16. A photovoltaic module comprising a solar cell according to any one of claims 1-12 and an encapsulation layer, the encapsulation layer covering the surface of the solar cell.

17. A method for tracing production information of a solar cell, applied to a solar cell as described in any one of claims 1-12, the method comprising: Acquire optical images of at least one set of graphical markings formed on the surface of the target solar cell; The optical image is analyzed to identify the first feature commonly presented by multiple graphic sub-markers in each group of graphic marks, and the first production information corresponding to the solar cell is determined according to the pre-stored mapping relationship between the first feature and the first production information. The optical image is analyzed, the value of at least one second feature of each graphic sub-marker is measured, and at least one second production information corresponding to the solar cell is determined according to the pre-stored mapping relationship between the second feature value and the second production information. The first feature is different from the second feature.

18. The traceability method according to claim 17, characterized in that, The method further includes: In the case where multiple graphic marks are present on the surface of the solar cell, at least one third feature commonly presented by the multiple graphic marks is identified; Based on the pre-stored mapping relationship between the third feature and the third production information, the third production information corresponding to the solar cell is determined; The third feature is different from both the first and second features.

19. The traceability method according to claim 17, characterized in that, The method further includes: The first and second production information are associated with the electrical performance data of the solar cell.

20. A traceability system for solar cell production information, used to implement the traceability method as described in any one of claims 17-19, the system comprising: An image acquisition module is configured to image the surface of a target solar cell to obtain optical images of at least one set of graphical markings; The image processing and decoding module, which is communicatively connected to the image acquisition module, is configured as follows: The optical image is analyzed to identify the first feature commonly presented by multiple graphic sub-markers in each group of graphic marks, and the corresponding first production information is determined according to the pre-stored mapping relationship between the first feature and the first production information. Furthermore, the optical image is analyzed, the value of at least one second feature of each graphic sub-marker is measured, and at least one corresponding second production information is determined based on the pre-stored mapping relationship between the second feature value and the second production information; The data fusion and storage module is communicatively connected to the image processing and decoding module and is configured to encapsulate and store the decoded first production information and second production information.

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