Back contact solar cell and manufacturing method thereof
By forming a multi-layer structure and simplifying process steps in the manufacturing method of back contact solar cells, the problems of large silver paste consumption and cumbersome patterning process are solved, and efficient and low-cost solar cell production is achieved, combining HJT and TOPCon batteries. Advantages of
Patent Information
- Application Number
- CN202411660366.1
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2024-11-20
- Publication Date
- 2025-02-25
AI Technical Summary
In the existing back contact solar cell manufacturing methods, silver paste consumption is large and the graphical process steps are complicated, which limits the development of the battery.
A new manufacturing method is adopted, including forming a multilayer structure on the backlight surface of the silicon matrix, forming conductive structures and isolation grooves through laser etching and electroplating of copper, simplifying process steps and reducing the use of silver paste.
This method reduces process steps and manufacturing costs while improving the photoelectric conversion efficiency of solar cells, combining the advantages of HJT and TOPCon batteries.
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Figure CN119521848A_ABST
Abstract
Description
Technical Field
[0001] The present invention mainly relates to the technical field of solar cells, and in particular to a back-contact solar cell and a manufacturing method thereof. Background Art
[0002] Back-contact cell technology moves the PN junction and metal contact to the back of the cell so that there is no electrode blocking the front, thereby increasing the area of the cell that absorbs sunlight and improving conversion efficiency.
[0003] In the prior art, back-contact solar cells all use screen-printed silver paste as positive and negative electrodes. However, with the continuous expansion of photovoltaic production capacity, the consumption of silver paste increases, and the cost also rises accordingly. In addition, in the prior art, many graphic processes are used in the process of preparing back-contact cells. For example, the passivation layer and the transmission layer are graphicized, the transparent conductive film is graphicized, and the insulating layer between the first transmission layer and the second transmission layer is graphicized. The process steps are very cumbersome, which limits the further development of back-contact cells. Summary of the invention
[0004] The technical problem to be solved by the present invention is to provide a back-contact solar cell and a method for manufacturing the same, so as to solve the problems of large silver paste consumption and complicated graphic process steps in the existing back-contact solar cell manufacturing method.
[0005] In order to solve the above technical problems, the present invention provides a method for manufacturing a back-contact solar cell, comprising:
[0006] Step S1: forming a first passivation layer and a first transmission layer in a first preset area on the backlight surface of the silicon substrate;
[0007] Step S2: depositing a second passivation layer and a second transmission layer on the entire backlight surface of the silicon substrate after being processed in step S1;
[0008] Step S3: etching the second passivation layer and the second transmission layer of the second preset area by laser so that the second preset area is located within the first preset area in the horizontal direction;
[0009] Step S4: depositing a transparent conductive layer and a seed layer on the entire backlight surface of the silicon substrate after being processed in step S3;
[0010] Step S5: forming a mask in a third preset area of the seed layer, and forming a copper electrode layer by copper electroplating technology in an area of the seed layer not covered by the mask;
[0011] Step S6: removing the mask, and wet-etching the transparent conductive layer and the seed layer at positions corresponding to the mask to form an isolation groove, wherein the isolation groove electrically isolates the first transmission layer from the second transmission layer.
[0012] Optionally, the seed layer is a single layer or multiple layers, and the material of the seed layer is one or more alloys of metals selected from copper, silver, zinc, tin, nickel, and tungsten.
[0013] Optionally, step S1 includes:
[0014] Step S11: depositing a first passivation layer and a first transmission layer on the backlight surface of the silicon substrate at a first temperature, and forming a doped silicon glass layer on the first transmission layer;
[0015] Step S12: etching the doped silicon glass layer outside the first preset area by laser, and wet cleaning the first passivation layer and the first transmission layer not covering the doped silicon glass layer by wet cleaning; or,
[0016] By laser etching the doped silicon glass layer and the first passivation layer outside the first preset area, and by wet cleaning the first transmission layer not covering the doped silicon glass layer; or,
[0017] Etching the doped silicon glass layer, the first passivation layer and the first transmission layer outside the first preset area by laser;
[0018] Wherein, the first passivation layer comprises silicon oxide, and the first transmission layer comprises first doped polysilicon.
[0019] Optionally, step S2 includes step S21: at a second temperature, depositing a second passivation layer and a second transmission layer on the backlight surface of the silicon substrate, the second passivation layer comprising intrinsic amorphous silicon, the second transmission layer comprising second doped amorphous silicon or second doped microcrystalline silicon, and the first doping and the second doping polarity are opposite; wherein the first temperature is higher than the second temperature.
[0020] Optionally, the second passivation layer further includes intrinsic amorphous silicon oxide or intrinsic amorphous silicon carbide; and the second transmission layer further includes second doped nano-silicon or second doped silicon carbide.
[0021] Optionally, the thickness of the doped silicon glass layer is 30-200 nm.
[0022] Optionally, the method further includes the steps of: depositing a third passivation layer and an anti-reflection layer on the light-receiving surface of the silicon substrate; wherein the third passivation layer comprises intrinsic amorphous silicon, intrinsic amorphous silicon oxide or intrinsic amorphous silicon carbide; the anti-reflection layer is a single layer or a multilayer, and the material of the anti-reflection layer comprises silicon nitride, silicon oxynitride, silicon oxide or a combination of the above materials.
[0023] In order to solve the above technical problems, the present invention provides a back-contact solar cell, which is manufactured by any of the manufacturing methods described above, and includes: a silicon substrate, a backlight surface of the silicon substrate including a first passivation structure and a second passivation structure arranged crosswise, a first conductive structure located on the first passivation structure, a second conductive structure located on the second passivation structure, and an isolation groove; the first passivation structure is located in a first preset area, the first conductive structure is located in a second preset area, and the second preset area is located in the first preset area in the horizontal direction, the isolation groove isolates the first conductive structure from the second conductive structure, and the isolation groove is located in a third preset area; the first passivation structure includes a first passivation layer and a first transmission layer, the first passivation layer includes silicon oxide, and the first transmission layer includes first doped polycrystalline silicon; the second passivation structure includes a second passivation layer and a second transmission layer, the second passivation layer includes intrinsic amorphous silicon, the second transmission layer includes second doped amorphous silicon or second doped microcrystalline silicon, and the first doping is opposite to the second doping polarity; the first conductive structure and the second conductive structure both include a transparent conductive layer, a seed layer and a copper electrode layer.
[0024] Optionally, the second passivation layer further includes intrinsic amorphous silicon oxide or intrinsic amorphous silicon carbide; and the second transmission layer further includes second doped nano-silicon or second doped silicon carbide.
[0025] Optionally, the seed layer is a single layer or multiple layers, and the material of the seed layer is one or more alloys of metals selected from copper, silver, zinc, tin, nickel, and tungsten.
[0026] Optionally, the thickness of the transparent conductive layer is 30-150 nm, and the thickness of the seed layer is 30-200 nm.
[0027] Optionally, it also includes: the light-receiving surface of the silicon substrate includes a third passivation layer and an anti-reflection layer; wherein the third passivation layer includes intrinsic amorphous silicon, intrinsic amorphous silicon oxide or intrinsic amorphous silicon carbide; the anti-reflection layer is a single layer or a multilayer, and the material of the anti-reflection layer includes silicon nitride, silicon oxynitride, silicon oxide or a combination of the above materials.
[0028] Optionally, the thickness of the third passivation layer is 3-8 nm.
[0029] Compared with the prior art, the present invention has the following advantages:
[0030] In the manufacturing method of the back contact solar cell of the present invention, the patterning process of the transparent conductive layer is exactly the same as the patterning process of the electroplating copper. In other words, the mask of the present invention can be used to make both the patterned transparent conductive layer and the patterned copper electrode layer. Therefore, the electroplating copper technology of the back contact cell does not require an additional patterning process, which greatly reduces the process steps and saves manufacturing costs. The back contact solar cell of the present invention combines the intrinsic amorphous silicon passivation structure and the tunnel passivation structure of the traditional heterojunction, and has both the high open circuit voltage of the HJT cell and the high short circuit current of the TOPCon cell, and has a high photoelectric conversion efficiency. BRIEF DESCRIPTION OF THE DRAWINGS
[0031] The accompanying drawings are included to provide a further understanding of the present application. They are included and constitute a part of the present application. The accompanying drawings illustrate embodiments of the present application and together with the present specification serve to explain the principles of the present application. In the accompanying drawings:
[0032] Figure 1 is a flow chart of a method for manufacturing a back-contact solar cell according to an embodiment of the present invention.
[0033] Figure 2 to Figure 5 Schematic diagram of the battery manufacturing process of step S1 in an embodiment.
[0034] Figure 6 Schematic diagram of the battery manufacturing process of step S2 in an embodiment.
[0035] Figure 7 Schematic diagram of the battery manufacturing process of step S3 in an embodiment.
[0036] Figure 8 Schematic diagram of the battery manufacturing process of step S4 in an embodiment.
[0037] Figure 9-10 Schematic diagram of the battery manufacturing process of step S5 in an embodiment.
[0038] Fig.11 Schematic diagram of the battery manufacturing process of step S6 in an embodiment. DETAILED DESCRIPTION
[0039] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the following is a brief introduction to the drawings required for the description of the embodiments. Obviously, the drawings described below are only some examples or embodiments of the present application. For ordinary technicians in this field, the present application can also be applied to other similar scenarios based on these drawings without creative work. Unless it is obvious from the language environment or otherwise explained, the same reference numerals in the figures represent the same structure or operation.
[0040] Figure 1is a flow chart of a method for manufacturing a back-contact solar cell according to an embodiment of the present invention.
[0041] like Figure 1 As shown, the method 100 for manufacturing a back-contact solar cell includes:
[0042] Step S1: forming a first passivation layer and a first transmission layer in a first preset area of the backlight surface of the silicon substrate.
[0043] Figure 2 to Figure 5 FIG. 1 is a schematic diagram of a battery manufacturing process in an embodiment of step S1. Figure 5 As shown, a first passivation layer 2 and a first transmission layer 3 are formed in a first preset area A1 on the backlight surface of a silicon substrate 1. The first passivation layer 2 includes silicon oxide, and the first transmission layer 3 includes first doped polysilicon. Taking the silicon substrate 1 as an n-type silicon wafer as an example, the thickness of the silicon substrate 1 is 80-200 μm.
[0044] The first passivation layer 2 includes silicon oxide with a thickness of 1-2 nm. The first transmission layer 3 includes N-type doped polysilicon with a thickness of 50-150 nm and a doping concentration of 1e19 cm -3 -1e21 cm -3 .
[0045] Optionally, step S1 includes:
[0046] like Figure 2 As shown, at a first temperature, a first passivation layer 2 and a first transmission layer 3 are deposited on the backlight surface and the light-receiving surface of the silicon substrate 1, respectively, and a doped silica glass layer is formed on the first transmission layer 3. The doped silica glass layer includes phospho silicate glass (PSG) or borosilicate glass (BSG). Taking the first transmission layer 3 including N-type doped polysilicon as an example, the doped silica glass layer 13 includes PSG. Optionally, the thickness of the doped silica glass layer 13 is 30-200nm.
[0047] like Figures 2-3 As shown, the doped silicon glass layer 13 on the light-receiving surface is wet cleaned, and the doped silicon glass layer 13 outside the first preset area A1 on the backlight surface is etched by laser.
[0048] like Figures 3 to 5 As shown, the first passivation layer 2 and the first transmission layer 3 on the light-receiving side and the first passivation layer 2 and the first transmission layer 3 on the backlight side that are not covered with the doped silicon glass layer 13 are wet cleaned. Then, the doped silicon glass layer 13 at the first preset area A1 is wet cleaned.
[0049] In the above embodiment, the first passivation layer 2, the first transmission layer 3 and the doped silicon glass layer 13 are prepared on both sides of the silicon substrate 1, and then the obtained Figure 5 As shown, a first passivation layer 2 and a first transmission layer 3 are formed in a first preset area A1 of the backlight surface of the silicon substrate 1 .
[0050] In other embodiments, the first passivation layer 2, the first transmission layer 3 and the doped silicon glass layer 13 can also be prepared only on the backlight side of the silicon substrate 1 by shielding, and then the obtained Figure 5 As shown, a first passivation layer 2 and a first transmission layer 3 are formed in a first preset area A1 of the backlight surface of the silicon substrate 1. At this time, step S1 includes:
[0051] Step S11: depositing a first passivation layer and a first transmission layer on the backlight surface of the silicon substrate at a first temperature, and forming a doped silicon glass layer on the first transmission layer.
[0052] Step S12: etching the doped silicon glass layer outside the first preset area by laser, and cleaning the first passivation layer and the first transmission layer not covering the doped silicon glass layer by wet cleaning.
[0053] Optionally, step S12 may also be: etching the doped silicon glass layer and the first passivation layer outside the first preset area by laser, and cleaning the first transmission layer not covered by the doped silicon glass layer by wet cleaning.
[0054] Optionally, step S12 may also be: etching the doped silicon glass layer, the first passivation layer and the first transmission layer outside the first preset area by laser.
[0055] In the prior art, during the patterning process of the first passivation layer and the first transmission layer, whether it is laser etching or photolithography, an insulating layer needs to be deposited on the first transmission layer. For example, HBC cells need to deposit a SiNx insulating layer on the first transmission layer. First, it serves as a window film layer for the patterning process, and second, when the first transmission layer in the patterned opening area is wet-etched, it plays a role in protecting the first transmission layer in the unopened area. The insulating layer increases the process steps, which increases the manufacturing cost of the back contact cell accordingly.
[0056] In the present invention, the first passivation layer 2 and the first transmission layer 3 of the back contact solar cell are respectively made of SiO2 and N-type doped polysilicon layer. The PSG formed when depositing N-type doped polysilicon replaces the insulating layer in the prior art. The PSG can be used as a window layer in the back contact cell patterning process, and can also protect the first passivation layer 2 and the first transmission layer 3 in the unopened area when wet etching the first passivation layer 2 and the first transmission layer 3 in the open area. The application of the back contact cell structure and the PSG layer of the present invention can reduce the process steps of the back contact cell and reduce the equipment cost.
[0057] Optionally, before step S1, the method further includes providing a silicon substrate and performing double-sided polishing on the silicon substrate.
[0058] Step S2: depositing a second passivation layer and a second transmission layer on the entire backlight surface of the silicon substrate after being processed in step S1.
[0059] Figure 6 FIG. 1 is a schematic diagram of a battery manufacturing process in an embodiment of step S2. Figure 6 As shown, at the second temperature, the second passivation layer 4 and the second transmission layer 5 are deposited on the entire backlight surface of the silicon substrate 1. The first temperature is higher than the second temperature.
[0060] Optionally, the second passivation layer 4 includes, but is not limited to, intrinsic amorphous silicon, intrinsic amorphous silicon oxide or intrinsic amorphous silicon carbide. Optionally, the second passivation layer 4 has a thickness of 3-8 nm.
[0061] The second transmission layer 5 includes but is not limited to second doped amorphous silicon, second doped microcrystalline silicon, second doped nanosilicon or second doped silicon carbide, and the first doping has opposite polarity to the second doping. Taking the first transmission layer 3 including N-type doped polycrystalline silicon as an example, the second transmission layer 5 includes but is not limited to P-type doped amorphous silicon, P-type doped microcrystalline silicon, P-type doped nanosilicon or P-type doped silicon carbide.
[0062] The back contact solar cell of the present invention combines the intrinsic amorphous silicon passivation structure of the traditional heterojunction with the tunnel passivation structure, and has both the high open circuit voltage of HJT and the high short circuit current of TOPCon cell, and has high photoelectric conversion efficiency. Secondly, in the manufacturing process of the back contact solar cell, the first passivation layer 2 and the first transmission layer 3 are first deposited at high temperature, and then the second passivation layer 4 and the second transmission layer 5 are deposited at low temperature, which avoids the damage of the amorphous silicon or microcrystalline silicon film structure by the high temperature process, thereby causing the film passivation performance to deteriorate, and greatly improving the cell production yield.
[0063] Alternatively, if Figure 6 As shown, the manufacturing method of the back contact solar cell further includes: depositing a third passivation layer 10 and an anti-reflection layer 11 on the light-receiving surface of the silicon substrate. The third passivation layer 10 includes intrinsic amorphous silicon, intrinsic amorphous silicon oxide or intrinsic amorphous silicon carbide; the anti-reflection layer 11 is a single layer or multiple layers, and the material of the anti-reflection layer includes silicon nitride, silicon oxynitride, silicon oxide or a combination of the above materials.
[0064] The third passivation layer 10 can be prepared together with the second passivation layer 4, or can be prepared separately, which is not limited in the present application. Optionally, the thickness of the third passivation layer 10 is 3-8 nm.
[0065] Step S3: etching the second passivation layer and the second transmission layer in the second preset area by laser so that the second preset area is located in the first preset area in the horizontal direction.
[0066] Figure 7FIG. 1 is a schematic diagram of a battery manufacturing process in an embodiment of step S3. Figure 7 As shown, by laser etching the second passivation layer 4 and the second transmission layer 5 of the second preset area A2, the second preset area A2 is located within the first preset area A1 in the horizontal direction. In other words, in the horizontal direction, the width of the opening of the second preset area A2 is less than or equal to the width of the opening of the first preset area A1.
[0067] Step S4: depositing a transparent conductive layer and a seed layer on the entire backlight surface of the silicon substrate after being processed in step S3.
[0068] Figure 8 Schematic diagram of the battery manufacturing process of step S4 in an embodiment. Figure 9-10 FIG. 1 is a schematic diagram of a battery manufacturing process in an embodiment of step S5. Figures 8-9 As shown, a transparent conductive layer 6 and a seed layer 7 are deposited on the entire backlight surface of the silicon substrate 1. Optionally, the thickness of the transparent conductive layer 6 is 30-150 nm, and the thickness of the seed layer 7 is 30-200 nm.
[0069] Optionally, the seed layer 7 is a single layer or multiple layers, and the material of the seed layer 7 is one or more alloys of metals selected from copper, silver, zinc, tin, nickel, and tungsten.
[0070] Step S5: forming a mask in the third preset area of the seed layer, and forming a copper electrode layer in the area of the seed layer not covered by the mask by using a copper electroplating technique.
[0071] like Fig. 9 As shown, a mask 14 is formed in the third preset area A3 of the seed layer 7. Optionally, the mask 14 is formed by printing or inkjet.
[0072] like Fig.10 As shown, a copper electrode layer 8 is formed by copper electroplating technology in the area where the seed layer 7 does not cover the mask 14. The copper electroplating technology completely uses copper as the slurry, the consumption of silver is zero, and the conductivity of the electroplated copper grid line is stronger than that of the silver paste. Therefore, the present invention uses the copper electroplating technology to form the copper electrode layer, which can improve efficiency and reduce costs.
[0073] Step S6: removing the mask, and wet-etching the transparent conductive layer and the seed layer at positions corresponding to the mask to form an isolation groove, wherein the isolation groove electrically isolates the first transmission layer from the second transmission layer.
[0074] Fig.11 FIG. 1 is a schematic diagram of a battery manufacturing process in an embodiment of step S6. Figures 10-11As shown, the mask 14 is removed, and then the transparent conductive layer 6 and the seed layer 7 at the corresponding position of the mask 14 are wet-etched to form an isolation groove 9. The isolation groove 9 electrically isolates the first transmission layer 3 and the second transmission layer 5. Specifically, the isolation groove 9 electrically isolates the N region of the first transmission layer 3 and the P region of the second transmission layer 5 to prevent the P region and the N region from short-circuiting.
[0075] At present, copper electroplating technology is widely studied mainly on HJT and TOPCon batteries. Both types of batteries require a graphic process before the final metallization copper electroplating process, including ink printing, photolithography, drying and development, which increases the steps of the battery process.
[0076] In the present invention, after the transparent conductive layer 6 is deposited, the back contact solar cell needs to undergo a patterning process, the purpose of which is to isolate the N region of the first transmission layer 3 and the P region of the second transmission layer 5 to prevent the P region and the N region from short-circuiting. This patterning process is exactly the same as the patterning process of electroplating copper. In other words, the mask of the present invention can be used to make both a patterned transparent conductive layer and a patterned copper electrode layer. Therefore, the electroplating copper technology of the back contact cell does not require an additional patterning process, which greatly reduces the process steps and saves manufacturing costs.
[0077] The present application also provides a back contact solar cell. Fig.11 As shown, the back contact solar cell includes: a silicon substrate 1, and the backlight surface of the silicon substrate includes a first passivation structure and a second passivation structure arranged crosswise. Among them, the first passivation structure includes a first passivation layer 2 and a first transmission layer 3. The first passivation layer 2 includes silicon oxide, and the first transmission layer 3 includes a first doped polycrystalline silicon. The second passivation structure includes a second passivation layer 4 and a second transmission layer 5. The second passivation layer 4 includes but is not limited to intrinsic amorphous silicon, intrinsic amorphous silicon oxide or intrinsic amorphous silicon carbide. The second transmission layer includes but is not limited to a second doped amorphous silicon, a second doped microcrystalline silicon, a second doped nanosilicon or a second doped silicon carbide. The first doping is opposite to the second doping polarity.
[0078] The back contact solar cell further comprises a first conductive structure located on the first passivation structure, a second conductive structure located on the second passivation structure, and an isolation groove 9. The isolation groove 9 isolates the first conductive structure from the second conductive structure. Both the first conductive structure and the second conductive structure comprise a transparent conductive layer 6, a seed layer 7, and a copper electrode layer 8.
[0079] Optionally, the back contact solar cell further includes a third passivation layer 10 and an anti-reflection layer 11. The third passivation layer 10 and the anti-reflection layer 11 are located on the light-receiving surface of the silicon substrate 1. Optionally, the third passivation layer 10 includes but is not limited to intrinsic amorphous silicon, intrinsic amorphous silicon oxide or intrinsic amorphous silicon carbide. The anti-reflection layer 11 is a single layer or a multilayer, and the material of the anti-reflection layer includes silicon nitride, silicon oxynitride, silicon oxide or a combination of the above materials.
[0080] Optionally, the thickness of the third passivation layer 10 is 3-8 nm, and the thickness of the second passivation layer 4 is 3-8 nm.
[0081] Optionally, the seed layer 7 is a single layer or multiple layers, and the material of the seed layer 7 is one or more alloys of metals selected from copper, silver, zinc, tin, nickel, and tungsten.
[0082] Optionally, the thickness of the transparent conductive layer 6 is 30-150 nm, and the thickness of the seed layer 7 is 30-200 nm.
[0083] Optionally, the thickness of the silicon substrate 1 is 80-200 μm. The first passivation layer 2 comprises silicon oxide with a thickness of 1-2 nm. The first transmission layer 3 comprises N-type doped polysilicon with a thickness of 50-150 nm and a doping concentration of 1e19 cm -3 -1e21 cm -3 .
[0084] The back contact solar cell of the present invention combines the intrinsic amorphous silicon passivation structure and the tunnel passivation structure of the traditional heterojunction, and has both the high open circuit voltage of HJT and the high short circuit current of TOPCon battery, and has high photoelectric conversion efficiency; secondly, the present invention forms the copper electrode layer by electroplating copper technology. Electroplating copper technology completely uses copper as slurry, the consumption of silver is zero, and the conductivity of electroplated copper grid line is stronger than silver paste. Therefore, the back contact solar cell of the present invention can both improve efficiency and reduce cost.
[0085] Flowcharts are used in the present application to illustrate the operations performed by the system according to the embodiments of the present application. It should be understood that the preceding or following operations are not necessarily performed accurately in order. On the contrary, various steps may be processed in reverse order or simultaneously. At the same time, other operations may be added to these processes, or one or more operations may be removed from these processes.
[0086] The basic concepts have been described above. Obviously, for those skilled in the art, the above invention disclosure is only used as an example and does not constitute a limitation of the present application. Although not explicitly stated herein, those skilled in the art may make various modifications, improvements and amendments to the present application. Such modifications, improvements and amendments are suggested in the present application, so such modifications, improvements and amendments still belong to the spirit and scope of the exemplary embodiments of the present application.
[0087] At the same time, the present application uses specific words to describe the embodiments of the present application. For example, "one embodiment", "an embodiment", and / or "some embodiments" refer to a certain feature, structure or characteristic related to at least one embodiment of the present application. Therefore, it should be emphasized and noted that "one embodiment" or "an embodiment" or "an alternative embodiment" mentioned twice or more in different positions in this specification does not necessarily refer to the same embodiment. In addition, some features, structures or characteristics in one or more embodiments of the present application can be appropriately combined.
[0088] As shown in this application, unless the context clearly indicates an exception, the words "a", "an", "a kind" and / or "the" do not refer to the singular, but also include the plural. Generally speaking, the terms "include" and "comprise" only indicate the inclusion of the steps and elements that have been clearly identified, and these steps and elements do not constitute an exclusive list. The method or device may also include other steps or elements.
[0089] Unless otherwise specifically stated, the relative arrangement, numerical expressions and numerical values of the parts and steps set forth in these embodiments do not limit the scope of the application. Meanwhile, it should be understood that, for ease of description, the sizes of the various parts shown in the accompanying drawings are not drawn according to actual proportional relationships. The technology, methods and equipment known to those of ordinary skill in the relevant art may not be discussed in detail, but in appropriate cases, the technology, methods and equipment should be considered as a part of the specification. In all examples shown and discussed here, any specific value should be interpreted as being merely exemplary, rather than as a limitation. Therefore, other examples of exemplary embodiments may have different values. It should be noted that similar reference numerals and letters represent similar items in the following drawings, and therefore, once a certain item is defined in an accompanying drawing, it does not need to be further discussed in subsequent drawings.
[0090] In the description of the present application, it should be understood that the directions or positional relationships indicated by directional words such as "front, back, up, down, left, right", "lateral, vertical, perpendicular, horizontal" and "top, bottom" are usually based on the directions or positional relationships shown in the drawings, and are only for the convenience of describing the present application and simplifying the description. Unless otherwise specified, these directional words do not indicate or imply that the device or element referred to must have a specific direction or be constructed and operated in a specific direction, and therefore cannot be understood as limiting the scope of protection of the present application; the directional words "inside and outside" refer to the inside and outside relative to the contours of each component itself.
[0091] For ease of description, spatially relative terms such as "above", "above", "on the upper surface of", "above", etc. may be used here to describe the spatial positional relationship between a device or feature and other devices or features as shown in the figure. It should be understood that spatially relative terms are intended to include different orientations of the device in use or operation in addition to the orientation described in the figure. For example, if the device in the accompanying drawings is inverted, the device described as "above other devices or structures" or "above other devices or structures" will be positioned as "below other devices or structures" or "below other devices or structures". Thus, the exemplary term "above" can include both "above" and "below". The device can also be positioned in other different ways (rotated 90 degrees or in other orientations), and the spatially relative descriptions used here are interpreted accordingly.
[0092] In addition, it should be noted that the use of words such as "first" and "second" to define components is only for the convenience of distinguishing the corresponding components. If not otherwise stated, the above words have no special meaning and cannot be understood as limiting the scope of protection of this application. In addition, although the terms used in this application are selected from well-known and commonly used terms, some terms mentioned in the specification of this application may be selected by the applicant at his or her discretion, and their detailed meanings are explained in the relevant parts of the description of this article. In addition, it is required to understand this application not only by the actual terms used, but also by the meaning implied by each term.
[0093] It should be understood that when a component is referred to as being "on another component," "connected to another component," "coupled to another component," or "contacting another component," it may be directly on, connected to, coupled to, or contacting the other component, or there may be intervening components. In contrast, when a component is referred to as being "directly on another component," "directly connected to," "directly coupled to," or "directly contacting" another component, there are no intervening components. Similarly, when a first component is referred to as being "electrically in contact with" or "electrically coupled to" a second component, there is an electrical path between the first component and the second component that allows current to flow. The electrical path may include capacitors, coupled inductors, and / or other components that allow current to flow, even without direct contact between conductive components.
[0094] Similarly, it should be noted that in order to simplify the description of the disclosure of this application and thus help understand one or more embodiments of the invention, in the above description of the embodiments of the present application, multiple features are sometimes combined into one embodiment, figure or description thereof. However, this disclosure method does not mean that the subject of the present application requires more features than the features mentioned. In fact, the features of the embodiment are less than all the features of the single embodiment disclosed above.
[0095] In some embodiments, numbers describing the number of components and attributes are used. It should be understood that such numbers used in the description of the embodiments are modified by the modifiers "about", "approximately" or "substantially" in some examples. Unless otherwise specified, "about", "approximately" or "substantially" indicate that the numbers are allowed to vary by ±20%. Accordingly, in some embodiments, the numerical parameters used in the specification are approximate values, which may change according to the required features of individual embodiments. In some embodiments, the numerical parameters should take into account the specified significant digits and adopt the general method of retaining the digits. Although the numerical domains and parameters used to confirm the breadth of the range in some embodiments of the present application are approximate values, in specific embodiments, the setting of such numerical values is as accurate as possible within the feasible range.
[0096] Although the present application has been described with reference to the current specific embodiments, ordinary technicians in this technical field should recognize that the above embodiments are only used to illustrate the present application, and various equivalent changes or substitutions may be made without departing from the spirit of the present application. Therefore, as long as the changes and modifications to the above embodiments are within the essential spirit of the present application, they will fall within the scope of the present application.
Claims
1. A method for manufacturing a back-contact solar cell, characterized in that: include: Step S1: forming a first passivation layer and a first transmission layer in a first preset area on the backlight surface of the silicon substrate; Step S2: depositing a second passivation layer and a second transmission layer on the entire backlight surface of the silicon substrate after being processed in step S1; Step S3: etching the second passivation layer and the second transmission layer of the second preset area by laser so that the second preset area is located within the first preset area in the horizontal direction; Step S4: depositing a transparent conductive layer and a seed layer on the entire backlight surface of the silicon substrate after being processed in step S3; Step S5: forming a mask in a third preset area of the seed layer, and forming a copper electrode layer by copper electroplating technology in an area of the seed layer not covered by the mask; Step S6: removing the mask, and wet-etching the transparent conductive layer and the seed layer at positions corresponding to the mask to form an isolation groove, wherein the isolation groove electrically isolates the first transmission layer from the second transmission layer.
2. The method for manufacturing a back contact solar cell according to claim 1, characterized in that: The seed layer is a single layer or multiple layers, and the material of the seed layer is one or more alloys of metals selected from copper, silver, zinc, tin, nickel, and tungsten.
3. The method for manufacturing a back contact solar cell according to claim 1, characterized in that: Step S1 includes: Step S11: depositing a first passivation layer and a first transmission layer on the backlight surface of the silicon substrate at a first temperature, and forming a doped silicon glass layer on the first transmission layer; Step S12: etching the doped silicon glass layer outside the first preset area by laser, and wet cleaning the first passivation layer and the first transmission layer not covering the doped silicon glass layer by wet cleaning; or, By laser etching the doped silicon glass layer and the first passivation layer outside the first preset area, and by wet cleaning the first transmission layer not covering the doped silicon glass layer; or, Etching the doped silicon glass layer, the first passivation layer and the first transmission layer outside the first preset area by laser; Wherein, the first passivation layer comprises silicon oxide, and the first transmission layer comprises first doped polysilicon.
4. The method for manufacturing a back contact solar cell according to claim 3, characterized in that: Step S2 includes: Step S21: depositing a second passivation layer and a second transmission layer on the backlight surface of the silicon substrate at a second temperature, wherein the second passivation layer comprises intrinsic amorphous silicon, and the second transmission layer comprises second doped amorphous silicon or second doped microcrystalline silicon, and the first doping has opposite polarity to the second doping; Wherein, the first temperature is higher than the second temperature.
5. The method for manufacturing a back contact solar cell according to claim 4, characterized in that: The second passivation layer further includes intrinsic amorphous silicon oxide or intrinsic amorphous silicon carbide; the second transmission layer further includes second doped nano-silicon or second doped silicon carbide.
6. The method for manufacturing a back contact solar cell according to claim 3, characterized in that: The thickness of the doped silicon glass layer is 30-200 nm.
7. The method for manufacturing a back contact solar cell according to claim 1, characterized in that: Also includes the steps: Depositing a third passivation layer and an anti-reflection layer on the light-receiving surface of the silicon substrate; Wherein, the third passivation layer comprises intrinsic amorphous silicon, intrinsic amorphous silicon oxide or intrinsic amorphous silicon carbide; The anti-reflection layer is a single layer or a multi-layer, and the material of the anti-reflection layer includes silicon nitride, silicon oxynitride, silicon oxide or a combination of the above materials.
8. A back contact solar cell, characterized in that: The method is as described in any one of claims 1 to 7, comprising: The silicon substrate and the backlight surface of the silicon substrate include a first passivation structure and a second passivation structure arranged crosswise, a first conductive structure located on the first passivation structure, a second conductive structure located on the second passivation structure, and an isolation groove; The first passivation structure is located in a first preset region, the first conductive structure is located in a second preset region, the second preset region is located in the first preset region in a horizontal direction, the isolation groove isolates the first conductive structure from the second conductive structure, and the isolation groove is located in a third preset region; The first passivation structure comprises a first passivation layer and a first transmission layer, the first passivation layer comprises silicon oxide, and the first transmission layer comprises first doped polysilicon; The second passivation structure comprises a second passivation layer and a second transmission layer, the second passivation layer comprises intrinsic amorphous silicon, the second transmission layer comprises second doped amorphous silicon or second doped microcrystalline silicon, and the first doping has opposite polarity to the second doping; The first conductive structure and the second conductive structure both include a transparent conductive layer, a seed layer and a copper electrode layer.
9. The back contact solar cell according to claim 8, characterized in that: The second passivation layer further includes intrinsic amorphous silicon oxide or intrinsic amorphous silicon carbide; the second transmission layer further includes second doped nano-silicon or second doped silicon carbide.
10. The back contact solar cell according to claim 8, characterized in that: The seed layer is a single layer or multiple layers, and the material of the seed layer is one or more alloys of metals selected from copper, silver, zinc, tin, nickel, and tungsten.
11. The back contact solar cell according to claim 8, characterized in that: The thickness of the transparent conductive layer is 30-150 nm, and the thickness of the seed layer is 30-200 nm.
12. The back contact solar cell according to claim 8, characterized in that: Also includes: The light-receiving surface of the silicon substrate includes a third passivation layer and an anti-reflection layer; Wherein, the third passivation layer comprises intrinsic amorphous silicon, intrinsic amorphous silicon oxide or intrinsic amorphous silicon carbide; The anti-reflection layer is a single layer or a multi-layer, and the material of the anti-reflection layer includes silicon nitride, silicon oxynitride, silicon oxide or a combination of the above materials.
13. The back contact solar cell according to claim 12, characterized in that: The thickness of the third passivation layer is 3-8 nm.