Solar cell structure with three passivation contact layers and preparation method thereof
By setting up three passivation contact layers arranged spaced apart on the front and back of the silicon wafer of the solar cell, combined with specific materials and process design, the problem of difficulty in taking into account high opening voltage and high current in the prior art is solved, and an efficient solar cell structure is achieved.
Patent Information
- Application Number
- CN202510300323.0
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-03-14
- Publication Date
- 2025-06-24
AI Technical Summary
The existing solar cell technology is difficult to take into account both high opening voltage and high current. The single passivation contact film layer has a single performance and cannot effectively improve battery efficiency.
A three-passivation contact layer structure is adopted, in which the front and back of the silicon wafer are provided with first, second and third passivation contact layers arranged spaced apart, the second passivation contact layer material includes silicon nitride, etc., and the third passivation contact layer material includes amorphous silicon and doped polycrystalline silicon. Through a specific passivation process and layer structure design, the passivation contact effect is improved.
The performance of high opening voltage and high current is achieved, the efficiency of solar cells is improved, and the photoelectron collection ability of the battery and the matching performance of metallized slurry are enhanced.
Smart Images
Figure CN120201820A_ABST
Abstract
Description
Technical Field
[0001] The invention belongs to the technical field of solar cells, and in particular relates to a triple-passivation contact layer solar cell structure and a preparation method thereof. Background Art
[0002] High efficiency and low cost are the two most important directions in solar cell research. For crystalline silicon solar cells, with the improvement of crystalline silicon technology, the body carrier lifetime of the substrate silicon wafer continues to increase, and it is no longer the key factor restricting the improvement of battery efficiency. The passivation of the battery surface has an increasingly obvious impact on the conversion efficiency. In the production process of solar cells, the cost of the substrate silicon wafer accounts for the highest proportion of the entire production cost. In order to reduce production costs, achieve "grid parity" for photovoltaic electricity prices as soon as possible, and improve market competitiveness, thinning is an inevitable trend. The problem that arises is that the battery surface is seriously compounded. This poses a challenge to the surface passivation technology of solar cells. In the process of thinning, the high conversion efficiency of the battery is still maintained. Research on the surface passivation technology of crystalline silicon solar cells is essential. Therefore, whether it is to improve the conversion efficiency of solar cells or to reduce the production cost of solar cells, research on the surface passivation technology of crystalline silicon solar cells is essential.
[0003] Existing solar cell technologies mostly use a single passivation contact film layer, which has a single performance. A single passivation contact layer covering the entire surface usually loses one thing while gaining another. Taking SHJ cells as an example, the SHJ cell structure uses amorphous silicon as the passivation contact material on the light-receiving side of the cell to obtain a good open circuit voltage. Although the amorphous silicon layer has good passivation performance, its light absorption effect is serious. The SHJ cell loses current while having an excellent open voltage.
[0004] Therefore, how to balance the high voltage and high current of solar cells is a technical problem that needs to be solved urgently in this field.
[0005] It should be noted that the above information disclosed in this background technology section is only used to understand the background technology of the present application concept, and therefore, the above description is not considered to constitute information of the prior art. Summary of the invention
[0006] The embodiments of the present disclosure at least provide a triple-passivation contact layer solar cell structure and a method for preparing the same.
[0007] In a first aspect, an embodiment of the present disclosure provides a three-passivation contact layer solar cell structure, including: a silicon wafer, on the front surface of which third passivation contact layers are arranged at intervals, and a second passivation contact layer is provided in the gaps and on the outer sides of the third passivation contact layers located on the front surface of the silicon wafer; on the back surface of the silicon wafer, a first passivation contact layer and a third passivation contact layer are arranged at intervals in sequence, and a second passivation contact layer is provided in the gaps and on the outer sides of the first passivation contact layer and the third passivation contact layer located on the back surface of the silicon wafer.
[0008] In an optional embodiment, the material of the first passivation contact layer includes amorphous silicon and doped amorphous silicon; the thickness of the first passivation contact layer is 5 - 20 nm, and the width is 300 - 700 μm.
[0009] In an optional embodiment, the doped amorphous silicon in the first passivation contact layer has the opposite doping property to that in the silicon wafer.
[0010] In an optional embodiment, the material of the second passivation contact layer includes any one or a combination of silicon nitride, aluminum oxide, silicon oxynitride, and silicon oxide; the thickness of the second passivation contact layer is 30 - 90 nm, and the width of the filling gap is 30 - 90 μm.
[0011] In an optional embodiment, the material of the third passivation contact layer includes any one or a combination of amorphous silicon, doped amorphous silicon, silicon oxide, and doped polysilicon; the thickness of the third passivation contact layer is 5 - 150 nm, and the width is 100 - 700 μm.
[0012] In an optional embodiment, the area where the third passivation contact layer is located is a metallization area for printing metallization paste.
[0013] In a second aspect, an embodiment of the present disclosure further provides a preparation method for the three-passivation contact layer solar cell structure as described above, including the following steps: Step S1, growing a third passivation contact layer on the front surface of the silicon wafer; Step S2, growing a second passivation contact layer on the outer side of the third passivation contact layer located on the front surface; Step S3, growing a third passivation contact layer on the outer side of the second passivation contact layer located on the front surface; Step S4, preparing a local area of the outermost third passivation contact layer as a laser oxidation area; Step S5, configuring an acidic solution to clean the silicon wafer to remove the laser oxidation area and the second passivation contact layer inside it; Step S6, configuring an alkaline solution to clean the silicon wafer to remove the outermost third passivation contact layer and the innermost third passivation contact layer exposed after acid etching in Step S5; Step S7, depositing a second passivation contact layer in the void area to obtain a front passivation layer structure; Step S8, repeating Steps S1 - S7 to obtain a back passivation layer structure on the back surface of the silicon wafer.
[0014] In an alternative embodiment, the passivation process of the third passivation contact layer in step S1 includes any one or a combination of PVD, PECVD, and LPCVD; the passivation process of the second passivation contact layer in step S2 includes any one or a combination of PVD, PECVD, and ALD; the passivation process of the third passivation contact layer in step S3 includes any one or both of PVD and PECVD.
[0015] In an alternative embodiment, the acidic solution in step S5 is mainly composed of HF solution; the alkaline solution in step S6 is mainly composed of NaOH or KOH.
[0016] The beneficial effects of the present invention are that the structure of the triple passivation contact layer solar cell and its preparation method use a composite passivation film as the front and back sides. The second passivation contact layer has good light transmittance and can better collect photoelectrons. The third passivation contact layer has good contact performance and can match the metallization paste. At the same time, the multi-region hybrid passivation film on the back can further improve the passivation contact effect, thereby achieving both high open-circuit voltage and high current performance and improving the battery efficiency.
[0017] Other features and advantages of the present invention will be described in the following specification, and some of them will become obvious from the specification or be understood by implementing the present invention. The objectives and other advantages of the present invention are achieved and obtained by the structures specifically pointed out in the specification, claims, and drawings.
[0018] To make the above objectives, features, and advantages of the present invention more obvious and understandable, the following specific preferred embodiments are given in conjunction with the accompanying drawings and are described in detail as follows. BRIEF DESCRIPTION OF THE DRAWINGS
[0019] To more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the following will briefly introduce the drawings required for the description of the specific embodiments or the prior art. Obviously, the following drawings are some embodiments of the present invention. For those of ordinary skill in the art, other drawings can be obtained based on these drawings without creative efforts.
[0020] Figure 1 FIG. [FIG. NUMBER] is a schematic structural diagram of a triple passivation contact layer solar cell provided by an embodiment of the present disclosure; Figure 2 FIG. [FIG. NUMBER] is a schematic structural diagram of a triple passivation contact layer solar cell provided by an embodiment of the present disclosure; Figure 3 FIG. [FIG. NUMBER] is a schematic structural diagram of a triple passivation contact layer solar cell provided by an embodiment of the present disclosure; Figure 4Schematic structural diagram of a triple-passivated contact layer solar cell provided by an embodiment of the present disclosure; Figure 5 Schematic structural diagram of a triple-passivated contact layer solar cell provided by an embodiment of the present disclosure; Figure 6 Schematic structural diagram of a triple-passivated contact layer solar cell provided by an embodiment of the present disclosure; Figure 7 Schematic structural diagram of a triple-passivated contact layer solar cell provided by an embodiment of the present disclosure; Figure 8 Schematic structural diagram of a triple-passivated contact layer solar cell provided by an embodiment of the present disclosure.
[0021] In the figure: 1. silicon wafer; 2. first passivated contact layer; 3. second passivated contact layer; 4. third passivated contact layer; 5. laser oxidation region. Specific embodiments
[0022] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings. Apparently, the described embodiments are some, but not all, of the embodiments of the present invention. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts shall fall within the protection scope of the present invention.
[0023] As used herein, phrases such as "in one embodiment", "according to one embodiment", "in some embodiments", etc. generally refer to the fact that the specific features, structures, or characteristics after the phrase can be included in at least one embodiment of the present disclosure. Therefore, a specific feature, structure, or characteristic can be included in more than one embodiment of the present disclosure, such that these phrases do not necessarily refer to the same embodiment. As used herein, terms such as "example", "exemplary", etc. are used "as an example, instance, or illustration. Any embodiment, aspect, or design described herein as "example" or "exemplary" is not necessarily to be construed as preferred or superior to other embodiments, aspects, or designs. Instead, the use of terms such as "example", "exemplary", etc. is intended to present concepts in a specific manner.
[0024] In this document, example embodiments of the present disclosure will be described in more detail with reference to the accompanying drawings. As used herein, expressions such as "at least one of..." modify the entire list of elements when following a list of elements, rather than modifying individual elements in the list. For example, the expression "at least one of a, b, and c" should be understood to include only a, only b, only c, both a and b, both a and c, both b and c, or all of a, b, and c.
[0025] The terms used in this document are only for describing specific exemplary configurations and are not intended to be restrictive. As used herein, the singular articles "a", "an", and "the" may also be intended to include the plural forms, unless clearly indicated otherwise in the context. The terms "comprising", "including", and "having" are inclusive, thus specifying the presence of the features, steps, operations, elements, and / or components, but not precluding the presence or addition of one or more other features, steps, operations, elements, components, and / or their combinations. The method steps, processes, and operations described herein should not be construed as necessarily requiring them to be performed in the specific order discussed or illustrated, unless specifically identified as the order of execution. Additional or alternative steps may be employed.
[0026] For TOPCon cells, which currently dominate the production capacity, the back side uses silicon oxide and polysilicon for passivated contact. The polysilicon layer has good contact performance, but its overall passivation performance is not good, and there is a bottleneck in the open-circuit voltage of the cell.
[0027] All the defects existing in the above solutions are the results obtained by the inventors through practice and careful research. Therefore, the process of discovering the above problems and the solutions proposed by the present disclosure for the above problems in the following text should be the contributions made by the inventors to the present disclosure during the process of the present disclosure.
[0028] It should be noted that similar reference numerals and letters denote similar items in the following figures. Therefore, once an item is defined in one figure, it does not need to be further defined and explained in subsequent figures.
[0029] The following will, with reference to the accompanying drawings, elaborate on some embodiments of the present invention. Without conflict, the following embodiments and the features in the embodiments can be combined with each other.
[0030] The embodiment of the present disclosure provides a triple passivated contact layer solar cell structure, including: a silicon wafer, on the front surface of which a third passivated contact layer is arranged at intervals, and a second passivated contact layer is arranged at the gap and outside of the third passivated contact layer located on the front surface of the silicon wafer; on the back surface of the silicon wafer, a first passivated contact layer and a third passivated contact layer are arranged at intervals in sequence, and a second passivated contact layer is arranged at the gap and outside of the first passivated contact layer and the third passivated contact layer located on the back surface of the silicon wafer.
[0031] In some embodiments, specifically, the material of the first passivated contact layer includes amorphous silicon and doped amorphous silicon; the thickness of the first passivated contact layer is 5 - 20 nm, and the width is 300 - 700 μm.
[0032] In some embodiments, specifically, the doped amorphous silicon in the first passivated contact layer has the opposite doping property to that in the silicon wafer.
[0033] In some embodiments, specifically, the material of the second passivation contact layer includes any one or a combination of silicon nitride, aluminum oxide, silicon oxynitride, and silicon oxide; the thickness of the second passivation contact layer is 30 - 90 nm, and the width of the filling gap is 30 - 90 μm.
[0034] In some embodiments, specifically, the material of the third passivation contact layer includes any one or a combination of amorphous silicon, doped amorphous silicon, silicon oxide, and doped polysilicon; the thickness of the third passivation contact layer is 5 - 150 nm, and the width is 100 - 700 μm.
[0035] In some embodiments, specifically, the area where the third passivation contact layer is located is a metallization area for printing metallization paste.
[0036] The embodiments of the present disclosure also provide a preparation method for the three - passivation - contact - layer solar cell structure as described above, including the following steps: Step S1, grow a third passivation contact layer on the front side of the silicon wafer; Step S2, grow a second passivation contact layer on the outside of the third passivation contact layer located on the front side; Step S3, grow a third passivation contact layer on the outside of the second passivation contact layer located on the front side; Step S4, prepare a local area of the outermost third passivation contact layer as a laser oxidation area; Step S5, configure an acidic solution to clean the silicon wafer to remove the laser oxidation area and the second passivation contact layer inside it; Step S6, configure an alkaline solution to clean the silicon wafer to remove the outermost third passivation contact layer and the innermost third passivation contact layer exposed after acid etching in Step S5; Step S7, deposit a second passivation contact layer in the void area to obtain a front - side passivation layer structure; Step S8, repeat Steps S1 - S7 to obtain a back - side passivation layer structure on the back side of the silicon wafer.
[0037] In some embodiments, specifically, the passivation process of the third passivation contact layer in Step S1 includes any one or a combination of PVD, PECVD, and LPCVD; the passivation process of the second passivation contact layer in Step S2 includes any one or a combination of PVD, PECVD, and ALD; the passivation process of the third passivation contact layer in Step S3 includes any one or two combinations of PVD and PECVD.
[0038] In some embodiments, specifically, the acidic solution in Step S5 is mainly composed of HF solution; the alkaline solution in Step S6 is mainly composed of NaOH or KOH.
[0039] Embodiments include the following steps: Step S1, please refer to Figure 1 , as Figure 1 shown, use the PECVD process to grow a third passivation contact layer on the front side of the silicon wafer; Step S2, refer to Figure 2 , as shown in Figure 2 , grow a second passivation contact layer on the outside of the third passivation contact layer located on the front side by using the PECVD process; Step S3, refer to Figure 3 , as shown in Figure 3 , grow a third passivation contact layer on the outside of the second passivation contact layer located on the front side by using the PECVD process; Step S4, refer to Figure 4 , as shown in Figure 4 , use an ultraviolet picosecond laser to prepare a local laser oxidation region on the outermost third passivation contact layer; Step S5, refer to Figure 5 , as shown in Figure 5 , configure an HF acidic solution to clean the silicon wafer to remove the laser oxidation region and the second passivation contact layer inside it; Step S6, refer to Figure 6 , as shown in Figure 6 , configure an NaOH alkaline solution to clean the silicon wafer to remove the outermost third passivation contact layer and the innermost third passivation contact layer exposed after the acid etching in Step S5; Step S7, refer to Figure 7 , as shown in Figure 7 , deposit a second passivation contact layer in the void region to obtain a front passivation layer structure; Step S8, refer to Figure 8 , as shown in Figure 8 , repeat Steps S1 - S7 to obtain a back passivation layer structure on the back side of the silicon wafer.
[0040] In summary, the structure of this triple - passivation - contact - layer solar cell and its preparation method use a composite passivation film as the front and back sides. The second passivation contact layer has good light transmittance and can better collect photoelectrons. The third passivation contact layer has good contact performance and can match the metallization paste. At the same time, the multi - region hybrid passivation film located on the back side can further improve the passivation contact effect, thereby achieving the balance of both high open - circuit voltage and high current performance and improving the cell efficiency.
[0041] Taking the above - mentioned ideal embodiments of the present invention as inspiration, through the above - described description, relevant staff can completely make various changes and modifications without departing from the technical idea of this invention. The technical scope of this invention is not limited to the content in the specification, and its technical scope must be determined according to the scope of the claims.
Claims
1. A triple passivation contact layer solar cell structure, characterized in that: include: A silicon wafer, wherein third passivation contact layers are arranged at intervals on the front side of the silicon wafer, and second passivation contact layers are arranged in the gaps and outsides of the third passivation contact layers on the front side of the silicon wafer; A first passivation contact layer and a third passivation contact layer are arranged in sequence and at intervals on the back of the silicon wafer, and a second passivation contact layer is arranged in the gap and outside of the first passivation contact layer and the third passivation contact layer on the back of the silicon wafer.
2. The triple passivation contact layer solar cell structure according to claim 1, characterized in that: The material of the first passivation contact layer includes amorphous silicon and doped amorphous silicon; The first passivation contact layer has a thickness of 5-20 nm and a width of 300-700 μm.
3. The triple passivation contact layer solar cell structure according to claim 2, characterized in that: The doped amorphous silicon in the first passivation contact layer has opposite doping properties to that in the silicon wafer.
4. The triple passivation contact layer solar cell structure according to claim 1, characterized in that: The material of the second passivation contact layer includes any one or more combinations of silicon nitride, aluminum oxide, silicon oxynitride and silicon oxide; The thickness of the second passivation contact layer is 30-90 nm, and the width of the filling gap is 30-90 μm.
5. The triple passivation contact layer solar cell structure according to claim 1, characterized in that: The material of the third passivation contact layer includes any one or more combinations of amorphous silicon, doped amorphous silicon, silicon oxide and doped polysilicon; The third passivation contact layer has a thickness of 5-150 nm and a width of 100-700 μm.
6. The triple passivation contact layer solar cell structure according to claim 1, characterized in that: The area where the third passivation contact layer is located is a metallization area for printing metallization paste.
7. A method for preparing a triple passivation contact layer solar cell structure according to any one of claims 1 to 6, characterized in that: The steps include: Step S1, growing a third passivation contact layer on the front side of the silicon wafer; Step S2, growing a second passivation contact layer on the outer side of the third passivation contact layer located on the front side; Step S3, growing a third passivation contact layer on the outer side of the second passivation contact layer located on the front side; Step S4, preparing a portion of the third passivation contact layer located on the outermost side as a laser oxidation region; Step S5, preparing an acid solution to clean the silicon wafer to remove the laser oxidized area and the second passivation contact layer inside the laser oxidized area; Step S6, preparing an alkaline solution to clean the silicon wafer to remove the outermost third passivation contact layer and the innermost third passivation contact layer exposed after acid etching in step S5; Step S7, depositing a second passivation contact layer in the gap region to obtain a front passivation layer structure; Step S8, repeating steps S1-S7 to obtain a back passivation layer structure on the back side of the silicon wafer.
8. The preparation method according to claim 7, characterized in that: The passivation process of the third passivation contact layer in step S1 includes any one or more combinations of PVD, PECVD and LPCVD; The passivation process of the second passivation contact layer in step S2 includes any one or more combinations of PVD, PECVD and ALD; The passivation process of the third passivation contact layer in step S3 includes any one of PVD and PECVD or a combination of the two.
9. The preparation method according to claim 7, characterized in that: In step S5, the acidic solution is mainly composed of HF solution; In step S6, the alkaline solution is mainly composed of NaOH or KOH.