Solar cell and solar cell module
By setting a polycrystalline silicon thin film layer between the passivation layers of solar cells, the problem of rapid degradation of solar cells under UV irradiation is solved, and the high efficiency of extinction performance and performance maintenance of the cells are achieved.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- TRINA SOLAR CO LTD
- Filing Date
- 2025-05-30
- Publication Date
- 2026-07-21
Smart Images
Figure CN224538656U_ABST
Abstract
Description
Technical Field
[0001] This application relates primarily to the field of battery technology, and more particularly to a solar cell and a solar cell module. Background Technology
[0002] Solar cells are an important way for people to generate electricity in the future, and solar cells made of crystalline silicon are the mainstream technology in the photovoltaic industry for the next few years. Currently, the mainstream N-type cells have poor UV resistance, with a degradation of >1.5% under UV60 testing.
[0003] Currently, TOPCon cells mainly suffer from poor UV resistance. Their mainstream structure is a combination of alumina and silicon nitride. Alumina provides field passivation for the cell, but it has a dense negative charge. The silicon nitride structure provides good H+ passivation, but it has a dense positive charge. When the cell or module is exposed to UV light, the Si-H bonds in the silicon matrix and silicon nitride break, the hydrogen content decreases significantly, the porosity increases, and a large number of positively charged H+ will recombine with the negative charge in the alumina, resulting in a decrease in overall passivation and thus causing module degradation.
[0004] Currently, improving the UV resistance of batteries mainly starts with the encapsulation materials at the module level, such as using encapsulation structures like films and glass. However, using these encapsulation structures will further increase the module cost, which is not conducive to module cost control. Summary of the Invention
[0005] The technical problem to be solved by this application is to provide a solar cell and a solar cell module that can enhance the short-wave extinction capability of the solar cell, improve the extinction performance of the cell, and thus reduce the loss of UV light.
[0006] To address the aforementioned technical problems, this application provides a solar cell, comprising: a substrate having a first surface; a first passivation layer, a second passivation layer, a third passivation layer, a fourth passivation layer, and a plurality of polycrystalline silicon thin film layers, wherein the first passivation layer is located on the first surface, the second passivation layer is located on the side of the first passivation layer away from the substrate, and the polycrystalline silicon thin film layer is included between the first passivation layer and the second passivation layer; the third passivation layer is located on the side of the second passivation layer away from the first passivation layer, and the polycrystalline silicon thin film layer is included between the second passivation layer and the third passivation layer; the fourth passivation layer is located on the side of the third passivation layer away from the second passivation layer, and the polycrystalline silicon thin film layer is included between the third passivation layer and the fourth passivation layer.
[0007] Optionally, the substrate includes an N-type substrate, and the first passivation layer includes aluminum oxide.
[0008] Optionally, the thickness of the polycrystalline silicon thin film layer is in the range of 1 nm to 3 nm, and the refractive index of the polycrystalline silicon thin film layer is greater than 3.2.
[0009] Optionally, the second passivation layer comprises silicon nitride, and the thickness of the second passivation layer ranges from 10 nm to 30 nm, and the refractive index of the second passivation layer ranges from 1.9 to 2.2.
[0010] Optionally, the third passivation layer comprises silicon oxynitride, and the thickness of the third passivation layer ranges from 20 nm to 40 nm, and the refractive index of the third passivation layer is greater than 3.
[0011] Optionally, the fourth passivation layer comprises silicon oxide, and the thickness of the fourth passivation layer ranges from 20 nm to 40 nm, and the refractive index of the fourth passivation layer ranges from 1.4 to 1.6.
[0012] Optionally, the substrate further includes a second surface opposite to the first surface, the first surface being closer to the sun than the second surface, and the solar cell further includes a tunneling oxide layer located on the second surface, with a doped polycrystalline silicon layer sequentially included on the side of the tunneling oxide layer away from the substrate.
[0013] Optionally, the solar cell further includes an emitter, a first metal electrode, and a second metal electrode, wherein the emitter is located within the substrate, the first metal electrode is electrically connected to the emitter, and the second metal electrode is electrically connected to the doped polycrystalline silicon layer.
[0014] Optionally, the first metal electrode is in contact with the emitter, and the substrate thickness of the contact portion of the first metal electrode within the substrate ranges from 0 nm to 100 nm.
[0015] To address the aforementioned technical problems, this application also provides a solar cell module, including the solar cell described above.
[0016] Compared with existing technologies, this application achieves the effect of essentially eliminating ultraviolet light in the battery structure by setting a polycrystalline silicon thin film layer with high short-wavelength extinction capability between different passivation layers. This further prevents ultraviolet light from entering the silicon substrate. At the same time, by adjusting the thickness range of the polycrystalline silicon thin film layer, the battery structure can selectively transmit medium and long-wavelength light, which can enhance the short-wavelength extinction capability of the solar cell while maintaining the battery's electrical performance, thereby improving the battery's extinction performance and reducing UV light loss. Attached Figure Description
[0017] The accompanying drawings are included to provide a further understanding of this application; they are incorporated into and constitute a part of this application. The drawings illustrate embodiments of this application and, together with this specification, serve to explain the principles of this application. In the drawings:
[0018] Figure 1 This is a schematic diagram of the film structure of a solar cell according to one embodiment of this application;
[0019] Figure 2 This is one embodiment of the present application that employs, as follows Figure 1 The diagram shows the overall structure of a solar cell with a film layer structure. Detailed Implementation
[0020] To more clearly illustrate the technical solutions of the embodiments of this application, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are merely some examples or embodiments of this application. For those skilled in the art, these drawings can be applied to other similar scenarios without creative effort. Unless obvious from the context or otherwise specified, the same reference numerals in the drawings represent the same structures or operations.
[0021] As indicated in this application and claims, unless the context clearly indicates otherwise, the words "a," "an," "an," and / or "the" are not specifically singular and may include plural forms. Generally speaking, the terms "comprising" and "including" only indicate the inclusion of explicitly identified steps and elements, which do not constitute an exclusive list, and the method or apparatus may also include other steps or elements.
[0022] Unless otherwise specifically stated, the relative arrangement, numerical expressions, and values of the components and steps described in these embodiments do not limit the scope of this application. It should also be understood that, for ease of description, the dimensions of the various parts shown in the drawings are not drawn to actual scale. Techniques, methods, and devices known to those skilled in the art may not be discussed in detail, but where appropriate, such techniques, methods, and devices should be considered part of the specification. In all examples shown and discussed herein, any specific values should be interpreted as merely exemplary and not as limitations. Therefore, other examples of exemplary embodiments may have different values. It should be noted that similar reference numerals and letters in the following drawings denote similar items; therefore, once an item is defined in one drawing, it need not be further discussed in subsequent drawings.
[0023] In the description of this application, it should be understood that the orientation or positional relationship indicated by directional terms such as "front, back, up, down, left, right", "horizontal, vertical, horizontal" and "top, bottom" is usually based on the orientation or positional relationship shown in the accompanying drawings, and is only for the convenience of describing this application and simplifying the description. Unless otherwise stated, these directional terms do not indicate or imply that the device or element referred to must have a specific orientation or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation on the scope of protection of this application; the directional terms "inner" and "outer" refer to the inner and outer contours relative to the outline of each component itself.
[0024] For ease of description, spatial relative terms such as "above," "on top of," "on the upper surface of," "above," etc., are used herein to describe the spatial positional relationship of a device or feature as shown in the figures to other devices or features. It should be understood that spatial relative terms are intended to encompass different orientations in use or operation beyond the orientation of the device as described in the figures. For example, if the device in the figures were inverted, a device described as "above" or "on top of" other devices or structures would subsequently be positioned as "below" or "under" other devices or structures. Thus, the exemplary term "above" can include both "above" and "below." The device may also be positioned in other different ways (rotated 90 degrees or in other orientations), and the spatial relative descriptions used herein will be interpreted accordingly.
[0025] Furthermore, it should be noted that the use of terms such as "first" and "second" to define components is merely for the purpose of distinguishing the corresponding components. Unless otherwise stated, these terms have no special meaning and therefore should not be construed as limiting the scope of protection of this application. In addition, although the terminology used in this application is selected from commonly known and used terms, some terms mentioned in this application's specification may have been chosen by the applicant according to his or her judgment, and their detailed meanings are explained in the relevant sections of this description. Moreover, this application should be understood not only through the actual terms used, but also through the meaning implied by each term.
[0026] This application refers to Figures 1-2 A solar cell 10 is proposed. Figure 1 The film structure of solar cell 10 is shown. Figure 2 The overall cell structure of solar cell 10 is shown. Now, combined with... Figure 1 and Figure 2 The specific structure of solar cell 10 will be further explained below. (Refer to...) Figure 1 and Figure 2The film layers of the solar cell 10 mainly include a substrate 21, a first passivation layer 11, a second passivation layer 12, a third passivation layer 13, a fourth passivation layer 14, and multiple polycrystalline silicon thin film layers 15.
[0027] Specifically, the substrate 21 has a first surface S1 and a second surface S2 opposite to the first surface S1, wherein the first surface S1 is closer to the sun than the second surface S2. In this embodiment, the substrate includes an N-type substrate, and the first surface S1 of the solar cell 10 can be a textured structure. The textured structure has superior light-harvesting performance and can further improve the light spot conversion efficiency of the solar cell 10.
[0028] Further, more detailed reference Figure 1 ,like Figure 1 As shown, in the solar cell 10, a first passivation layer 11 is located on a first surface S1, and a second passivation layer 12 is located on the side of the first passivation layer 11 away from the substrate 21. A polycrystalline silicon thin film layer 15 is included between the first passivation layer 11 and the second passivation layer 12. For example, the first passivation layer 11 can be aluminum oxide, and the second passivation layer 12 can be silicon nitride.
[0029] More specifically, the thickness of the polycrystalline silicon thin film layer 15 ranges from 1 nm to 3 nm, for example, 1 nm, 2 nm, and 3 nm, and the refractive index of the polycrystalline silicon thin film layer is greater than 3.2. The thickness of the second passivation layer ranges from 10 nm to 30 nm, for example, 10 nm, 15 nm, 20 nm, 25 nm, and 30 nm, and the refractive index of the second passivation layer ranges from 1.9 to 2.2, for example, 1.9, 2.0, 2.1, and 2.2.
[0030] In this embodiment, the first passivation layer 11 can be implemented as aluminum oxide, thereby providing a field passivation effect for the battery. The second passivation layer 12 can be implemented as silicon nitride, which can provide good H+ passivation for the battery. However, aluminum oxide and silicon nitride both have dense negative charges, making them prone to metal recombination when the solar cell 10 receives ultraviolet radiation. In the structure of the solar cell 10, a polycrystalline silicon thin film layer 15 is located between the first passivation layer 11 and the second passivation layer 12. Since the refractive index of the polycrystalline silicon thin film layer 15 is greater than 3.2, it has high short-wave extinction capability. Therefore, it can isolate ultraviolet light within the film layer when the solar cell 10 receives ultraviolet radiation, thereby further reducing the loss of ultraviolet light and greatly reducing the probability of metal recombination between the first passivation layer 11 and the second passivation layer 12. This improves the extinction performance of the solar cell 10 while ensuring its overall performance.
[0031] Further, continue to refer to Figure 1 ,Depend on Figure 1It can be seen that the third passivation layer 13 is located on the side of the second passivation layer 12 away from the first passivation layer 11. The second passivation layer 12 and the third passivation layer 13 also include a polycrystalline silicon thin film layer 15. The fourth passivation layer 14 is located on the side of the third passivation layer 13 away from the second passivation layer 12. The third passivation layer 13 and the fourth passivation layer 14 also include a polycrystalline silicon thin film layer 15.
[0032] In the structure of the solar cell 10, the third passivation layer 13 can be silicon oxynitride, with a thickness ranging from 20 nm to 40 nm, such as 20 nm, 25 nm, 30 nm, 35 nm, and 40 nm, and a refractive index greater than 3. The fourth passivation layer 14 is silicon oxide, also with a thickness ranging from 20 nm to 40 nm, and a refractive index ranging from 1.4 to 1.6. In this embodiment, by setting the third passivation layer 13 as silicon oxynitride and the fourth passivation layer 14 as silicon oxide, adjusting their thickness relationship and inherent refractive index characteristics can provide the solar cell 10 with better optical channels and optical traps, allowing for better absorption of mid-to-long wavelength light, further increasing the current of the solar cell 10, and thus further improving the performance of the solar cell 10.
[0033] On the other hand, refer to Figure 2 The solar cell 10 further includes a tunneling oxide layer 22 located on the second surface S2. On the side of the tunneling oxide layer 22 away from the substrate 21, a doped polycrystalline silicon layer 23 and an anti-reflection layer 24 are sequentially included. The solar cell 10 further includes an emitter 25, a first metal electrode 26, and a second metal electrode 27. The emitter 25 is located within the substrate 21. The first metal electrode 26 is in direct contact with the emitter 25, i.e., electrically connected. The second metal electrode 27 is in direct contact with the doped polycrystalline silicon layer 23, i.e., electrically connected.
[0034] Preferably, in this application, the first metal electrode 26 is in direct contact with the emitter 25. This means that in the solar cell 10 provided in this application, the first metal electrode 26 extends all the way into the substrate 21. Figure 1 As shown, the thickness x of the contact portion of the first metal electrode 26 located in the substrate 21 ranges from 0 nm to 100 nm, for example, 0 nm, 10 nm, 20 nm, 30 nm, 40 nm, 50 nm, 60 nm, 70 nm, 80 nm, 90 nm and 100 nm.
[0035] Furthermore, to better understand the above structure, the fabrication process of the 10-layer film in solar cells is briefly described below:
[0036] First, a silicon substrate needs to be prepared, and an aluminum oxide film layer with a thickness of 1nm to 3nm is deposited on the first surface of the silicon substrate using PECVD. Then, an amorphous silicon film layer is deposited on the aluminum oxide film layer to ensure that the thickness of the amorphous silicon film is between 1nm and 3nm.
[0037] Next, a silicon nitride film with a thickness between 10 nm and 30 nm is deposited on the amorphous silicon thin film using PECVD, and then an amorphous silicon thin film with a thickness between 1 nm and 3 nm is deposited on the silicon nitride film.
[0038] Then, PECVD is used to deposit a silicon oxynitride film with a thickness between 20 nm and 40 nm on the amorphous silicon film, and an amorphous silicon film with a thickness between 1 nm and 3 nm is deposited on the silicon oxynitride film.
[0039] Finally, PECVD is used to deposit a silicon oxide film layer with a thickness between 20 nm and 40 nm on the amorphous silicon film, and annealing is used to convert all amorphous silicon films into polycrystalline silicon films.
[0040] The fabrication method of the back structure of solar cell 10 can refer to existing technology, and since it is not the focus of this application, it will not be described in detail here. In this embodiment, the solar cell fabricated by the above method can be converted from an amorphous silicon thin film to a polycrystalline silicon thin film layer by thermal annealing. Since amorphous silicon has more H+ ions than silicon nitride, thermal annealing can push more H+ ions into the silicon substrate, thereby further improving the passivation capability of the cell.
[0041] This application achieves the effect of essentially eliminating ultraviolet light in the battery structure by setting a polycrystalline silicon thin film layer with high short-wavelength extinction capability between different passivation layers. This further prevents ultraviolet light from entering the silicon substrate. At the same time, by adjusting the thickness range of the polycrystalline silicon thin film layer, the battery structure can selectively transmit medium and long-wavelength light. This can enhance the short-wavelength extinction capability of the solar cell while maintaining the battery's electrical performance, thereby improving the battery's extinction performance and reducing UV light loss.
[0042] The basic concepts have been described above. Obviously, for those skilled in the art, the above disclosure is merely illustrative and does not constitute a limitation of this application. Although not explicitly stated herein, those skilled in the art may make various modifications, improvements, and corrections to this application. Such modifications, improvements, and corrections are suggested in this application, and therefore remain within the spirit and scope of the exemplary embodiments of this application.
[0043] Furthermore, this application uses specific terms to describe embodiments of the application. For example, "an embodiment," "one embodiment," and / or "some embodiments" refer to a particular feature, structure, or characteristic related to at least one embodiment of the application. Therefore, it should be emphasized and noted that "an embodiment," "one embodiment," or "an alternative embodiment" mentioned twice or more in different locations in this specification do not necessarily refer to the same embodiment. In addition, certain features, structures, or characteristics in one or more embodiments of the application can be appropriately combined.
[0044] Similarly, it should be noted that, in order to simplify the description of the present application and thus aid in the understanding of one or more embodiments, the foregoing description of the embodiments of the present application sometimes combines multiple features into a single embodiment, drawing, or description thereof. However, this disclosure method does not imply that the subject matter of the present application requires more features than those mentioned in the claims. In fact, the embodiments contain fewer features than all the features of the single embodiments disclosed above.
[0045] In some embodiments, numbers describing the quantity of components and attributes are used. It should be understood that such numbers used in the description of embodiments are modified in some examples with the terms "approximately," "approximately," or "generally." Unless otherwise stated, "approximately," "approximately," or "generally" indicates that the numbers are allowed to vary by ±20%. Accordingly, in some embodiments, the numerical parameters used in the specification and claims are approximate values, which may be changed depending on the characteristics required by individual embodiments. In some embodiments, numerical parameters should take into account specified significant digits and employ a general method of digit reservation. Although the numerical ranges and parameters used to confirm their breadth of scope in some embodiments of this application are approximate values, in specific embodiments, such values are set as precisely as feasible.
[0046] Although this application has been described with reference to specific embodiments, those skilled in the art should recognize that the above embodiments are only used to illustrate this application, and various equivalent changes or substitutions can be made without departing from the spirit of this application. Therefore, any changes or modifications to the above embodiments within the essential spirit of this application will fall within the scope of the claims of this application.
Claims
1. A solar cell, characterized in that, include: Substrate, the substrate having a first surface; The system comprises a first passivation layer, a second passivation layer, a third passivation layer, a fourth passivation layer, and multiple polycrystalline silicon thin film layers, wherein... The first passivation layer is located on the first surface, the second passivation layer is located on the side of the first passivation layer away from the substrate, and the polycrystalline silicon thin film layer is included between the first passivation layer and the second passivation layer; The third passivation layer is located on the side of the second passivation layer away from the first passivation layer, and the polycrystalline silicon thin film layer is included between the second passivation layer and the third passivation layer; The fourth passivation layer is located on the side of the third passivation layer away from the second passivation layer, and the polycrystalline silicon thin film layer is located between the third passivation layer and the fourth passivation layer.
2. The solar cell as described in claim 1, characterized in that, The substrate includes an N-type substrate, and the first passivation layer includes aluminum oxide.
3. The solar cell as described in claim 1, characterized in that, The thickness of the polycrystalline silicon thin film layer ranges from 1 nm to 3 nm, and the refractive index of the polycrystalline silicon thin film layer is greater than 3.
2.
4. The solar cell as described in claim 1, characterized in that, The second passivation layer comprises silicon nitride, and the thickness of the second passivation layer ranges from 10 nm to 30 nm, and the refractive index of the second passivation layer ranges from 1.9 to 2.
2.
5. The solar cell as described in claim 1, characterized in that, The third passivation layer comprises silicon oxynitride, and the thickness of the third passivation layer ranges from 20 nm to 40 nm, and the refractive index of the third passivation layer is greater than 3.
6. The solar cell as claimed in claim 1, characterized in that, The fourth passivation layer comprises silicon oxide, and the thickness of the fourth passivation layer ranges from 20 nm to 40 nm, and the refractive index of the fourth passivation layer ranges from 1.4 to 1.
6.
7. The solar cell according to claim 1, characterized in that, The substrate further includes a second surface opposite to the first surface, the first surface being closer to the sun than the second surface, and the solar cell further includes a tunneling oxide layer located on the second surface, with a doped polycrystalline silicon layer sequentially included on the side of the tunneling oxide layer away from the substrate.
8. The solar cell as claimed in claim 7, characterized in that, It also includes an emitter, a first metal electrode, and a second metal electrode. The emitter is located within the substrate, the first metal electrode is electrically connected to the emitter, and the second metal electrode is electrically connected to the doped polycrystalline silicon layer.
9. The solar cell as claimed in claim 8, characterized in that, The first metal electrode is in contact with the emitter, and the substrate thickness of the contact portion of the first metal electrode within the substrate ranges from 0 nm to 100 nm.
10. A solar cell module, characterized in that, Includes one or more solar cells as described in any one of claims 1 to 9.