Solar cells, cell strings and photovoltaic modules

Abstract

The present application provides a solar cell, a cell string and a photovoltaic module, wherein the solar cell comprises: a semiconductor substrate; a plurality of emitters, each of which has a plurality of first teeth and a plurality of second teeth, the plurality of first teeth are arranged at intervals in the first direction, the plurality of second teeth are arranged at intervals in the second direction, and one end of each second tooth is connected to the corresponding first tooth; a plurality of bases, each of which has a plurality of third teeth and a plurality of fourth teeth, the plurality of third teeth are arranged at intervals in the first direction, the plurality of fourth teeth are arranged at intervals in the second direction, and one end of each fourth tooth is connected to the corresponding third tooth, the plurality of first teeth and the plurality of third teeth are arranged alternately in the first direction, and the plurality of second teeth and the plurality of fourth teeth are arranged alternately in the second direction. The solar cell, cell string and photovoltaic module of the present application can reduce the distance for the base to collect carriers, and at the same time have lower requirements for metallization equipment.

Description

Technical Field

[0001] The present application mainly relates to the field of photovoltaic technology, and in particular to a solar cell, a battery string and a photovoltaic module. Background Art

[0002] Full back contact cells are beautiful and efficient, and are increasingly widely used in the solar cell industry. The emitter and base in the full back contact cell are arranged alternately on the back of the cell. This arrangement determines that the carriers need to move laterally in the semiconductor substrate to reach the emitter and base, so the pitch between adjacent emitter electrodes and base electrodes has a greater impact on the cell conversion efficiency. Ideally, the smaller the pitch size, the higher the cell conversion efficiency, but at the same time, the requirements for metallization equipment stability and alignment accuracy are also higher. How to reduce the distance for the base to collect carriers while reducing the requirements for metallization equipment is one of the important research directions in this field. Utility Model Content

[0003] The technical problem to be solved by the present application is to provide a solar cell, a cell string and a photovoltaic module, which can reduce the distance for the base to collect carriers and have lower requirements for metallization equipment.

[0004] To solve the above technical problems, the present application provides a solar cell, comprising: a semiconductor substrate; a plurality of emitters, located on the back side of the semiconductor substrate, each of the emitters having a plurality of first teeth and a plurality of second teeth, the plurality of first teeth being arranged at intervals in a first direction, the plurality of second teeth being arranged at intervals in a second direction, and one end of each second tooth being connected to a corresponding first tooth; a plurality of bases, located on the back side of the semiconductor substrate, each of the bases having a plurality of third teeth and a plurality of fourth teeth, the plurality of third teeth being arranged at intervals in the first direction, the plurality of fourth teeth being arranged at intervals in the second direction, one end of each fourth tooth being connected to a corresponding third tooth, the plurality of first teeth and the plurality of third teeth being arranged alternately in the first direction, the plurality of second teeth and the plurality of fourth teeth being arranged alternately in the second direction; and a plurality of emitter electrodes and a plurality of base electrodes, the plurality of emitter electrodes being electrically connected to the corresponding emitters, and the plurality of base electrodes being electrically connected to the corresponding bases.

[0005] In an embodiment of the present application, the emitter electrode is located above the first tooth portion, and the extending direction of the emitter electrode is the same as that of the first tooth portion.

[0006] In an embodiment of the present application, the base electrode is located above the third tooth portion, and the extension direction of the base electrode is the same as that of the third tooth portion.

[0007] In an embodiment of the present application, a distance between adjacent emitter electrodes and base electrodes is less than 750 μm.

[0008] In an embodiment of the present application, the width of the first tooth portion is less than 100 μm, and the width of the second tooth portion is less than 300 μm.

[0009] In an embodiment of the present application, the width of the third tooth portion is less than 100 μm, and the width of the fourth tooth portion is less than 200 μm.

[0010] In an embodiment of the present application, a spacing region is provided between adjacent teeth with opposite polarities, and a width of the spacing region is less than 70 μm.

[0011] In an embodiment of the present application, the distance between the second teeth is less than 750 μm.

[0012] On the other hand, the present application further provides a battery string, comprising a plurality of solar cells as described above.

[0013] On the other hand, the present application also provides a photovoltaic module, comprising the battery string as described above.

[0014] Compared with the prior art, this application has the following advantages:

[0015] (1) In addition to forming a fork-tine structure in the first direction D1, the solar cell of the present application also forms a fork-tine structure in the second direction D2, which can reduce the distance for the base to collect carriers.

[0016] (2) Compared with a solar cell that forms a fork-tooth structure only in the first direction D1, the solar cell of the present application forms a fork-tooth structure in both the first direction D1 and the second direction D2. This can reduce the distance for the base to collect carriers under the same electrode spacing, thereby avoiding the increase in the requirements for metallization equipment due to reducing the electrode spacing. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] 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:

[0018] Figure 1 is a three-dimensional schematic diagram of a solar cell in one embodiment of the present application;

[0019] Figure 2 yes Figure 1 A partial enlarged schematic diagram of a solar cell;

[0020] Figure 3It is a three-dimensional schematic diagram of a solar cell in a comparative example. DETAILED DESCRIPTION

[0021] 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.

[0022] As shown in this application and claims, unless the context clearly indicates an exception, the words "a", "an", "an" and / or "the" do not refer to the singular and may 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.

[0023] 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 present application. At the same time, 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 the actual proportional relationship. The technology, method and equipment known to those of ordinary skill in the relevant field may not be discussed in detail, but in appropriate cases, the technology, method and equipment should be considered as a part of the authorization 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, so that once a certain item is defined in an accompanying drawing, it does not need to be further discussed in subsequent drawings.

[0024] 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.

[0025] 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.

[0026] 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.

[0027] Next, the solar cell, battery string and photovoltaic module of the present application are described through embodiments.

[0028] refer to Figure 1 A three-dimensional schematic diagram of a solar cell in an embodiment shown in FIG. Figure 2 shown Figure 1 A partial enlarged schematic diagram of a solar cell, where: Figure 2 Indicated Figure 1 The solar cell on the left side of the dashed cross section. Figure 1 and Figure 2 In the embodiment of the present invention, the solar cell includes a semiconductor substrate 110, multiple emitters 120, multiple bases 130, multiple emitter electrodes 140 and multiple base electrodes 150, the emitters 120 and the bases 130 are located on the back side of the semiconductor substrate 110, the emitter electrodes 140 are electrically connected to the corresponding emitters 120, and the base electrodes 150 are electrically connected to the corresponding bases 130.

[0029] Specifically, the semiconductor substrate 110 has a front side and a back side opposite to each other. When the solar cell is working, the front side faces the sun and the back side faces away from the sun. The semiconductor substrate 110 can be N-type doped or P-type doped.

[0030] The emitter 120 is located on the back side of the semiconductor substrate 110. The emitter 120 has a plurality of first teeth 121 and a plurality of second teeth 122. The plurality of first teeth 121 are arranged at intervals in the first direction D1, and each first tooth 121 extends along the second direction D2. The plurality of second teeth 122 are arranged at intervals in the second direction D2, and each second tooth 122 extends along the first direction D1.

[0031] One end of each second tooth portion 122 is connected to the corresponding first tooth portion 121 to Figure 1 The first tooth portion 121 on the left side is taken as an example for specific description. Figure 1 As shown, there are four second tooth portions 122 connected to the first tooth portion 121 located on the left side, wherein two second tooth portions 122 are located on the left side of the first tooth portion 121, and the right ends of the two second tooth portions 122 are connected to the first tooth portion 121, and two second tooth portions 122 are located on the right side of the first tooth portion 121, and the left ends of the two second tooth portions 122 are connected to the first tooth portion 121.

[0032] In one embodiment, the width of the first tooth portion 121 is less than 100 μm, for example, the width is 10 μm, 20 μm, 30 μm, 40 μm, 50 μm, 60 μm, 70 μm, 80 μm or 90 μm. The width of the second tooth portion 122 is less than 300 μm, for example, the width is 50 μm, 100 μm, 150 μm, 200 μm or 250 μm. If the width of the first tooth portion 121 and the second tooth portion 122 is too large, the distance of the base collecting carriers will increase.

[0033] A plurality of base electrodes 130 are located on the back side of the semiconductor substrate 110, and each base electrode 130 has a plurality of third tooth portions 131 and a plurality of fourth tooth portions 132. The plurality of third tooth portions 131 are arranged at intervals in the first direction D1, and each third tooth portion 131 extends along the second direction D2. The plurality of fourth tooth portions 132 are arranged at intervals in the second direction D2, and each fourth tooth portion 132 extends along the first direction D1.

[0034] One end of each fourth tooth portion 132 is connected to the corresponding third tooth portion 131 to Figure 1 The third tooth portion 131 located in the middle is taken as an example for specific description. Figure 1As shown, there are six fourth tooth portions 132 connected to the third tooth portion 131 located in the middle, wherein three fourth tooth portions 132 are located on the left side of the third tooth portion 131, and the right ends of the three fourth tooth portions 132 are connected to the third tooth portion 131, and three fourth tooth portions 132 are located on the right side of the third tooth portion 131, and the left ends of the three fourth tooth portions 132 are connected to the third tooth portion 131.

[0035] In one embodiment, the width of the third tooth 131 is less than 100 μm, for example, the width is 10 μm, 20 μm, 30 μm, 40 μm, 50 μm, 60 μm, 70 μm, 80 μm or 90 μm. The width of the fourth tooth 132 is less than 200 μm. For example, the width is 20 μm, 40 μm, 60 μm, 80 μm, 100 μm, 120 μm, 140 μm, 160 μm or 180 μm. If the width of the third tooth 131 and the fourth tooth 132 is too large, the distance of carrier transmission to the electrode will be increased.

[0036] refer to Figure 1 As shown, the first teeth 121 and the third teeth 131 are arranged alternately in the first direction D1, and the second teeth 122 and the fourth teeth 132 are arranged alternately in the second direction D2. Thus, in the first direction D1, the first teeth 121 and the third teeth 131 form a fork structure; in the second direction D2, the second teeth 122 and the fourth teeth 132 form a fork structure. Forming the fork structure in the first direction D1 and the second direction D2 is beneficial to reducing the distance for the base to collect carriers ( Figure 3 The curve with arrows in the figure shows the flow path of the carriers. Figure 3 As shown, in Figure 3 In the comparative example, the emitter and the base have no teeth structure arranged at intervals in the second direction D2, and the emitter and the base only form a fork structure in the first direction D1. Figure 3 The distance for the base to collect carriers is longer. Figure 1 and Figure 2 As shown, in addition to forming a fork structure in the first direction D1, the solar cell of the present application also forms a fork structure in the second direction D2 through the second tooth portion 122 and the fourth tooth portion 132, which can reduce the distance for the base to collect carriers ( Figure 2 The curved lines with arrows in the figure illustrate the flow paths of the charge carriers.

[0037] In one embodiment, a spacing region is provided between adjacent teeth of opposite polarity, and the width of the spacing region is less than 70 μm. Figure 1 As shown, in the first direction D1, a spacing area 161 is provided between the first tooth portion 121 and the fourth tooth portion 132; Figure 2As shown, in the second direction D2, a spacer 162 is provided between the second tooth portion 122 and the fourth tooth portion 132, and the spacer can electrically isolate the teeth with opposite polarities. The width of the spacer can be 10 μm, 20 μm, 30 μm, 40 μm, 50 μm or 60 μm, and a smaller width of the spacer can reduce the transmission distance of the carriers.

[0038] In one embodiment, reference Figure 2 As shown, the distance between the adjacent second teeth 122 in the second direction D2 is less than 750 μm, for example, the distance between the adjacent second teeth 122 is 50 μm, 150 μm, 200 μm, 250 μm, 300 μm, 350 μm, 400 μm, 450 μm, 500 μm, 550 μm, 600 μm, 650 μm or 700 μm. If the distance between the second teeth 122 is too large, the distance for the base to collect carriers will increase.

[0039] Back to Figure 1 As shown, a plurality of emitter electrodes 140 are arranged at intervals in the first direction D1, each emitter electrode 140 extends along the second direction D2, each emitter electrode 140 is located above the corresponding first tooth portion 121, and the emitter electrode 140 is electrically connected to the corresponding first tooth portion 121. A plurality of base electrodes 150 are arranged at intervals in the first direction D1, each base electrode 150 extends along the second direction D2, each base electrode 150 is located above the corresponding third tooth portion 131, and the base electrode 150 is electrically connected to the corresponding third tooth portion 131.

[0040] Compared with a solar cell that only forms a fork-tooth structure in the first direction D1, since the solar cell of the present application forms a fork-tooth structure in both the first direction D1 and the second direction D2, the solar cell of the present application can reduce the distance at which the base collects carriers under the same electrode pitch, thereby avoiding the increase in the requirements for metallization equipment due to reducing the electrode pitch.

[0041] In one embodiment, the distance between the emitter electrode 140 and the base electrode 150 adjacent to each other in the first direction D1 is less than 750 μm, for example, 50 μm, 100 μm, 150 μm, 200 μm, 250 μm, 300 μm, 350 μm, 400 μm, 450 μm, 500 μm, 550 μm, 600 μm, 650 μm or 700 μm. If the distance between the emitter electrode 140 and the base electrode 150 is too large, the transmission path of the carriers will be longer.

[0042] On the other hand, the present application further provides a battery string, which includes a plurality of solar cells as described above.

[0043] On the other hand, the present application also provides a photovoltaic module, which includes the battery string as described above.

[0044] The basic concepts have been described above. Obviously, for those skilled in the art, the above application disclosure is only 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.

[0045] 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.

[0046] 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 application embodiments, in the above description of the embodiments of this application, multiple features are sometimes merged into one embodiment, figure or description thereof. However, this disclosure method does not mean that the features required by the object of this application are more than the features mentioned in the claims. In fact, the features of the embodiments are less than all the features of the single embodiment disclosed above.

[0047] 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 and claims 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 digits. Although the numerical domains and parameters used to confirm the breadth of their 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.

[0048] 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 claims of the present application.

Claims

1. A solar cell, characterized in that: include: Semiconductor substrate; A plurality of emitters, located on the back side of the semiconductor substrate, each of the emitters having a plurality of first teeth and a plurality of second teeth, the plurality of first teeth are arranged at intervals in a first direction, the plurality of second teeth are arranged at intervals in a second direction, and one end of each second tooth is connected to the corresponding first tooth; A plurality of bases, located on the back side of the semiconductor substrate, each of the bases having a plurality of third teeth and a plurality of fourth teeth, the plurality of third teeth are arranged at intervals in the first direction, the plurality of fourth teeth are arranged at intervals in the second direction, one end of each fourth tooth is connected to the corresponding third tooth, the plurality of first teeth and the plurality of third teeth are arranged alternately in the first direction, and the plurality of second teeth and the plurality of fourth teeth are arranged alternately in the second direction; as well as A plurality of emitter electrodes and a plurality of base electrodes, wherein the plurality of emitter electrodes are electrically connected to corresponding emitters, and the plurality of base electrodes are electrically connected to corresponding bases.

2. The solar cell according to claim 1, wherein: The emitter electrode is located above the first tooth portion, and an extending direction of the emitter electrode is the same as that of the first tooth portion.

3. The solar cell according to claim 1, wherein: The base electrode is located above the third tooth portion, and the extension direction of the base electrode is the same as that of the third tooth portion.

4. The solar cell according to claim 1, wherein: The distance between adjacent emitter electrodes and base electrodes is less than 750 μm.

5. The solar cell according to claim 1, wherein: The width of the first tooth portion is less than 100 μm, and the width of the second tooth portion is less than 300 μm.

6. The solar cell according to claim 1, wherein: The width of the third tooth portion is less than 100 μm, and the width of the fourth tooth portion is less than 200 μm.

7. The solar cell according to claim 1, wherein: A spacing region is arranged between adjacent teeth with opposite polarities, and a width of the spacing region is less than 70 μm.

8. The solar cell according to claim 1, wherein: The distance between the second teeth is less than 750 μm.

9. A battery string, characterized in that: The invention comprises a plurality of solar cells according to any one of claims 1 to 8.

10. A photovoltaic module, characterized in that: Comprising the battery string as claimed in claim 9.

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