Solar cells and photovoltaic modules

Abstract

The application provides a solar cell and a photovoltaic module. The solar cell comprises a semiconductor region and a plurality of sub-grids arranged at intervals on at least one side of the semiconductor region in a first direction. Each sub-grid comprises a first layer and a second layer stacked together. The second layer has a width greater than that of the first layer. The second layer has a first blocking portion and a second blocking portion opposite to each other in the first direction. The first and second blocking portions extend towards the semiconductor region and protrude from the side of the first layer in the first direction. The first and second blocking portions extend towards the semiconductor region and protrude from the side of the first layer. During the process of flowing of the adhesive film towards the side of the first layer, the first and second blocking portions have a blocking effect on the adhesive film, thereby preventing (or reducing) the contact between the adhesive film and the side of the first layer, and avoiding the corrosion of the first layer by the adhesive film.

Description

Technical Field

[0001] This application relates primarily to the field of photovoltaic technology, and more particularly to a solar cell and a photovoltaic module. Background Technology

[0002] Metal grid lines in solar cells are used to collect charge carriers generated within the cell. During the lamination process, the encapsulant film may corrode the metal grid lines, which adversely affects the performance of the solar cell. Therefore, how to prevent the encapsulant film from corroding the metal grid lines is one of the important research directions in this field. Summary of the Invention

[0003] The technical problem to be solved by this application is to provide a solar cell and a photovoltaic module that can avoid the corrosion of metal grid lines by the encapsulant film.

[0004] To address the aforementioned technical problems, this application provides a solar cell, comprising: a semiconductor region; and a plurality of sub-gates, the plurality of sub-gates being spaced apart in a first direction on at least one side of the semiconductor region, each of the sub-gates comprising a stacked first layer and a second layer, the width of the second layer being greater than the width of the first layer, the second layer having a first blocking portion and a second blocking portion opposite to each other in the first direction, wherein the first blocking portion and the second blocking portion extend toward the semiconductor region, and the first blocking portion and the second blocking portion protrude from the side of the first layer in the first direction.

[0005] In one embodiment of this application, the maximum distance between the first blocking portion and the adjacent first layer side surface in the first direction is greater than 0 μm and equal to or less than 5 μm, and / or the maximum distance between the second blocking portion and the adjacent first layer side surface in the first direction is greater than 0 μm and equal to or less than 5 μm.

[0006] In one embodiment of this application, the acid corrosion resistance of the second layer is stronger than that of the first layer.

[0007] In one embodiment of this application, the cross-section of the first layer is rectangular, and the cross-section of the second layer is triangular, wherein the angle between the two hypotenuses of the triangular shape and the horizontal line is greater than 45° and less than 90°.

[0008] In one embodiment of this application, the material of the first layer includes silver, and the material of the second layer includes a base metal.

[0009] In one embodiment of this application, the second layer is formed after the first layer is sintered.

[0010] In one embodiment of this application, the method for forming the second layer includes screen printing sintering or electroplating.

[0011] This application also proposes a photovoltaic module, comprising: a cover plate; a solar cell as described above; and a back sheet, wherein an adhesive film is filled between the solar cell and the cover plate, and between the solar cell and the back sheet.

[0012] In one embodiment of this application, the adhesive film filling portion is located in the space below the first blocking portion and the second blocking portion.

[0013] In one embodiment of this application, the adhesive film does not fill the space located below the first blocking portion and the second blocking portion.

[0014] Compared with the prior art, the present application has the following advantages: the first blocking part and the second blocking part of the present application extend toward the semiconductor region and both protrude from the side of the first layer. During the process of the adhesive film flowing toward the side of the first layer, the first blocking part and the second blocking part have a blocking effect on the adhesive film, thereby preventing (or reducing) the contact between the adhesive film and the side of the first layer, and thus avoiding the adhesive film from corroding the first layer. Attached Figure Description

[0015] 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:

[0016] Figure 1 This is a top view schematic diagram of a solar cell according to an embodiment of this application;

[0017] Figure 2 This is a schematic cross-sectional view of the sub-gate in one embodiment of this application;

[0018] Figure 3 This is a cross-sectional schematic diagram of the sub-gate in another embodiment of this application;

[0019] Figure 4 This is a cross-sectional schematic diagram of the sub-gate in one embodiment of this application.

[0020] Figure Labels

[0021] Semiconductor region 110, second layer 122

[0022] Sub-gate 120 First blocking part 122a

[0023] First layer 121 Second blocking section 122b

[0024] First side panel 121a Main grille 130

[0025] Second side 121b Detailed Implementation

[0026] 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.

[0027] 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.

[0028] 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.

[0029] 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.

[0030] 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.

[0031] 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.

[0032] The solar cells and photovoltaic modules of this application will be described below through examples.

[0033] Figure 1 This is a top view schematic diagram of a solar cell in one embodiment. Figure 2 This is a schematic cross-sectional view of the sub-gate in one embodiment. (Reference) Figure 1 and Figure 2 As shown, in Figure 1 and Figure 2 In one embodiment, the solar cell includes a semiconductor region 110 and multiple sub-gates 120. Charge carriers are transported through the semiconductor region 110 to the multiple sub-gates 120. To better understand the semiconductor region 110, an example is given here: for a solar cell including a tunnel oside passivated contact structure, the semiconductor region 110 can be a tunnel oside passivated contact structure, and the sub-gates 120 can contact a doped polycrystalline silicon layer in the tunnel oside passivated contact structure.

[0034] Multiple sub-gates 120 are spaced apart on one side of the semiconductor region 110 in a first direction D1. Alternatively, multiple sub-gates 120 can be arranged on the other side of the semiconductor region 110, or multiple sub-gates 120 can be arranged on both sides of the conductor region 110. The solar cell may also include multiple main gates 130 spaced apart in a second direction D2, each main gate 130 being electrically connected to multiple sub-gates 120.

[0035] refer to Figure 2 As shown, the sub-gate 120 includes a first layer 121 and a second layer 122. The first layer 121 is in contact with the semiconductor region 110, and the bottom surface of the second layer 122 is in contact with the top surface of the first layer 121. The width W2 of the second layer 122 is greater than the width W1 of the first layer 121. "Width W2" refers to the maximum dimension of the second layer 122 in the first direction D1, and "width W1" refers to the maximum dimension of the first layer 121 in the first direction D1. The second layer 122 has a first blocking portion 122a and a second blocking portion 122b opposite to each other in the first direction D1. The first blocking portion 122a extends toward the semiconductor region 110 in the thickness direction D3. The first layer 121 has a first side surface 121a and a second side surface 121b opposite to each other in the first direction D1. The first blocking portion 122a protrudes beyond the first side surface 121a in the first direction D1, or in other words, the first blocking portion 122a is located to the right of the first side surface 121a in the first direction D1. The second blocking portion 122b extends toward the semiconductor region 110 in the thickness direction D3. The second blocking portion 122b protrudes from the second side surface 121b in the first direction D1, or in other words, the second blocking portion 122b is located to the left of the second side surface 121b in the first direction D1.

[0036] During the fabrication of solar cells into laminates, the compressed adhesive film flows to the sub-gate and may come into contact with it, thus corroding the sub-gate. In this application, the first blocking portion 122a and the second blocking portion 122b extend toward the semiconductor region 110 and both protrude from the side of the first layer 121. As the adhesive film flows toward the side of the first layer 121, the first blocking portion 122a and the second blocking portion 122b act as a barrier, thereby preventing (or reducing) contact between the adhesive film and the side of the first layer 121, and thus avoiding corrosion of the first layer 121 by the adhesive film.

[0037] In one embodiment, the second layer 122 has stronger acid corrosion resistance than the first layer 121. Specifically, the second layer 122 is located above the first layer 121. The stronger acid corrosion resistance of the second layer 122 can improve its own resistance to acidic film corrosion, and can also prevent acidic film from penetrating the second layer 122 to corrode the first layer 121.

[0038] refer to Figure 2and Figure 3 As shown, in one embodiment, the maximum distance d1 between the first blocking portion 122a and the first side surface 121a in the first direction D1 is greater than 0 μm and equal to or less than 5 μm. For example, the maximum distance d1 is 1 μm, 2 μm, 3 μm, 4 μm, or 5 μm. Similarly, the maximum distance d2 between the second blocking portion 122b and the second side surface 121b in the first direction D1 is greater than 0 μm and equal to or less than 5 μm. For example, the maximum distance d2 is 1 μm, 2 μm, 3 μm, 4 μm, or 5 μm. This application has found that when the maximum distance between the blocking portion and the side surface of the first layer is greater than 0 μm and equal to or less than 5 μm, the blocking portion can prevent (or reduce) the contact between the adhesive film and the side surface of the first layer, and can also avoid the secondary grid blocking too much light due to the excessive distance between them.

[0039] refer to Figure 2 As shown, in one embodiment, the cross-section of the first layer 121 is rectangular, and the cross-section of the second layer 122 is triangular in shape. "Triangular in shape" means that the cross-section generally presents a triangular appearance. The angle between the two hypotenuses of the triangular shape and the horizontal line is greater than 45° and less than 90°. Specifically, the angle between the left hypotenuse of the triangle and the horizontal line is α, which is greater than 45° and less than 90°, for example, 55°, 65°, 75°, or 85°. The angle between the right hypotenuse of the triangle and the horizontal line is β, which is greater than 45° and less than 90°, for example, 55°, 65°, 75°, or 85°. An angle greater than 45° and less than 90° can reflect light incident on the hypotenuses back to the semiconductor region 110.

[0040] The cross-sectional shape of the first layer 121 is not limited to Figure 2 The rectangle in the second layer 122 has a cross-sectional shape that is not limited to... Figure 2 Triangle-like structures. For example, in... Figure 3 In one embodiment, the cross-section of the second layer 122 is trapezoidal, meaning that the cross-section is generally trapezoidal.

[0041] In one embodiment, the width of the second layer 122 is 5μm to 20μm, for example, the width is 5μm, 10μm, 15μm or 20μm, and the height of the second layer 122 is 1μm to 10μm, for example, the height is 1μm, 3μm, 5μm, 7μm, 9μm or 10μm.

[0042] In one embodiment, the first layer 121 is made of silver, and the second layer 122 is made of base metal. "Base metal" is the opposite of "precious metal," and includes metals such as copper and aluminum that are cheaper than precious metals. For example, the second layer 122 may be made of aluminum. The second layer 122 may or may not contain silver. Removing silver from the second layer 122 reduces the amount of silver used in manufacturing the sub-gate. Preferably, when the second layer 122 contains silver, the silver content in the second layer 122 is less than the silver content in the first layer 121, thus reducing the amount of silver used and consequently lowering the cost of the sub-gate.

[0043] In one embodiment, a second layer 122 is formed after the first layer 121 is sintered. Specifically, a paste for forming the first layer 121 is first printed; then, the paste is sintered to form the first layer 121; subsequently, the second layer 122 is formed. Methods for forming the second layer 122 include screen printing sintering or electroplating.

[0044] This application also proposes a photovoltaic module, which includes a cover plate, a solar cell as described above, and a backsheet, wherein the solar cell is located between the cover plate and the backsheet, and an encapsulating film is filled between the solar cell and the cover plate, and between the solar cell and the backsheet. (Reference) Figure 4 As shown, the space below the first blocking portion 122a is marked as S1, and the space below the second blocking portion 122b is marked as S2. In one embodiment, the adhesive film fills a portion of space S1 and a portion of space S2. In another embodiment, the adhesive film does not fill spaces S1 and S2, meaning there is no adhesive film in spaces S1 and S2. Filling spaces S1 and S2 with adhesive film reduces the contact area between the adhesive film and the side surface of the first layer 121, thereby reducing corrosion of the first layer 121 by the adhesive film. Not filling spaces S1 and S2 with adhesive film avoids contact between the adhesive film and the side surface of the first layer 121, thereby preventing corrosion of the first layer 121 by the adhesive film.

[0045] 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.

[0046] 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.

[0047] Some aspects of this application can be executed entirely by hardware, entirely by software (including firmware, resident software, microcode, etc.), or by a combination of hardware and software. The aforementioned hardware or software may be referred to as a "data block," "module," "engine," "unit," "component," or "system." The processor may be one or more application-specific integrated circuits (ASICs), digital signal processors (DSPs), digital signal processing devices (DAPDs), programmable logic devices (PLDs), field-programmable gate arrays (FPGAs), processors, controllers, microcontrollers, microprocessors, or combinations thereof. Furthermore, aspects of this application may manifest as computer products residing in one or more computer-readable media, including computer-readable program code. For example, computer-readable media may include, but are not limited to, magnetic storage devices (e.g., hard disks, floppy disks, magnetic tapes, etc.), optical discs (e.g., compressed CDs, digital multifunction DVDs, etc.), smart cards, and flash memory devices (e.g., cards, sticks, key drives, etc.).

[0048] A computer-readable medium may contain a propagated data signal containing computer program code, for example, on baseband or as part of a carrier wave. This propagated signal may take various forms, including electromagnetic, optical, and so on, or suitable combinations thereof. A computer-readable medium can be any computer-readable medium other than a computer-readable storage medium, which can be connected to an instruction execution system, apparatus, or device to enable communication, propagation, or transmission of a program for use. The program code located on the computer-readable medium can be propagated through any suitable medium, including radio, cable, fiber optic cable, radio frequency signals, or similar media, or any combination of the above media.

[0049] 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.

[0050] 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.

[0051] 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: Semiconductor region; A plurality of sub-gates are spaced apart in a first direction and arranged at least on one side of the semiconductor region. Each sub-gate includes a stacked first layer and a second layer, the width of the second layer being greater than the width of the first layer. The second layer has a first blocking portion and a second blocking portion opposite to each other in the first direction, wherein the first blocking portion and the second blocking portion extend toward the semiconductor region and protrude from the side of the first layer in the first direction to form a first space and a second space below the first blocking portion and the second blocking portion, respectively. The first space and the second space expose the side of the first layer. The maximum distance between the first blocking portion and the adjacent side of the first layer in the first direction is greater than 0 μm and equal to or less than 5 μm, and / or the maximum distance between the second blocking portion and the adjacent side of the first layer in the first direction is greater than 0 μm and equal to or less than 5 μm. The method of forming the second layer includes screen printing and sintering.

2. The solar cell as described in claim 1, characterized in that, The second layer has a stronger acid corrosion resistance than the first layer.

3. The solar cell as described in claim 1, characterized in that, The first layer has a rectangular cross-section, and the second layer has a triangular cross-section. The angle between the two hypotenuses of the triangular shape and the horizontal line is greater than 45° and less than 90°.

4. The solar cell as described in claim 1, characterized in that, The first layer is made of silver, and the second layer is made of base metals.

5. The solar cell as described in claim 1, characterized in that, After the first layer is formed by sintering, the second layer is formed.

6. A photovoltaic module, characterized in that, include: Cover plate; The solar cell as described in any one of claims 1 to 5; A backsheet is provided, and an adhesive film is filled between the solar cell and the cover plate, and between the solar cell and the backsheet.

7. The photovoltaic module as described in claim 6, characterized in that, The adhesive film filling portion is located in the space below the first blocking portion and the second blocking portion.

8. The photovoltaic module as described in claim 6, characterized in that, The adhesive film does not fill the space located below the first and second blocking portions.

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