Solar cell and method of manufacturing the same

Abstract

The application provides a solar cell and a manufacturing method thereof. The solar cell comprises a first transparent conductive layer and a first wrap plating layer on the front side; and a second transparent conductive layer and a second wrap plating layer on the back side of a photoelectric conversion unit. In an embodiment, the second wrap plating layer is at least partially connected with the first wrap plating layer, and a blank area is formed on the outer side of the second transparent conductive layer. Compared with the prior art, the blank area is reduced, the collection of carriers is increased through the second transparent conductive layer and the second wrap plating layer, the photoelectric conversion efficiency of the solar cell is improved, and the leakage phenomenon is avoided. In another embodiment, an anti-reflection insulating layer is arranged between the second wrap plating layer and the first wrap plating layer. The anti-reflection insulating layer can prevent leakage on one hand, and can also ensure the collection of photons in the covering area on the outer side of the photoelectric conversion unit on the other hand, so that the photoelectric conversion efficiency of the solar cell is improved.

Description

Technical Field

[0001] This invention relates to the field of solar cell technology, and more specifically to a solar cell and its manufacturing method. Background Technology

[0002] A solar cell is a device that converts sunlight into electrical energy through the photovoltaic effect. Currently, the most common type of solar cell is the silicon solar cell, which uses a PN structure made of silicon semiconductor material to form a photoelectric conversion unit, which converts light energy into electrical signals.

[0003] Improving the photoelectric conversion efficiency of solar cells is a topic of widespread concern in the industry. Summary of the Invention

[0004] In view of the problems in the prior art, the purpose of this invention is to provide a solar cell and a method for manufacturing the same, so as to solve the problem of low photoelectric conversion efficiency of solar cells in the prior art.

[0005] This invention provides a type of solar cell, comprising:

[0006] Photoelectric conversion unit;

[0007] The first transparent conductive layer and the first surrounding coating layer located on the front of the photoelectric conversion unit;

[0008] The second transparent conductive layer located on the back of the photoelectric conversion unit and the second wrap-around coating layer on its outer side;

[0009] The first electrode is located on the side of the first transparent conductive layer opposite to the photoelectric conversion unit;

[0010] The second electrode is located on the side of the second transparent conductive layer opposite to the photoelectric conversion unit;

[0011] The positional relationship between the first surrounding coating and the second surrounding coating is set as follows:

[0012] The first and second coating layers are at least partially in contact, and the second transparent conductive layer is divided into a first section and a second section from top to bottom. The second coating layer is formed in the first section, and a blank area is formed on the outer side of the second section; or,

[0013] An anti-reflective insulating layer is provided between the first and second coating layers.

[0014] In an alternative embodiment, the first partition and the second partition are configured as a stacked structure formed in different process steps.

[0015] In an optional embodiment, the second transparent conductive layer includes a first sub-transparent conductive layer and a second sub-transparent conductive layer. The second sub-transparent conductive layer has a body segment covering the first sub-transparent conductive layer and an epitaxial segment extending outward from the body segment along the back side of the photoelectric conversion unit.

[0016] The first partition is formed in the epitaxial segment and the first sub-transparent conductive layer inside the epitaxial segment;

[0017] The second partition is formed in the body segment and the first sub-transparent conductive layer covering the body segment.

[0018] In an alternative embodiment, the thickness of the first partition is less than that of the second partition.

[0019] In an optional embodiment, the solar cell further includes:

[0020] The third transparent conductive layer and the third surrounding coating layer on its outer side;

[0021] The third transparent conductive layer is located between the second transparent conductive layer and the photoelectric conversion unit; both the first and third surrounding coating layers are located inside the anti-reflection insulating layer and are at least partially in contact with it; or

[0022] The third transparent conductive layer is located on the side of the second transparent conductive layer away from the photoelectric conversion unit, and the first and third surrounding coatings are located on the outside of the anti-reflection insulation and are at least in contact.

[0023] In an optional embodiment, the photoelectric conversion unit is a heterojunction photoelectric conversion unit.

[0024] This invention also provides a method for manufacturing a solar cell, comprising:

[0025] Fabrication of photoelectric conversion unit;

[0026] A first transparent conductive layer and a first wrap-around layer are formed on the front side of the photoelectric conversion unit;

[0027] A second transparent conductive layer and a second wrap-around layer are formed on the back of the photoelectric conversion unit;

[0028] A first electrode is formed on the side of the first transparent conductive layer opposite to the photoelectric conversion unit, and a second electrode is formed on the side of the second transparent conductive layer opposite to the photoelectric conversion unit.

[0029] The positional relationship between the first and second surrounding coatings is set as follows:

[0030] The first and second coating layers are at least partially in contact, and the second transparent conductive layer is divided into a first section and a second section from top to bottom. The second coating layer is formed in the first section, and a blank area is formed on the outside of the second section; or,

[0031] An anti-reflective insulating layer is formed between the first and second coating layers.

[0032] In an optional embodiment, a second transparent conductive layer and a second surrounding coating are formed on the back side of the photoelectric conversion unit, including:

[0033] A first sub-transparent conductive layer is formed on the back of the photoelectric conversion unit, and the first sub-transparent conductive layer serves as the first partition.

[0034] A second sub-transparent conductive layer is formed on the side of the first sub-transparent conductive layer that is away from the photoelectric conversion unit, and the second sub-transparent conductive layer serves as the second partition.

[0035] In an optional embodiment, a second transparent conductive layer and a second surrounding coating are formed on the back side of the photoelectric conversion unit, including:

[0036] A first sub-transparent conductive layer is formed on the back side of the photoelectric conversion unit;

[0037] A second sub-transparent conductive layer is fabricated. The second sub-transparent conductive layer has a body segment covering the first sub-transparent conductive layer and an epitaxial segment extending outward from the body segment along the back side of the photoelectric conversion unit. A first partition is formed on the epitaxial segment and the first sub-transparent conductive layer inside the epitaxial segment. A second coating layer is formed on the epitaxial segment. A second partition is formed on the body segment and the first sub-transparent conductive layer covered by the body segment. The first sub-transparent conductive layer and the second sub-transparent conductive layer constitute the second transparent layer.

[0038] In an alternative embodiment, the thickness of the first partition is less than that of the second partition.

[0039] In an optional embodiment, the method for manufacturing a solar cell further includes:

[0040] Before or after the formation of the second transparent conductive layer, the second wrap-around coating, and the anti-reflection insulating layer, a third transparent conductive layer and a third wrap-around coating on the outer side of the photoelectric conversion unit are formed on the back side of the unit.

[0041] The first and third coating layers are both located on the same side of the antireflective insulating layer and are at least partially in contact.

[0042] In an optional embodiment, the photoelectric conversion unit is a heterojunction photoelectric conversion unit.

[0043] The solar cell and its manufacturing method provided by this invention have the following advantages:

[0044] In one embodiment of the solar cell, the second wrap-around coating is at least partially in contact with the first wrap-around coating, and the second transparent conductive layer is divided into a first partition and a second partition from top to bottom. The second wrap-around coating is formed in the first partition, and a blank area is formed on the outside of the second partition. This reduces the blank area compared to related technologies, and while avoiding leakage, it increases the collection of charge carriers through the second transparent conductive layer and the second wrap-around coating, thereby improving the photoelectric conversion efficiency of the solar cell.

[0045] In another embodiment, an anti-reflection insulating layer is provided between the second and first coating layers. This layer not only isolates the interaction between the first and second coating layers but also ensures light intake in the covered area. In this embodiment, there is no blank area around the second transparent conductive layer, but by providing the anti-reflection insulating layer, leakage can be prevented, and photon collection in the covered area outside the photoelectric conversion unit can be ensured, thereby improving the photoelectric conversion efficiency of the solar cell. Attached Figure Description

[0046] Other features, objects, and advantages of the invention will become more apparent from the following detailed description of non-limiting embodiments with reference to the accompanying drawings.

[0047] Figure 1 A cross-sectional view of a solar cell of a related technology;

[0048] Figure 2 A cross-sectional view of a solar cell provided in an embodiment of this disclosure;

[0049] Figure 3 One of the cross-sectional views of a solar cell provided in an embodiment of this disclosure;

[0050] Figure 4 A second cross-sectional view of a solar cell provided in an embodiment of this disclosure;

[0051] Figure 5 A third cross-sectional view of a solar cell provided in an embodiment of this disclosure;

[0052] Figure 6 A flowchart illustrating a method for manufacturing a solar cell according to an embodiment of this disclosure;

[0053] Figure 7-9 for Figure 2 The diagram shows cross-sectional views of the solar cell at various stages of its fabrication process.

[0054] Figure 10-12 for Figure 3 The diagram shows cross-sectional views of the solar cell at various stages of its fabrication process.

[0055] Figure 13-14 for Figure 4 The diagram shows cross-sectional views of the solar cell at various stages of its fabrication process.

[0056] Figure 15-17 for Figure 5 The image shows cross-sectional views of the solar cell at various stages of its fabrication process. Detailed Implementation

[0057] The following specific examples illustrate the implementation methods of this application. Those skilled in the art can easily understand the other advantages and effects of this application from the content disclosed herein. This application can also be implemented or applied through other different specific embodiments, and various details in this application can be modified or changed according to different viewpoints and application systems without departing from the spirit of this application. It should be noted that, unless otherwise specified, the embodiments and features in the embodiments of this application can be combined with each other.

[0058] The embodiments of this application will now be described in detail with reference to the accompanying drawings, so that those skilled in the art can easily implement the application. This application may be embodied in many different forms and is not limited to the embodiments described herein.

[0059] In this application, the terms "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., refer to specific features, structures, materials, or characteristics represented in connection with that embodiment or example, which are included in at least one embodiment or example of this application. Furthermore, the specific features, structures, materials, or characteristics represented may be combined in any suitable manner in one or more embodiments or examples. Moreover, without contradiction, those skilled in the art can combine and integrate different embodiments or examples represented in this application, as well as features of different embodiments or examples.

[0060] Furthermore, the terms "first" and "second" are used for illustrative purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one of that feature. In the representation of this application, "multiple" means two or more, unless otherwise explicitly specified.

[0061] For the purpose of clearly describing this application, devices that are not relevant to the description are omitted, and the same or similar components throughout the specification are given the same reference numerals.

[0062] Throughout this specification, when it is said that a device is "connected" to another device, this includes not only "direct connection" but also "indirect connection" by placing other components in between. Furthermore, when it is said that a device "comprises" a certain constituent element, unless otherwise stated otherwise, this does not exclude other constituent elements, but rather implies that other constituent elements may be included.

[0063] When we say that a device is "above" another device, this can mean that it is directly above the other device, or it can mean that other devices are present in between. Conversely, when we say that a device is "directly" "above" another device, there are no other devices present in between.

[0064] Although not explicitly defined, all terms, including technical and scientific terms used herein, shall have the same meaning as commonly understood by one of ordinary skill in the art to which this application pertains. Terms defined in commonly used dictionaries shall be further interpreted as having a meaning consistent with the relevant technical literature and the content of this present application, and shall not be over-interpreted as having an ideal or overly formulaic meaning unless otherwise defined.

[0065] In related technologies, such as Figure 1 The solar cell shown has transparent conductive layers formed on both its front and back sides, such as a first transparent conductive layer 100 on the front side and a second transparent conductive layer 200 on the back side. During the fabrication of the first transparent conductive layer 100, a plating process occurs, where a plating layer 400 is formed around the photoelectric conversion unit 300. To prevent leakage, a blank area L is typically formed around the second transparent conductive layer 200, exposing the back side of the photoelectric conversion unit 300.

[0066] However, in practice, it has been noted that the photogenerated carriers in this blank area are seriously wasted, resulting in a loss of photoelectric conversion efficiency in the solar cell.

[0067] Figure 2 A cross-sectional view of a solar cell provided in one embodiment of this disclosure is shown, such as... Figure 2 The solar cell includes:

[0068] Photoelectric conversion unit 1;

[0069] The first transparent conductive layer 11 located on the front of the photoelectric conversion unit 1 and the first wrap-around coating layer 110 located on the outer side;

[0070] The second transparent conductive layer 12 located on the back of the photoelectric conversion unit 1 and the second winding coating 120 located outside the first winding coating 110;

[0071] The first electrode 13 is located on the side of the first transparent conductive layer 11 that is away from the photoelectric conversion unit 1;

[0072] The second electrode 14 is located on the side of the second transparent conductive layer 12 that is away from the photoelectric conversion unit 1.

[0073] The first wrap-around plating layer 110 and the second wrap-around plating layer 120 are at least partially in contact with each other, and the second transparent conductive layer 12 includes a first sub-transparent conductive layer 121 and a second sub-transparent conductive layer 122. The first sub-transparent conductive layer 121 serves as a first partition 12a and the second sub-transparent conductive layer 122 serves as a second partition 12b. The second wrap-around plating layer 120 serves as the first partition 12a, and a blank area S is formed on the outer side of the second partition 12b, exposing the back side of the photoelectric conversion unit 1.

[0074] In this embodiment, the second transparent conductive layer 12 is configured as a stacked structure, with a blank area S formed only around the second sub-transparent conductive layer 122 at the top layer. That is, the outer surface of the second sub-transparent conductive layer 122 and the outer surface of the photoelectric conversion unit 1 are separated. This reduces the blank area compared to related technologies. While avoiding leakage, the collection of charge carriers is increased through the second transparent conductive layer 12 and its second surrounding coating layer 120, thereby improving the photoelectric conversion efficiency of the solar cell.

[0075] In this embodiment of the disclosure, the solar cell is a heterojunction solar cell, and the photoelectric conversion unit 1 includes:

[0076] Base 10;

[0077] The first intrinsic amorphous silicon layer 101 and the first doped layer 102 are located on the front side of the substrate 10 and arranged in sequence. The first doped layer 102 has the same doping type as the substrate 10.

[0078] A second intrinsic amorphous silicon layer 103 and a second doped layer 104 are arranged sequentially on the back side of the substrate 10, with the doping type of the second doped layer 104 being opposite to that of the substrate 10.

[0079] In one embodiment, the substrate 10 is n-type doped, the first doped layer 102 is n-type doped, and the second doped layer 104 is p-type doped, or the substrate 10, the first doped layer 102, and the second doped layer 104 are doped in opposite directions.

[0080] In this embodiment of the disclosure, the first intrinsic amorphous silicon layer 101, the first doped layer 102, the second intrinsic amorphous silicon layer 103, and the second doped layer 104 also have an outer surrounding coating. Figure 1 Not shown in the image.

[0081] In another embodiment of this disclosure, the heterojunction solar cell may also be a tunnel oxide passivated contact (TOPcon) solar cell with transparent conductive layers on the front and back sides based on the selective carrier principle, or a thin-film solar cell, etc., which are not limited here.

[0082] In this embodiment, the thickness of the first partition 12a is less than that of the second partition 12b. Thus, the first partition 12a is thinner and has a high sheet resistance, for example, above 1000 Ohm / sq, resulting in lower leakage current. Even if it is at least partially in contact with the first coating layer 110, it will not affect the overall electrical performance of the solar cell.

[0083] In another embodiment of this disclosure, the thickness of the first partition may also be no less than that of the second partition.

[0084] In this embodiment, the first transparent conductive layer 11 and the second transparent conductive layer 12 may be made of transparent conductive oxide film (TCO), metal nanowires, carbon nanotubes, graphene, conductive polymers, or a combination of several of these. The TCO may be selected as one or more of indium tin oxide (ITO), zinc aluminum oxide (AZO), indium tungsten oxide (IWO), and ICO.

[0085] In this embodiment, the area where the second wrap-around coating 120 contacts the first wrap-around coating 110 is located on the outer side of the first wrap-around coating 110; this is just an example. In another embodiment, the area where the second wrap-around coating contacts the first wrap-around coating is located on the inner side of the first wrap-around coating, or the first wrap-around coating abuts against the second wrap-around coating; in this case, there may be no distinction between inner and outer sides.

[0086] Figure 3 This illustration shows a cross-sectional view of a solar cell provided in another embodiment of this disclosure, and... Figure 2 compared to, Figure 3 The difference in the solar cells shown is that:

[0087] The second transparent conductive layer 22 includes a first sub-transparent conductive layer 221 and a second sub-transparent conductive layer 222. The second sub-transparent conductive layer 222 has a body segment 2221 covering the first sub-transparent conductive layer 221 and an extension segment 2222 extending outward from the body segment 2221 along the back side of the photoelectric conversion unit 2.

[0088] In this embodiment, the body segment 2221 of the second sub-transparent conductive layer 222 completely covers the side and top surfaces of the first sub-transparent conductive layer 221, while the epitaxial segment 2222 is located at the bottom of the body segment 2221 and extends outward, and the second coating layer 220 is formed on the epitaxial segment 2222.

[0089] and Figure 1 In contrast, from top to bottom, the first partition 22a is formed on the epitaxial segment 2222 and the first sub-transparent conductive layer inside the epitaxial segment 2222, and the second partition 22b is formed on the body segment 2221 and the first sub-transparent conductive layer covered by the body segment 2221. Due to the height difference between the body segment 2221 and the extension segment 2222, the blank area S is located outside the body segment 2221.

[0090] In another embodiment of the solar cell disclosed herein, the first partition and the second partition may be an integral structure in the second transparent conductive layer on the back side. The second partition may be formed by thinning the periphery of the second transparent conductive layer, and the area in the middle that is not thinned may be used as the first partition.

[0091] Figure 4 This illustration shows a cross-sectional view of a solar cell provided in another embodiment of this disclosure, and... Figure 2 and 3 compared to, Figure 4 The difference in the solar cells shown is that:

[0092] An anti-reflective insulating layer 30 is disposed between the first coating layer 310 and the second coating layer 320, thereby insulating the first coating layer 310 and the second coating layer 320. The anti-reflective insulating layer 30 located at the periphery not only isolates the first coating layer 310 and the second coating layer 320 but also ensures the light intake of the covered area.

[0093] In this embodiment, there is no blank area around the second transparent conductive layer 32, but by setting an anti-reflection insulating layer 30, the anti-reflection insulating layer 30 can prevent leakage on the one hand, and ensure photon collection in the coverage area located outside the photoelectric conversion unit 3 on the other hand.

[0094] In this embodiment, the antireflective insulating layer 30 can extend from the top surface of the first transparent conductive layer 31 to the back surface of the photoelectric conversion unit 3. In this way, the antireflective insulating layer 30 can fully cover the inner first wrap-around layer 310, thereby forming good insulation between the first wrap-around layer 310 and the second wrap-around layer 320.

[0095] In this embodiment, the first surrounding plating layer 310 is located inside the antireflective insulating layer 30, and the second surrounding plating layer 320 is located outside the antireflective insulating layer 30. In another embodiment, the first surrounding plating layer is located outside the antireflective insulating layer, and the second surrounding plating layer is located outside the antireflective insulating layer.

[0096] Figure 5 This illustration shows a cross-sectional view of a solar cell provided in another embodiment of this disclosure, and... Figure 4 compared to, Figure 5 The difference in the solar cells shown is that:

[0097] The solar cell also includes: a third transparent conductive layer 43 and a third wrap-around coating 430 on its outer side;

[0098] The third transparent conductive layer 43 is located between the second transparent conductive layer 42 and the photoelectric conversion unit 4;

[0099] The first and third coating layers 410 and 430 are both located inside the antireflective insulating layer 40 and are at least in contact with each other, while the second coating layer 420 is located outside the antireflective insulating layer 40.

[0100] In this embodiment, the third transparent conductive layer 43 can ensure that there is no blank space around it, while the second transparent conductive layer 42 can also be without blank space because of the presence of the anti-reflection insulating layer 40, but blank space areas can also be set.

[0101] The positional relationship between the first coating layer 410 and the third coating layer 430 can be referenced. Figure 2 The positional relationship between the first surrounding coating 110 and the second surrounding coating 120 shown will not be described again here.

[0102] In another embodiment, the third transparent conductive layer is located on the side of the second transparent conductive layer away from the photoelectric conversion unit, and the first and third surrounding coatings are located on the outside of the anti-reflection insulation and are at least in contact.

[0103] Figure 6 A flowchart illustrating a method for manufacturing a solar cell according to an embodiment of this disclosure is shown, such as... Figure 6 As shown, this method may include the following steps:

[0104] Step 510: Fabricate the photoelectric conversion unit;

[0105] Step 520: Form a first transparent conductive layer and a first wrap-around coating layer on the front side of the photoelectric conversion unit;

[0106] Step 530: A second transparent conductive layer and a second wrap-around coating layer are formed on the back of the photoelectric conversion unit. The first wrap-around coating layer and the second wrap-around coating layer are at least partially in contact and connected. The second transparent conductive layer is divided into a first partition and a second partition from top to bottom. The second wrap-around coating layer is formed in the first partition, and a blank area is formed on the outside of the second partition.

[0107] Step 540: A first electrode is formed on the side of the first transparent conductive layer opposite to the photoelectric conversion unit, and a second electrode is formed on the side of the second transparent conductive layer opposite to the photoelectric conversion unit.

[0108] Using this embodiment, a form can be created Figure 2 or Figure 3The solar cell shown, in another embodiment, Figure 2 or Figure 3 The solar cells shown can also be formed using other methods.

[0109] In this embodiment, step 520 precedes step 530, that is, the first transparent conductive layer and its first wrap-around coating are fabricated before the second transparent conductive layer and its second wrap-around coating. In another embodiment, step 530 precedes step 520, that is, the second transparent conductive layer and its second wrap-around coating are fabricated before the first transparent conductive layer and its first wrap-around coating.

[0110] The following section uses cross-sectional views of each step in the manufacturing process of solar cells to illustrate the manufacturing method in detail.

[0111] by Figure 2 Taking solar cells as an example, the manufacturing method of solar cells is explained as follows:

[0112] like Figure 7 As shown, a photoelectric conversion unit 1 is fabricated. In this embodiment, the photoelectric conversion unit 1 can be a heterojunction photoelectric conversion unit, or it can be other types of photoelectric conversion units.

[0113] like Figure 8 As shown, a first transparent conductive layer 11 and a first wrap-around coating 110 are formed on the front side of the photoelectric conversion unit 1. The first wrap-around coating 110 is located on the outside of the photoelectric conversion unit 1. A first sub-transparent conductive layer 121 and a second wrap-around coating 120 are formed on the back side of the photoelectric conversion unit 1. The second wrap-around coating 120 is at least partially in contact with the first wrap-around coating 110, and the area in contact between the second wrap-around coating 120 and the first wrap-around coating 110 is located on the outside of the first wrap-around coating 110. The first sub-transparent conductive layer 121 serves as the first partition 12a.

[0114] like Figure 9 As shown, a second sub-transparent conductive layer 122 is formed on the side of the first sub-transparent conductive layer 121 away from the photoelectric conversion unit 1. The second sub-transparent conductive layer 122 serves as the second partition 12b. A blank area S is formed on the outer side of the second sub-transparent conductive layer 122. The first sub-transparent conductive layer 121 and the second sub-transparent conductive layer 122 together constitute the second transparent conductive layer 12.

[0115] Then, the first electrode and the second electrode are formed, thereby obtaining... Figure 2 The solar cell shown.

[0116] In another embodiment of this disclosure, a second transparent conductive layer may be formed first, in which case the area where the second wrap-around coating contacts the first wrap-around coating is located inside the first wrap-around coating.

[0117] In other embodiments of this disclosure, the first surrounding coating layer and the second surrounding coating layer may abut each other, in which case there is no distinction between the inner and outer sides.

[0118] Figure 3 The fabrication method of the solar cell shown is explained below:

[0119] like Figure 10 As shown, a first transparent conductive layer 21 and a first wrap-around coating 210 are formed on the front side of the photoelectric conversion unit 2.

[0120] like Figure 11 As shown, a first sub-transparent conductive layer 221 is formed on the back side of the photoelectric conversion unit 2, and a blank area S0 is formed around the first sub-transparent conductive layer 221;

[0121] like Figure 12 As shown, a second sub-transparent conductive layer 222 and a second wrap-around layer 220 on its outer side are fabricated. The second sub-transparent conductive layer 222 has a body segment 2221 covering the first sub-transparent conductive layer 221 and an epitaxial segment 2222 extending outward from the body segment 2221 along the back side of the photoelectric conversion unit 2. A first partition 22a is formed on the epitaxial segment 2222 and the first sub-transparent conductive layer inside the epitaxial segment 2222. The second wrap-around layer 220 is formed on the epitaxial segment 2222. The second partition 22b is formed on the body segment 2221 and the first sub-transparent conductive layer covered by the body segment 2221. The first sub-transparent conductive layer 221 and the second sub-transparent conductive layer 222 constitute the second transparent layer 22.

[0122] Then, the first electrode and the second electrode are formed, thereby obtaining... Figure 3 The solar cell shown.

[0123] Figure 4 The fabrication method of the solar cell shown is explained below:

[0124] like Figure 13 As shown, a first transparent conductive layer 31 and a first wrap-around coating layer 310 are formed on the front side of the photoelectric conversion unit 3, and an anti-reflection insulating layer 30 is formed on the outside of the first wrap-around coating layer 310.

[0125] like Figure 14 As shown, a second transparent conductive layer 32 and a second wrap-around layer 320 are formed on the back side of the photoelectric conversion unit 3. The second wrap-around layer 320 is located outside the anti-reflection insulating layer 30, and the anti-reflection insulating layer 30 is located between the first wrap-around layer 310 and the second wrap-around layer 320 for insulation isolation.

[0126] Then, the first electrode and the second electrode are formed, thereby obtaining... Figure 4 The solar cell shown.

[0127] In this embodiment, the antireflective insulating layer 30 covers the first wrap-around coating layer 310 and extends from the top surface of the first transparent conductive layer 31 to the back surface of the photoelectric conversion unit 3. Specifically, the antireflective insulating layer 30 can be fabricated using a coating process. This antireflective insulating layer 30 does not affect the optical performance of the area, and the coating can be fully transparent and have certain antireflective properties.

[0128] The solar cell in this embodiment can maximize the utilization of the area on the back of the silicon wafer and improve the photoelectric conversion efficiency without leaving blank space on the back of the photoelectric conversion unit 3, while ensuring extremely low edge leakage rate.

[0129] In another embodiment of this disclosure, a second transparent conductive layer and a second surrounding plating layer and an anti-reflective insulating layer may be formed first, followed by the formation of a first transparent conductive layer and a first surrounding plating layer. In this case, the second surrounding plating layer is located inside the anti-reflective insulating layer, and the first surrounding plating layer is located outside the anti-reflective insulating layer.

[0130] Figure 5 The fabrication method of the solar cell shown is explained below:

[0131] like Figure 15 As shown, a first transparent conductive layer 41 and a first wrap-around coating 410 are formed on the front side of the photoelectric conversion unit 4, and a third transparent conductive layer 43 and a third wrap-around coating 430 are formed on the back side of the photoelectric conversion unit 4. The first wrap-around coating 410 and the third wrap-around coating 430 are at least partially in contact with each other.

[0132] like Figure 16 As shown, an anti-reflection insulating layer 40 is formed on the outside of the first coating layer 410 and the third coating layer 430. The anti-reflection insulating layer 40 can extend from the top surface of the first transparent conductive layer 41 to the third transparent conductive layer 43.

[0133] like Figure 17 As shown, a second transparent conductive layer 42 and a second wrap-around layer 420 are formed on the side of the third transparent conductive layer 43 away from the photoelectric conversion unit 4. The second wrap-around layer 420 is located on the outside of the anti-reflection insulating layer 40. The first wrap-around layer 410 and the third wrap-around layer 430 are both located on the same side of the anti-reflection insulating layer 40, i.e., the inside.

[0134] Then, the first electrode and the second electrode are formed, thereby obtaining... Figure 5 The solar cell shown.

[0135] In one embodiment of this disclosure, the first transparent conductive layer 41 and the first wrap-around plating layer 410 on its outer side are fabricated before the third transparent conductive layer 43 and the third wrap-around plating layer 430 on its outer side. In another embodiment of this disclosure, the third transparent conductive layer and the third wrap-around plating layer on its outer side are fabricated before the first transparent conductive layer and the first wrap-around plating layer on its outer side.

[0136] In other embodiments of this disclosure, a second transparent conductive layer and a second transparent conductive layer outside the photoelectric conversion unit are first formed on the back side of the photoelectric conversion unit, then an anti-reflection insulating layer is fabricated, and then a first transparent conductive layer and a first wrap-around coating layer outside the photoelectric conversion unit are formed on the front side of the photoelectric conversion unit, and a third transparent conductive layer and a third wrap-around coating layer outside the photoelectric conversion unit are formed on the side of the second transparent conductive layer away from the photoelectric conversion unit. The first wrap-around coating layer and the third wrap-around coating layer are both located outside the anti-reflection layer and are at least partially in contact with each other.

[0137] The above description, in conjunction with specific preferred embodiments, provides a further detailed explanation of the present invention. It should not be construed that the specific implementation of the present invention is limited to these descriptions. For those skilled in the art, various simple deductions or substitutions can be made without departing from the concept of the present invention, and all such modifications and substitutions should be considered within the scope of protection of the present invention.

Claims

1. A solar cell, characterized by, The solar cell comprises: a photoelectric conversion unit; a first transparent conductive layer on the front surface of the photoelectric conversion unit and a first wrap plating layer outside the first transparent conductive layer; a second transparent conductive layer on the back surface of the photoelectric conversion unit and a second wrap plating layer outside the second transparent conductive layer; a first electrode on the side of the first transparent conductive layer away from the photoelectric conversion unit; a second electrode on the side of the second transparent conductive layer away from the photoelectric conversion unit; wherein the positional relationship between the first wrap plating layer and the second wrap plating layer is set as one of the following: the first wrap plating layer and the second wrap plating layer are at least partially in contact, and the second transparent conductive layer is divided into a first sub-zone and a second sub-zone from top to bottom, the second wrap plating layer is formed in the first sub-zone, a blank area is formed outside the second sub-zone, the thickness of the first sub-zone is smaller than that of the second sub-zone, and the sheet resistance of the first sub-zone is higher than 10000hm / sq.

2. The solar cell according to claim 1, characterized in that, the first sub-zone and the second sub-zone are arranged as a laminated structure formed in different process steps.

3. The solar cell according to claim 1, characterized in that, the second transparent conductive layer comprises a first sub-transparent conductive layer and a second sub-transparent conductive layer, the second sub-transparent conductive layer has a body segment covering the first sub-transparent conductive layer and an extension segment extending outward from the body segment along the back surface of the photoelectric conversion unit; the first sub-zone is formed in the extension segment and the first sub-transparent conductive layer inside the extension segment; the second sub-zone is formed in the body segment and the first sub-transparent conductive layer covered by the body segment.

4. The solar cell of claim 1, wherein when an anti-reflection insulating layer is arranged between the first wrap plating layer and the second wrap plating layer, the solar cell further comprises: a third transparent conductive layer and a third wrap plating layer outside the third transparent conductive layer, the sheet resistance of the third wrap plating layer is higher than 10000hm / sq; the third transparent conductive layer is located between the second transparent conductive layer and the photoelectric conversion unit, and the first wrap plating layer and the third wrap plating layer are at least partially in contact and located inside the anti-reflection insulating layer; or the third transparent conductive layer is located on the side of the second transparent conductive layer away from the photoelectric conversion unit, and the first wrap plating layer and the third wrap plating layer are at least partially in contact and located outside the anti-reflection insulating layer.

5. The solar cell of claim 1, wherein the photoelectric conversion unit is a heterojunction photoelectric conversion unit.

6. A method for manufacturing a solar cell, characterized by, The solar cell comprises: manufacturing a photoelectric conversion unit; forming a first transparent conductive layer and a first wrap plating layer outside the first transparent conductive layer on the front surface of the photoelectric conversion unit; forming a second transparent conductive layer and a second wrap plating layer outside the second transparent conductive layer on the back surface of the photoelectric conversion unit; forming a first electrode on the side of the first transparent conductive layer away from the photoelectric conversion unit, and forming a second electrode on the side of the second transparent conductive layer away from the photoelectric conversion unit; the positional relationship between the first wrap plating layer and the second wrap plating layer is set as one of the following: the first wrap plating layer and the second wrap plating layer are at least partially in contact, and the second transparent conductive layer is divided into a first sub-zone and a second sub-zone from top to bottom, the second wrap plating layer is formed in the first sub-zone, a blank area is formed outside the second sub-zone, the thickness of the first sub-zone is smaller than that of the second sub-zone, and the sheet resistance of the first sub-zone is higher than 10000hm / sq.

7. The method of producing a solar cell according to claim 6, wherein Forming a second transparent conductive layer and a second wrap-around layer thereof on the back of the photoelectric conversion unit, comprising: forming a first sub-transparent conductive layer on the back of the photoelectric conversion unit, the first sub-transparent conductive layer as the first sub-area; forming a second sub-transparent conductive layer on the side of the first sub-transparent conductive layer away from the photoelectric conversion unit, the second sub-transparent conductive layer as the second sub-area.

8. The method of producing a solar cell according to claim 6, wherein Forming a second transparent conductive layer and a second wrap-around layer thereof on the back of the photoelectric conversion unit, comprising: forming a first sub-transparent conductive layer on the back of the photoelectric conversion unit; making a second sub-transparent conductive layer, the second sub-transparent conductive layer having a body segment covering the first sub-transparent conductive layer and an extension segment extending outward from the body segment along the back of the photoelectric conversion unit, the first sub-area being formed in the extension segment and the first sub-transparent conductive layer inside the extension segment, the second wrap-around layer being formed in the extension segment, and the second sub-area being formed in the body segment and the first sub-transparent conductive layer covered by the body segment, the first sub-transparent conductive layer and the second sub-transparent conductive layer constituting the second transparent conductive layer.

9. The method of producing a solar cell according to claim 6, wherein When an anti-reflection insulating layer is arranged between the first wrap-around layer and the second wrap-around layer, the method for manufacturing the solar cell further comprises: forming a third transparent conductive layer and a third wrap-around layer thereof on the outside of the third transparent conductive layer before or after the formation of the second transparent conductive layer, the second wrap-around layer and the anti-reflection insulating layer, the sheet resistance of the third wrap-around layer being higher than 10000hm / sq; the first wrap-around layer and the third wrap-around layer are both located on the same side of the anti-reflection insulating layer and at least partially contact each other.

10. The method of producing a solar cell according to claim 6, wherein The photoelectric conversion unit is a heterojunction photoelectric conversion unit.

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