Solar cell and method of manufacturing the same

Abstract

The application provides a solar cell and a preparation method thereof, and belongs to the technical field of solar cells. The solar cell can at least partially solve the problems of difficult alignment of structural layers, poor edge quality and influence on cell performance in existing solar cells. The preparation method of the solar cell comprises the following steps: forming an isolation structure in an edge area of a first side of a conductive base layer; the edge area is a region of a predetermined size of the conductive base layer from the edge along the radial direction to the inside, and the isolation structure can prevent electrical conduction between structures in contact with both sides thereof; forming at least one conductive functional layer on the first side of the conductive base layer; a part of the orthographic projection of the conductive functional layer on the conductive base layer overlaps with the orthographic projection of the isolation structure on the conductive base layer.

Description

Technical Field

[0001] This invention belongs to the field of solar cell technology, specifically relating to a solar cell and its preparation method. Background Technology

[0002] Perovskite / polycrystalline silicon tandem (calcium / silicon tandem) solar cells consist of a stacked perovskite top cell and a polycrystalline silicon bottom cell, which are connected by a composite layer; compared with polycrystalline silicon solar cells, perovskite / polycrystalline silicon tandem solar cells can significantly improve efficiency.

[0003] To ensure efficient vertical transport and collection of photogenerated carriers within the device, some structural layers in perovskite / polycrystalline silicon tandem solar cells (such as the top transparent electrode layer and the composite layer) need to be aligned vertically. However, due to limited process precision, the structural layers may not be aligned, causing carrier shunting and affecting charge transport. At the same time, due to process limitations, the film quality at the edges of some structural layers (such as the perovskite layer) is poor, resulting in poor uniformity and affecting cell performance. Summary of the Invention

[0004] This invention at least partially solves the problems of poor edge quality and difficulty in aligning structural layers in existing solar cells, which affect cell performance, and provides a solar cell and its preparation method that can guarantee film layer alignment and improve edge quality.

[0005] In a first aspect, embodiments of the present invention provide a method for preparing a solar cell, comprising:

[0006] An isolation structure is formed in the edge region of the first side of the conductive substrate; the edge region is a region of a predetermined size radially inward from the edge of the conductive substrate, and the isolation structure can prevent electrical conduction between structures in contact with its two sides;

[0007] At least one conductive functional layer is formed on the first side of the conductive base layer; a portion of the orthographic projection of the conductive functional layer on the conductive base layer coincides with the orthographic projection of the isolation structure on the conductive base layer.

[0008] Optionally, the isolation structure may be provided at any position along the circumference of the conductive base layer;

[0009] The orthographic projection of the conductive functional layer onto the conductive base layer coincides with the orthographic projection of the isolation structure onto the conductive base layer at any position along the circumference of the conductive base layer.

[0010] Optionally, the isolation structure covers the edge region.

[0011] Optionally, the conductive functional layer covers the first side of the conductive base layer.

[0012] Optionally, the thickness of the isolation structure is between 1 nm and 10 cm.

[0013] Optionally, the width of the isolation structure is between 1 nm and 10 cm; the width of the isolation structure is the radial dimension of the isolation structure on the conductive substrate.

[0014] Optionally, the material of the isolation structure includes one or more of the following: silicon nitride, silicon carbide, aluminum oxide, silicon oxide, magnesium oxide, zirconium oxide, titanium oxide, zinc oxide, tin oxide, nickel oxide, boron nitride, aluminum nitride, gallium nitride, titanium nitride, polyethylene, polyvinyl chloride, phenolic resin, epoxy resin, unsaturated polyester resin, viscose fiber, cellulose acetate, nylon, polyester, polypropylene, polystyrene, nylon, acrylic fiber, vinylon, styrene-butadiene rubber, cis-butadiene rubber, isoprene rubber, ethylene propylene rubber, polyoxymethylene, polycarbonate, polyimide, polyarylene ether, polyarylamide, polysiloxane, and polyvinyl chloride.

[0015] Optionally, the isolation structure is formed by any one of the following methods: vapor deposition, sputtering, printing, coating, chemical vapor deposition, atomic layer deposition, and mechanical stacking.

[0016] Optionally, after forming the isolation structure in the edge region on the first side of the conductive substrate, the method further includes:

[0017] Using the location of the isolation structure as a support position, at least one structural layer is formed on the second side of the conductive base layer; the second side is the side of the conductive base layer opposite to the first side.

[0018] Optionally, the solar cell is a perovskite / polycrystalline silicon tandem cell; the perovskite / polycrystalline silicon tandem cell includes a stacked perovskite top cell and a polycrystalline silicon bottom cell, and a composite layer connecting the perovskite top cell and the polycrystalline silicon bottom cell.

[0019] Optionally, the conductive base layer is the silicon substrate of the polycrystalline silicon bottom cell;

[0020] The conductive functional layer includes the composite layer, the top transparent electrode layer of the perovskite top cell, and the perovskite layer of the perovskite top cell.

[0021] In a second aspect, embodiments of the present invention provide a solar cell, comprising:

[0022] A conductive substrate, wherein an isolation structure is provided in the edge region of the first side of the conductive substrate; the edge region is a region of a predetermined size radially inward from the edge of the conductive substrate, and the isolation structure can prevent electrical conduction between structures in contact with its two sides;

[0023] At least one conductive functional layer is disposed on the side of the isolation structure away from the conductive base layer; a portion of the orthographic projection of the conductive functional layer on the conductive base layer coincides with the orthographic projection of the isolation structure on the conductive base layer.

[0024] Optionally, the isolation structure may be provided at any position along the circumference of the conductive base layer;

[0025] The orthographic projection of the conductive functional layer onto the conductive base layer coincides with the orthographic projection of the isolation structure onto the conductive base layer at any position along the circumference of the conductive base layer.

[0026] The isolation structure covers the edge area.

[0027] Optionally, the thickness of the isolation structure is between 1 nm and 10 cm;

[0028] The width of the isolation structure is between 1 nm and 10 cm; the width of the isolation structure is the radial dimension of the isolation structure on the conductive substrate.

[0029] The materials of the isolation structure include one or more of the following: silicon nitride, silicon carbide, aluminum oxide, silicon oxide, magnesium oxide, zirconium oxide, titanium oxide, zinc oxide, tin oxide, nickel oxide, boron nitride, aluminum nitride, gallium nitride, titanium nitride, polyethylene, polyvinyl chloride, phenolic resin, epoxy resin, unsaturated polyester resin, viscose fiber, cellulose acetate, nylon, polyester, polypropylene, polystyrene, nylon, acrylic fiber, vinylon, styrene-butadiene rubber, cis-butadiene rubber, isoprene rubber, ethylene-propylene rubber, polyoxymethylene, polycarbonate, polyimide, polyarylene ether, polyarylamide, polysiloxane, and polyvinyl chloride.

[0030] Optionally, the solar cell is a perovskite / polycrystalline silicon tandem cell; the perovskite / polycrystalline silicon tandem cell includes a stacked perovskite top cell and a polycrystalline silicon bottom cell, and a composite layer connecting the perovskite top cell and the polycrystalline silicon bottom cell;

[0031] The conductive base layer is the silicon substrate of the polycrystalline silicon bottom battery;

[0032] The conductive functional layer includes the composite layer, the top transparent electrode layer of the perovskite top cell, and the perovskite layer of the perovskite top cell.

[0033] In this embodiment of the invention, an isolation structure is first prepared at the edge region of the conductive base layer, and then a conductive functional layer is prepared. The edge of the conductive functional layer overlaps with the isolation structure and is located above the isolation structure. Therefore, the isolation structure acts like a "mask," separating the edge portion of the conductive functional layer from the edge portion of the isolation structure, preventing electrical conduction between them. Thus, the edge of the conductive functional layer is an "ineffective" inactive region. Even if the conductive functional layers (different conductive functional layers, or conductive functional layers and conductive base layers) are not aligned, the misaligned portion is also in an inactive region. Similarly, even if the edge of the conductive functional layer has poor film quality or is uneven, it is still located in an inactive region. Therefore, the actual "effective" active region of the conductive functional layer (the region that overlaps longitudinally with the conductive base layer and is electrically conductive) is aligned, and the film quality, uniformity, charge transport, and battery performance are good. Attached Figure Description

[0034] Figure 1 This is a flowchart illustrating a method for preparing a solar cell according to an embodiment of the present invention;

[0035] Figure 2 This is a flowchart illustrating another method for preparing a solar cell according to an embodiment of the present invention;

[0036] Figure 3 This is a top view schematic diagram of the conductive substrate in a method for preparing a solar cell according to an embodiment of the present invention;

[0037] Figure 4 This is a schematic cross-sectional view of the conductive substrate in a method for preparing a solar cell according to an embodiment of the present invention.

[0038] Figure 5 This is a top view schematic diagram of the structure after the isolation structure is formed in a method for fabricating a solar cell according to an embodiment of the present invention;

[0039] Figure 6 This is a schematic cross-sectional view of the structure after the isolation structure is formed in a method for fabricating a solar cell according to an embodiment of the present invention.

[0040] Figure 7 This is a top view schematic diagram of the structure after the conductive functional layer is formed in a method for fabricating a solar cell according to an embodiment of the present invention;

[0041] Figure 8 This is a schematic cross-sectional view of the structure after the formation of the conductive functional layer in a method for fabricating a solar cell according to an embodiment of the present invention.

[0042] Figure 9 This is a schematic cross-sectional view of a solar cell according to an embodiment of the present invention;

[0043] In the attached figures, the reference numerals are as follows: Q1, edge region; 1, isolation structure; 2, conductive functional layer; 5, metal electrode; 6, perovskite top cell; 61, top transparent electrode layer; 62, hole transport layer; 63, perovskite layer; 64, electron transport layer; 7, composite layer; 8, polycrystalline silicon bottom cell; 81, silicon substrate; 811, first doped layer; 812, first intrinsic layer; 813, silicon base layer; 814, second intrinsic layer; 815, second doped layer; 82, bottom transparent electrode layer; 9, conductive base layer. Detailed Implementation

[0044] To enable those skilled in the art to better understand the technical solution of the present invention, the present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0045] It is understood that the specific embodiments and accompanying drawings described herein are merely for explaining the invention and are not intended to limit the invention.

[0046] It is understood that, without conflict, the various embodiments of the present invention and the features thereof can be combined with each other.

[0047] It is understood that, for ease of description, the accompanying drawings of this invention only show the parts related to the embodiments of this invention, while the parts unrelated to the embodiments of this invention are not shown in the drawings.

[0048] In some related technologies, perovskite / polycrystalline silicon tandem (calcium / silicon tandem) solar cell technology can be used to upgrade the relatively mature polycrystalline silicon solar cell technology.

[0049] Perovskite / polycrystalline silicon tandem solar cells consist of a stacked perovskite top cell and a polycrystalline silicon bottom cell, connected by a transparent composite layer (composed of a transparent conductive material). The perovskite top cell, located closer to the light-receiving side, primarily absorbs short-wavelength light, while the polycrystalline silicon bottom cell, located further away, primarily absorbs long-wavelength light. This combination enables effective absorption of the entire light spectrum, significantly improving efficiency (which can exceed 30%).

[0050] A perovskite top solar cell may include structural layers such as an electron transport layer, a perovskite layer, a hole transport layer, and a top transparent electrode layer (composed of a transparent conductive material). Both the top transparent electrode layer and the composite layer need to have strong lateral and longitudinal conductivity. To ensure efficient longitudinal transport and collection of photogenerated carriers within the device, the composite layer and the top transparent electrode layer (which may also include the bottom transparent electrode layer in a polycrystalline silicon bottom solar cell) must be aligned longitudinally.

[0051] However, the composite layer and the top transparent electrode layer are prepared separately in different process steps. Due to the limitation of alignment accuracy, it is difficult to ensure that the positions of the two are completely overlapping. That is, the edges of the two may not be aligned, which will cause carrier shunting and affect charge transport.

[0052] Meanwhile, perovskite layers can be prepared using processes such as spin coating and thermal evaporation. However, due to the self-assembly phenomenon between the components in the perovskite layer, it is difficult for the perovskite layer to be completely uniform (especially when preparing large areas). Its edges are often uneven and prone to poor crystallization, resulting in poor film quality and thus affecting the performance of the battery.

[0053] In a first aspect, embodiments of the present invention provide a method for preparing a solar cell.

[0054] The method of this invention can be used to prepare solar cells, such as perovskite / polycrystalline silicon tandem cells.

[0055] Reference Figure 1 The method for preparing a solar cell according to an embodiment of the present invention includes:

[0056] S101, An isolation structure 1 is formed in the edge region Q1 on the first side of the conductive substrate 9.

[0057] Among them, the edge region Q1 is a region of predetermined size in the conductive base layer 9 from the edge inward along the radial direction, and the isolation structure 1 can prevent electrical conduction between the structures in contact with its two sides.

[0058] Reference Figure 3 , Figure 4 A portion of the structure in the solar cell is used as the conductive substrate 9, and the edge portion of the conductive substrate 9 is the edge region Q1.

[0059] Reference Figure 5 , Figure 6 An isolation structure 1 is formed at least partially in the edge region Q1 on one side (first side) of the conductive base layer 9, that is, the isolation structure 1 is formed directly on the conductive base layer 9 and is in contact with the conductive base layer 9 in the edge region Q1.

[0060] The isolation structure 1 is in contact with the conductive base layer 9 and the subsequently formed conductive functional layer 2 on both sides, respectively. The properties of the isolation structure 1 itself can ensure that the conductive base layer 9 and the conductive functional layer 2 in contact with it (see reference) Figure 7 , Figure 8 (Following further explanation) between them, effective current transfer cannot be achieved, that is, effective electrical conduction is impossible.

[0061] For example, the isolation structure 1 can be made of insulating material to prevent electrical conduction.

[0062] Alternatively, the isolation structure 1 can also be made of a material that is not an insulating material but has very poor conductivity (such as a non-doped semiconductor with very poor conductivity); thus, although there may be a small leakage current between the conductive base layer 9 and the conductive functional layer 2 in contact with its two sides, it does not constitute effective electrical conduction.

[0063] For example, the conductivity of isolation structure 1 can be less than <10. 3 S / cm, and can be further reduced to <10S / cm.

[0064] S102. At least one conductive functional layer 2 is formed on the first side of the conductive base layer 9.

[0065] Among them, a portion of the orthographic projection of the conductive functional layer 2 onto the conductive base layer 9 coincides with the orthographic projection of the isolation structure 1 onto the conductive base layer 9.

[0066] Reference Figure 7 , Figure 8 After the isolation structure 1 is formed, one or more conductive structural layers (conductive functional layers 2) are formed on the first side of the conductive base layer 9. Each conductive functional layer 2 has a part that overlaps with the isolation structure 1 (therefore, each conductive functional layer 2 also has a part that does not overlap with the isolation structure 1, but overlaps with the part of the conductive base layer 9 that does not have an isolation structure).

[0067] As can be seen, the isolation structure 1 is located at the edge region Q1 of the conductive base layer 9. Therefore, the portion of the conductive functional layer 2 that overlaps with the isolation structure 1 must also be located at the edge of the conductive functional layer 2. Since the conductive functional layer 2 is formed after the isolation structure 1, the portion of the conductive functional layer 2 that overlaps with the isolation structure 1 must be located "above (away from the conductive base layer 9)" of the isolation structure 1, i.e., referring to... Figure 8 The edge of the conductive functional layer 2 is separated from the conductive base layer 9 by the isolation structure 1, and they cannot conduct electricity.

[0068] Obviously, the non-conductive portion of the solar cell cannot conduct electricity, so it is actually a non-functional, "ineffective" inactive region; in contrast, the region located inside the isolation structure 1 is an "effective" active region.

[0069] It should be understood that both the conductive base layer 9 and the conductive functional layer 2 are conductive structural layers in the solar cell that can play a certain role. Their specific forms are determined by the form of the solar cell and the location of the isolation structure 1. That is, the structural layer on which the isolation structure 1 is located is the conductive base layer 9, and the structural layer formed after the isolation structure 1 that overlaps with it is the conductive functional layer 2.

[0070] It should be understood that the above only describes the process of forming the isolation structure 1 and the conductive functional layer 2 on one side of the conductive substrate 9. It is also feasible to form the isolation structure 1 on the other side (second side) of the conductive substrate 9 and then form the conductive functional layer 2 (such as the subsequent bottom transparent electrode layer 82).

[0071] It should be understood that although the solar cell surface is described as "rectangular" in the accompanying drawings, the embodiments of the present invention are not limited to rectangular solar cells, and can also be used for solar cells of any other shape such as circular, hexagonal, etc.

[0072] In this embodiment of the invention, an isolation structure 1 is first prepared in the edge region Q1 of the conductive base layer 9, and then a conductive functional layer 2 is prepared. The edge of the conductive functional layer 2 overlaps with the isolation structure 1 and is located above the isolation structure 1. Therefore, the isolation structure 1 acts as a kind of "mask", separating the edge portion of the conductive functional layer 2 from the edge portion of the isolation structure 1, so that they cannot conduct electricity. Therefore, the edge of the conductive functional layer 2 is an "ineffective" inactive region. Even if the conductive functional layers 2 (different conductive functional layers, or conductive functional layers and conductive base layers) are not aligned, the misaligned part is also in an inactive region. Similarly, even if the edge of the conductive functional layer 2 has poor film quality or unevenness, it is also located in an inactive region. Therefore, the actual "effective" active region of the conductive functional layer 2 (the region that overlaps longitudinally with the conductive base layer 9 and conducts electricity) is aligned, and the film quality is good, the uniformity is good, the charge transport is good, and the battery performance is good.

[0073] Optionally, an isolation structure 1 is provided at any position along the circumference of the conductive base layer 9;

[0074] The orthographic projection of the conductive functional layer 2 onto the conductive base layer 9 coincides with the orthographic projection of the isolation structure 1 onto the conductive base layer 9 at any position along the circumference of the conductive base layer 9.

[0075] Reference Figure 3 The edge region Q1 is clearly a closed ring, and as one embodiment of the present invention, refer to... Figure 5 Along the circumference of the conductive base layer 9, an isolation structure 1 can be provided in the edge area Q1 at each location, that is, the isolation structure 1 can also form a "ring".

[0076] Correspondingly, the conductive functional layer 2 can overlap with the isolation structure 1 at various positions around the conductive base layer 9. In other words, the theoretical area of ​​the conductive functional layer 2 should be larger than the "inner circle" of the isolation structure 1, thus referring to... Figure 7 Its edges in all directions overlap with the isolation structure 1.

[0077] Therefore, it can be ensured that when the conductive functional layer 2 has problems such as misalignment at the edge in any direction or poor film quality, it will be isolated by the isolation structure 1 and become "ineffective", and will not affect the performance of the battery.

[0078] Optionally, the isolation structure 1 is filled with the edge region Q1.

[0079] Optionally, the conductive functional layer 2 covers the first side of the conductive base layer 9.

[0080] Reference Figure 7 As one embodiment of the present invention, the isolation structure 1 can be "covered" with the edge area Q1, that is, the isolation structure 1 extends all the way to the "edge" of the conductive base layer 9, so as to ensure that the conductive functional layer 2 will not be electrically connected to the conductive base layer 9 on the outside of the isolation structure 1.

[0081] Furthermore, the conductive functional layer 2 can also be "covered" on the surface of the conductive base layer 9, making its preparation and alignment more convenient.

[0082] It should be understood that the specific distribution of the isolation structure 1 and the conductive functional layer 2 is not limited to the above forms.

[0083] For example, it is also feasible to provide the isolation structure 1 only at a portion of the edge region Q1 along the circumference of the conductive base layer 9, that is, the isolation structure 1 may not form a closed ring.

[0084] For example, it is also feasible for the isolation structure 1 to be distributed only in a portion of the conductive base layer 9 radially in the edge region Q1, such as the outermost ring of the conductive base layer 9 (edge ​​region Q1) without the isolation structure 1.

[0085] For example, it is also feasible if the conductive functional layer 2 is not fully covered by the conductive base layer 9. For example, the outermost ring of the conductive base layer 9 (edge ​​region Q1) may not have the conductive base layer 9, or the conductive functional layer 2 may not be present in the active part.

[0086] Optionally, the thickness of the isolation structure 1 is between 1 nm and 10 cm.

[0087] As one embodiment of the present invention, the thickness of the isolation structure 1 (the dimension in the direction perpendicular to the conductive base layer 9) can be from 1 nm to 10 cm, further from 10 nm to 10 mm, further from 100 nm to 100 μm, and further from 1 μm to 10 μm.

[0088] The isolation structure 1 within the above thickness range can ensure reliable isolation while avoiding adverse effects on the basic structure of the solar cell.

[0089] When the thickness of the isolation structure 1 is high, the conductive functional layer 2 on top of it can be "cut off" from the conductive functional layer 2 on the inner side, so as to achieve better isolation. At the same time, such an isolation structure 1 is also in contact with the outer side of the conductive functional layer 2 on the inner side, so as to encapsulate the outer side of the conductive functional layer 2 and prevent the conductive functional layer 2 from being damaged (such as preventing moisture from seeping in from the outer side).

[0090] Optionally, the width of the isolation structure 1 is between 1 nm and 10 cm; the width of the isolation structure 1 is the radial dimension of the isolation structure 1 on the conductive substrate 9.

[0091] As one embodiment of the present invention, the width of the isolation structure 1 (when the isolation structure 1 fills the edge region Q1, that is, the width of the edge region Q1) can be from 1 nm to 10 cm, further from 10 nm to 10 mm, further from 100 nm to 100 μm, and further from 1 μm to 10 μm.

[0092] The isolation structure 1 within the above width range can ensure that the edge of the conductive functional layer 2 coincides with the isolation structure 1, and also ensure that the proportion of "effective" active area in the solar cell is relatively high, so that the area utilization rate will not be seriously reduced due to the presence of the isolation structure 1.

[0093] Optionally, the material of the isolation structure 1 includes one or more of the following: silicon nitride, silicon carbide, aluminum oxide, silicon oxide, magnesium oxide, zirconium oxide, titanium oxide, zinc oxide, tin oxide, nickel oxide, boron nitride, aluminum nitride, gallium nitride, titanium nitride, polyethylene, polyvinyl chloride, phenolic resin, epoxy resin, unsaturated polyester resin, viscose fiber, cellulose acetate, nylon, polyester, polypropylene, polystyrene, nylon, acrylic fiber, vinylon, styrene-butadiene rubber, cis-butadiene rubber, isoprene rubber, ethylene propylene rubber, polyoxymethylene, polycarbonate, polyimide, polyarylene ether, polyarylamide, polysiloxane, and polyvinyl chloride.

[0094] As one embodiment of the present invention, the isolation structure 1 may be composed of inorganic insulating materials such as silicon nitride (SiNx), silicon carbide, aluminum oxide, silicon oxide, magnesium oxide, zirconium oxide, titanium oxide, zinc oxide, tin oxide, nickel oxide, boron nitride, aluminum nitride, gallium nitride, and titanium nitride, or it may be composed of organic insulating materials such as polyethylene, polyvinyl chloride, phenolic resin, epoxy resin, unsaturated polyester resin, viscose fiber, cellulose acetate, nylon, polyester, polypropylene, polystyrene, nylon, acrylic fiber, vinylon, styrene-butadiene rubber, butadiene rubber, isoprene rubber, ethylene propylene rubber, polyoxymethylene, polycarbonate, polyimide, polyaryl ether, polyarylamide, polysiloxane, and polyvinyl chloride.

[0095] It should be understood that it is also feasible if the material of the isolation structure 1 is a mixture or combination of the above-mentioned inorganic insulating materials and organic insulating materials (such as different materials being used for isolation structures 1 at different locations), or if the isolation structure 1 also includes other materials that can prevent electrical conduction (such as semiconductor materials with poor conductivity).

[0096] Optionally, the isolation structure 1 is formed by any one of the following methods: vapor deposition, sputtering, printing, coating, chemical vapor deposition, atomic layer deposition, and mechanical stacking.

[0097] As one embodiment of the present invention, the isolation structure 1 can be prepared by processes such as vapor deposition, sputtering, printing, coating, chemical vapor deposition (CVD), atomic layer deposition (ALD), and mechanical stacking.

[0098] It should be understood that the size, material, and fabrication process of the isolation structure 1 are not limited to the forms described above. For example, the material of the isolation structure 1 can also be other organic polymers, ceramics, glass, metals, etc. (as long as they can prevent electrical conduction), and the fabrication process of the isolation structure 1 can also be other physical vapor deposition (PVD) processes, etc.

[0099] Optional, refer to Figure 2 After forming the isolation structure 1 in the edge region Q1 on the first side of the conductive substrate 9, it also includes:

[0100] S103. Using the location of the isolation structure 1 as a support position, at least one structural layer is formed on the second side of the conductive base layer 9.

[0101] The second side is the side opposite to the first side of the conductive base layer 9.

[0102] In solar cells, some structural layers may also need to be formed on the other side (second side) of the conductive base layer 9. When forming structural layers, the solar cells need to be supported and fixed in a certain way.

[0103] In this embodiment of the invention, after the isolation structure 1 is formed, other structural layers may be formed on the second side of the conductive base layer 9 as needed; and when these structural layers are formed, the location of the isolation structure 1 may be used as a support (support position).

[0104] In some related technologies, all areas of a solar cell can be active areas. Therefore, when fabricating a structural layer on one side of the solar cell, it is necessary to use other structural layers on the other side of the solar cell as support sites. The structural layers at the support sites need to be in contact with the support structure, which can easily lead to damage or contamination of the corresponding structural layers, causing problems such as increased transmission resistance.

[0105] In this embodiment of the invention, the location of the isolation structure 1 is an "invalid" inactive region. Therefore, support positions are set at these locations. Even if the structural layer (such as the perovskite layer 63) at the corresponding location is damaged or contaminated, it will not affect the actual performance of the product.

[0106] It should be understood that step S103 can be performed after the formation of the isolation structure 1 (step S101). It can be performed before the formation of the conductive functional layer 2, after the formation of the conductive functional layer 2, or after the formation of some of the multiple conductive functional layers 2. That is, step S103 can be performed before, after, or between step S102. The numbering order does not represent the necessary execution order.

[0107] It should be understood that if all the structures on the second side of the conductive base layer 9 have been prepared in advance before the formation of the isolation structure 1, then the above step S103 is not required, which is also feasible.

[0108] Optionally, the solar cell is a perovskite / polycrystalline silicon tandem cell; the perovskite / polycrystalline silicon tandem cell includes a stacked perovskite top cell 6 and a polycrystalline silicon bottom cell 8, and a composite layer 7 connecting the perovskite top cell 6 and the polycrystalline silicon bottom cell 8.

[0109] The method described in this embodiment of the invention can be specifically used to prepare perovskite / polycrystalline silicon tandem solar cells.

[0110] Reference Figure 9 The perovskite / polycrystalline silicon tandem solar cell includes a stacked perovskite top cell 6 and a polycrystalline silicon bottom cell 8, wherein the perovskite top cell 6 can be located on the light-incident side, and the perovskite top cell 6 and the polycrystalline silicon bottom cell 8 can be connected by a composite layer 7.

[0111] The composite layer 7 can be made of a transparent conductive material, which is used to conduct the perovskite top cell 6 and the polycrystalline silicon bottom cell 8.

[0112] The perovskite top solar cell 6 may include a top transparent electrode layer 61, a hole transport layer 62 (p-type charge transport layer), a perovskite layer 63, and an electron transport layer 64 (n-type charge transport layer) arranged sequentially, wherein the electron transport layer 64 may be disposed close to the composite layer 7.

[0113] The polycrystalline silicon bottom cell 8 may include a silicon substrate 81. Along the direction gradually away from the composite layer 7, the silicon substrate 81 may include a first doped layer 811 of monocrystalline silicon (e.g., n-type doped), a first intrinsic layer 812 of monocrystalline silicon, a silicon base layer 813 of polycrystalline silicon (e.g., n-type), a second intrinsic layer 814 of monocrystalline silicon, and a second doped layer 815 of monocrystalline silicon (e.g., p-type doped). A bottom transparent electrode layer 82 (made of transparent conductive material) is provided on the side of the silicon substrate 81 away from the composite layer 7.

[0114] Reference Figure 9 Metal electrodes 5 (leads) may also be provided on the outer side of the top transparent electrode layer 61 and the bottom transparent electrode layer 82 (away from the composite layer 7).

[0115] The following provides an illustrative example of some structural layers in perovskite / polycrystalline silicon tandem solar cells. It should be understood that the specific structural layers in perovskite / polycrystalline silicon tandem solar cells are not limited to the following examples:

[0116] (1) The material of hole transport layer 62 can be one or more of NiOx (x is between 0.1 and 10), CuFeO2, CuAlO2, CuSCN, Cu2O, WO3, CuI2, MoS2, FeS2, P3HT, Spiro-meoTAD, Poly-TBD, PFN, PEDOT:PSS, PTAA, and Spiro-TTB; and the preparation process of hole transport layer 62 can be selected from solution method, thermal evaporation method, sputtering method, and atomic layer deposition method; the thickness of hole transport layer 62 can be between 0.1 and 1000 nm.

[0117] (2) The material of electron transport layer 64 is one or more of TiO2, SnO2, ZnO, ZrO2, In2O3, CdS, CdSe, BaSnO3, Nb2O5, C60, and PCBM.

[0118] (3) The material of the perovskite layer 63 can be of the general formula ABX3, where A is selected from one or more of FA(HC(NH2)2), MA(CH3NH3), Cs, and Rb, B is selected from one or more of Pb, Sn, and Sr, and X is selected from one or more of Br, I, and Cl; the band gap of the material of the perovskite layer 63 can be 1.40 to 2.3 eV; the thickness of the perovskite layer 63 can be 1 to 5000 nm.

[0119] (4) The materials of each transparent conductive layer (such as composite layer 7, bottom transparent electrode layer 82, top transparent electrode layer 61) can be selected from one or more of ITO, IZO, IWO, TiO2, SnO2, ZnO, ZrO2, GZO, AZO, FTO, BaSnO3, Ti-doped SnO2, and Zn-doped SnO2.

[0120] (5) The material of the metal electrode 5 can be selected from one or more of Cu, Al and Ag, and the thickness can be 1 to 1000 μm.

[0121] It should be understood that the specific form of the perovskite / polycrystalline silicon tandem solar cell in the embodiments of the present invention is not limited to the above examples. For example, it may also include more other known structural layers.

[0122] It should be understood that the embodiments of the present invention are not limited to perovskite / polycrystalline silicon tandem cells, but can also be used in any other form of solar cell with multiple structural layers.

[0123] Optionally, the conductive base layer 9 is the silicon substrate 81 of the polycrystalline silicon bottom cell 8; the conductive functional layer 2 includes a composite layer 7, a top transparent electrode layer 61 of the perovskite top cell 6, and a perovskite layer 63 of the perovskite top cell 6.

[0124] As one embodiment of the present invention, refer to Figure 9 For perovskite / polycrystalline silicon tandem solar cells, the silicon substrate 81 of the polycrystalline silicon bottom cell 8 can be used as the conductive base layer 9, and the side of the silicon substrate 81 facing the perovskite top cell 6 is the first side. Thus, at least the composite layer 7, as well as the perovskite layer 63 and the top transparent electrode layer 61 of the perovskite top cell 6, are all the above conductive functional layers 2.

[0125] Therefore, the embodiments of the present invention can achieve alignment of the composite layer 7 and the top transparent electrode layer 61, thereby improving charge transport efficiency; at the same time, the poorly crystallized and unevenly uniform portions of the perovskite layer 63 at the edge are located in the inactive region.

[0126] It should be understood that when perovskite / polycrystalline silicon tandem solar cells are used, the conductive functional layer 2 and the conductive base layer 9 are not limited to the specific examples mentioned above.

[0127] For example, you can refer to Figure 9 The hole transport layer 62, electron transport layer 64 and other structural layers are also conductive functional layers 2.

[0128] For example, an isolation structure 1 can also be formed on the other side of the silicon substrate 81, so that the bottom transparent electrode layer 82 also serves as a conductive functional layer 2, thereby achieving the alignment of the three transparent conductive layers: the top transparent electrode layer 61, the composite layer 7, and the bottom transparent electrode layer 82.

[0129] For example, the isolation structure 1 is also located in other positions, such as on the side of the composite layer 7 away from the silicon substrate 81, so that the composite layer 7 is a conductive base layer 9.

[0130] Secondly, referring to Figures 1 to 9 This invention provides a solar cell comprising:

[0131] The conductive base layer 9 has an isolation structure 1 in the edge region Q1 on the first side of the conductive base layer 9; the edge region Q1 is a region of a predetermined size radially inward from the edge of the conductive base layer 9; the isolation structure 1 can prevent electrical conduction between the structures in contact with its two sides.

[0132] At least one conductive functional layer 2 is provided on the side of the isolation structure 1 away from the conductive base layer 9; the orthographic projection of the conductive functional layer 2 on the conductive base layer 9 coincides with the orthographic projection of the isolation structure 1 on the conductive base layer 9.

[0133] The solar cell of this invention is obtained by the above preparation method. Therefore, the edge of the conductive functional layer 2 is separated from the conductive base layer 9 by the isolation structure 1. In the actual "effective" active area, the conductive functional layer 2 is aligned and has good film quality, resulting in good battery performance.

[0134] Optionally, an isolation structure 1 is provided at any position along the circumference of the conductive base layer 9;

[0135] The orthographic projection of the conductive functional layer 2 onto the conductive base layer 9 coincides with the orthographic projection of the isolation structure 1 onto the conductive base layer 9 at any position along the circumference of the conductive base layer 9.

[0136] The isolation structure 1 is covered by the edge region Q1.

[0137] Optionally, the thickness of the isolation structure 1 is between 1 nm and 10 cm;

[0138] The width of the isolation structure 1 is between 1 nm and 10 cm; the width of the isolation structure 1 is the radial dimension of the isolation structure 1 in the conductive substrate 9;

[0139] The material of the isolation structure 1 includes one or more of the following: silicon nitride, silicon carbide, aluminum oxide, silicon oxide, magnesium oxide, zirconium oxide, titanium oxide, zinc oxide, tin oxide, nickel oxide, boron nitride, aluminum nitride, gallium nitride, titanium nitride, polyethylene, polyvinyl chloride, phenolic resin, epoxy resin, unsaturated polyester resin, viscose fiber, cellulose acetate, nylon, polyester, polypropylene, polystyrene, nylon, acrylic fiber, vinylon, styrene-butadiene rubber, cis-butadiene rubber, isoprene rubber, ethylene propylene rubber, polyoxymethylene, polycarbonate, polyimide, polyarylene ether, polyarylamide, polysiloxane, and polyvinyl chloride.

[0140] Optionally, the solar cell is a perovskite / polycrystalline silicon tandem cell; the perovskite / polycrystalline silicon tandem cell includes a stacked perovskite top cell 6 and a polycrystalline silicon bottom cell 8, and a composite layer 7 connecting the perovskite top cell 6 and the polycrystalline silicon bottom cell 8.

[0141] The conductive base layer 9 is the silicon substrate 81 of the polycrystalline silicon bottom cell 8;

[0142] The conductive functional layer 2 includes a composite layer 7, a top transparent electrode layer 61 of the perovskite top cell 6, and a perovskite layer 63 of the perovskite top cell 6.

[0143] It is understood that the above embodiments are merely exemplary implementations used to illustrate the principles of the present invention, and the present invention is not limited thereto. For those skilled in the art, various modifications and improvements can be made without departing from the spirit and essence of the present invention, and these modifications and improvements are also considered to be within the scope of protection of the present invention.

Claims

1. A method for preparing a solar cell, characterized in that, include: An isolation structure is formed in the edge region of the first side surface of the conductive substrate, and the isolation structure is provided at any position along the circumference of the conductive substrate; the edge region is a region of a predetermined size radially inward from the edge of the conductive substrate, and the isolation structure can prevent electrical conduction between structures in contact with its two sides; wherein, the solar cell is a perovskite / polycrystalline silicon tandem cell; the perovskite / polycrystalline silicon tandem cell includes a stacked perovskite top cell and a polycrystalline silicon bottom cell, and a composite layer connecting the perovskite top cell and the polycrystalline silicon bottom cell; the conductive substrate is the silicon substrate of the polycrystalline silicon bottom cell; At least one conductive functional layer is formed on a first side of the conductive substrate; a portion of the orthographic projection of the conductive functional layer on the conductive substrate coincides with the orthographic projection of the isolation structure on the conductive substrate; wherein the conductive functional layer includes the composite layer, the top transparent electrode layer of the perovskite top cell, and the perovskite layer of the perovskite top cell.

2. The preparation method according to claim 1, characterized in that, The orthographic projection of the conductive functional layer onto the conductive base layer coincides with the orthographic projection of the isolation structure onto the conductive base layer at any position along the circumference of the conductive base layer.

3. The preparation method according to claim 2, characterized in that, The isolation structure covers the edge area.

4. The preparation method according to claim 3, characterized in that, The conductive functional layer covers the first side of the conductive base layer.

5. The preparation method according to claim 1, characterized in that, The thickness of the isolation structure is between 1 nm and 10 cm.

6. The preparation method according to claim 1, characterized in that, The width of the isolation structure is between 1 nm and 10 cm; the width of the isolation structure is the radial dimension of the isolation structure on the conductive substrate.

7. The preparation method according to claim 1, characterized in that, The materials of the isolation structure include one or more of the following: silicon nitride, silicon carbide, aluminum oxide, silicon oxide, magnesium oxide, zirconium oxide, titanium oxide, zinc oxide, tin oxide, nickel oxide, boron nitride, aluminum nitride, gallium nitride, titanium nitride, polyethylene, phenolic resin, epoxy resin, unsaturated polyester resin, viscose fiber, cellulose acetate, nylon, polyester, polypropylene, polystyrene, nylon, acrylic fiber, vinylon, styrene-butadiene rubber, cis-butadiene rubber, isoprene rubber, ethylene-propylene rubber, polyoxymethylene, polycarbonate, polyimide, polyarylene ether, polyarylamide, polysiloxane, and polyvinyl chloride.

8. The preparation method according to claim 1, characterized in that, The isolation structure is formed by any one of the following methods: vapor deposition, sputtering, coating, chemical vapor deposition, atomic layer deposition, and mechanical stacking.

9. The preparation method according to any one of claims 1 to 8, characterized in that, After forming the isolation structure in the edge region of the first side of the conductive substrate, the method further includes: Using the location of the isolation structure as a support position, at least one structural layer is formed on the second side of the conductive base layer; the second side is the side of the conductive base layer opposite to the first side.

10. A solar cell, characterized in that, include: A conductive substrate has an isolation structure in the edge region of its first side surface, and the isolation structure is provided at any position along the circumference of the conductive substrate; the edge region is a predetermined area of ​​the conductive substrate radially inward from the edge, and the isolation structure can prevent electrical conduction between structures in contact with its two sides; wherein, the solar cell is a perovskite / polycrystalline silicon tandem cell; the perovskite / polycrystalline silicon tandem cell includes a stacked perovskite top cell and a polycrystalline silicon bottom cell, and a composite layer connecting the perovskite top cell and the polycrystalline silicon bottom cell; the conductive substrate is the silicon substrate of the polycrystalline silicon bottom cell; At least one conductive functional layer is disposed on the side of the isolation structure away from the conductive base layer; a portion of the orthographic projection of the conductive functional layer on the conductive base layer coincides with the orthographic projection of the isolation structure on the conductive base layer; wherein, the conductive functional layer includes the composite layer, the top transparent electrode layer of the perovskite top cell, and the perovskite layer of the perovskite top cell.

11. The solar cell according to claim 10, characterized in that, The orthographic projection of the conductive functional layer onto the conductive base layer coincides with the orthographic projection of the isolation structure onto the conductive base layer at any position along the circumference of the conductive base layer. The isolation structure covers the edge area.

12. The solar cell according to claim 10, characterized in that, The thickness of the isolation structure is between 1 nm and 10 cm; The width of the isolation structure is between 1 nm and 10 cm; the width of the isolation structure is the radial dimension of the isolation structure on the conductive substrate. The isolation structure includes one or more of the following: silicon nitride, silicon carbide, aluminum oxide, silicon oxide, magnesium oxide, zirconium oxide, titanium oxide, zinc oxide, tin oxide, nickel oxide, boron nitride, aluminum nitride, gallium nitride, titanium nitride, polyethylene, phenolic resin, epoxy resin, unsaturated polyester resin, viscose fiber, cellulose acetate, nylon, polyester, polypropylene, polystyrene, nylon, acrylic fiber, vinylon, styrene-butadiene rubber, cis-butadiene rubber, isoprene rubber, ethylene-propylene rubber, polyoxymethylene, polycarbonate, polyimide, polyarylene ether, polyarylamide, polysiloxane, and polyvinyl chloride.

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