Solar cell, photovoltaic module

Abstract

The application provides a solar cell, comprising a cell body, a barrier layer arranged on the cell body, and a plurality of electrode structures arranged on the barrier layer, wherein the electrode structures comprise an organic layer and an electrode layer arranged in sequence, and the electrode layer comprises an organic carrier and first metal particles, and the organic material of the organic layer is the same as the organic material of the organic carrier. Compared with the prior art in which the electrode is formed on the barrier layer by screen printing, the organic layer is additionally arranged between the barrier layer and the electrode layer, so that the bonding force between the barrier layer and the electrode layer is increased, and the reliability of the solar cell is improved. The same organic material is used, so that the bonding between the organic layer and the electrode layer is more firm, the bonding force between the organic layer and the electrode layer is improved, and the reliability of the solar cell is improved. The application further provides a photovoltaic module comprising the above solar cell.

Description

Technical Field

[0001] This application relates to the field of solar cells, and more specifically, to a solar cell and a photovoltaic module including the solar cell. Background Technology

[0002] A solar cell is a device that converts solar energy into electrical energy using the photoelectric effect of semiconductor materials. In a solar cell, when sunlight shines on the semiconductor material, the atoms within the material undergo a transition reaction due to the influence of photons, forming electron-hole pairs. These pairs, under the influence of an electric field, generate a photovoltage. To utilize this photovoltage, electrodes are typically formed on P-type and N-type semiconductors. When electrons and holes accumulate on these semiconductors, they flow through these electrodes to an external circuit, forming a current, thus realizing the conversion of light energy into electrical energy.

[0003] Currently, conductive paste is typically printed directly using screen printing technology to form electrodes, thereby enabling the collection of electrons and holes. However, this method of directly printing conductive paste results in poor contact and weak adhesion between the electrodes and other structures in the solar cell, thus affecting the photoelectric conversion efficiency and reliability of the solar cell. Summary of the Invention

[0004] In view of this, this application provides a solar cell and a photovoltaic module to solve the above-mentioned problems existing in the prior art.

[0005] Specifically, according to a first aspect of this application, a solar cell is provided, comprising: a cell body; a barrier layer disposed on the cell body; and a plurality of electrode structures disposed on the barrier layer, wherein the electrode structures include an organic layer and an electrode layer stacked sequentially; wherein the electrode layer includes an organic carrier and a first metal particle, and the organic material of the organic layer is the same as the organic material of the organic carrier.

[0006] The solar cell provided in this application increases the bonding force between the barrier layer and the electrode layer by additionally setting an organic layer between them, preventing the electrode layer from detaching and improving the reliability of the solar cell. Furthermore, using the same organic material makes the bond between the organic layer and the electrode layer even stronger, thereby further improving the bonding force between the organic layer and the electrode layer and further enhancing the reliability of the solar cell.

[0007] In some implementations, the thickness of the organic layer is 0.01 nm to 50 nm.

[0008] In some implementations, the thickness of at least one location in the organic layer is 0.01 nm to 5 nm.

[0009] In some implementations, the thickness of at least one location in the organic layer is 0.01 nm to 10 nm.

[0010] In some implementations, the width of the organic layer is greater than or equal to the width of the electrode layer.

[0011] In some implementations, the projection area of ​​the organic layer on the battery body completely covers the projection area of ​​the electrode layer on the battery body.

[0012] In some implementations, the material of the first metal particle includes copper, silver, nickel, aluminum, their alloys, or any combination thereof.

[0013] In some embodiments, the first metal particle includes at least one of spherical particles and flake particles.

[0014] In some implementations, the first metal particles in the electrode layer penetrate the organic layer and contact the barrier layer.

[0015] In some embodiments, the organic layer includes at least one conductive contact point within a 50 μm range, and the thickness of the organic layer at the conductive contact point is 0.01 nm to 10 nm; or, a first metal particle in the electrode layer at the conductive contact point penetrates the organic layer and contacts the barrier layer.

[0016] In some implementations, the organic layer is a conductive organic layer.

[0017] In some embodiments, the organic layer contains second metal particles with a smaller particle size than the first metal particles.

[0018] In some implementations, the organic material in the organic layer is a conductive organic material.

[0019] In some embodiments, the first metal particle includes sheet-like particles, which include monolayer sheet-like particles.

[0020] In some embodiments, the first metal particle includes a sheet-like particle whose outline is surrounded by a smooth curved surface.

[0021] In some implementations, the particle size of the second metal particle is 1-20 nm.

[0022] In some implementations, the barrier layer is an integral structure.

[0023] In some implementations, the barrier layer includes multiple sub-barrier layers, each corresponding to a specific electrode structure.

[0024] In some implementations, the barrier layer is a metal layer or a transparent conductive oxide layer.

[0025] In some embodiments, the material of the transparent conductive oxide layer includes one or more combinations of indium tin oxide (ITO), indium tungsten oxide (IWO), and indium titanium oxide (ITiO).

[0026] In some implementations, the material of the metal layer includes one or more combinations of nickel, silver, tin, and aluminum.

[0027] In some embodiments, the battery body includes a semiconductor substrate and a doped semiconductor layer disposed on the semiconductor substrate, a barrier layer is in contact with the doped semiconductor layer, and an electrode structure is electrically connected to the doped semiconductor layer through the barrier layer.

[0028] In some embodiments, the battery body includes a semiconductor substrate and a doped semiconductor layer and a dielectric layer sequentially disposed on the semiconductor substrate. The dielectric layer has multiple openings, and each opening corresponds to an electrode structure. A barrier layer passes through the opening and contacts the doped semiconductor layer. The electrode structure is electrically connected to the doped semiconductor layer through the barrier layer.

[0029] According to a second aspect of this application, a photovoltaic module is provided, comprising a plurality of cell strings, each cell string including a plurality of solar cells and a plurality of interconnecting elements for connecting the plurality of solar cells in series; wherein the solar cells are any of the solar cells described in the first aspect of this application. Attached Figure Description

[0030] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other implementation schemes can be obtained based on these drawings without creative effort.

[0031] Figure 1 A schematic diagram of the structure of a solar cell according to some embodiments of this application is shown.

[0032] Figure 2 A schematic diagram of the structure of a battery body according to some embodiments of this application is shown.

[0033] Figure 3 A schematic diagram of the structure of a battery body according to some other embodiments of this application is shown.

[0034] Figure 4 A schematic diagram of the structure of a solar cell according to some other embodiments of this application is shown.

[0035] Figure 5 SEM images of the barrier layer, organic layer, and electrode layer in a solar cell according to some embodiments of this application are shown. Figure 5 B is Figure 5 Enlarged view of the boxed area in A.

[0036] Figure 6 SEM images of the barrier layer, organic layer, and electrode layer in a solar cell according to some other embodiments of this application are shown.

[0037] Figure 7 SEM images of the barrier layer, electrode layer and organic layer in a solar cell according to some embodiments of this application are shown.

[0038] Figure 8 SEM images of the barrier layer, electrode layer, and organic layer in a solar cell containing a second metal particle within the organic layer, according to some embodiments of this application, are shown.

[0039] The reference numerals in the attached figures are as follows: 100 represents a solar cell; 10 represents the cell body; 101 represents a semiconductor substrate; 102 represents a doped semiconductor layer; 103 represents a dielectric layer; 104 represents an opening; 20 represents a barrier layer; 201 represents a sub-barrier layer; 30 represents an electrode structure; 301 represents an organic layer; and 302 represents an electrode layer. Detailed Implementation

[0040] The present application will now be clearly and completely described in conjunction with its embodiments and accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of the present application, and not all of them. All other embodiments that can be obtained by those skilled in the art based on the embodiments in this application are within the scope of protection of this application.

[0041] In this application, the terms "first" and "second" are used only to describe features for the purpose of description and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Features defined with "first" or "second" may explicitly or implicitly include at least one of the defined features. It is understood that "at least one" includes one or more, while "multiple" generally means at least two, such as two, three, four, five, six, etc., unless otherwise explicitly specified.

[0042] In this application, unless otherwise explicitly specified and limited, terms such as "installation," "connection," "joining," and "fixing" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can be a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in this application based on the specific circumstances.

[0043] In this application, the terms "one embodiment," "some embodiments," "one example," "some embodiments," "example," "specific example," or "some examples," etc., refer to a specific feature, structure, material, or characteristic described in connection with that embodiment, example, or example, which is included in at least one embodiment, example, or example of this application. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment, example, or example. Moreover, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments, examples, or examples. Furthermore, without contradiction, those skilled in the art can combine and integrate the different embodiments, examples, or examples described in this specification, as well as the features of different embodiments, examples, or examples.

[0044] The photovoltaic module of this application includes a structure consisting of a transparent cover plate, an encapsulating film, a battery string, and an encapsulation backplate stacked together for photovoltaic power generation.

[0045] In photovoltaic (PV) modules, the transparent cover plate protects the internal solar cells and other materials from external environmental influences while maintaining high light transmittance to ensure effective solar energy absorption. It can be a transparent polymer film, such as ethylene-tetrafluoroethylene copolymer film, or transparent glass, such as ultra-clear photovoltaic glass. The encapsulating film is primarily used to bond the solar cell strings to the transparent cover plate and the encapsulation backsheet; it can be ethylene-octene copolymer (POE), ethylene-vinyl acetate copolymer (EVA), etc. The encapsulation backsheet, located on the outermost layer of the PV module's back, encapsulates and protects the solar cell strings from external environmental corrosion, providing weather resistance and insulation. It can be made of glass or organic polymer films. The solar cell strings convert solar energy into electrical energy and are the core component of the PV module.

[0046] Photovoltaic modules typically comprise multiple cell strings, which can be connected together in series and / or parallel. Each cell string includes multiple solar cells 100 and multiple interconnects for connecting the multiple solar cells in series. It is understood that the interconnects connect the multiple solar cells in series by electrically connecting them to the electrode structures of the multiple solar cells 100. Here, the solar cells 100 include any of the solar cells described below in this application. Furthermore, the aforementioned interconnects can be, for example, solder ribbons, metal wires, conductive tape, etc.

[0047] Figure 1 A schematic diagram of the structure of a solar cell 100 according to some embodiments of this application is shown. (Reference) Figure 1As can be seen, the solar cell 100 includes a cell body 10, a barrier layer 20 disposed on the cell body 10, and a plurality of electrode structures 30 disposed on the barrier layer 20.

[0048] Figure 2 A schematic diagram of the structure of the battery body 10 according to some embodiments of this application is shown. (Reference) Figure 2 As can be seen, the battery body 10 includes a semiconductor substrate 101 and a doped semiconductor layer 102 disposed on the semiconductor substrate 101. The semiconductor substrate 101 includes a first surface and a second surface opposite to each other, and the doped semiconductor layer 102 can be disposed on the first surface and / or the second surface of the semiconductor substrate 101. Figure 2 The illustration shows the case where the doped semiconductor layer 102 is disposed on only one surface of the semiconductor substrate 101. It is understood that the doped semiconductor layer 102 can also be disposed on both surfaces of the semiconductor substrate 101 simultaneously, and those skilled in the art can choose as needed. In this case, no dielectric layer is disposed between the doped semiconductor layer 102 and the barrier layer.

[0049] In some embodiments, the semiconductor substrate 101 includes a silicon substrate, a germanium substrate, a silicon-germanium substrate, etc. When the semiconductor substrate 101 is a silicon substrate, it can be monocrystalline silicon, polycrystalline silicon, amorphous silicon, microcrystalline silicon, etc., and this application does not limit it. In some embodiments, the material of the doped semiconductor layer 102 can be monocrystalline silicon, polycrystalline silicon, amorphous silicon, microcrystalline silicon, nanocrystalline silicon, etc., and this application does not limit it.

[0050] Figure 3 A schematic diagram of the battery body 10 according to some other embodiments of this application is shown. (Reference) Figure 3 As can be seen, the battery body 10 includes a semiconductor substrate 101, a doped semiconductor layer 102 and a dielectric layer 103 sequentially stacked on the semiconductor substrate 101, and the dielectric layer 103 has multiple openings 104. Figure 3 This illustration only shows the case where the doped semiconductor layer 102 and the dielectric layer 103 are stacked on only one surface of the semiconductor substrate 101. It is understood that the doped semiconductor layer 102 and the dielectric layer 103 can also be stacked on both surfaces of the semiconductor substrate 101 simultaneously, and those skilled in the art can choose according to their needs. In some embodiments, the material of the dielectric layer 103 can be one or more of silicon nitride, silicon oxide, silicon oxynitride, aluminum oxide, and amorphous silicon. Of course, other materials can also be used, and this application does not further limit their application.

[0051] Furthermore, the dielectric layer 103 can be a single-layer structure or a multi-layer structure. In some examples, the dielectric layer 103 may include a passivation layer, or other possible layers such as an anti-reflection layer, or a passivation layer and an anti-reflection layer stacked together. The material of the passivation layer may be, for example, one or more of amorphous silicon and aluminum oxide, and the material of the anti-reflection layer may be, for example, one or more of silicon nitride, silicon oxide, and silicon oxynitride.

[0052] Continue to refer to Figure 1 A barrier layer 20 is disposed on the battery body 10. The barrier layer 20 protects the battery body 10 and reduces the risk of mechanical damage to the battery body 10 during the fabrication of the electrode structure 30. In some examples, the barrier layer 20 can also prevent some elements in the electrode structure 30 from diffusing into the battery body 10, affecting the photoelectric conversion efficiency of the solar cell 100. In other examples, the barrier layer 20 can also reduce the lateral transport resistance of charge carriers, improve the transport efficiency of charge carriers, and thus improve the photoelectric conversion efficiency.

[0053] The barrier layer 20 can be a single, integral structure, or it can comprise multiple sub-barrier layers 201, meaning it includes multiple independent structures. This is understandable. Figure 1 This shows a structure where the barrier layer 20 is an integral unit. Figure 4 The illustration shows a case where the barrier layer 20 comprises multiple sub-barrier layers 201. Furthermore, the barrier layer 20 can be a metal layer or a transparent conductive oxide layer. The aforementioned barrier layers, with different structures and materials, can be configured according to different types of solar cells.

[0054] In this application, the solar cell 100 can be either a bifacial cell or a back-contact cell. When the solar cell 100 is a bifacial cell, it can be, for example, including but not limited to, a TOPCon cell, a heterojunction cell (HIT cell), or a bifacial hybrid cell. It is understood that when it is a bifacial cell, the barrier layer 20 and electrode structure 30 of this application can be disposed on either side or both sides of its cell body 10. When the solar cell 100 is a back-contact cell, it can be, for example, including but not limited to, a TBC cell, an HBC cell (heterojunction back-contact cell), or a hybrid back-contact cell. In some examples, the back-contact cell, such as a TBC cell, an HBC cell, or a hybrid back-contact cell, can be designed as an interdigitated back-contact cell (IBC cell). When the solar cell is a back-contact cell, the barrier layer 20 and electrode structure 30 of this application can be disposed on at least one of the P-region and N-region of the cell body 10.

[0055] In the case of a TOPCon solar cell 100, the cell body 10 includes a semiconductor substrate 101 and a tunneling layer (e.g., a tunneling oxide layer), a doped polycrystalline silicon layer (equivalent to a doped semiconductor layer 102), and a dielectric layer 103 sequentially stacked on the semiconductor substrate 101. The dielectric layer 103 has openings, and the electrode structure 30 is correspondingly disposed within these openings. In a TOPCon cell, the stacked tunneling layer and the doped polycrystalline silicon layer together constitute a passivation contact structure, which effectively reduces surface recombination and metal-to-metal recombination. In some examples, the semiconductor substrate 101 is an n-type silicon substrate, and the doped semiconductor layer 102 is an n-type doped polycrystalline silicon layer. In this case, the barrier layer 20 disposed on the cell body 10 can be a single structure or can include multiple sub-barrier layers 201. When the barrier layer 20 is a single structure, it can be a TCO layer; when it includes multiple sub-barrier layers 201, it can be a TCO layer or a metal layer.

[0056] In the case where the solar cell 100 is a HIT cell, the cell body 10 includes a semiconductor substrate 101 and two doped semiconductor layers 102 respectively disposed on two opposite surfaces of the semiconductor substrate 101. These two doped semiconductor layers 102 have opposite doping types, i.e., one is n-type doped and the other is p-type doped. In this case, the material of the doped semiconductor layer 102 can be one or more of doped amorphous silicon, doped microcrystalline silicon, and doped nanocrystalline silicon. The HIT cell also includes an intrinsic amorphous silicon layer disposed between the semiconductor substrate 101 and the doped semiconductor layers 102. The intrinsic amorphous silicon layer has excellent passivation properties on the surface of the silicon substrate, which can significantly prevent carrier recombination and achieve higher minority carrier lifetime and open-circuit voltage. In this case, the barrier layer 20 disposed on the cell body 10 is an integral structure, and the barrier layer 20 can be a TCO layer.

[0057] In the case where the solar cell 100 is a bifacial hybrid cell, the cell body 10 includes a semiconductor substrate 101, a tunneling layer (e.g., a tunneling oxide layer), a doped polycrystalline silicon layer (equivalent to a first doped semiconductor layer 102), and a dielectric layer 103 sequentially stacked on a first surface of the semiconductor substrate 101, and an intrinsic amorphous silicon layer and a second doped semiconductor layer sequentially stacked on a second surface opposite to the first surface. The material of the second doped semiconductor layer can be one or more of doped amorphous silicon, doped microcrystalline silicon, and doped nanocrystalline silicon. The doped polycrystalline silicon layer and the second doped semiconductor layer have opposite conductivity types, i.e., one is n-type doped and the other is p-type doped. The tunneling layer and the doped polycrystalline silicon layer can be disposed in a local area or the entire area of ​​the first surface. The doped semiconductor layer can include at least one of the first doped semiconductor layer 102 and the second doped semiconductor layer. In this case, the barrier layers 20 disposed on both sides of the battery body 10 can be a single integrated structure; alternatively, the barrier layer 20 on the side with the intrinsic amorphous silicon layer and the doped semiconductor layer 102 can be a single integrated structure, while the barrier layer 20 on the side with the tunneling layer and the doped polycrystalline silicon layer includes multiple sub-barrier layers 201, which are disposed together with the electrode structure 30 corresponding to the opening 104 of the dielectric layer 103. When the barrier layer 20 is a single integrated structure, the barrier layer 20 can be a TCO layer; when it includes multiple sub-barrier layers 201, the barrier layer 20 can be a TCO layer or a metal layer.

[0058] When the solar cell 100 is an HBC cell, the cell body 10 includes a semiconductor substrate 101, which includes P-regions and N-regions alternately disposed in sequence. The cell body 10 includes a first intrinsic amorphous silicon layer and a P-type doped semiconductor layer disposed in sequence in the P-region, and a second intrinsic amorphous silicon layer and an N-type doped semiconductor layer disposed in sequence in the N-region. The doped semiconductor layer 102 includes at least one of a P-type doped semiconductor layer and an N-type doped semiconductor layer. The materials of the P-type doped semiconductor layer and the N-type doped semiconductor layer can be one or more of doped amorphous silicon, doped microcrystalline silicon, and doped nanocrystalline silicon. In some examples, the semiconductor substrate 101 also includes an overlapping region disposed between the P-region and the N-region. The first intrinsic amorphous silicon layer, the P-type doped semiconductor layer, the second intrinsic amorphous silicon layer, and the N-type doped semiconductor layer are stacked in sequence in the overlapping region. The second intrinsic amorphous silicon layer and the N-type doped semiconductor layer can be disposed on the first intrinsic amorphous silicon layer and the P-type doped semiconductor layer, or the first intrinsic amorphous silicon layer and the P-type doped semiconductor layer can be disposed on the second intrinsic amorphous silicon layer and the N-type doped semiconductor layer. Electrode structures 30 are respectively provided in the P-region and N-region. HBC cells help improve carrier lifetime and reduce surface recombination. In this case, the barrier layer 20 provided on the doped semiconductor layer 102 of the cell body 10 includes a plurality of sub-barrier layers 201, each sub-barrier layer 201 corresponding to a P-region or an N-region, wherein the plurality of sub-barrier layers 201 correspond one-to-one with a plurality of electrode structures 30, and the barrier layer 20 can be a TCO layer.

[0059] In the case where the solar cell 100 is a TBC cell, the cell body 10 includes a semiconductor substrate 101, which includes P-regions and N-regions alternately disposed in sequence. The cell body 10 includes a tunneling layer (e.g., a tunneling oxide layer) and a P-type doped polysilicon layer disposed in the P-region, and a tunneling layer and an N-type doped polysilicon layer disposed in the N-region. The doped semiconductor layer 102 includes at least one of the P-type doped polysilicon and N-type doped polysilicon layers. The cell body 10 also includes a dielectric layer 103 disposed on the P-type doped polysilicon and N-type doped semiconductor layers. A sub-barrier layer 201 is disposed together with the electrode structure 30 corresponding to the opening 104 of the dielectric layer 103, and the sub-barrier layer 201 is in contact with the doped semiconductor layer 102. In some examples, the semiconductor substrate 101 also includes an isolation region disposed between the P-region and the N-region, which may be, for example, an isolation trench. Electrode structures 30 are disposed in the P-region and the N-region, respectively. In this case, the barrier layer 20 disposed on the doped semiconductor layer 102 of the battery body 10 includes a plurality of sub-barrier layers 201, wherein the plurality of sub-barrier layers 201 correspond one-to-one with a plurality of electrode structures 30, and the barrier layer 20 can be a metal layer or a TCO layer.

[0060] In the case where the solar cell 100 is a hybrid back-contact cell, the cell body 10 includes a semiconductor substrate 101 and alternating tunneling passivation contact structures and heterojunction contact structures disposed on the semiconductor substrate 101. The tunneling passivation contact structure includes a stacked tunneling layer (e.g., a tunneling oxide layer) and a doped polycrystalline silicon layer (equivalent to a first doped semiconductor layer). The heterojunction contact structure includes a stacked intrinsic amorphous silicon layer and a second doped semiconductor layer. The doped semiconductor layer 102 includes at least one of the first and second doped semiconductor layers. The material of the second doped semiconductor layer can be one or more of doped amorphous silicon, doped microcrystalline silicon, and doped nanocrystalline silicon. The doped polycrystalline silicon layer and the second doped semiconductor layer have opposite conductivity types, i.e., one is n-type doped and the other is p-type doped. In some examples, the heterojunction contact structure extends and overlaps on a portion of the tunneling passivation contact structure. In this case, the barrier layer 20 disposed on the doped semiconductor layer 102 of the battery body 10 includes a plurality of sub-barrier layers 201, wherein the plurality of sub-barrier layers 201 correspond one-to-one with a plurality of electrode structures 30, and the barrier layer 20 can be a TCO layer.

[0061] It can be understood that n-type silicon substrate, n-type doped layer, or n-type doping refers to doping using dopants containing group V elements such as P and As, which are used to provide electrons after doping. p-type silicon substrate, p-type doped layer, or p-type doping refers to doping using dopants containing group III elements such as B and Al, which are used to provide holes after doping.

[0062] In this application, the solar cell 100 can be any of the above-mentioned types of cells.

[0063] In some embodiments, the material of the transparent conductive oxide layer includes one or more combinations of indium tin oxide (ITO), indium tungsten oxide (IWO), and indium titanium oxide (ITiO). Of course, other materials can also be used, and this application does not further limit their application. The transparent conductive oxide layer not only facilitates the collection of charge carriers in the doped semiconductor layer 102 but also provides a certain degree of anti-reflection effect.

[0064] In some embodiments, the material of the metal layer includes one or a combination of nickel, silver, tin, and aluminum. Of course, other materials may also be used, and this application does not further limit them.

[0065] Continue to refer to Figure 1Multiple electrode structures 30 are disposed on the barrier layer 20, and each electrode structure 30 includes an organic layer 301 and an electrode layer 302 stacked sequentially. Compared to the prior art where the electrode layer is formed on the barrier layer 20 by screen printing, the additional organic layer 301 between the barrier layer 20 and the electrode layer 302 can increase the bonding force between the barrier layer 20 and the electrode layer 302, thereby improving the reliability of the solar cell 100. Figure 5 SEM images of the barrier layer 20, organic layer 301 and electrode layer 302 in a solar cell according to some embodiments of this application are shown, wherein the barrier layer 20 is a TCO layer. Figure 6 SEM images of the barrier layer 20, organic layer 301 and electrode layer 302 in a solar cell according to some embodiments of this application are shown, wherein the barrier layer 20 is a metal layer.

[0066] In this application, the electrode layer 302 includes an organic carrier and first metal particles, i.e., the electrode layer is a slurry layer. The organic carrier of the electrode layer 302 can be any commonly used organic material known in the art for forming slurries, typically including, for example, resins, curing accelerators, and other additives such as dispersants and coupling agents. The resin can be selected from epoxy resins such as glycidyl ether type epoxy resins, glycidyl ester type epoxy resins, alicyclic epoxy resins, polyurethane resins, polyester resins, phenolic resins, and phenoxy resins, or a combination of one or more of these. The curing accelerator is selected from amine curing accelerators, acid curing accelerators, and quaternary ammonium salt curing accelerators. Those skilled in the art can choose the specific type as needed, and this application does not limit this selection. It is understood that the above-mentioned organic materials are generally non-conductive, but they can be made conductive by modifying them or adding conductive fillers (e.g., graphene, carbon nanotubes, carbon black, nano-metals and their oxides). The first metal particles filled in the organic carrier in the electrode layer 302 form a conductive network, thus achieving conductivity. In some embodiments, the material of the first metal particle may include copper, silver, nickel, aluminum, their alloys, or any combination thereof, wherein the alloy may be a copper-silver alloy, a copper-nickel alloy, a silver-nickel alloy, a silver-aluminum alloy, etc. It is understood that the materials of the organic carrier and the first metal particle described above are merely exemplary, and those skilled in the art may use other materials to form the electrode layer 302; this application does not further limit this. In some embodiments, the material of the electrode layer may be silver paste, copper paste, silver-coated copper paste, etc.

[0067] In some embodiments, the first metal particle can be at least one of spherical particles and sheet-like particles. Such first metal particles can form a conductive network in the electrode layer 302, improving the conductivity of the electrode layer 302 and increasing the carrier collection efficiency. Here, the size of the spherical particles ranges from 50 nm to 1.5 μm, for example, 50 nm, 60 nm, 100 nm, 150 nm, 200 nm, 300 nm, 500 nm, 1 μm, or 1.5 μm. This size range ensures good conductivity in the electrode layer 302. The size of the sheet-like particles ranges from 1 μm to 6 μm, for example, 1 μm, 2 μm, 3 μm, 4 μm, 5 μm, or 6 μm. This size range also ensures good conductivity in the electrode layer 302.

[0068] In some examples, the first metal particle described above includes sheet-like particles, which in turn include monolayer sheet-like particles. Because the sheet-like particles are monolayer sheet-like particles, a greater number of these particles are dispersed in the electrode layer, which is more beneficial for improving the conductivity of the electrode layer 302. Compared to multilayer sheet-like particles, monolayer sheet-like particles have a smoother surface.

[0069] In other examples, the sheet-like particles include multilayer sheet-like particles, that is, sheet-like particles formed by stacking multiple sheets. In this case, the sheet-like particles have lower resistance.

[0070] In some examples, the first metal particle described above includes plate-like particles whose outlines are enclosed by smooth curved surfaces. Here, the outline of the plate-like particles can refer to the outer outline of the plate-like particles as observed from any viewing angle when examined under an electron microscope (e.g., a scanning electron microscope). Because the outline of the plate-like particles is enclosed by smooth curved surfaces, the uniformity of the first metal particles in the electrode layer can be improved, thereby improving the conductivity of the electrode layer.

[0071] It should be noted that the first metal particle can be formed by the accumulation of at least one of metal ions and metal atoms.

[0072] In this application, the organic material of the organic layer 301 is the same as the organic material of the organic carrier of the electrode layer 302. Using the same organic material makes the bond between the organic layer 301 and the electrode layer 302 stronger, thereby improving the bonding force between the organic layer 301 and the electrode layer 302 and improving the reliability of the solar cell 100.

[0073] It is understandable that the organic layer 301 can be formed separately from the electrode layer 302, for example, the organic layer 301 can be formed first, and then the electrode layer 302 can be formed; or the organic layer 301 can be formed simultaneously with the electrode layer 302. In the case of simultaneous formation, during the formation of the electrode layer 302, by controlling process conditions such as printing speed and temperature, the organic material in the electrode layer 302 can be formed between the electrode layer 302 and the barrier layer 20, thereby forming the organic layer 301. This not only simplifies the process, but also allows the organic material of the organic layer 301 to be connected with the organic material of the organic carrier of the electrode layer 302 to form an integrated structure, which is more conducive to increasing the bonding force between the electrode layer 302 and the barrier layer 20.

[0074] In some implementations, the thickness of the organic layer 301 is 0.01 nm to 50 nm. For example, the thickness of the organic layer 301 can be 0.01 nm, 0.5 nm, 0.1 nm, 1 nm, 2 nm, 3 nm, 4 nm, 5 nm, 6 nm, 7 nm, 8 nm, 9 nm, 10 nm, 15 nm, 18 nm, 19 nm, 20 nm, 25 nm, 30 nm, 40 nm, or 50 nm. If the thickness of the organic layer 301 is too small, it cannot firmly bond the electrode layer 302 and the barrier layer 20. If the thickness is too large, it will result in an excessively high bulk resistance of the organic layer 301, affecting the collection of charge carriers and thus the photoelectric conversion efficiency of the solar cell 100. Controlling the thickness of the organic layer 301 within the above range not only ensures that the organic layer 301 can firmly bond the electrode layer 302 and the barrier layer 20, but also prevents the bulk resistance of the organic layer 301 from becoming too high, thus ensuring efficient collection of charge carriers.

[0075] It is understandable that the thickness of the organic layer 301 can be uniform or non-uniform. When the thickness of the organic layer is non-uniform, in this case, the thickness of the organic layer is 0.01nm-50nm, meaning that the thickness at any location in the organic layer 301 is within the thickness range of the organic layer 301 (0.01nm-50nm). Of course, in some examples, it can also mean that the thickness at any location in the organic layer 301 is within the range of the organic layer 301 (0.01nm-50nm).

[0076] In order to achieve electrical connection between electrode layer 302 and barrier layer 20, ensure low contact resistance between electrode layer 302 and barrier layer 20, and ensure strong bonding force between electrode layer 302 and barrier layer 20, this application can achieve this by adjusting the thickness, material of organic layer 301, electrode layer 302, etc., as illustrated by some examples below.

[0077] In some embodiments, the thickness of at least one location in the organic layer 301 is 0.01 nm to 5 nm, for example, 0.01 nm, 0.5 nm, 1 nm, 2 nm, 3 nm, 4 nm, or 5 nm. In other embodiments, the thickness of at least one location in the organic layer is 0.01 nm to 10 nm, for example, 0.01 nm, 0.5 nm, 1 nm, 2 nm, 3 nm, 4 nm, 5 nm, 6 nm, 7 nm, 8 nm, 9 nm, or 10 nm. It is understood that the thickness of one or more locations in the organic layer 301 may be in the range of 0.01 nm to 5 nm, or in the range of 0.01 nm to 10 nm; alternatively, the thickness of any location in the organic layer 301 may be in the range of 0.01 nm to 5 nm, or in the range of 0.01 nm to 10 nm. The thinner organic layer 301 can achieve conductivity through a tunneling mechanism. Therefore, even when the organic layer 301 itself is not conductive, this thickness of organic layer 301 can still electrically connect the electrode layer 302 and the barrier layer 20. The organic material of the organic layer 301 is the same as the organic material of the electrode layer 302. Figure 7 SEM images of the barrier layer 20, electrode layer 302, and organic layer 301 in a solar cell 100 according to some embodiments of this application are shown. Figure 7 As can be seen, the thickness of the organic layer 301 is approximately 3.5 nm. Due to the relatively small thickness of the organic layer 301, charge carriers can tunnel through the organic layer 301 to achieve electrical connection between the electrode layer 301 and the barrier layer 20. In this case, the organic material in the organic layer 301 can be conductive or non-conductive.

[0078] It is understood that in some embodiments, the organic layer 301 itself has conductive properties, i.e., it is a conductive organic layer, to electrically connect the electrode layer 302 and the barrier layer 20. In this case, the thickness of the organic layer 301 is not limited.

[0079] To enable the organic layer 301 to possess conductive properties, this can be achieved through at least one of the following two methods: Firstly, the organic layer 301 may contain second metal particles. That is, the second metal particles in the organic layer 301 are filled within the organic material, forming a conductive network within the organic layer 301, thus achieving conductivity. Here, the second metal particles can be formed by the accumulation of at least one of metal ions or metal atoms. Secondly, the organic material of the organic layer 301 can be a conductive organic material, achieving conductivity through the use of a conductive organic material. The organic material of the organic layer 301 is the same as the aforementioned organic material of the electrode layer 302. Figure 8SEM images of the barrier layer 20, electrode layer 302 and organic layer 301 in a solar cell 100 according to some embodiments of the present application are shown, wherein the barrier layer 20 is a metal layer and the organic layer 301 contains second metal particles.

[0080] In some embodiments, the particle size of the second metal particle is smaller than that of the first metal particle. In some embodiments, the second metal particle is a nanoscale metal particle, which makes it easier for the metal particle to disperse in the organic layer 301. Optionally, the particle size of the second metal particle is 1nm-20nm, for example, it can be 1nm, 3nm, 5nm, 10nm, 15nm, or 20nm. Figure 8 As can be seen from the examples, in some cases, the second metal particles contained within the conductive organic layer 301 are nanoscale metal particles. Optionally, the particle size of the second metal particles is less than 10 nm.

[0081] In some embodiments, the second metal particle may be made of the same or different material as the first metal particle. In some embodiments, the material of the second metal particle may be copper, silver, nickel, aluminum, their alloys, or any combination thereof, wherein the alloy may be a copper-silver alloy, a copper-nickel alloy, a silver-nickel alloy, a silver-aluminum alloy, etc. It is understood that the materials of the second metal particles described above are merely exemplary, and those skilled in the art may use other metallic materials; this application does not further limit their use.

[0082] In some implementation schemes, such as Figure 6 As shown, the first metal particles in the electrode layer 302 penetrate the organic layer 301 and contact the barrier layer 20 (e.g., in...). Figure 6 (as indicated by the red arrow in the diagram), thereby achieving an electrical connection between the electrode layer 302 and the barrier layer 301.

[0083] To ensure that the transport resistance of charge carriers passing through the organic layer 301 is not too high, and to ensure that the bonding force between the electrode layer 302 and the barrier layer 20 through the organic layer 301 is sufficient, in some examples, the organic layer 301 includes at least one conductive contact point within a 50 μm range, and the thickness of the organic layer 301 at the conductive contact point is 0.01 nm-10 nm; or, the first metal particle in the electrode layer 302 at the conductive contact point passes through the organic layer 301 and contacts the barrier layer 20.

[0084] Here, the organic layer 301 includes at least one conductive contact point within a 50 μm range. This can be either along the width direction of the electrode layer 302 within a 50 μm range or along the length direction of the electrode layer 302 within a 50 μm range.

[0085] In addition, the organic layer 301 includes at least one conductive contact point within a 50μm range, which may include one conductive contact point or two or more conductive contact points.

[0086] In some embodiments, the width of the organic layer 301 is greater than or equal to the width of the electrode layer 302. By controlling any width of the organic layer 301 to be greater than or equal to any width of the electrode layer 302, it can be ensured that any position in the electrode layer 302 can be electrically connected to the barrier layer through the organic layer 310, further increasing the bonding force between the electrode structure and the barrier layer, thereby preventing the electrode structure from detaching.

[0087] In some embodiments, the projection area of ​​the organic layer 301 on the surface of the battery body 10 completely covers the projection area of ​​the electrode layer 302 on the surface of the battery body 10. That is, when both the organic layer 301 and the electrode layer 302 are projected onto the battery body 10, only the projection area of ​​the organic layer 301 is visible. It can be understood that "complete coverage" includes two situations: one is that the projection area of ​​the organic layer 301 is larger than the projection area of ​​the electrode layer 302, and the other is that the projection areas of the organic layer 301 and the electrode layer 302 overlap. The beneficial effect of the width of the organic layer 301 being greater than or equal to the width of the electrode layer 302 can be referred to above, and will not be elaborated further here.

[0088] This application also provides a photovoltaic module, including multiple battery strings, each battery string including multiple solar cells and multiple interconnects, the interconnects being used to connect the multiple solar cells in series; wherein, the solar cell is any of the aforementioned solar cells 100 of this application.

[0089] The features and effects described in this application for the solar cell 100 are also applicable to the photovoltaic module of this application, and will not be repeated here.

[0090] The above are merely preferred embodiments of this application and are not intended to limit this application. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this application should be included within the protection scope of this application.

Claims

1. A solar cell, characterized in that, include: A battery body, the battery body comprising a semiconductor substrate and a doped semiconductor layer disposed on the semiconductor substrate; A barrier layer is disposed on the battery body, and the barrier layer is a metal layer or a transparent conductive oxide layer; Multiple electrode structures are disposed on the barrier layer, and each electrode structure includes an organic layer and an electrode layer stacked sequentially, with the organic layer disposed between the barrier layer and the electrode layer; The electrode layer comprises an organic carrier and first metal particles. The organic material of the organic layer is the same as the organic material of the organic carrier. The thickness of the organic layer is 0.01 nm-50 nm.

2. The solar cell according to claim 1, characterized in that, The thickness of at least one location in the organic layer is 0.01 nm to 5 nm.

3. The solar cell according to claim 1, characterized in that, The thickness of at least one location in the organic layer is 0.01 nm to 10 nm.

4. The solar cell according to claim 1, characterized in that, The width of the organic layer is greater than or equal to the width of the electrode layer.

5. The solar cell according to claim 1, characterized in that, The projection area of ​​the organic layer on the battery body completely covers the projection area of ​​the electrode layer on the battery body.

6. The solar cell according to claim 1, characterized in that, The first metal particle in the electrode layer passes through the organic layer and comes into contact with the barrier layer.

7. The solar cell according to claim 1, characterized in that, The organic layer includes at least one conductive contact point within a 50 μm range, and the thickness of the organic layer at the conductive contact point is 0.01 nm-10 nm; or, the first metal particle in the electrode layer at the conductive contact point passes through the organic layer and contacts the barrier layer.

8. The solar cell according to claim 1, characterized in that, The organic layer is a conductive organic layer.

9. The solar cell according to claim 8, characterized in that, The organic layer contains second metal particles, the particle size of which is smaller than that of the first metal particles. And / or, the organic material in the organic layer is a conductive organic material.

10. The solar cell according to claim 1, characterized in that, The first metal particle includes sheet-like particles, the sheet-like particles including a single layer of sheet-like particles; and / or, the outline of the sheet-like particles is surrounded by a smooth curved surface.

11. The solar cell according to claim 1, characterized in that, The barrier layer is a single, integral structure.

12. The solar cell according to claim 1, characterized in that, The barrier layer includes multiple sub-barrier layers, wherein each of the multiple sub-barrier layers corresponds one-to-one with a multiple of the electrode structures.

13. The solar cell according to any one of claims 1-12, characterized in that, The barrier layer is disposed on the doped semiconductor layer and is in contact with the doped semiconductor layer. The electrode structure is electrically connected to the doped semiconductor layer through the barrier layer.

14. The solar cell according to any one of claims 1-12, characterized in that, The battery body further includes a dielectric layer disposed on the doped semiconductor layer. The dielectric layer has multiple openings, and one opening corresponds to one electrode structure. The barrier layer passes through the opening and contacts the doped semiconductor layer. The electrode structure is electrically connected to the doped semiconductor layer through the barrier layer.

15. A photovoltaic module, characterized in that, It includes multiple battery strings, each battery string comprising multiple solar cells and multiple interconnecting elements, the interconnecting elements being used to connect the multiple solar cells together in series; The solar cell is any one of claims 1-14.

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