A solar cell and a manufacturing method thereof, a photovoltaic module

Abstract

The application discloses a solar cell and a manufacturing method thereof and a photovoltaic module, and relates to the technical field of photovoltaics, and aims to reduce the contact resistance between the electrode structure and the cell substrate. The solar cell comprises a first carrier transport layer, a first light absorption layer, a second carrier transport layer, a first electrode and a second electrode. The first carrier transport layer, the first light absorption layer and the second carrier transport layer are sequentially stacked. The conductive types of the first carrier transport layer and the second carrier transport layer are opposite. The first electrode is formed on the side of the first carrier transport layer away from the first light absorption layer. The second electrode is formed on the side of the second carrier transport layer away from the first light absorption layer. In the direction away from the first light absorption layer, at least one of the first electrode and the second electrode comprises a metal composite layer and a metal conductive layer on the metal composite layer. The phase transition temperature of the metal composite layer is less than the phase transition temperature of the metal conductive layer, and the resistivity of the metal conductive layer is less than the resistivity of the metal composite layer.

Description

Technical Field

[0001] This invention relates to the field of photovoltaic technology, and in particular to a solar cell, its manufacturing method, and a photovoltaic module. Background Technology

[0002] Thermal evaporation is a process that involves heating a solid material in a high-vacuum environment, causing it to sublimate or evaporate and deposit onto a specific substrate to obtain a thin film. Electron beam evaporation, on the other hand, uses an electron beam under vacuum conditions to directly heat and evaporate the material, causing it to vaporize and be transported to a substrate, where it condenses to form a thin film. In the manufacturing process of solar cells, thermal evaporation or electron beam processes are typically used to fabricate the electrode structures, thereby reducing the degree of thermal damage to the cell substrate during electrode fabrication.

[0003] However, the contact resistance between the electrode structure formed by existing manufacturing methods and the battery substrate is relatively large, which is not conducive to improving the working performance of solar cells. Summary of the Invention

[0004] The purpose of this invention is to provide a solar cell and its manufacturing method, as well as a photovoltaic module, for reducing the contact resistance between the electrode structure and the battery substrate, thereby improving the working performance of the solar cell.

[0005] To achieve the above objectives, in a first aspect, the present invention provides a solar cell comprising: a first carrier transport layer, a first light-absorbing layer, a second carrier transport layer, a first electrode, and a second electrode. The first carrier transport layer, the first light-absorbing layer, and the second carrier transport layer are stacked sequentially. The first carrier transport layer and the second carrier transport layer have opposite conductivity types. The first electrode is formed on the side of the first carrier transport layer opposite to the first light-absorbing layer. The second electrode is formed on the side of the second carrier transport layer opposite to the first light-absorbing layer. Along the direction opposite to the first light-absorbing layer, at least one of the first electrode and the second electrode includes a metal composite layer and a metal conductive layer located on the metal composite layer. The phase transition temperature of the metal composite layer is lower than the phase transition temperature of the metal conductive layer, and the resistivity of the metal conductive layer is lower than the resistivity of the metal composite layer.

[0006] With the above technical solution, when the solar cell is in operation, the electrons and holes generated after the first light-absorbing layer absorbs photons can be conducted to the first and second electrodes respectively through the first and second carrier transport layers, and then discharged by the first and second electrodes to form a photocurrent that flows through the external circuit. The contact conditions between the first electrode and the first carrier transport layer, and between the second electrode and the second carrier transport layer, affect the fill factor of the solar cell, thus affecting its performance. Therefore, along the direction away from the first light-absorbing layer, one of the first and second electrodes includes a metal composite layer and a metal conductive layer located on the metal composite layer. The following explanation uses the example of a first electrode comprising the aforementioned metal composite layer and a metal conductive layer: In this case, the metal composite layer of the first electrode is located on the first carrier transport layer. Because the phase transition temperature of the metal composite layer is lower than that of the metal conductive layer, when the metal composite layer is manufactured on the first carrier transport layer using thermal evaporation and / or electron beam evaporation processes, less heat is released during the phase transition of the alloy phase corresponding to the metal composite layer from a gaseous state to a solid alloy. This results in less thermal stress at the interface between the first carrier transport layer and the metal composite layer, reducing the deformation of the metal composite layer after the phase transition. This allows for a larger contact area between the metal composite layer and the first carrier transport layer, thereby reducing the contact resistance between the first electrode and the first carrier transport layer, improving the interfacial contact between the first electrode and the first carrier transport layer, increasing the fill factor of the solar cell, and enhancing its performance. Meanwhile, because the distance between the metal composite layer and the first light-absorbing layer is smaller than that between the metal conductive layer and the first light-absorbing layer, the first light-absorbing layer is more affected by the heat generated during the manufacturing of the metal composite layer. Therefore, when the phase transition temperature of the metal composite layer is lower than that of the metal conductive layer, the degree of thermal damage to the first light-absorbing layer during the manufacturing of the metal composite layer can be reduced, which is beneficial to improving the quality of the solar cell. Furthermore, after forming the metal composite layer, a metal conductive layer is formed on the side of the metal composite layer away from the first carrier transport layer. The resistivity of this metal conductive layer is lower than that of the metal composite layer, which can give the first electrode a lower transport resistance, which is beneficial to the conduction of carriers and further improves the working performance of the solar cell. In addition, the beneficial effects of only the second electrode including the metal composite layer and the metal conductive layer, or both the first electrode and the second electrode including the metal composite layer and the metal conductive layer, can be found in the analysis of the beneficial effects of only the first electrode including the metal composite layer and the metal conductive layer, which will not be repeated here.

[0007] As one possible implementation, the thickness of the aforementioned metal composite layer is greater than or equal to 10 nm and less than or equal to 20 nm.

[0008] Taking the first electrode, comprising a metal composite layer and a metal conductive layer, as an example, the following explanation illustrates the use of the above-mentioned technical solution: The thickness of the metal composite layer, within the aforementioned range, prevents the relatively high heat released during the phase transition of the metal conductive layer (which has a relatively high phase transition temperature) from affecting the contact interface between the first electrode and the first carrier transport layer due to a larger gap between them. This ensures good interfacial contact between the first electrode and the first carrier transport layer. Simultaneously, because the contact resistivity of the metal composite layer is greater than that of the metal conductive layer, the thickness of the metal composite layer is less than or equal to 20 nm. This prevents the increased thickness of the metal composite layer from affecting the conductivity of the first electrode, thus reducing the carrier recombination rate and further improving the performance of the solar cell.

[0009] As one possible implementation, the thickness of the aforementioned metal conductive layer is greater than or equal to 350 nm and less than or equal to 750 nm.

[0010] Using the above technical solution, taking the first electrode comprising a metal composite layer and a metal conductive layer as an example: When the thickness of the metal conductive layer is within the aforementioned range, it prevents a small conductive area from resulting in a large on-resistance of the first electrode, thus ensuring good conductivity of the first electrode. Furthermore, it prevents a large amount of material used for the metal conductive layer from being consumed excessively, thus helping to control the manufacturing cost of the first electrode. Simultaneously, it prevents excessive heat released during the manufacturing of the metal conductive layer from affecting the interface contact between the first electrode and the first carrier transport layer, ensuring a large contact area and low contact resistance between the first electrode and the first carrier transport layer.

[0011] As one possible implementation, the aforementioned metal composite layer is a composite layer comprising a first metal and a second metal. The first metal includes at least one selected from indium, nickel, titanium, and gold, and the second metal includes at least one selected from silver, copper, and aluminum.

[0012] When the above technical solution is adopted, the phase transition temperature of the alloy phase of the first metal and the second metal when it transforms from a gaseous state to a solid alloy is lower than that of the second metal. Therefore, compared to the commonly used electrodes made solely of the second metal, when the metal composite layer is a composite layer including both the first and second metals, the phase transition temperature of the metal composite layer is lower, which is beneficial for improving the interfacial contact between the electrode, which includes both the metal composite layer and the metal conductive layer, and the corresponding charge carrier transport layer. Furthermore, the phase transition temperature of the metal composite layer may also differ depending on the types of the first and second metals, and both the first and second metals include multiple options. Therefore, a suitable option can be selected according to the phase transition temperature requirements of the metal composite layer in different practical application scenarios, improving the applicability of the solar cell provided by this invention in various scenarios.

[0013] As one possible implementation, the chemical ratio of the first metal and the second metal is greater than or equal to 1:1 and less than or equal to 3:2.

[0014] When using the above technical solution, the stoichiometric ratio of the first metal and the second metal in the metal composite layer affects the phase transition temperature of the metal composite layer. Therefore, a stoichiometric ratio of the first metal and the second metal within the aforementioned range allows the metal composite layer, comprising both the first and second metals, to have a lower phase transition temperature when transitioning from a gaseous to a solid state. This results in the release of less heat, further ensuring good interfacial contact between the electrode comprising the metal composite layer and the corresponding charge carrier transport layer, and further improving the performance of the solar cell.

[0015] As one possible implementation, each material in the aforementioned metal composite layer is randomly and uniformly distributed.

[0016] When employing the above technical solution, in the fabrication of metal composite layers using thermal evaporation or electron beam evaporation processes, each material in the metal composite layer is in a gaseous state upon contact with its corresponding forming area. Since gases have high fluidity, a random and uniform distribution of each material within the metal composite layer reduces the manufacturing difficulty associated with thermal or electron beam evaporation. Furthermore, a random and uniform distribution of each material in the metal composite layer facilitates the formation of approximately the same phase transition temperature across all parts of the layer, ensuring good interfacial contact between each part and its corresponding charge carrier composite layer.

[0017] As one possible implementation, the material of the aforementioned metal composite layer includes the material of the metal conductive layer. In this case, the variety of metal materials used in manufacturing electrodes comprising both the metal composite layer and the metal conductive layer can be reduced, thus simplifying the manufacturing process. Furthermore, it can mitigate problems related to structural integration and electrical contact between the metal composite layer and the metal conductive layer caused by differences in their materials, ensuring that the electrodes comprising both the metal composite layer and the metal conductive layer possess high structural reliability and conductivity.

[0018] As one possible implementation, the material of the aforementioned metal conductive layer includes at least one of silver, copper, and aluminum.

[0019] As one possible implementation, the solar cell described above also includes a first transparent conductive layer located between the first electrode and the first carrier transport layer.

[0020] When the above technical solution is adopted, the presence of the first transparent conductive layer can reduce the contact barrier between the first electrode and the first carrier transport layer, which is conducive to the transport of carriers of the corresponding conductivity type from the first carrier transport layer to the first electrode through the first transparent conductive layer, thereby improving the photoelectric conversion efficiency of the solar cell.

[0021] As one possible implementation, the solar cell described above further includes a second transparent conductive layer located between the second electrode and the second carrier transport layer. The beneficial effects of this configuration can be found in the preceding analysis of the beneficial effects of a solar cell further including a first transparent conductive layer located between the first electrode and the first carrier transport layer, and will not be repeated here.

[0022] As one possible implementation, the first light-absorbing layer is a perovskite light-absorbing layer, and the phase transition temperature of the metal composite layer is lower than the thermal decomposition temperature of the perovskite light-absorbing layer.

[0023] When the first light-absorbing layer is a perovskite light-absorbing layer, the solar cell provided by the present invention includes a perovskite cell. Based on this, the perovskite cell is composed of multiple thin films with perovskite crystals as the main material, possessing advantages such as high efficiency, low cost, and environmental friendliness, thus further improving the operating performance of the solar cell provided by the present invention. Furthermore, when the phase transition temperature of the metal composite layer is lower than the thermal decomposition temperature of the perovskite light-absorbing layer, forming an electrode including a metal composite layer and a metal conductive layer on one side of the perovskite light-absorbing layer can improve the interfacial contact between the electrode and the corresponding charge carrier transport layer while preventing thermal decomposition of the perovskite light-absorbing layer, thereby improving the yield of the solar cell.

[0024] As one possible implementation, the aforementioned solar cell is a perovskite solar cell. Both the first and second electrodes include a metal composite layer and a metal conductive layer.

[0025] When the solar cell provided by this invention is a perovskite solar cell, the first light-absorbing layer is a perovskite light-absorbing layer, as described above. Furthermore, as mentioned earlier, perovskite solar cells require low-temperature fabrication to prevent thermal decomposition of the perovskite light-absorbing layer. Therefore, when both the first and second electrodes include a metal composite layer and a metal conductive layer, fabricating metal composite layers on the side of the first carrier transport layer facing away from the perovskite light-absorbing layer and on the side of the second carrier transport layer facing away from the perovskite light-absorbing layer respectively reduces the heat released when the alloy phase corresponding to the metal composite layer transforms from a gaseous metal state to a solid alloy state. This improves the interfacial contact between the first and second electrodes and the first and second carrier transport layers, respectively, while also reducing the degree of thermal damage to the perovskite light-absorbing layer during the fabrication of the first and second electrodes, thereby increasing the yield of the perovskite solar cell.

[0026] As one possible implementation, the aforementioned solar cell is a tandem solar cell. The tandem solar cell includes a top cell and a bottom cell connected in series, and a conductive composite layer located between the top and bottom cells. The top cell includes a first carrier transport layer, a first light absorption layer, and a third carrier transport layer, with the third carrier transport layer located on the side of the first light absorption layer opposite to it. The bottom cell includes a second carrier transport layer, a second light absorption layer, and a fourth carrier transport layer, with the second and fourth carrier transport layers located on opposite sides of the second light absorption layer along its thickness direction. The conductive composite layer is located between the fourth and third carrier transport layers.

[0027] When the above technical solution is adopted, the shorter wavelength sunlight can be utilized by the top cell when the tandem solar cell is in operation, and the longer wavelength sunlight can be transmitted through the top cell to the bottom cell and utilized by the bottom cell. Therefore, the tandem solar cell can utilize a wide range of sunlight wavelengths, which can make the solar cell provided by the present invention have a high light energy utilization rate.

[0028] As one possible implementation, the top cell is a perovskite cell, and the first electrode includes a metal composite layer and a metal conductive layer, wherein the phase transition temperature of the metal composite layer is lower than the thermal decomposition temperature of the first light-absorbing layer.

[0029] When the above technical solution is adopted, if the top cell of the tandem solar cell is a perovskite cell, the perovskite cell includes a first electrode, a first carrier transport layer, a first light absorption layer, and a third carrier transport layer along the direction from the top cell to the bottom cell. In this case, the first light absorption layer is a perovskite light absorption layer, and compared to the second electrode located on the back side of the bottom cell, the distance between the first cell and the perovskite light absorption layer is smaller. Therefore, when the first electrode includes a metal composite layer and a metal conductive layer, and the phase transition temperature of the metal composite layer is lower than the thermal decomposition temperature of the first light absorption layer, the interfacial contact between the first electrode and the first carrier transport layer in the tandem solar cell can be improved, while also reducing the degree of thermal damage to the perovskite light absorption layer during the manufacture of the first electrode, thereby improving the yield of the perovskite cell.

[0030] As one possible implementation, the aforementioned bottom cell is a silicon heterojunction cell.

[0031] With the above technical solution, silicon heterojunction solar cells can achieve excellent interface passivation and selective carrier collection, thereby further improving the working performance of the solar cells provided by the present invention.

[0032] In a second aspect, the present invention provides a photovoltaic module comprising the solar cells provided in the first aspect and various implementations thereof.

[0033] The beneficial effects of the second aspect of this invention can be understood by referring to the analysis of the beneficial effects of the first aspect and its various implementations, and will not be repeated here.

[0034] Thirdly, the present invention provides a method for manufacturing a solar cell, the method comprising: firstly, forming a first carrier transport layer, a first light absorption layer, and a second carrier transport layer sequentially stacked. Next, forming a first electrode on the side of the first carrier transport layer opposite to the first light absorption layer. Then, forming a second electrode on the side of the second carrier transport layer opposite to the first light absorption layer. The formation of either or both of the first and second electrodes includes: forming a metal composite layer and a metal conductive layer on the metal composite layer along a direction opposite to the first light absorption layer using a thermal evaporation process or an electron beam evaporation process. The phase transition temperature of the metal composite layer is lower than that of the metal conductive layer, and the resistivity of the metal conductive layer is lower than that of the metal composite layer.

[0035] As one possible implementation, forming the metal composite layer includes: simultaneously depositing at least a first metal and a second metal to form a metal composite layer comprising the first metal and the second metal. The first metal includes at least one selected from indium, nickel, titanium, and gold, and the second metal includes at least one selected from silver, copper, and aluminum.

[0036] As one possible implementation, the ratio between the deposition rates of the first metal and the second metal is greater than or equal to 1:1 and less than or equal to 3:2.

[0037] When the above technical solution is adopted, the deposition rates of the first metal and the second metal are approximately the same as the stoichiometric ratio of the first metal and the second metal within the metal composite layer. Based on this, when the ratio between the deposition rates of the first metal and the second metal is greater than or equal to 1:1 and less than or equal to 3:2, the stoichiometric ratio of the first metal and the second metal within the metal composite layer is also approximately greater than or equal to 1:1 and less than or equal to 3:2. In this case, the metal composite layer, comprising the first metal and the second metal, corresponds to a lower phase transition temperature when it transforms from a gaseous state to a solid state, thereby releasing less heat. This further ensures good interfacial contact between the electrode comprising the metal composite layer and the corresponding carrier transport layer, further improving the operating performance of the manufactured solar cell.

[0038] As one possible implementation, the deposition rate of the aforementioned metal composite layer is greater than or equal to and less than or equal to

[0039] When the above technical solution is adopted, the deposition rate of the metal composite layer is within the aforementioned range, which can prevent the low process efficiency of the electrode including the metal composite layer due to a low deposition rate. Furthermore, it can prevent excessive heat accumulation from the phase transition of the metal composite layer due to a high deposition rate, which could affect the interfacial contact between the metal composite layer and the corresponding carrier transport layer, as well as the quality of the first light-absorbing layer, thereby improving the yield of the solar cell.

[0040] As one possible implementation, the deposition rate of the aforementioned metallic conductive layer is greater than or equal to and less than or equal to

[0041] When the above technical solution is adopted, the deposition rate of the metal conductive layer is within the aforementioned range, which can prevent low process efficiency of the electrode including the metal conductive layer due to a low deposition rate. Furthermore, it can prevent poor density of the formed metal conductive layer due to a high deposition rate, ensuring high conductivity of the electrode including the metal conductive layer. Simultaneously, it can prevent excessive heat accumulation from the phase transition of the metal conductive layer due to a high deposition rate, which could affect the interfacial contact between the metal composite layer and the corresponding carrier transport layer, as well as the quality of the first light-absorbing layer, thereby improving the yield of the solar cell.

[0042] As one possible implementation, after forming the first carrier transport layer and before forming the first electrode on the side of the first carrier transport layer away from the first light absorption layer, the method for manufacturing a solar cell further includes: forming a first transparent conductive layer on the side of the first carrier transport layer away from the light absorption layer.

[0043] As one possible implementation, after forming the second carrier transport layer and before forming the second electrode on the side of the second carrier transport layer away from the first light absorption layer, the method for manufacturing a solar cell further includes: forming a second transparent conductive layer on the side of the second carrier transport layer away from the light absorption layer.

[0044] As one possible implementation, the solar cell is a tandem solar cell. A tandem solar cell includes a top cell and a bottom cell connected in series, and a conductive composite layer located between the top cell and the bottom cell. In the above case, after forming the second carrier transport layer and before forming the first light absorption layer and the first carrier transport layer, the manufacturing method of the solar cell further includes: sequentially forming a second light absorption layer, a fourth carrier transport layer, a conductive composite layer, and a third carrier transport layer stacked on the second carrier transport layer along the direction from the bottom cell to the top cell. The top cell includes the first carrier transport layer, the first light absorption layer, and the third carrier transport layer, and the bottom cell includes the second carrier transport layer, the second light absorption layer, and the fourth carrier transport layer.

[0045] The beneficial effects of the third aspect and its various implementations in this invention can be found in the analysis of the beneficial effects of the first aspect and its various implementations, and will not be repeated here. Attached Figure Description

[0046] The accompanying drawings, which are included to provide a further understanding of the invention and form part of this invention, illustrate exemplary embodiments of the invention and are used to explain the invention, but do not constitute an undue limitation of the invention. In the drawings:

[0047] Figure 1 This is a longitudinal cross-sectional view of a first structure of a solar cell provided in an embodiment of the present invention;

[0048] Figure 2 This is a longitudinal cross-sectional view of a second structure of a solar cell provided in an embodiment of the present invention;

[0049] Figure 3 This is a longitudinal cross-sectional schematic diagram of a third structure of a solar cell provided in an embodiment of the present invention;

[0050] Figure 4 This is a longitudinal cross-sectional view of a fourth structure of a solar cell provided in an embodiment of the present invention;

[0051] Figure 5A longitudinal cross-sectional view of the fifth structure of a solar cell provided in an embodiment of the present invention;

[0052] Figure 6 This is a longitudinal cross-sectional view of the sixth structure of a solar cell provided in an embodiment of the present invention.

[0053] Reference numerals in the figures: 11 is the first carrier transport layer, 12 is the first light absorption layer, 13 is the second carrier transport layer, 14 is the first electrode, 15 is the second electrode, 16 is the metal composite layer, 17 is the metal conductive layer, 18 is the first transparent conductive layer, 19 is the second transparent conductive layer, 20 is the top cell, 21 is the bottom cell, 22 is the conductive composite layer, 23 is the third carrier transport layer, 24 is the second light absorption layer, and 25 is the fourth carrier transport layer. Detailed Implementation

[0054] Embodiments of the present disclosure will now be described with reference to the accompanying drawings. However, it should be understood that these descriptions are exemplary only and are not intended to limit the scope of the disclosure. Furthermore, descriptions of well-known structures and technologies are omitted in the following description to avoid unnecessarily obscuring the concepts of the present disclosure.

[0055] The accompanying drawings illustrate various structural schematics according to embodiments of the present disclosure. These drawings are not to scale, and some details have been enlarged for clarity, and some details may have been omitted. The shapes of the various regions and layers shown in the drawings, as well as their relative sizes and positional relationships, are merely exemplary and may deviate from reality due to manufacturing tolerances or technical limitations. Furthermore, those skilled in the art can design regions / layers with different shapes, sizes, and relative positions as needed.

[0056] In the context of this disclosure, when a layer / element is referred to as being "on top of" another layer / element, the layer / element may be directly on top of the other layer / element, or there may be an intermediate layer / element between them. Additionally, if a layer / element is "on top of" another layer / element in one orientation, then when the orientation is reversed, the layer / element may be "below" the other layer / element. To make the technical problems, technical solutions, and beneficial effects of this invention clearer, the invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the invention and are not intended to limit the invention.

[0057] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this invention, "a plurality of" means two or more, unless otherwise explicitly specified. "Several" means one or more, unless otherwise explicitly specified.

[0058] In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to 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 invention according to the specific circumstances.

[0059] Thermal evaporation is a process that involves heating a solid material in a high-vacuum environment, causing it to sublimate or evaporate and deposit onto a specific substrate to obtain a thin film. Electron beam evaporation, on the other hand, uses an electron beam under vacuum conditions to directly heat and evaporate the material, causing it to vaporize and be transported to a substrate, where it condenses to form a thin film. In the manufacturing process of solar cells, thermal evaporation or electron beam processes are typically used to fabricate the electrode structures, thereby reducing the degree of thermal damage to the cell substrate during electrode fabrication.

[0060] However, the phase transition temperature of the electrode structure formed by the existing manufacturing methods is still relatively high when the metal changes from a gaseous state to a solid state. This means that a lot of heat is released when manufacturing the electrode structure, resulting in high interfacial thermal stress between the electrode structure and the battery substrate. Consequently, the interfacial contact between the electrode structure and the battery substrate is poor (both small and large contact areas), which is not conducive to improving the working performance of the solar cell.

[0061] To address the aforementioned technical problems, in a first aspect, embodiments of the present invention provide a solar cell. Specifically, regarding cell type, such as... Figure 1 As shown, the solar cell provided in this embodiment of the invention can be a single-layer solar cell; or, as... Figure 2 As shown, the solar cell provided in this embodiment of the invention can also be a tandem solar cell.

[0062] From the perspective of battery structure, when the solar cell is a single-layer solar cell, the solar cell provided in this embodiment of the invention can be any one of a silicon solar cell, a perovskite solar cell, or a cadmium telluride solar cell. When the solar cell is a tandem solar cell, the solar cell can include a combination of at least two types of solar cells, such as silicon solar cells, perovskite solar cells, and cadmium telluride solar cells.

[0063] Specifically, such as Figure 1 As shown, the solar cell provided in this embodiment of the invention includes: a first carrier transport layer 11, a first light absorption layer 12, a second carrier transport layer 13, a first electrode 14, and a second electrode 15. The first carrier transport layer 11, the first light absorption layer 12, and the second carrier transport layer 13 are stacked sequentially. The first carrier transport layer 11 and the second carrier transport layer 13 have opposite conductivity types. The first electrode 14 is formed on the side of the first carrier transport layer 11 facing away from the first light absorption layer 12. The second electrode 15 is formed on the side of the second carrier transport layer 13 facing away from the first light absorption layer 12. Along the direction facing away from the first light absorption layer 12, at least one of the first electrode 14 and the second electrode 15 includes a metal composite layer 16 and a metal conductive layer 17 located on the metal composite layer 16. The phase transition temperature of the metal composite layer 16 is lower than the phase transition temperature of the metal conductive layer 17, and the resistivity of the metal conductive layer 17 is lower than the resistivity of the metal composite layer 16.

[0064] With the above technical solution, when the solar cell is in operation, the electrons and holes generated after the first light-absorbing layer absorbs photons can be conducted to the first and second electrodes respectively through the first and second carrier transport layers, and then discharged by the first and second electrodes to form a photocurrent that flows through the external circuit. The contact conditions between the first electrode and the first carrier transport layer, and between the second electrode and the second carrier transport layer, affect the fill factor of the solar cell, thus affecting its performance. Therefore, along the direction away from the first light-absorbing layer, one of the first and second electrodes includes a metal composite layer and a metal conductive layer located on the metal composite layer. For example... Figure 1As shown, the following explanation uses the first electrode 14, which includes the aforementioned metal composite layer 16 and metal conductive layer 17, as an example: The metal composite layer 16 of the first electrode 14 is located on the first carrier transport layer 11. Because the phase transition temperature of the metal composite layer 16 is lower than that of the metal conductive layer 17, when the metal composite layer 16 is manufactured on the first carrier transport layer 11 using thermal evaporation and / or electron beam evaporation processes, less heat is released during the phase transition of the alloy phase corresponding to the metal composite layer 16 from a gaseous metal state to a solid alloy. This results in less thermal stress at the interface between the first carrier transport layer 11 and the metal composite layer 16, reducing the deformation of the metal composite layer 16 after the phase transition. This allows for a larger contact area between the metal composite layer 16 and the first carrier transport layer 11, thereby reducing the contact resistance between the first electrode 14 and the first carrier transport layer 11, improving the interfacial contact between the first electrode 14 and the first carrier transport layer 11, increasing the fill factor of the solar cell, and improving its performance. Meanwhile, because the distance between the metal composite layer 16 and the first light-absorbing layer 12 is smaller than that between the metal conductive layer 17 and the first light-absorbing layer 12, the first light-absorbing layer 12 is more affected by the heat generated during the fabrication of the metal composite layer 16. Therefore, when the phase transition temperature of the metal composite layer 16 is lower than that of the metal conductive layer 17, the degree of thermal damage to the first light-absorbing layer 12 during the fabrication of the metal composite layer 16 can be reduced, which is beneficial to improving the quality of the solar cell. Furthermore, after forming the metal composite layer 16, a metal conductive layer 17 is formed on the side of the metal composite layer 16 away from the first carrier transport layer 11. The resistivity of the metal conductive layer 17 is lower than that of the metal composite layer 16, which can give the first electrode 14 a lower transport resistance, which is beneficial to the conduction of carriers and further improves the working performance of the solar cell. In addition, the beneficial effects of only the second electrode including the metal composite layer and the metal conductive layer, or both the first electrode 14 and the second electrode 15 including the metal composite layer 16 and the metal conductive layer 17, can be referred to the analysis of the beneficial effects of only the first electrode 14 including the metal composite layer 16 and the metal conductive layer 17, which will not be repeated here.

[0065] In practical applications, one of the first and second carrier transport layers is an electron transport layer, and the other is a hole transport layer. The solar cell provided in this embodiment of the invention does not specifically limit the conductivity type of the first and second carrier transport layers. Furthermore, the structure, specific materials, and specific thickness of the first carrier transport layer, the first light absorption layer, and the second carrier transport layer can be determined according to the specific type of solar cell in the actual application scenario, and are not specifically limited here.

[0066] For example, such as Figure 1As shown, in the case of a single-layer solar cell provided in this embodiment of the invention, if the solar cell is a silicon solar cell, then one of the first carrier transport layer 11 and the second carrier transport layer 13 is an N-type doped silicon layer and the other is a P-type doped silicon layer. The first light absorption layer 12 can be an intrinsic silicon substrate, an N-type doped silicon substrate, or a P-type doped silicon substrate.

[0067] For example, such as Figure 1 As shown, in the case of a single-layer solar cell provided in the embodiments of the present invention, if the solar cell is a perovskite cell, then one of the first carrier transport layer 11 and the second carrier transport layer 13 can be made of a material including methyl [6,6]-phenyl C60 butyrate (abbreviated as PC). 60 BM), [6,6]-phenyl C70 methyl butyrate (which can be abbreviated as PC) 70 BM), [6,6]-phenyl C80 methyl butyrate (which can be abbreviated as PC) 80 BM) and [6,6]-phenyl C82-butyrate methyl ester (which can be abbreviated as PC) 82 The electron transport layer is at least one of the following: (BM), and the other can be a material including (2-(9H-carbazole-9-yl)ethyl)phosphonic acid (abbreviated as 2PACz), (4-(9H-carbazole-9-yl)ethyl)phosphonic acid (abbreviated as 4PACz), [2-(3,6-dimethoxy-9H-carbazole-9-yl)ethyl]phosphonic acid (abbreviated as MeO-2PACz), [4-(3,6-dimethoxy-9H-carbazole-9-yl)... The hole transport layer is composed of at least one of the following: [ethyl]phosphonic acid (abbreviated as MeO-4PACz), [2-(3,6-dimethyl-9H-carbazole-9-yl)ethyl]phosphonic acid (abbreviated as Me-2PACz), [4-(3,6-dimethyl-9H-carbazole-9-yl)ethyl]phosphonic acid (abbreviated as Me-4PACz), and [4-(3,6-dibromo-9H-carbazole-9-yl)butyl] (abbreviated as 2Br-4PACz). The material of the first light-absorbing layer 12 has the general molecular formula ABX3. Here, A and B are cations of different sizes, and X is an anion bonded to both. Furthermore, cation B coordinates with anion X to form an octahedral symmetrical structure, with cation A located at the center of each of the eight octahedrons. Specifically, the materials contained in the perovskite absorber layer can be inorganic perovskite materials, organic perovskite materials, or organic-inorganic hybrid perovskite materials. For example, the materials contained in the perovskite absorber layer can be CsPbI2Br, MAPbBr3, FAPbI3, or Cs 1-y-z FA y MA z PbI 3-x Br x(Where FA is dimethyl ether, MA is methylamine, 0≤x≤3, 0≤y≤1, 0≤z≤1, and 0≤y+z≤1), etc. Under these conditions, the solar cell provided by the embodiments of the present invention can have advantages such as high conversion efficiency, low exciton binding energy, flexible and adjustable band gap, simple manufacturing process, and low cost.

[0068] For example, such as Figure 2 As shown, in the case of a tandem solar cell provided in this embodiment of the invention, the tandem solar cell includes a top cell 20 and a bottom cell 21 connected in series, and a conductive composite layer 22 located between the top cell 20 and the bottom cell 21. The top cell 20 includes a first carrier transport layer 11, a first light absorption layer 12, and a third carrier transport layer 23. The third carrier transport layer 23 is located on the side of the first light absorption layer 12 away from the first carrier transport layer 11. The bottom cell 21 includes a second carrier transport layer 13, a second light absorption layer 24, and a fourth carrier transport layer 25. The second carrier transport layer 13 and the fourth carrier transport layer 25 are respectively located on both sides of the second light absorption layer 24 along the thickness direction. The conductive composite layer 22 is located between the fourth carrier transport layer 25 and the third carrier transport layer 23. In this case, when the tandem solar cell is in operation, shorter wavelength sunlight can be utilized by the top cell 20 located above, and longer wavelength sunlight can be transmitted through the top cell 20 to the bottom cell 21 and utilized by the bottom cell 21. Therefore, the tandem solar cell can utilize a wide range of sunlight wavelengths, which can enable the solar cell provided in this embodiment of the invention to have a high light energy utilization rate.

[0069] Specifically, the materials and thicknesses of the first carrier transport layer, first light absorption layer, and third carrier transport layer in the top cell can be determined based on the specific type of top cell in the actual application scenario. Similarly, the materials and thicknesses of the second carrier transport layer, second light absorption layer, and fourth carrier transport layer in the bottom cell can be determined based on the specific type of bottom cell in the actual application scenario. Furthermore, the conductivity types of the fourth carrier transport layer and the second carrier transport layer can be determined based on the conductivity types of the first and third carrier transport layers in the top cell, as long as it allows the top and bottom cells in the tandem solar cell to be connected in series. Specifically, the conductivity types of the first carrier transport layer in the top cell and the second carrier transport layer in the bottom cell are opposite, and the conductivity types of the third carrier transport layer in the top cell and the fourth carrier transport layer in the bottom cell are also opposite.

[0070] For example, in the case of a perovskite solar cell as the top cell, if the perovskite solar cell has a conventional structure, then the first carrier transport layer is an electron transport layer, the third carrier transport layer is a hole transport layer, and the first light absorption layer is a perovskite light absorption layer. If the perovskite solar cell has an inverted structure, then the first carrier transport layer is a hole transport layer, the third carrier transport layer is an electron transport layer, and the first light absorption layer is a perovskite light absorption layer. The materials for the electron transport layer, hole transport layer, and perovskite light absorption layer can be referred to the previous text and will not be repeated here.

[0071] For example, when the bottom cell is a silicon heterojunction cell, the second light-absorbing layer can be an intrinsic silicon substrate, an N-type doped silicon substrate, or a P-type doped silicon substrate. Furthermore, when the first carrier transport layer of the top cell is P-type, the fourth carrier transport layer of the bottom cell is made of P-type doped silicon, and the second carrier transport layer of the bottom cell is made of N-type doped silicon. Conversely, when the first carrier transport layer of the top cell is N-type, the fourth carrier transport layer of the bottom cell is made of N-type doped silicon, and the second carrier transport layer of the bottom cell is made of P-type doped silicon. At least one of the P-type and N-type doped silicon layers is a doped amorphous silicon layer, and the bottom cell also includes an intrinsic amorphous silicon layer located between the doped amorphous silicon layer and the second light-absorbing layer.

[0072] Of course, in addition to silicon heterojunction cells, the bottom cell can also be an emitter-back passivated cell, a tunnel oxide passivated contact solar cell, or a back contact cell, etc.

[0073] Regarding the conductive composite layer included in the aforementioned tandem solar cell, the material of the conductive composite layer can be set according to actual needs, as long as it can be applied to the solar cell provided in the embodiments of the present invention. For example, the conductive composite layer can be at least one of a tunnel junction composite layer, an indium zinc oxide layer, an indium tin oxide layer, and an aluminum zinc oxide layer.

[0074] In addition, such as Figure 1 and Figure 2 As shown, the solar cell provided in this embodiment of the invention can have both its light-facing and back-facing surfaces as planar surfaces. Alternatively, as... Figure 3 and Figure 4 As shown, the solar cell provided in this embodiment of the invention can have both its light-facing and back-facing surfaces textured to improve the utilization rate of light by the solar cell. The surface morphology of the back-facing and light-facing surfaces of the solar cell can be determined according to actual needs and is not specifically limited here.

[0075] Regarding the first electrode and the second electrode mentioned above, in terms of conductivity type, the conductivity type of the first electrode and the second electrode can be determined according to the conductivity type of the first carrier transport layer and the second carrier transport layer, respectively.

[0076] For example: Figure 1 As shown, in the case of a single-layer solar cell provided in the embodiment of the present invention, if the solar cell is a perovskite cell, the first carrier transport layer 11 is an electron transport layer, and the second carrier transport layer 13 is a hole transport layer, then the first electrode 14 is the negative electrode and the second electrode 15 is the positive electrode.

[0077] For example: Figure 2 As shown, in the case of a tandem solar cell provided in this embodiment of the invention, if the first carrier transport layer 11 of the top cell 20 is an electron transport layer and the second carrier transport layer 13 of the bottom cell 21 is a hole transport layer, then the first electrode 14 is the negative electrode and the second electrode 15 is the positive electrode.

[0078] From a structural perspective, such as Figure 3 As shown, both the first electrode 14 and the second electrode 15 may include the aforementioned metal composite layer 16 and metal conductive layer 17. Alternatively, as... Figure 4 As shown, the first electrode 14 may consist only of the aforementioned metal composite layer 16 and metal conductive layer 17, while the second electrode 15 has a conventional structure. Alternatively, the first electrode may have a conventional structure, while only the second electrode includes the metal composite layer and the metal conductive layer.

[0079] The specific structures of the first and second electrodes can be determined according to the type of solar cell and actual needs in the actual application scenario, and no specific limitations are made here.

[0080] For example, in the case of a perovskite solar cell provided in the embodiments of the present invention, only either the first electrode or the second electrode may include the aforementioned metal composite layer and metal conductive layer. Alternatively, both the first electrode and the second electrode may include the metal composite layer and the metal conductive layer. In this case, as... Figure 1As shown, when the solar cell provided in this embodiment of the invention is a perovskite solar cell, the first light-absorbing layer 12 is a perovskite light-absorbing layer. Furthermore, the perovskite solar cell needs to be fabricated using a low-temperature process to prevent thermal decomposition of the perovskite light-absorbing layer. Based on this, when both the first electrode 14 and the second electrode 15 include a metal composite layer 16 and a metal conductive layer 17, when the metal composite layer 16 is fabricated on the side of the first carrier transport layer 11 facing away from the perovskite light-absorbing layer and on the side of the second carrier transport layer 13 facing away from the perovskite light-absorbing layer, the heat released when the alloy phase corresponding to the metal composite layer 16 changes from a gaseous metal state to a solid alloy is less. This can improve the interfacial contact between the first electrode 14 and the second electrode 15 and the first carrier transport layer 11 and the second carrier transport layer 13, respectively, while also reducing the degree of thermal damage to the perovskite light-absorbing layer during the fabrication of the first electrode 14 and the second electrode 15, thereby improving the yield of the perovskite solar cell.

[0081] For example, such as Figure 2As shown, in the case where the solar cell provided in this embodiment of the invention is a tandem solar cell and the top cell 20 is a perovskite cell, the first electrode 14 includes the aforementioned metal composite layer 16 and metal conductive layer 17. In the above case, when the top cell 20 of the tandem solar cell is a perovskite cell, along the direction from the top cell 20 to the bottom cell 21, the perovskite cell includes a first electrode 14, a first carrier transport layer 11, a first light absorption layer 12, and a third carrier transport layer 23. At this time, the first light absorption layer 12 is a perovskite light absorption layer, and compared with the second electrode 15 located on the back surface side in the bottom cell 21, the distance between the first cell and the perovskite light absorption layer is smaller. Therefore, when the first electrode 14 includes the metal composite layer 16 and the metal conductive layer 17, it can improve the interface contact between the first electrode 14 and the first carrier transport layer 11 of the tandem solar cell, and also help reduce the degree of thermal damage to the perovskite light absorption layer during the manufacturing of the first electrode 14, thereby improving the yield of the perovskite cell. Furthermore, in this case, the structure of the second electrode 15 can be determined according to the type of the base cell 21. When the base cell 21 is a solar cell that does not require low-temperature manufacturing like a perovskite cell, the second electrode 15 may not include the aforementioned metal composite layer 16 and metal conductive layer 17, and may have only a conventional structure to simplify the manufacturing process. Alternatively, the second electrode 15 may include the aforementioned metal composite layer 16 and metal conductive layer 17 to improve the interfacial contact between the second electrode 15 and the second carrier transport layer 13, thereby improving the operating performance of the base cell 21. When the base cell 21 is a solar cell that requires low-temperature manufacturing like a perovskite cell, the second electrode 15 may include the metal composite layer 16 and metal conductive layer 17 to improve the interfacial contact between the second electrode 15 and the second carrier transport layer 13, while also preventing the thermal decomposition of the second light absorption layer 24, thus improving the yield of the base cell 21.

[0082] In terms of materials, when one of the first electrode and the second electrode does not include the aforementioned metal composite layer and metal conductive layer, the material of the electrode can be at least one conductive material such as copper, aluminum, or silver that can be applied to the solar cell provided in the embodiments of the present invention.

[0083] For the aforementioned metal conductive layer, the material of the metal conductive layer can be any conductive material with a resistivity lower than that of the metal composite layer, as long as it can be applied to the solar cell provided in the embodiments of the present invention. For example, the material of the aforementioned metal conductive layer includes at least one of silver, copper, and aluminum.

[0084] As for the material of the aforementioned metal composite layer, since the phase transition temperature of alloy materials composed of different types of metals may be different, and the phase transition temperature of the metal composite layer at least affects the interface contact between the corresponding electrode and the corresponding charge carrier transport layer, it can be determined according to the requirements of the interface contact between the electrode including the metal composite layer and the metal conductive layer and the corresponding charge carrier composite layer in the actual application scenario. As long as the phase transition temperature of the metal composite layer is lower than that of the metal conductive layer, it is acceptable.

[0085] Furthermore, when solar cells, including perovskite cells, require low-temperature fabrication, the phase transition temperature of the metal composite layer must be lower than the thermal decomposition temperature of the light-absorbing layer in the cell. For example, when the first light-absorbing layer is a perovskite light-absorbing layer, the phase transition temperature of the metal composite layer is lower than the thermal decomposition temperature of the perovskite light-absorbing layer. In this case, forming an electrode comprising a metal composite layer and a metal conductive layer on one side of the perovskite light-absorbing layer can improve the interfacial contact between the electrode and the corresponding charge carrier transport layer, while also preventing the thermal decomposition of the perovskite light-absorbing layer and improving the yield of the solar cell.

[0086] Specifically, when solar cells, including perovskite cells and other cells that need to be fabricated under low-temperature processes, are provided in the embodiments of the present invention as single-layer solar cells, the first electrode and the second electrode both include a metal composite layer and a metal conductive layer, and the phase transition temperature of the metal composite layer included in the first electrode and the second electrode is lower than the thermal decomposition temperature of the first light-absorbing layer.

[0087] If the solar cell provided in this embodiment of the invention is a tandem solar cell, the relationship between whether the first electrode and the second electrode include a metal composite layer and a metal conductive layer, and the relationship between the phase transition temperature of the metal composite layer and the thermal decomposition temperature of the light-absorbing layer of the cell prepared by the low-temperature process can be determined based on the distance between the first electrode and the second electrode and the light-absorbing layer of the cell prepared by the low-temperature process.

[0088] For example: Figure 2As shown, in the case where the solar cell provided in this embodiment of the invention is a tandem solar cell and the top cell 20 is a perovskite cell, the first electrode 14 includes a metal composite layer 16 and a metal conductive layer 17, and the phase transition temperature of the metal composite layer 16 included in the first electrode 14 is lower than the thermal decomposition temperature of the first light-absorbing layer 12. In this case, if the bottom cell 21 is a solar cell that does not require low-temperature manufacturing like a perovskite cell, the second electrode 15 may not include the aforementioned metal composite layer 16 and metal conductive layer 17, and it may only have a conventional structure; or, the second electrode 15 may also include the aforementioned metal composite layer 16 and metal conductive layer 17, in which case the phase transition temperature of the metal composite layer 16 included in the second electrode 15 may be lower than the thermal decomposition temperature of the first light-absorbing layer 12, or it may be greater than or equal to the thermal decomposition temperature of the first light-absorbing layer 12. If the bottom cell 21 is a solar cell that requires low-temperature manufacturing like a perovskite cell, the second electrode 15 includes a metal composite layer 16 and a metal conductive layer 17, and the phase transition temperature of the metal composite layer 16 included in the second electrode 15 is lower than the thermal decomposition temperature of the second light-absorbing layer 24.

[0089] In practical applications, the thermal decomposition temperature of the light absorption layer of the battery that needs to be prepared under low-temperature processes may be different. Therefore, in the case of the solar cells provided in the embodiments of the present invention, including batteries such as perovskite batteries that need to be prepared under low-temperature processes, the specific material of the metal composite layer can be determined according to the type of material of the metal composite layer and the thermal decomposition temperature of the light absorption layer in the battery that needs to be prepared under low-temperature processes.

[0090] For example, the aforementioned metal composite layer can be a composite layer comprising a first metal and a second metal. The first metal includes at least one of indium, nickel, titanium, and gold, and the second metal includes at least one of silver, copper, and aluminum. In this case, the phase transition temperature of the alloy phase of the first and second metals when it transforms from a gaseous state to a solid alloy is lower than the phase transition temperature of the second metal. Therefore, compared to electrodes typically made solely of the second metal, when the metal composite layer comprises both the first and second metals, the phase transition temperature of the metal composite layer is lower, which is beneficial for improving the interfacial contact between the electrode comprising the metal composite layer and the metal conductive layer and the corresponding charge carrier transport layer. Furthermore, the phase transition temperature of the metal composite layer may also differ when the types of the first and second metals are different, and both the first and second metals include multiple options. Therefore, a suitable option can be selected according to the phase transition temperature requirements of the metal composite layer in different practical application scenarios, improving the applicability of the solar cell provided by the embodiments of the present invention in different scenarios.

[0091] For example, the materials used in the metal composite layer can be indium-silver alloys, nickel-silver alloys, titanium-silver alloys, gold-silver alloys, indium-copper alloys, nickel-copper alloys, indium-aluminum alloys, etc. Specifically, the metal composite layer can be a binary metal alloy, or a ternary or higher-order metal alloy. Furthermore, the chemical ratio of the various materials within the aforementioned metal composite layer affects its phase transition temperature. Therefore, the chemical ratio of the various materials within the metal composite layer can be determined based on the phase transition temperature requirements of the actual application scenario; no specific limitations are imposed here.

[0092] For example, when the material of the metal composite layer includes the first metal and the second metal described above, the stoichiometric ratio of the first metal to the second metal can be greater than or equal to 1:1 and less than or equal to 3:2. When the stoichiometric ratio of the first metal to the second metal is within the above range, the metal composite layer, comprising the first metal and the second metal, corresponds to a lower phase transition temperature when it transforms from a gaseous state to a solid state. This results in the release of less heat, further ensuring good interfacial contact between the electrode including the metal composite layer and the corresponding carrier transport layer, and further improving the operating performance of the solar cell.

[0093] The distribution of various materials within the metal composite layer can be determined based on the actual manufacturing process and actual needs, and no specific restrictions are imposed here.

[0094] For example, each material in the metal composite layer can be randomly and uniformly distributed. In this case, when manufacturing the metal composite layer using thermal evaporation or electron beam evaporation processes, each material is in a gaseous state when it comes into contact with the corresponding area to be formed. Since gases have high fluidity, randomly and uniformly distributing each material in the metal composite layer reduces the manufacturing difficulty when using thermal evaporation or electron beam evaporation processes. Furthermore, when each material in the metal composite layer is randomly and uniformly distributed, it is beneficial to ensure that each part of the metal composite layer has approximately the same phase transition temperature, ensuring good interfacial contact between each part of the metal composite layer and the corresponding charge carrier composite layer.

[0095] Secondly, in practical applications, the materials of the metal composite layer can be completely different from those of the metal conductive layer. For example, the metal composite layer may be made of indium-silver alloy, while the metal conductive layer may be made of aluminum.

[0096] Alternatively, some materials of the metal composite layer may be the same as those of the conductive metal layer. For example, the metal composite layer may be made of indium-silver alloy, while the conductive metal layer may be made of silver-aluminum alloy.

[0097] Alternatively, the material of the aforementioned metal composite layer may include the material of the conductive metal layer. For example, the metal composite layer may be made of an indium-silver alloy, while the conductive metal layer may be made of silver. In this case, the variety of metal materials used in manufacturing electrodes comprising both the metal composite layer and the conductive metal layer can be reduced, thus simplifying the manufacturing process. Furthermore, it can mitigate problems arising from the different materials used in the metal composite layer and the conductive metal layer, such as structural integration and electrical contact issues, ensuring that the electrodes comprising both layers possess high structural reliability and conductivity.

[0098] In terms of thickness, the thickness of the metal composite layer and the metal conductive layer in the solar cell provided in the embodiments of the present invention is not specifically limited.

[0099] For example, the thickness of the aforementioned metal composite layer can be greater than or equal to 10 nm and less than or equal to 20 nm. For instance, the thickness of the metal composite layer can be 10 nm, 12 nm, 14 nm, 16 nm, 18 nm, or 20 nm. In this case, taking the first electrode comprising a metal composite layer and a metal conductive layer as an example: The thickness of the metal composite layer within the aforementioned range prevents the relatively high heat released during the phase transition of the metal conductive layer (which has a relatively high phase transition temperature) from affecting the contact interface between the first electrode and the first carrier transport layer due to a larger gap between them, thus ensuring good interfacial contact. Simultaneously, because the contact resistivity of the metal composite layer is greater than that of the metal conductive layer, a thickness of less than or equal to 20 nm prevents the conductivity of the first electrode from being affected by a larger thickness, which helps reduce the carrier recombination rate and further improves the operating performance of the solar cell.

[0100] For example, the thickness of the aforementioned metal conductive layer can be greater than or equal to 350 nm and less than or equal to 750 nm. For instance, the thickness of the metal conductive layer can be 350 nm, 400 nm, 450 nm, 500 nm, 550 nm, 600 nm, 650 nm, 700 nm, or 750 nm, etc. In this case, taking the first electrode comprising a metal composite layer and a metal conductive layer as an example: A thickness within the aforementioned range prevents a small conductive layer from resulting in a small conductive area and thus a large on-resistance of the first electrode, ensuring good conductivity of the first electrode. Furthermore, it prevents a large amount of material used for the metal conductive layer from being consumed due to a large thickness, thus helping to control the manufacturing cost of the first electrode. Simultaneously, it prevents excessive heat released during the manufacturing of the metal conductive layer from affecting the interface contact between the first electrode and the first carrier transport layer, ensuring a large contact area and low contact resistance between the first electrode and the first carrier transport layer.

[0101] As one possible implementation scheme, such as Figure 5 and Figure 6 As shown, the aforementioned solar cell may further include a first transparent conductive layer 18 located between the first electrode 14 and the first carrier transport layer 11. In this case, the presence of the first transparent conductive layer 18 can reduce the contact barrier between the first electrode 14 and the first carrier transport layer 11, facilitating the transport of carriers of the corresponding conductivity type from the first carrier transport layer 11 through the first transparent conductive layer 18 to the first electrode 14, thereby improving the photoelectric conversion efficiency of the solar cell.

[0102] Specifically, the material of the first transparent conductive layer can be indium zinc oxide, indium tin oxide, or zinc aluminum oxide, etc. The thickness of the first transparent conductive layer in the solar cell provided in this embodiment of the invention is not specifically limited.

[0103] As one possible implementation scheme, such as Figure 5 and Figure 6 As shown, the solar cell further includes a second transparent conductive layer 19 located between the second electrode 15 and the second carrier transport layer 13. The beneficial effects of this configuration can be referenced in the analysis of the beneficial effects of the first transparent conductive layer 18 located between the first electrode 14 and the first carrier transport layer 11, as described above. Furthermore, the material of the second transparent conductive layer 19 can be referenced from the material of the first transparent conductive layer 18, and will not be repeated here. Secondly, the thickness of the second transparent conductive layer 19 is not specifically limited in the solar cell provided in this embodiment of the invention.

[0104] Secondly, embodiments of the present invention provide a photovoltaic module, which includes solar cells provided in the first aspect and various implementations thereof.

[0105] The beneficial effects of the second aspect in the embodiments of the present invention can be referred to the analysis of the beneficial effects of the first aspect and its various implementations, and will not be repeated here.

[0106] Thirdly, embodiments of the present invention provide a method for manufacturing a solar cell. Specifically, the method for manufacturing the solar cell includes the following steps: First, as... Figures 1 to 4 As shown, a first carrier transport layer 11, a first light absorption layer 12, and a second carrier transport layer 13 are formed in sequence. Next, a first electrode 14 is formed on the side of the first carrier transport layer 11 opposite to the first light absorption layer 12. Next, a second electrode 15 is formed on the side of the second carrier transport layer 13 opposite to the first light absorption layer 12. Forming either or both of the first electrode 14 and the second electrode 15 includes forming a metal composite layer 16 and a metal conductive layer 17 on the metal composite layer 16 along a direction opposite to the first light absorption layer 12 using a thermal evaporation process or an electron beam evaporation process. The phase transition temperature of the metal composite layer 16 is lower than the phase transition temperature of the metal conductive layer 17, and the resistivity of the metal conductive layer 17 is lower than the resistivity of the metal composite layer 16.

[0107] Specifically, the types of solar cells manufactured, the materials and thicknesses of the first carrier transport layer, the second carrier transport layer, and the first light-absorbing layer, as well as the structure and materials of the first and second electrodes, can be referred to the previous text and will not be repeated here. Furthermore, it is understandable that the manufacturing process of solar cells may differ depending on the type of solar cell. Below, based on the different types of solar cells, the manufacturing process of solar cells will be divided into at least two types:

[0108] The first method involves manufacturing a single-layer solar cell. Depending on the specific type of solar cell, a first carrier transport layer, a first light absorption layer, and a second carrier transport layer can be sequentially formed using processes such as thermal evaporation, spin coating, or deposition. Then, the specific manufacturing process for the first and second electrodes can be determined based on their specific structures and materials.

[0109] Specifically, if the first electrode includes a metal composite layer and a metal conductive layer, then during the fabrication of the first electrode, a metal composite layer is formed on the side of the first carrier transport layer away from the first light absorption layer, using a thermal evaporation process or an electron beam evaporation process, along the direction away from the first light absorption layer, and a metal conductive layer is formed on the metal composite layer.

[0110] If the second electrode includes a metal composite layer and a metal conductive layer, then during the fabrication of the second electrode, a metal composite layer and a metal conductive layer located on the metal composite layer are formed on the side of the second carrier transport layer away from the first light absorption layer, using a thermal evaporation process or an electron beam evaporation process, along the direction away from the first light absorption layer.

[0111] Specifically, the formation process of the metal composite layer can be determined based on the distribution of various materials in the metal composite layer. For example, forming a metal composite layer may include the steps of simultaneously depositing at least a first metal and a second metal to form a metal composite layer comprising the first metal and the second metal. The first metal includes at least one of indium, nickel, titanium, and gold, and the second metal includes at least one of silver, copper, and aluminum.

[0112] In addition, since the deposition rate of the first metal and the second metal is approximately the same as the chemical dosage ratio of the first metal and the second metal in the metal composite layer, the deposition rate of the first metal and the second metal can be determined based on the chemical dosage ratio of the first metal and the second metal in the metal composite layer in the actual application scenario.

[0113] For example, the ratio between the deposition rates of the first metal and the second metal can be greater than or equal to 1:1 and less than or equal to 3:2. In this case, it is advantageous that the stoichiometric ratio of the first metal and the second metal in the metal composite layer is also approximately greater than or equal to 1:1 and less than or equal to 3:2. This, in turn, allows the metal composite layer, which includes the first metal and the second metal, to have a lower phase transition temperature when it transitions from a gaseous state to a solid state, thereby releasing less heat. This further ensures good interfacial contact between the electrode including the metal composite layer and the corresponding carrier transport layer, further improving the operating performance of the manufactured solar cell.

[0114] The specific deposition rates of the first and second metals can be determined based on the actual application scenario, and no specific limits are set here.

[0115] For example, the deposition rate of the aforementioned metal composite layer can be greater than or equal to and less than or equal to For example, the deposition rate of the metal composite layer can be... or Therefore, by maintaining the deposition rate of the metal composite layer within the aforementioned range, the low process efficiency of the electrode including the metal composite layer can be prevented due to a low deposition rate. Furthermore, a high deposition rate can prevent excessive heat accumulation from the phase transition of the metal composite layer, which could affect the interfacial contact between the metal composite layer and the corresponding carrier transport layer, as well as the quality of the first light-absorbing layer, thereby improving the yield of the solar cell.

[0116] For example, the deposition rate of the aforementioned metal conductive layer is greater than or equal to and less than or equal to For example, the deposition rate of the aforementioned metallic conductive layer can be... or In this case, a deposition rate of the metal conductive layer within the aforementioned range can prevent low process efficiency of the electrode including the metal conductive layer due to a low deposition rate. Furthermore, it can prevent poor compactness of the formed metal conductive layer due to a high deposition rate, ensuring high conductivity of the electrode including the metal conductive layer. Simultaneously, it can prevent excessive heat accumulation from the phase transition of the metal conductive layer due to a high deposition rate, which could affect the interfacial contact between the metal composite layer and the corresponding carrier transport layer, as well as the quality of the first light-absorbing layer, thereby improving the yield of the solar cell.

[0117] If either the first electrode or the second electrode does not include the aforementioned metal composite layer and metal conductive layer, the electrode can be manufactured using screen printing, electroplating, sputtering, thermal evaporation, or electron beam evaporation processes, depending on the type of solar cell and the material of the electrode.

[0118] The manufacturing method provided in this embodiment of the invention does not specifically limit the manufacturing order of the first electrode and the second electrode. Specifically, the second electrode can be formed after the first electrode is formed; or the first electrode can be formed after the second electrode is formed; or the first electrode and the second electrode can be manufactured simultaneously when their structures are identical.

[0119] The second method: When the manufactured solar cell is a tandem solar cell, and the tandem solar cell includes a top cell and a bottom cell connected in series, and a conductive composite layer located between the top cell and the bottom cell, a second carrier transport layer can be formed using a thermal evaporation process, spin coating process, or deposition process, depending on the specific type of solar cell. Then, along the direction from the bottom cell to the top cell, a second light-absorbing layer, a fourth carrier transport layer, a conductive composite layer, and a third carrier transport layer are sequentially formed on the second carrier transport layer. Then, as... Figure 2 or Figure 4 As shown, a first light absorption layer 12 and a first carrier transport layer 11 are formed on the third carrier transport layer 23.

[0120] Specifically, the formation processes of the aforementioned second light-absorbing layer, fourth carrier transport layer, conductive composite layer, third carrier transport layer, first light-absorbing layer, and first carrier transport layer can be determined based on the type of solar cell and the materials of each film layer, and are not specifically limited here. Furthermore, after forming the aforementioned first carrier transport layer, the first and second electrodes of the tandem solar cell can be formed according to the structures of the first and second electrodes included in the tandem solar cell, and with reference to the manufacturing process of the first and second electrodes in the first method described above.

[0121] In one example, such as Figure 5 and Figure 6 As shown, after forming the first carrier transport layer 11 and before forming the first electrode 14 on the side of the first carrier transport layer 11 opposite to the first light absorption layer 12, the manufacturing method of the solar cell further includes the step of forming a first transparent conductive layer 18 on the side of the first carrier transport layer 11 opposite to the light absorption layer using a process such as physical vapor deposition. The material of the first transparent conductive layer 18 can be referred to the previous text and will not be repeated here.

[0122] For example, such as Figure 5 and Figure 6 As shown, after forming the second carrier transport layer 13 and before forming the second electrode 15 on the side of the second carrier transport layer 13 opposite to the first light absorption layer 12, the manufacturing method of the solar cell further includes the step of forming a second transparent conductive layer 19 on the side of the second carrier transport layer 13 opposite to the light absorption layer using a process such as physical vapor deposition. The material of the second transparent conductive layer 19 can be referred to the previous text and will not be repeated here.

[0123] The beneficial effects of the third aspect and its various implementations in the embodiments of the present invention can be referred to the analysis of the beneficial effects of the first aspect and its various implementations, and will not be repeated here.

[0124] The present invention also provides the following specific embodiments to further illustrate the manufacturing method of the solar cell of the present invention, and the specific operation steps are as follows:

[0125] Example 1:

[0126] The manufactured solar cell is a tandem solar cell. The top cell of this tandem solar cell is a perovskite cell, and the bottom cell is a silicon heterojunction cell. Based on this, after fabricating the silicon heterojunction cell, a conductive composite layer of indium tin oxide (ITO) is deposited on the N-type doped silicon layer of the silicon heterojunction cell using physical vapor deposition (PVD). Next, a precursor solution for a hole transport layer is spin-coated onto the conductive composite layer and annealed at 100°C for 5 minutes. Specifically, the hole transport layer is made of MeO-2PACz, and its thickness is approximately 20 nm.

[0127] Next, a perovskite light-absorbing layer is spin-coated onto the hole transport layer. Specifically, according to Cs... 0.05 FA 0.8 MA 0.15 Pb(I 0.75 Br 0.25 A precursor solution was prepared at a ratio of 3:1. Then, the precursor solution was spin-coated onto the hole transport layer, followed by annealing at 120°C for 15 min. The thickness of the prepared perovskite light-absorbing layer was 1 μm to 3 μm. Next, a charge-insulating layer of LiF was thermally evaporated and deposited on the perovskite light-absorbing layer. Specifically, the deposition rate of this charge-insulating layer was... Furthermore, the thickness of the charge-insulating layer is approximately 1 nm. Then, an electron transport layer made of C60 is deposited on the LiF charge-insulating layer using thermal evaporation. The deposition rate of this electron transport layer is... Furthermore, the thickness of the electron transport layer is approximately 15 nm. Next, an electron transport layer and a buffer layer made of SnO2 are prepared on the electron transport layer made of C60 material using an atomic layer deposition process. The total thickness of the SnO2 electron transport layer and the buffer layer is approximately 20 nm.

[0128] Next, a transparent conductive layer made of indium zinc oxide, indium tin oxide, or zinc aluminum oxide is formed on the electron transport layer and buffer layer made of SnO2 using physical vapor deposition (PVD). Then, an antireflection layer made of MgF2, LiF, or SiO2 is formed on the transparent conductive layer using PVD and other processes.

[0129] Next, a first electrode and / or a second electrode, comprising a metal composite layer and a metal conductive layer, are prepared using a thermal evaporation method. The metal composite layer is primarily made of indium-silver alloy. Specifically, the metal composite layer is prepared by first depositing a 20 nm thick metal composite layer made of indium-silver alloy, followed by depositing a 700 nm thick metal conductive layer made of silver. The deposition rate of the metal composite layer is [missing information]. The deposition rate of the metallic conductive layer is

[0130] Example 2:

[0131] The metal composite layer manufactured by the manufacturing method provided in Example 2 is made of titanium-silver alloy, and all other aspects are the same as the manufacturing method provided in Example 1.

[0132] Example 3:

[0133] The metal composite layer manufactured by the manufacturing method provided in Example 3 is made of nickel-silver alloy, and all other aspects are the same as the manufacturing method provided in Example 1.

[0134] Example 4:

[0135] The metal composite layer manufactured by the manufacturing method provided in Example 4 is made of a gold-silver alloy, and all other aspects are the same as the manufacturing method provided in Example 1.

[0136] Furthermore, the present invention also provides the following comparative example of manufacturing a solar cell, with the specific operation steps as follows:

[0137] Comparative Example 1:

[0138] The first and second electrodes manufactured by the manufacturing method provided in Comparative Example 1 are both conventional electrodes with a thickness of 700 nm and made of silver. All other aspects are the same as the manufacturing method provided in Example 1.

[0139] Table 1 shows the solar cells manufactured using Examples 1 to 4 and Comparative Example 1, and compares the parameters of the three types of solar cells.

[0140] Table 1: Comparison of various parameters of solar cells manufactured in Comparative Example 1 and Examples 1-4

[0141]

[0142] As can be seen from the data shown in Table 1, the fill factor and energy conversion efficiency of the solar cells manufactured in Examples 1-4 are higher than those of the solar cell manufactured in Comparative Example 1, indicating that the performance of the solar cells manufactured in Examples 1-4 is superior to that of the solar cell manufactured in Comparative Example 1. Furthermore, because the phase transition temperature of the indium-silver alloy is lower than that of the titanium-silver alloy, nickel-silver alloy, gold-silver alloy, and silver, and because indium is relatively soft, it is beneficial to improve the adhesion of the metal composite layer on the side of the corresponding carrier transport layer away from the first light absorption layer, further improving the interfacial contact between the electrode including the metal composite layer and the corresponding carrier transport layer.

[0143] The above description does not provide detailed explanations of the technical aspects of each layer's patterning, etching, etc. However, those skilled in the art should understand that various technical means can be used to form layers and regions of the desired shape. Furthermore, to form the same structure, those skilled in the art can also design methods that are not entirely identical to those described above. Additionally, although various embodiments have been described above, this does not mean that the measures in the various embodiments cannot be used advantageously in combination.

[0144] The embodiments of this disclosure have been described above. However, these embodiments are for illustrative purposes only and are not intended to limit the scope of this disclosure. The scope of this disclosure is defined by the appended claims and their equivalents. Various substitutions and modifications can be made by those skilled in the art without departing from the scope of this disclosure, and all such substitutions and modifications should fall within the scope of this disclosure.

Claims

1. A solar cell, characterized in that, include: A first carrier transport layer, a first light absorption layer, and a second carrier transport layer are stacked sequentially; the first carrier transport layer and the second carrier transport layer have opposite conductivity types; A first electrode is formed on the side of the first carrier transport layer opposite to the first light absorption layer; And a second electrode formed on the side of the second carrier transport layer away from the first light absorption layer; along the direction away from the first light absorption layer, at least one of the first electrode and the second electrode includes a metal composite layer and a metal conductive layer located on the metal composite layer; the phase transition temperature of the metal composite layer is lower than the phase transition temperature of the metal conductive layer, and the resistivity of the metal conductive layer is lower than the resistivity of the metal composite layer. The first light-absorbing layer is a perovskite light-absorbing layer, and the phase transition temperature of the metal composite layer is lower than the thermal decomposition temperature of the perovskite light-absorbing layer.

2. The solar cell according to claim 1, characterized in that, The thickness of the metal composite layer is greater than or equal to 10 nm and less than or equal to 20 nm; and / or, The thickness of the metal conductive layer is greater than or equal to 350 nm and less than or equal to 750 nm.

3. The solar cell according to claim 1, characterized in that, The metal composite layer is a composite layer of materials including a first metal and a second metal; the first metal includes at least one of indium, nickel, titanium and gold, and the second metal includes at least one of silver, copper and aluminum.

4. The solar cell according to claim 3, characterized in that, The chemical ratio of the first metal to the second metal is greater than or equal to 1:1 and less than or equal to 3:

2.

5. The solar cell according to claim 1, characterized in that, Each material in the metal composite layer is randomly and uniformly distributed.

6. The solar cell according to claim 1, characterized in that, The material of the metal composite layer includes the material of the metal conductive layer; and / or, The material of the metallic conductive layer includes at least one of silver, copper, and aluminum.

7. The solar cell according to claim 1, characterized in that, The solar cell further includes a first transparent conductive layer located between the first electrode and the first carrier transport layer; and / or, The solar cell further includes a second transparent conductive layer located between the second electrode and the second carrier transport layer.

8. The solar cell according to any one of claims 1 to 7, characterized in that, The solar cell is a perovskite cell; both the first electrode and the second electrode include the metal composite layer and the metal conductive layer.

9. The solar cell according to any one of claims 1 to 7, characterized in that, The solar cell is a tandem solar cell; the tandem solar cell includes a top cell and a bottom cell connected in series, and a conductive composite layer located between the top cell and the bottom cell; The top cell includes a first carrier transport layer, a first light absorption layer, and a third carrier transport layer. The third carrier transport layer is located on the side of the first light absorption layer opposite to the first carrier transport layer. The bottom cell includes a second carrier transport layer, a second light absorption layer, and a fourth carrier transport layer. The second carrier transport layer and the fourth carrier transport layer are respectively located on both sides of the second light absorption layer along the thickness direction. The conductive composite layer is located between the fourth carrier transport layer and the third carrier transport layer.

10. The solar cell according to claim 9, characterized in that, The top cell is a perovskite cell, and the first electrode includes the metal composite layer and the metal conductive layer, wherein the phase transition temperature of the metal composite layer is lower than the thermal decomposition temperature of the first light-absorbing layer; and / or, The bottom cell is a silicon heterojunction cell.

11. A photovoltaic module, characterized in that, Including the solar cell as described in any one of claims 1 to 10.

12. A method for manufacturing a solar cell, characterized in that, include: A first carrier transport layer, a first light absorption layer, and a second carrier transport layer are formed by stacking them sequentially. The first light-absorbing layer is a perovskite light-absorbing layer; A first electrode is formed on the side of the first carrier transport layer that is away from the first light absorption layer; A second electrode is formed on the side of the second carrier transport layer opposite to the first light absorption layer; wherein... Forming either or both of the first electrode and the second electrode includes: forming a metal composite layer and a metal conductive layer on the metal composite layer by means of a thermal evaporation process or an electron beam evaporation process along a direction away from the first light-absorbing layer; wherein the phase transition temperature of the metal composite layer is lower than the phase transition temperature of the metal conductive layer, and the resistivity of the metal conductive layer is lower than the resistivity of the metal composite layer; and the phase transition temperature of the metal composite layer is lower than the thermal decomposition temperature of the perovskite light-absorbing layer.

13. The method for manufacturing a solar cell according to claim 12, characterized in that, Forming the metal composite layer includes: simultaneously depositing at least a first metal and a second metal to form the metal composite layer comprising the first metal and the second metal; the first metal comprising at least one of indium, nickel, titanium and gold, and the second metal comprising at least one of silver, copper and aluminum.

14. The method for manufacturing a solar cell according to claim 13, characterized in that, The ratio between the deposition rates of the first metal and the second metal is greater than or equal to 1:1 and less than or equal to 3:

2.

15. The method for manufacturing a solar cell according to claim 12, characterized in that, The deposition rate of the metal composite layer is greater than or equal to 0.05 Å / s and less than or equal to 0.3 Å / s; and / or, The deposition rate of the metallic conductive layer is greater than or equal to 0.5 Å / s and less than or equal to 4 Å / s.

16. The method for manufacturing a solar cell according to claim 12, characterized in that, The solar cell is a tandem solar cell; the tandem solar cell includes a top cell and a bottom cell connected in series, and a conductive composite layer located between the top cell and the bottom cell; After forming the second carrier transport layer and before forming the first light absorption layer and the first carrier transport layer, the method for manufacturing the solar cell further includes: Along the direction from the bottom cell to the top cell, a second light-absorbing layer, a fourth carrier transport layer, a conductive composite layer, and a third carrier transport layer are sequentially formed on the second carrier transport layer; wherein... The top cell includes a first carrier transport layer, a first light absorption layer, and a third carrier transport layer, and the bottom cell includes a second carrier transport layer, a second light absorption layer, and a fourth carrier transport layer.

17. A method for manufacturing a solar cell according to any one of claims 12 to 16, characterized in that, After forming the first carrier transport layer, before forming the first electrode on the side of the first carrier transport layer opposite to the first light absorption layer, the method for manufacturing the solar cell further includes: forming a first transparent conductive layer on the side of the first carrier transport layer opposite to the light absorption layer; and / or, After the second carrier transport layer is formed, before forming the second electrode on the side of the second carrier transport layer opposite to the first light absorption layer, the method for manufacturing the solar cell further includes: forming a second transparent conductive layer on the side of the second carrier transport layer opposite to the light absorption layer.

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