Perovskite solar cell, preparation method thereof and photovoltaic module

Abstract

The invention discloses a perovskite solar cell and a preparation method thereof, and a photovoltaic module. The preparation method of the perovskite solar cell comprises the following steps: providing a perovskite cell substrate; the method for preparing the electrode on the perovskite cell substrate comprises the following steps of: printing electrode slurry on the perovskite cell substrate to form an electrode slurry layer with a grid line pattern; and selectively scanning the area where the grid line pattern is located by adopting first laser with the energy density of 0.05 J / cm < 2 >-0.8 J / cm < 2 > to obtain the electrode. According to the application, the compatibility between the metallized electrode preparation process and the temperature-sensitive perovskite layer can be effectively improved, so that the thermal influence on the perovskite layer is reduced while the electrode quality is improved, and finally the photoelectric conversion efficiency of the solar cell is effectively improved.

Description

Technical Field

[0001] This application relates to the technical field of solar cells, and more particularly to a perovskite solar cell and its preparation method, as well as a photovoltaic module. Background Technology

[0002] Solar cell technology continues to advance towards higher efficiency and lower cost. Perovskite solar cells, with their high efficiency potential, have become a current research focus in the photovoltaic field. However, in the fabrication process of perovskite solar cells, the compatibility challenge between the metallization electrode process and the temperature-sensitive perovskite layer has become one of the key technological bottlenecks restricting its industrialization. Summary of the Invention

[0003] To improve the compatibility between the metallization electrode fabrication process and the temperature-sensitive perovskite layer, thereby reducing the thermal impact on the perovskite layer while improving electrode quality, this application provides a perovskite solar cell, its fabrication method, and a photovoltaic module.

[0004] In a first aspect, embodiments of this application provide a method for preparing a perovskite solar cell.

[0005] A method for fabricating a perovskite solar cell includes the following steps: Provides perovskite solar cell substrate; Fabricating electrodes on the perovskite solar cell substrate includes: Electrode paste is printed on the perovskite solar cell substrate to form an electrode paste layer with a grid pattern; An energy density of 0.05 J / cm³ was used. 2 ~0.8 J / cm 2 The first laser selectively scans the area where the grid pattern is located to obtain the electrode.

[0006] As an optional implementation, in the embodiments of this application, the first laser is an infrared laser, and the first laser uses pulse scanning or intermittent scanning; The first laser is an ultraviolet laser or a visible laser, and the first laser is used for continuous scanning, pulse scanning or intermittent scanning.

[0007] As an optional implementation, in the embodiments of this application, when the first laser is an infrared laser, the wavelength of the infrared laser is 1.06 μm to 10.6 μm; When the first laser is an ultraviolet laser, the wavelength of the ultraviolet laser is 193 nm to 355 nm; When the first laser is a visible light laser, the wavelength of the visible light laser is 356 nm to 600 nm; and / or; When the first laser is used for pulse scanning, the dwell time of the first laser at a single point is 5 ms to 1000 ms, the pulse width of the first laser is 10 ns to 1000 ns, and the scanning rate of the first laser is 10 mm / s to 1000 mm / s.

[0008] As an optional implementation, in the embodiments of this application, the spot size of the first laser is smaller than the grid line width W of the electrode, and the spot size of the first laser is 10 μm to 100 μm.

[0009] As an optional implementation, in the embodiments of this application, after the electrode paste is printed, the electrode paste layer is first pre-dried to evaporate some of the organic solvents in the electrode paste, thereby obtaining a conformable electrode precursor. Then, an energy density of 0.05 J / cm³ was used. 2 ~0.8 J / cm 2 The first laser selectively scans the area where the grid pattern is located, and the electrode precursor is sintered and solidified to form the electrode.

[0010] As an optional implementation, in the embodiments of this application, the pre-drying process includes drying with hot air, drying with infrared heating, or drying the electrode slurry layer by scanning with a second laser.

[0011] As an optional implementation, in the embodiments of this application, when the pre-drying process uses a second laser to scan the electrode slurry layer for drying, the laser energy density of the second laser is lower than that of the first laser, and the laser scanning rate of the second laser is lower than that of the first laser. And / or, Before using the first laser or the second laser, a visual positioning system is used to determine the laser scanning path and the laser scanning area.

[0012] As an optional implementation, in the embodiments of this application, the electrode slurry includes any one of Ag, Cu, Al, Ag-encapsulated Cu, or Ag-encapsulated Al.

[0013] And / or, When the perovskite solar cell is a perovskite-silicon tandem cell, the bottom cell of the perovskite-silicon tandem cell includes any one of a passivated emitter and back contact cell, a heterojunction cell, a passivated contact cell, or a back contact cell. The top cell of the perovskite-silicon tandem cell includes a composite layer, a first transport layer, a perovskite layer, a second transport layer, and a transparent conductive layer stacked sequentially on the bottom cell. One of the first transport layer and the second transport layer is a hole transport layer, and the other is an electron transport layer. The electrode includes a first electrode and a second electrode. The first electrode is disposed on the transparent conductive layer, and the second electrode is disposed on the side of the bottom battery opposite to the top battery. The perovskite layer includes MAPbI3, FAPbI3, and FA. x1 Cs y1 PbI3, FA x2 MA y2 Cs z1 PbI3 and FA x3 MA y3 Cs z2 Pb(I) m Br n Any one or more combinations of 3, where x1+y1=1, x2+y2+z1=1, x3+y3+z2=1, m+n=1.

[0014] Secondly, embodiments of this application provide a perovskite solar cell.

[0015] A perovskite solar cell, said perovskite solar cell being prepared using the preparation method described in the first aspect.

[0016] Thirdly, embodiments of this application provide a photovoltaic module.

[0017] A photovoltaic module comprising a solar cell prepared by the method described in the first aspect.

[0018] Compared with the prior art, the beneficial effects of this application are as follows: This application optimizes the electrode fabrication process in the perovskite solar cell manufacturing process by employing a first laser with a specific energy density to selectively scan the area containing the grid pattern. This process ensures high-quality curing of the electrode slurry while limiting the heat-affected zone to the grid pattern area, effectively reducing thermal damage to the perovskite solar cell substrate (especially the perovskite layer). Specifically, this application uses selective scanning to confine the first laser to the grid pattern area, avoiding scanning the perovskite solar cell substrate outside the grid pattern area, thereby effectively preventing thermal damage to other areas of the perovskite solar cell substrate. Furthermore, controlling the energy density of the first laser within a specific range provides sufficient energy to the electrode slurry layer, allowing the organic solvent in the electrode slurry layer to fully evaporate and the metal particles to fully sinter and solidify, thus transforming it into a dense, low-resistance electrode with excellent adhesion, effectively improving electrode quality.

[0019] The specific range of first laser energy density mentioned above, combined with the electrode paste, is key to balancing and improving electrode quality while reducing thermal damage to the perovskite layer. When the first laser energy density is greater than 0.8 J / cm²... 2 Increased thermal damage to the perovskite layer leads to a significant decrease in the photoelectric conversion efficiency of the solar cell. When the energy density of the first laser is less than 0.05 J / cm², the thermal efficiency decreases. 2 The limited temperature rise of the electrode slurry layer leads to insufficient curing of the electrode slurry layer and a decline in quality.

[0020] In summary, this application effectively improves the compatibility of electrode fabrication processes with temperature-sensitive perovskite layers, ultimately achieving a significant increase in the photoelectric conversion efficiency of solar cells. Attached Figure Description

[0021] To more clearly illustrate the technical solutions in the embodiments of this application, the accompanying drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0022] Figure 1 This is a schematic diagram of the structure of a perovskite solar cell substrate disclosed in the embodiments of this application; Figure 2 This is a schematic diagram of the structure disclosed in the embodiments of this application for illustrating the formation of an electrode paste layer with a grid pattern on a perovskite solar cell substrate; Figure 3 This is a schematic diagram of the first laser action on the area where the grid pattern is located, as disclosed in the embodiments of this application; Figure 4 This is a schematic diagram of the structure of forming an electrode on a perovskite solar cell substrate as disclosed in the embodiments of this application; Figure 5 This is a schematic diagram of the structure of the perovskite solar cell disclosed in the embodiments of this application.

[0023] Icons: 1. Perovskite solar cell substrate; 11. Bottom cell; 12. Composite layer; 13. First transport layer; 14. Perovskite layer; 15. Second transport layer; 16. Transparent conductive layer; 17. Passivation layer; 18. Buffer layer; 19. Antireflection layer; 2. Electrode; 21. Electrode slurry layer; 22. Grid line; 2A. First electrode; 2B. Second electrode. Detailed Implementation

[0024] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0025] In this application, the terms "upper," "lower," "left," "right," "front," "rear," "top," "bottom," "inner," "outer," "middle," "vertical," "horizontal," "lateral," and "longitudinal" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. These terms are primarily for the purpose of better describing this application and its embodiments, and are not intended to limit the indicated device, element, or component to having a specific orientation, or to be constructed and operated in a specific orientation.

[0026] Furthermore, in addition to indicating location or positional relationship, some of the aforementioned terms may also have other meanings. For example, the term "above" may also be used in some cases to indicate a certain dependency or connection relationship. Those skilled in the art can understand the specific meaning of these terms in this application based on the specific circumstances.

[0027] Furthermore, the terms "installation," "setup," "equipped with," "connection," and "linked" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral structure; 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, or an internal connection between two devices, components, or parts. Those skilled in the art can understand the specific meaning of these terms in this application based on the specific circumstances.

[0028] Furthermore, the terms "first," "second," etc., are primarily used to distinguish different devices, components, or parts (which may be the same or different in specific type and construction), and are not intended to indicate or imply the relative importance or quantity of the indicated devices, components, or parts. Unless otherwise stated, "a plurality of" means two or more.

[0029] Perovskite materials are prone to thermal decomposition at temperatures exceeding 120°C. To ensure the stability of the perovskite layer, the electrode slurry should ideally be cured below 120°C when fabricating the electrodes for perovskite solar cells. However, at this temperature, the organic solvents in the electrode slurry are difficult to fully volatilize, resulting in a significantly higher resistivity of the electrode compared to traditional high-temperature processes, which severely restricts the photoelectric conversion efficiency of the cell. Furthermore, the aforementioned low-temperature curing conditions also make it difficult to achieve sufficient sintering and solidification of the metal particles in the electrode slurry, leading to insufficient adhesion and welding tensile strength between the electrode and the perovskite cell substrate, directly threatening the long-term mechanical stability and reliability of the perovskite solar cell.

[0030] In order to improve electrode quality while ensuring the stability of the perovskite layer and overcome the contradiction between electrode quality and perovskite performance in perovskite solar cells, this application provides a method for preparing a perovskite solar cell and a photovoltaic module.

[0031] The technical solution of this application will be further described below with reference to the embodiments and accompanying drawings.

[0032] In a first aspect, embodiments of this application provide a method for preparing a perovskite solar cell.

[0033] Reference Figures 1 to 4 A method for preparing a perovskite solar cell includes the following steps: Provide such as Figure 1 The perovskite solar cell substrate 1 shown; Electrode 2 is fabricated on perovskite solar cell substrate 1, including: Electrode paste was printed on the perovskite solar cell substrate 1 to form a structure such as... Figure 2 The electrode paste layer 21 with a grid pattern is shown; An energy density of 0.05 J / cm³ was used. 2 ~0.8 J / cm 2 The first laser selectively scans the area containing the grid pattern. Figure 3 The area filled with diagonal lines in the image represents the scanning area of ​​the first laser, resulting in the following: Figure 4 Electrode 2 is shown.

[0034] This application employs a first laser with a specific energy density to selectively scan the area containing the grid pattern. This process ensures high-quality curing of the electrode slurry while limiting the heat-affected zone to the grid pattern area, effectively reducing thermal damage to the perovskite solar cell substrate 1 (especially the perovskite layer 14). Specifically, by selectively scanning, this application confines the first laser to the grid pattern area, avoiding scanning the perovskite solar cell substrate 1 outside the grid pattern area, thereby effectively avoiding thermal damage to other areas of the perovskite solar cell substrate 1. Furthermore, controlling the energy density of the first laser within a specific range provides sufficient energy for the rapid curing of the electrode slurry layer 21, allowing the organic solvent in the electrode slurry layer 21 to fully evaporate and the metal particles to fully sinter and solidify, thereby transforming it into a dense, low-resistance electrode 2 with excellent adhesion, effectively improving the quality of the electrode 2.

[0035] The specific range of first laser energy density mentioned above, combined with the electrode paste, is key to balancing the improvement of electrode 2's quality and reducing thermal damage to the perovskite layer 14. When the energy density of the first laser is 0.05 J / cm²... 2 ~0.8 J / cm 2 During this process, the temperature in the area where the first laser strikes the grid pattern increases instantaneously, causing the electrode paste layer 21 to solidify rapidly and fully under the irradiation of the first laser, forming an electrode 21 of better quality. When the energy density of the first laser is too high (greater than 0.8 J / cm²), the temperature rises instantaneously, causing the electrode paste layer 21 to solidify quickly and fully under the irradiation of the first laser, resulting in a higher quality electrode 21. 2 Increased thermal damage to the perovskite layer 14 leads to a significant decrease in the photoelectric conversion efficiency of the solar cell. When the first laser energy density is low (less than 0.05 J / cm²), the thermal damage is further exacerbated. 2 The temperature rise of the electrode slurry layer 21 is limited, resulting in insufficient curing of the electrode slurry layer 21 and a decline in quality.

[0036] In summary, this application effectively improves the compatibility between the electrode 2 fabrication process and the temperature-sensitive perovskite layer 14, ultimately achieving an effective improvement in the photoelectric conversion efficiency of the solar cell.

[0037] It should be noted that the main components of the electrode paste include metal particles and organic solvents. Among them, the metal particles mainly serve to transport charge carriers; the organic carrier mainly serves to disperse the metal particles and glass frit, so that the metal particles are mixed evenly and can be fixed on the perovskite solar cell substrate 1 in the form of paste through printing methods such as screen printing and stencil printing.

[0038] Furthermore, the perovskite solar cell substrate 1 mentioned in this application refers to the main structure of the cell where the perovskite layer 14 and necessary functional films have been prepared, and the electrode 2 is to be formed. On the perovskite solar cell substrate 1, the electrode 2 is configured to collect and export the photocurrent generated by the perovskite solar cell substrate 1.

[0039] Figures 1 to 4 All images are taken from a top-down perspective and focus on a specific local area of ​​the perovskite solar cell fabrication, with the aim of clearly demonstrating the formation and transformation process of the electrode grid pattern.

[0040] For example, the energy density of the region where the first laser selectively scans the grating pattern can be 0.05 J / cm². 2 0.1 J / cm 2 0.4 J / cm 2 0.6 J / cm 2 or 0.8 J / cm 2 wait.

[0041] Furthermore, the electrode paste of this application is preferably a low-temperature curing electrode paste. A low-temperature curing electrode paste refers to a type of electrode paste that can be cured at a low temperature below 120°C under heating in air or infrared heating conditions. Preferably, the curing temperature of the low-temperature curing electrode paste is 85°C to 120°C. Exemplarily, the curing temperature of the low-temperature electrode paste may include 85°C, 90°C, 95°C, 100°C, 110°C, or 120°C. Using a low-temperature curing electrode paste allows for better coordination with a first laser of a specific energy density, enabling the temperature of the grid pattern area to rapidly rise to or above the curing temperature of the low-temperature curing electrode paste (e.g., 120°C to 150°C). This arrangement facilitates rapid and complete curing of the electrode 2 under the action of the first laser, thereby improving electrode quality, and also avoids excessive heat transfer to the perovskite layer 14, preventing damage to the perovskite layer 14 due to heat.

[0042] In some embodiments, the first laser is an infrared laser, and the first laser uses pulse scanning or intermittent scanning; The first laser is an ultraviolet laser or a visible laser, and the first laser uses continuous scanning, pulse scanning or intermittent scanning.

[0043] When infrared lasers are used, their photon energy is low, resulting in a significant thermal effect. To balance the thermal effect of infrared lasers, this application uses a first laser with a specific energy density, combined with a pulsed or intermittent scanning mode. This scanning mode can provide high energy density at the moment of laser action, causing the temperature of the grid area to rise rapidly, ensuring sufficient solidification of the electrode paste and sintering of the metal. The intervals between laser scans facilitate heat dissipation, preventing it from continuously diffusing into the perovskite solar cell substrate 1. Thus, this application can precisely control the total amount and rate of heat input, ultimately improving the quality of the electrode 2 while effectively reducing thermal damage to the perovskite layer 14.

[0044] Compared to infrared lasers, ultraviolet or visible light lasers have higher photon energy and shallower penetration depth, making them easily absorbed by the electrode slurry layer 21 but less likely to penetrate to the underlying perovskite layer 14. Continuous scanning can improve processing efficiency, while pulsed or intermittent scanning can provide more precise energy control, both of which can achieve high-quality electrode 2 curing and reduce the thermal impact on the underlying perovskite layer 14.

[0045] In some embodiments, when the first laser is an infrared laser, the wavelength of the infrared laser is 1.06 μm to 10.6 μm; When the first laser is an ultraviolet laser, the wavelength of the ultraviolet laser is 193 nm to 355 nm. When the first laser is a visible light laser, the wavelength of the visible light laser is 356 nm to 600 nm.

[0046] The aforementioned specific wavelength bands are optimized based on the optical absorption characteristics of the electrode slurry components or the perovskite solar cell substrate 1. Specifically, the organic solvents and glass powder in the electrode slurry exhibit strong absorption of infrared laser light at this wavelength. This allows the first laser energy to be selectively absorbed within the electrode slurry layer 21, facilitating the evaporation of organic solvents and the sintering of metal particles, thereby reducing thermal damage to the underlying perovskite layer 14. The ultraviolet and visible light lasers in the aforementioned wavelength bands also show excellent absorption in the electrode slurry, resulting in shallow penetration into the underlying perovskite solar cell substrate 1, effectively reducing the risk of thermal damage to the perovskite functional layer. The laser source for the first laser can be selected as needed; for example, a CO2 laser can be used to output 10.6 μm infrared light, or a fiber laser can be used to output 1.06 μm infrared light, or a pulsed green laser can be used to output 532 nm green light.

[0047] In some embodiments, when the first laser is a pulsed scan, the dwell time of the first laser at a single point is 5 ms to 1000 ms, the pulse width of the first laser is 10 ns to 1000 ns, and the scanning rate of the first laser is 10 mm / s to 1000 mm / s.

[0048] By controlling the parameters of the first laser during pulse scanning within the aforementioned range, the energy of the first laser acting on electrode 2 can be better controlled, further balancing the improvement of electrode 2's quality with the reduction of thermal damage to the perovskite layer 14. For example, the dwell time of the first laser at a single point can be 5 ms, 100 ms, 500 ms, or 1000 ms, etc.; the pulse width of the first laser can be 10 ns, 100 ns, 500 ns, or 1000 ns, etc.; and the scanning rate of the first laser can be 10 mm / s, 100 mm / s, 500 mm / s, or 1000 mm / s, etc.

[0049] In some embodiments, the spot size of the first laser is smaller than, for example... Figure 4 The linewidth W of the grid line 22 of the electrode 2 shown is 10 μm to 100 μm, and the spot size of the first laser is 10 μm to 100 μm.

[0050] The size of the first laser spot is set to be smaller than the linewidth of the grid line 22 to ensure that the first laser energy can be effectively limited within the width range of the predetermined grid line pattern. This further avoids the risk of accidentally damaging the perovskite cell substrate on both sides of the grid line pattern due to spot overflow, thereby further reducing the thermal impact on the perovskite layer 14.

[0051] Furthermore, setting the spot size to 10 μm to 100 μm can achieve a good match with the linewidth of the grid line 22 design of mainstream solar cells (typically 30 μm to 150 μm), thereby reducing the risk of accidentally damaging the perovskite cell substrate on both sides of the grid line pattern while improving the efficiency of the first laser processing. For example, the spot size can be 10 μm, 30 μm, 60 μm, or 100 μm, etc.

[0052] It should be noted that electrode 2 can be composed of vertically intersecting elongated grid lines 22, and the pattern formed by the combination of these grid lines 22 is called the grid pattern. The spot size refers to the maximum dimension along the length direction perpendicular to the grid lines 22 within the energy distribution area formed by the first laser on the processed surface. For example, for a rectangular spot, the spot size is the width of the rectangular spot along the length direction perpendicular to the grid lines 22; for a circular spot, it is the diameter of the circular spot along the length direction perpendicular to the electrode 2.

[0053] An energy density of 0.05 J / cm³ was used. 2 ~0.8 J / cm 2 The first laser directly scans the electrode paste layer 21, which can achieve the evaporation and sintering solidification of the organic solvent in the electrode paste layer 21. However, it is also prone to defects such as electrode morphology collapse and rough edges due to the high energy density of the first laser. In order to further improve the quality of the electrode 2, in some embodiments, after the electrode paste is printed, the electrode paste layer 21 is pre-dried to evaporate some of the organic solvent in the electrode paste and obtain a shape-preserving electrode precursor. Then, an energy density of 0.05 J / cm³ was used. 2 ~0.8 J / cm 2 The first laser selectively scans the area where the grid pattern is located, causing the electrode precursor to sinter and solidify to form electrode 2.

[0054] By pre-drying, most of the volatile organic solvents in the electrode paste can be removed in advance, thereby significantly reducing the fluidity of the electrode paste layer 21 and better maintaining the geometry of the grid pattern formed in the initial printing, achieving a better shape retention effect. This can effectively avoid the risk of defects such as electrode morphology collapse and rough edges caused by using a high-energy-density first laser scan, laying the foundation for the final formation of an electrode 2 with regular morphology and excellent conductivity.

[0055] In some embodiments, the pre-drying process includes drying with hot air, drying with infrared heating, or drying with a second laser scanning grid pattern.

[0056] Hot air drying, infrared heating drying, or drying using a second laser scanning method can all effectively achieve pre-drying of the electrode slurry layer 21. Among these, hot air drying and infrared heating drying are simple and low-cost processes, suitable for large-area uniform heating. Second laser scanning drying, on the other hand, offers higher spatial selectivity, enabling precise control of the heat-affected zone. This further reduces the overall thermal impact on the perovskite solar cell substrate 1 during the pre-drying stage, providing better process compatibility for the highly heat-sensitive perovskite solar cell substrate 1.

[0057] When using hot air drying or infrared drying, the electrode slurry layer 21 is heated at 60℃-110℃ for 2min-20min to allow the organic solvents in the electrode slurry to evaporate.

[0058] Furthermore, drying using a second laser scanning grid pattern is preferable. When the pre-drying process uses a second laser scanning grid pattern, the laser energy density of the second laser is lower than that of the first laser, and the laser scanning rate of the second laser is lower than that of the first laser.

[0059] The aforementioned pre-drying treatment uses relatively low energy, allowing for the gentle evaporation of organic solvents and thus achieving better shaping of the electrode slurry. Sintering after the electrode slurry has been shaped allows for better control of the electrode morphology.

[0060] The energy density of the second laser used in the pre-drying process is 0.01 J / cm². 2 ~0.4 J / cm 2 For example, the second laser energy density of the pre-drying treatment can be 0.01 J / cm³. 2 0.1 J / cm 2 0.2 J / cm 2 Or 0.4 J / cm 2 .

[0061] In some embodiments, a visual positioning system is used to determine the laser scanning path and laser scanning area before using the first or second laser.

[0062] To better determine the scanning path and scanning area of ​​the second laser, a visual positioning system, such as a CCD camera (charge coupled device), can be used first to accurately identify the grating pattern or the alignment marks on the grating pattern, thereby determining the scanning path and scanning area of ​​the second laser. Then, the second laser is used to scan the grating pattern according to the preset program path.

[0063] In some embodiments, the electrode slurry includes any one of Ag, Cu, Al, Ag-coated Cu, or Ag-coated Al. These materials not only possess good conductivity, but more importantly, they exhibit excellent absorption and response characteristics to a first laser of a specific energy density, enabling them to be fully sintered under a first laser selective scanning process, thereby forming a high-quality electrode 2 with both low resistance and high adhesion.

[0064] In some embodiments, the perovskite solar cell includes a perovskite single-junction cell or a perovskite-silicon tandem cell. Reference Figure 5 When the perovskite solar cell is a perovskite-silicon tandem cell, the bottom cell 11 of the perovskite-silicon tandem cell includes any one of the following: a passivated emitter and rear contact cell (PERC cell), a heterojunction cell (HJT cell), a tunnel osde passivating contact cell (TOPCon cell), or an interdigitated back-contact cell (IBC cell). In all the above types of perovskite solar cells, this application can improve the quality of the electrode 2 while effectively protecting the perovskite layer 14.

[0065] It should be noted that, with Figures 1-4 The difference is, Figure 5 The purpose of using a cross-sectional view of a perovskite solar cell is to reveal the layered structural relationship of the entire cell.

[0066] The top cell of the perovskite-silicon tandem solar cell includes a composite layer 12, a first transport layer 13, a perovskite layer 14, a second transport layer 15 and a transparent conductive layer 16 stacked sequentially on the bottom cell 11. One of the first transport layer 13 and the second transport layer 15 is a hole transport layer and the other is an electron transport layer. Electrode 2 includes a first electrode 2A and a second electrode 2B. The first electrode 2A is disposed on the transparent conductive layer 16, and the second electrode 2B is disposed on the side of the bottom cell 11 opposite to the top cell.

[0067] Both the first electrode 2A and the second electrode 2B can be prepared using the processes mentioned in the embodiments of this application, which can better reduce the thermal impact of the electrode 2 preparation process on the perovskite layer 14. Specifically, the first electrode 2A is located closer to the perovskite layer 14 and should be prepared using the electrode 2 preparation method mentioned in this application, rather than the conventional high-temperature sintering method. The second electrode 2B is located relatively far from the perovskite layer 14, therefore, it can be prepared using the conventional high-temperature sintering method or the above-mentioned electrode 2 preparation method.

[0068] This application demonstrates excellent compatibility and protection for heat-sensitive perovskite material systems. In some embodiments, the perovskite layer 14 comprises MAPbI3, FAPbI3, and FA. x1 Cs y1 PbI3, FA x2 MA y2 Cs z1 PbI3 and FA x3 MA y3 Cs z2 Pb(I) m Br n The method comprises any one or more combinations of x1+y1=1, x2+y2+z1=1, x3+y3+z2=1, and m+n=1. This application effectively avoids damage to the structure and properties of the aforementioned thermally unstable perovskite material during the forming process of electrode 2. It should be noted that MA is methylamine and FA is formamidinium.

[0069] Furthermore, the composite layer 12 can be made of indium tin oxide or indium zinc oxide, etc.; the hole transport layer can be made of nickel oxide (NiO). x Materials with high hole mobility, such as 2PACz (2-(9H-carbazole-9-yl)ethylphosphonic acid) or 4PACz (4-(9H-carbazole-9-yl)butylphosphonic acid); the electron transport layer material can be C 60 The transparent conductive layer 16 can be indium tin oxide or indium zinc oxide, etc.

[0070] Furthermore, when the first transport layer 13 is a hole transport layer and the second transport layer 15 is an electron transport layer, a passivation layer 17 is also provided between the perovskite layer 14 and the electron transport layer. The material of the passivation layer 17 can be LiF or MgF2, etc.; a buffer layer 18 is also provided between the electron transport layer and the transparent conductive layer 16. The material of the buffer layer 18 can be SnO2; an antireflection layer 19 is provided on the non-gateline pattern area on the transparent conductive layer 16 where the electrode 2 is not provided. The material of the antireflection layer 19 can be LiF or MgF2, etc.

[0071] Secondly, embodiments of this application provide a perovskite solar cell.

[0072] A perovskite solar cell, which is prepared by the preparation method mentioned in the first aspect.

[0073] Thirdly, embodiments of this application provide a photovoltaic module.

[0074] A photovoltaic module comprising a solar cell prepared by the method described in the first aspect.

[0075] The technical solution of this application will be further described below with reference to more specific embodiments.

[0076] Example 1 This application provides a perovskite solar cell, the preparation method of which includes the following steps: A perovskite-silicon tandem solar cell substrate for preparing electrodes is provided. The perovskite-silicon tandem solar cell substrate uses a heterojunction solar cell as the base cell, and an indium tin oxide composite layer, a nickel oxide hole transport layer, a perovskite layer, a lithium fluoride passivation layer, and a C2O2 layer are sequentially fabricated on the heterojunction solar cell. 60 Electron transport layer, tin oxide buffer layer, indium tin oxide transparent conductive layer; Electrodes are fabricated such that a first electrode is disposed on an indium tin oxide transparent conductive layer, and a second electrode is disposed on a bottom cell. The first and second electrodes are fabricated using the same method, specifically including: Electrode paste is screen printed to form an electrode paste layer with a grid pattern. When preparing the first electrode, the electrode paste layer with the grid pattern is printed onto the side of the indium tin oxide transparent conductive layer away from the bottom cell. When preparing the second electrode, the electrode paste layer with the grid pattern is printed onto the side of the bottom cell away from the indium tin oxide transparent conductive layer. An energy density of 0.2 J / cm³ was used. 2The infrared laser selectively scans the area where the grid pattern is located for pre-drying treatment. The temperature of the electrode slurry layer is raised to 80℃~120℃ during laser scanning and then rapidly cooled down to below 60℃ within 1-5s after the laser moves, so that most of the organic solvents evaporate to obtain a conformal electrode precursor and minimize damage to the perovskite layer. The infrared laser uses pulse scanning with a wavelength of 10.6 μm, a laser single-point dwell time of 100 ms, a pulse width of 100 ns, a scanning rate of 300 mm / s, and a spot size of 50 μm. Using an energy density of 0.5 J / cm³ 2 The infrared laser selectively scans the area where the grid pattern is located. The temperature of the electrode slurry layer will rise to 120℃~150℃ during laser scanning. At this temperature, the electrode precursor is sintered and solidified to form the electrode. The infrared laser uses pulse scanning with a wavelength of 10.6 μm, a laser single-point dwell time of 100 ms, a pulse width of 100 ns, a scanning rate of 300 mm / s, and a spot size of 50 μm. A lithium fluoride antireflection layer is deposited to cover the surface of the indium tin oxide transparent conductive layer without electrodes.

[0077] Example 2 This application provides a perovskite solar cell, which differs from Embodiment 1 in that: in the electrode fabrication step, an energy density of 0.8 J / cm³ is used. 2 The energy density of the ultraviolet laser substitution is 0.5 J / cm². 2 The infrared laser is used for sintering and solidification. The ultraviolet laser is continuously scanned with a wavelength of 300 nm, a single-point dwell time of 100 ms, a pulse width of 100 ns, a scanning rate of 300 mm / s, and a spot size of 50 μm. Everything else remains the same as in Example 1.

[0078] Example 3 This application provides a perovskite solar cell, which differs from Embodiment 1 in that: in the electrode fabrication step, an energy density of 0.05 J / cm² is used. 2 Visible light lasers are used as a replacement for lasers with an energy density of 0.5 J / cm². 2 The infrared laser is used for sintering and solidification. The visible light laser uses pulse scanning with a wavelength of 500 nm, a single-point dwell time of 100 ms, a pulse width of 100 ns, a scanning rate of 300 mm / s, and a spot size of 50 μm. Everything else remains the same as in Example 1.

[0079] Example 4 This application provides a perovskite solar cell, which differs from Embodiment 1 in that: in the electrode preparation step, infrared heating drying is used instead of using an energy density of 0.2 J / cm². 2 The infrared laser is used for pre-drying treatment, and the rest is the same as in Example 1.

[0080] Comparative Example 1 This application provides a comparative example of a perovskite solar cell, which differs from Example 1 in that: in the electrode preparation step, infrared heating drying is used to raise the temperature of the electrode precursor to 110°C and maintain it at 110°C for 5 minutes, allowing the electrode precursor to sinter and solidify to form the electrode, instead of using an energy density of 0.5 J / cm³. 2 The infrared laser is used for sintering and solidification, and the rest is consistent with Example 1.

[0081] Comparative Example 2 This application provides a perovskite solar cell as a comparative example, which differs from Example 1 in that: in the electrode preparation step, an energy density of 1 J / cm² is used. 2 The infrared laser, instead of using an energy density of 0.5 J / cm², is used. 2 The infrared laser is used for sintering and solidification, and the rest is consistent with Example 1.

[0082] Comparative Example 3 This application provides a comparative example of a perovskite solar cell, which differs from Example 1 in that: in the electrode fabrication step, an energy density of 0.03 J / cm² is used. 2 The infrared laser, instead of using an energy density of 0.5 J / cm², is used. 2 The infrared laser is used for sintering and solidification, and the rest is consistent with Example 1.

[0083] The performance of perovskite solar cells was tested using the Wavelabs solar simulator under the following conditions: AM1.5, 1000 W / m². 2 The test environment temperature was 25℃. Before testing, the light source was calibrated to simulate sunlight intensity using a standard silicon cell. Performance tests included open-circuit voltage (in V) and current density (in mA / cm²). 2 ), fill factor (in %) and energy conversion efficiency (in %).

[0084] Table 1

[0085] As can be seen from the comparison between Example 1 and Comparative Example 1 in Table 1, the fill factor and energy conversion efficiency of Example 1 are significantly improved. This indicates that, compared with placing the entire perovskite solar cell in an infrared heating environment, the method of selectively scanning the grid pattern region with a laser to complete electrode sintering in Example 1 not only achieves better electrode quality, but also reduces the thermal impact on the perovskite layer and lowers its thermal instability risk due to the selective scanning heating method, thereby effectively improving the photoelectric conversion efficiency of the cell.

[0086] Furthermore, a comparison of the data from Examples 1 to 3 with those from Comparative Examples 2 and 3 shows that, in the electrode preparation step, an energy density of 0.05 J / cm² is used. 2 ~0.8 J / cm 2 Both laser sintering and other methods can reduce the thermal impact on the perovskite layer while ensuring electrode quality, thereby improving the photoelectric conversion efficiency of the battery. In contrast, the laser energy density used in Comparative Example 2 is too low (0.03 J / cm²). 2 This resulted in insufficient electrode sintering and a decrease in carrier collection capability; while the energy density used in Comparative Example 3 was too high (1 J / cm³). 2 This causes localized thermal decomposition of the perovskite layer, resulting in a significant reduction in photoelectric conversion efficiency.

[0087] The technical solutions disclosed in the embodiments of this application have been described in detail above. Specific examples have been used to illustrate the principles and implementation methods of this application. The descriptions of the embodiments above are only for the purpose of helping to understand the technical solutions and core inventive points of the embodiments of this application. At the same time, for those skilled in the art, there will be changes in the specific implementation methods and application scope based on the ideas of this application. Therefore, the content of this specification should not be construed as a limitation of this application.

Claims

1. A method for preparing a perovskite solar cell, characterized in that, Includes the following steps: Provides perovskite solar cell substrate; Fabricating electrodes on the perovskite solar cell substrate includes: Electrode paste is printed on the perovskite solar cell substrate to form an electrode paste layer with a grid pattern; An energy density of 0.05 J / cm³ was used. 2 ~0.8 J / cm 2 The first laser selectively scans the area where the grid pattern is located to obtain the electrode.

2. The method for preparing a perovskite solar cell according to claim 1, characterized in that, The first laser is an infrared laser, and the first laser uses pulse scanning or intermittent scanning; The first laser is an ultraviolet laser or a visible laser, and the first laser is used for continuous scanning, pulse scanning or intermittent scanning.

3. The method for preparing a perovskite solar cell according to claim 2, characterized in that, When the first laser is an infrared laser, the wavelength of the infrared laser is 1.06 μm to 10.6 μm; When the first laser is an ultraviolet laser, the wavelength of the ultraviolet laser is 193 nm to 355 nm; When the first laser is a visible light laser, the wavelength of the visible light laser is 356 nm to 600 nm; and / or; When the first laser is used for pulse scanning, the dwell time of the first laser at a single point is 5 ms to 1000 ms, the pulse width of the first laser is 10 ns to 1000 ns, and the scanning rate of the first laser is 10 mm / s to 1000 mm / s.

4. The method for preparing a perovskite solar cell according to claim 1, characterized in that, The spot size of the first laser is smaller than the grid line width W of the electrode, and the spot size of the first laser is 10 μm to 100 μm.

5. The method for preparing a perovskite solar cell according to claim 1, characterized in that, After the electrode paste is printed, the electrode paste layer is pre-dried to evaporate some of the organic solvents in the electrode paste, thereby obtaining a conformable electrode precursor. Then, an energy density of 0.05 J / cm³ was used. 2 ~0.8 J / cm 2 The first laser selectively scans the area where the grid pattern is located, and the electrode precursor is sintered and solidified to form the electrode.

6. The method for preparing a perovskite solar cell according to claim 5, characterized in that, The pre-drying process includes drying with hot air, drying with infrared heating, or drying the electrode slurry layer by scanning with a second laser.

7. The method for preparing a perovskite solar cell according to claim 6, characterized in that, When the pre-drying process uses a second laser to scan the electrode slurry layer for drying, the laser energy density of the second laser is lower than that of the first laser, and the laser scanning rate of the second laser is lower than that of the first laser. And / or, Before using the first laser or the second laser, a visual positioning system is used to determine the laser scanning path and the laser scanning area.

8. The method for preparing a perovskite solar cell according to claim 1, characterized in that, The electrode paste includes any one of Ag, Cu, Al, Ag-encapsulated Cu, or Ag-encapsulated Al; And / or, The perovskite solar cell includes a perovskite single-junction cell or a perovskite-silicon tandem cell. When the perovskite solar cell is a perovskite-silicon tandem cell, the bottom cell of the perovskite-silicon tandem cell includes any one of a passivated emitter and back contact cell, a heterojunction cell, a passivated contact cell, or a back contact cell. The top cell of the perovskite-silicon tandem cell includes a composite layer, a first transport layer, a perovskite layer, a second transport layer, and a transparent conductive layer stacked sequentially on the bottom cell. One of the first transport layer and the second transport layer is a hole transport layer, and the other is an electron transport layer. The electrode includes a first electrode and a second electrode. The first electrode is disposed on the transparent conductive layer, and the second electrode is disposed on the side of the bottom battery opposite to the top battery. The perovskite layer includes MAPbI3, FAPbI3, and FA. x1 Cs y1 PbI3, FA x2 MA y2 Cs z1 PbI3 and FA x3 MA y3 Cs z2 Pb(I) m Br n Any one or more combinations of 3, where x1+y1=1, x2+y2+z1=1, x3+y3+z2=1, m+n=1.

9. A perovskite solar cell, characterized in that, The perovskite solar cell is prepared by the preparation method as described in any one of claims 1-8.

10. A photovoltaic module, characterized in that, This includes solar cells prepared by the method described in any one of claims 1-8.

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