Solar cell manufacturing method, solar cell, and laminated solar cell

Abstract

This application relates to a method for fabricating a solar cell, a solar cell, and a tandem solar cell. The solar cell fabrication method includes: providing a carrier plate and a separation auxiliary layer stacked sequentially; forming a perovskite absorber layer on the surface of the carrier plate away from the separation auxiliary layer, comprising an adhesive substrate and a plurality of single-crystal perovskite particles arranged in the adhesive substrate, the adhesive substrate having opposing first and second surfaces, the first surface being away from the separation auxiliary layer, at least some of the single-crystal perovskite particles having a first convex surface protruding relative to the first surface and a second convex surface protruding relative to the second surface, and a functional layer being formed on the surface of the single-crystal perovskite particles; forming a first carrier transport layer on the perovskite absorber layer; forming a first conductive layer on the first carrier transport layer; removing the carrier plate and the separation auxiliary layer, and forming a second conductive layer on the perovskite absorber layer. This application embodiment is beneficial for improving the photoelectric conversion capability and stability of perovskite solar cells.

Description

Technical Field

[0001] This application relates to the field of solar cell technology, and in particular to a method for preparing a solar cell, a solar cell, and a tandem solar cell. Background Technology

[0002] Fossil fuels cause air pollution and have limited reserves, while solar energy has advantages such as being clean, pollution-free, and abundant. Therefore, solar energy is gradually becoming the core clean energy source to replace fossil fuels. Due to the excellent photoelectric conversion efficiency of solar cells, solar cells have become the focus of development for clean energy utilization.

[0003] One crucial factor influencing the proportion of solar energy in energy utilization is the photoelectric conversion efficiency of solar cells. Optimizing and improving the structural design and material composition of solar cells is a fundamental approach to enhancing this efficiency. Perovskite solar cells, due to their long lifespan and relatively stable photoelectric conversion efficiency, have promising development prospects.

[0004] However, current perovskite solar cells suffer from limited photoelectric conversion efficiency and poor stability. Summary of the Invention

[0005] This application provides a method for preparing a solar cell, a solar cell, and a tandem solar cell, which at least facilitates the preparation of large-area perovskite solar cells with good photoelectric conversion efficiency and improves the photoelectric conversion capability and stability of perovskite solar cells.

[0006] This application provides a method for fabricating a solar cell, comprising: providing a carrier plate and a separation auxiliary layer sequentially stacked along a first direction; forming a perovskite absorber layer on the surface of the carrier plate away from the separation auxiliary layer, the perovskite absorber layer comprising an adhesive matrix and a plurality of single-crystal perovskite particles arranged in the adhesive matrix; the adhesive matrix comprising a first surface and a second surface opposite to each other along the first direction, the first surface being away from the separation auxiliary layer; at least a portion of the single-crystal perovskite particles having a first convex surface and a second convex surface, the first convex surface protruding relative to the first surface, the second convex surface protruding relative to the second surface, and a functional layer formed on the surface of the single-crystal perovskite particles; forming a first carrier transport layer located on the surface of the perovskite absorber layer away from the separation auxiliary layer; forming a first conductive layer located on the surface of the first carrier transport layer away from the first surface; removing the carrier plate and the separation auxiliary layer, and forming a second conductive layer located on the surface of the perovskite absorber layer away from the first carrier transport layer.

[0007] Alternatively, the functional layer can be formed by immersing the single-crystal perovskite particles in a functional layer growth mother solution to form a first functional layer covering all surfaces of the single-crystal perovskite particles.

[0008] In addition, after forming the perovskite absorber layer, the process further includes removing the first functional layer on the first convex surface.

[0009] In addition, after removing the first functional layer on the first convex surface, the method further includes: forming a second functional layer, the second functional layer covering the first surface and the first convex surface; forming the first carrier transport layer includes: forming the first carrier transport layer on the surface of the second functional layer away from the first surface.

[0010] In addition, after removing the separation auxiliary layer and the carrier plate, the method further includes removing the first functional layer on the second convex surface.

[0011] In addition, after removing the first functional layer on the second convex surface, the method further includes: forming a third functional layer, the third functional layer covering the second surface and the second convex surface; forming the second conductive layer includes: forming the second conductive layer on the surface of the third functional layer away from the second surface.

[0012] In addition, the functional layer can be formed in the following manner: after forming the perovskite absorber layer, a fourth functional layer is formed on the surface of the perovskite absorber layer away from the separation auxiliary layer, the fourth functional layer covering the first surface and the first convex surface; forming the first carrier transport layer includes: forming the first carrier transport layer on the surface of the fourth functional layer away from the first surface.

[0013] In addition, the functional layer can be formed in the following manner: after removing the carrier plate and the separation auxiliary layer, a fifth functional layer is formed on the surface of the perovskite absorption layer away from the first carrier transport layer, the fifth functional layer covering the second surface and the second convex surface; the formation of the second conductive layer includes: forming the second conductive layer on the surface of the fifth functional layer away from the second surface.

[0014] In addition, the solar cell fabrication method further includes: after removing the carrier plate and the separation auxiliary layer, forming a second carrier transport layer, the second carrier transport layer being located on the surface of the perovskite absorber layer away from the first carrier transport layer; the formation of the second conductive layer includes: forming the second conductive layer on the surface of the second carrier transport layer away from the second surface.

[0015] Accordingly, this application also provides a solar cell, including: a first conductive layer, a first carrier transport layer, a perovskite absorber layer and a second conductive layer sequentially stacked along a first direction;

[0016] The perovskite absorber layer includes an adhesive matrix and a plurality of single-crystal perovskite particles arranged in the adhesive matrix. Along the first direction, the adhesive matrix includes a first surface and a second surface opposite to each other. The first surface faces the first conductive layer. At least a portion of the single-crystal perovskite particles have a first convex surface and a second convex surface. The first convex surface protrudes relative to the first surface, and the second convex surface protrudes relative to the second surface. A functional layer is formed on the surface of the single-crystal perovskite particles.

[0017] In addition, the functional layer includes a first functional layer covering all surfaces of the single-crystal perovskite particles.

[0018] In addition, the functional layer includes a second functional layer covering all remaining surfaces of the single-crystal perovskite particle except for the first convex surface.

[0019] In addition, the functional layer includes a third functional layer covering all remaining surfaces of the single-crystal perovskite particle except for the second convex surface.

[0020] In addition, the functional layer includes a fourth functional layer covering all remaining surfaces of the single-crystal perovskite particles except for the first convex surface and the second convex surface.

[0021] In addition, the functional layer includes a fifth functional layer covering the first convex surface and the first surface.

[0022] In addition, the functional layer includes a sixth functional layer covering the second convex surface and the second surface.

[0023] In addition, the thickness of the functional layer is from 0.1 nm to 1 μm.

[0024] Furthermore, for any of the single-crystal perovskite particles, the interval between the current single-crystal perovskite particle and the adjacent single-crystal perovskite particles is no greater than the maximum interval between any two points on the surface of the current single-crystal perovskite particle.

[0025] In addition, the maximum interval between any two points on the surface of the single-crystal perovskite particle is 5 μm to 100 μm.

[0026] In addition, the area of ​​the perovskite absorber layer projected onto the first conductive layer is the first area, and the area of ​​the plurality of single-crystal perovskite particles projected onto the first conductive layer is the second area, with the ratio of the second area to the first area being 0.3 to 0.9.

[0027] Furthermore, along the first direction, the distance between any point on the first convex surface and the first surface, and / or the distance between any point on the second convex surface and the second surface, is not greater than half the maximum length of the single-crystal perovskite particle along the first direction.

[0028] In addition, the thickness of the adhesive substrate along the first direction is not less than 100 nm.

[0029] Additionally, the adhesive substrate includes a light-trapping surface facing the first carrier transport layer and / or facing the second conductive layer.

[0030] In addition, the light-trapping surface includes a first light-trapping structure that extends outward from the adhesive substrate along the first direction.

[0031] In addition, the light-trapping surface includes a second light-trapping structure, which is recessed into the adhesive substrate along the first direction.

[0032] In addition, the first carrier transport layer is an electron transport layer or a hole transport layer.

[0033] In addition, the solar cell further includes a second carrier transport layer, which is located between the perovskite absorber layer and the second conductive layer, and is in contact with the perovskite absorber layer and the second conductive layer, respectively.

[0034] Furthermore, when the first carrier transport layer is a hole transport layer, the second carrier transport layer is an electron transport layer; when the first carrier transport layer is an electron transport layer, the second carrier transport layer is a hole transport layer.

[0035] Accordingly, this application also provides a tandem solar cell, comprising: a top cell, a transparent bonding layer and a bottom cell stacked sequentially, wherein the top cell is a solar cell as described above.

[0036] In addition, the bottom cell includes crystalline silicon solar cells, CIGS thin-film solar cells, cadmium telluride thin-film solar cells, III-V thin-film solar cells, or narrow bandgap perovskite thin-film solar cells.

[0037] In addition, the bonding layer includes a mechanical bonding layer made of conductive adhesive.

[0038] The technical solution provided in this application has at least the following advantages:

[0039] In the solar cell fabrication scheme provided in this application embodiment, a bonding substrate and multiple monocrystalline perovskite particles arranged in the bonding substrate are used to form the perovskite absorber layer of the solar cell. The use of monocrystalline perovskite particles to construct the perovskite absorber layer ensures the stability of the perovskite absorber layer. The method of arranging the monocrystalline perovskite particles in the bonding substrate avoids damage to the monocrystalline perovskite caused by the cutting process, thus ensuring the efficiency of the solar cell. At the same time, the method of arranging monocrystalline particles to construct the perovskite absorber layer facilitates the fabrication of large-area monocrystalline perovskite solar cells. Among the multiple single-crystal perovskite particles arranged in the bonding substrate, at least a portion of the single-crystal perovskite particles have a first convex surface protruding relative to a first surface of the bonding substrate and a second convex surface protruding relative to a second surface of the bonding substrate, respectively. By constructing a perovskite absorption layer using single-crystal perovskite particles exposed on both opposite sides of the bonding substrate, the perovskite absorption layer itself has a textured structure, thus exhibiting excellent light absorption capability. Simultaneously, it enhances the ability of photogenerated carriers to transport from the perovskite absorption layer to the conductive layer or carrier transport layer, thereby improving the photoelectric conversion efficiency and capability of the solar cell. A functional layer is formed on the surface of the single-crystal perovskite particles, which can further reduce the probability of decomposition of the single-crystal perovskite particles during operation, thereby further improving the stability of the solar cell. Attached Figure Description

[0040] One or more embodiments are illustrated by way of example with reference to the accompanying drawings. These illustrations do not constitute a limitation on the embodiments, and unless otherwise stated, the figures in the drawings are not to be limited by scale.

[0041] Figure 1 A flowchart illustrating a method for fabricating a solar cell according to an embodiment of this application;

[0042] Figure 2 This is a schematic diagram of the structure of a semi-finished battery provided in one embodiment of this application;

[0043] Figure 3 This is a schematic diagram of the structure of a solar cell provided in one embodiment of this application;

[0044] Figure 4 A cross-sectional view of a solar cell provided in an embodiment of this application;

[0045] Figure 5 A cross-sectional view of another solar cell provided in an embodiment of this application;

[0046] Figure 6 A cross-sectional view of yet another solar cell provided in an embodiment of this application;

[0047] Figure 7 A cross-sectional view of another solar cell provided in an embodiment of this application;

[0048] Figure 8 A cross-sectional view of another solar cell provided in an embodiment of this application;

[0049] Figure 9 A cross-sectional view of another solar cell provided in an embodiment of this application;

[0050] Figure 10 A cross-sectional view of another solar cell provided in an embodiment of this application;

[0051] Figure 11 This is a schematic diagram of another solar cell structure provided in an embodiment of this application;

[0052] Figure 12 This is a schematic diagram of the structure of a solar cell provided in another embodiment of this application;

[0053] Figure 13 A cross-sectional view of a solar cell provided in an embodiment of this application;

[0054] Figure 14 This is a top view of a perovskite absorber layer provided in an embodiment of this application;

[0055] Figure 15 A cross-sectional view of another solar cell provided in an embodiment of this application;

[0056] Figure 16 A cross-sectional view of yet another solar cell provided in an embodiment of this application;

[0057] Figure 17 A cross-sectional view of another solar cell provided in an embodiment of this application;

[0058] Figure 18 A cross-sectional view of another solar cell provided in an embodiment of this application;

[0059] Figure 19 A cross-sectional view of another solar cell provided in an embodiment of this application;

[0060] Figure 20 A cross-sectional view of another solar cell provided in an embodiment of this application;

[0061] Figure 21 Cross-sectional views of two types of solar cells provided in an embodiment of this application;

[0062] Figure 22 A cross-sectional view of another perovskite absorber layer provided in an embodiment of this application;

[0063] Figure 23A cross-sectional view of another solar cell provided in an embodiment of this application;

[0064] Figure 24 A cross-sectional view of another solar cell provided in an embodiment of this application;

[0065] Figure 25 A cross-sectional view of another solar cell provided in an embodiment of this application;

[0066] Figure 26 A cross-sectional view of another solar cell provided in an embodiment of this application;

[0067] Figure 27 A cross-sectional view of another solar cell provided in an embodiment of this application;

[0068] Figure 28 This is a schematic diagram of another solar cell structure provided in an embodiment of this application;

[0069] Figure 29 This is a schematic diagram of a stacked solar cell provided in another embodiment of this application. Detailed Implementation

[0070] As can be seen from the background technology, perovskite solar cells have good development prospects due to their advantages in lifespan and photoelectric conversion efficiency. However, the current photoelectric conversion efficiency of perovskite solar cells is limited and their stability is poor.

[0071] One embodiment of this application provides a method for fabricating a solar cell. In the process of solar cell production, a bonding substrate and multiple monocrystalline perovskite particles arranged in the bonding substrate are used to form the perovskite absorber layer of the solar cell. The use of monocrystalline perovskite particles to construct the perovskite absorber layer ensures the stability of the perovskite absorber layer. The method of arranging the monocrystalline perovskite particles in the bonding substrate avoids damage to the monocrystalline perovskite caused by the cutting process, thus ensuring the efficiency of the solar cell. At the same time, the method of arranging monocrystalline particles to construct the perovskite absorber layer facilitates the fabrication of large-area monocrystalline perovskite solar cells. Among the multiple single-crystal perovskite particles arranged in the bonding substrate, at least a portion of the single-crystal perovskite particles have a first convex surface protruding relative to a first surface of the bonding substrate and a second convex surface protruding relative to a second surface of the bonding substrate, respectively. By constructing a perovskite absorption layer using single-crystal perovskite particles exposed on both opposite sides of the bonding substrate, the perovskite absorption layer itself has a textured structure, thus exhibiting good light absorption capability. Simultaneously, it enhances the ability of photogenerated carriers to transport from the perovskite absorption layer to the conductive layer or carrier transport layer, thereby improving the photoelectric conversion efficiency and capability of the solar cell. The formation of a functional layer on the surface of the single-crystal perovskite particles further reduces the probability of decomposition of the single-crystal perovskite particles during operation, thereby further improving the stability of the solar cell.

[0072] The embodiments of this application will now be described in detail with reference to the accompanying drawings. However, those skilled in the art will understand that many technical details have been provided in the embodiments of this application to facilitate a better understanding of the application. However, the technical solutions claimed in this application can be implemented even without these technical details and various variations and modifications based on the following embodiments.

[0073] One embodiment of this application provides a method for fabricating a solar cell, which is applied to a cell manufacturing device. The solar cell fabrication process can be referred to... Figure 1 .

[0074] refer to Figure 1 and Figure 2 A carrier plate 201 and a separation auxiliary layer 202 are provided, which are sequentially stacked along a first direction. Figure 2 This is a schematic diagram of the structure of a solar cell after the first conductive layer 205 has been fabricated, with the X direction being the first direction.

[0075] In the process of solar cell fabrication, a carrier plate 201 and a separation auxiliary layer 202 are first provided and stacked along a first direction. The carrier plate 201 serves as a temporary substrate, facilitating accurate completion of subsequent fabrication work on the temporary substrate. The separation auxiliary layer 202 separates the finished or semi-finished solar cell from the carrier plate 201, facilitating the removal of the carrier plate 201. Therefore, the carrier plate 201 can be made of materials that are not easily deformed and are relatively stable, such as polyamide, glass, or stable metals. The separation auxiliary layer 202 not only needs to isolate the carrier plate 201 from the cell but also needs to be easy to remove. Therefore, the material of the separation auxiliary layer 202 can be selected from materials that are easy to etch and remove, such as titanium dioxide, metal, or photoresist. By providing a carrier plate 201 and a separation auxiliary layer 202 stacked sequentially along the first direction, the solar cell fabrication has a stable temporary support, and the removal of the temporary support is relatively easy, ensuring the efficiency and effectiveness of solar cell fabrication.

[0076] It is worth mentioning that the carrier plate 201 and the separation auxiliary layer 202 can be arranged in the following ways: first, the separation auxiliary layer 202 is fabricated, then the carrier plate 201 is fabricated on one side surface of the separation auxiliary layer 202, and the fabricated separation auxiliary layer 202 and carrier plate 201 are arranged in a stacked relationship along the first direction. Alternatively, the carrier plate 201 can be fabricated first, then the separation auxiliary layer 202 is fabricated on one side surface of the carrier plate 201, and the fabricated separation auxiliary layer 202 and carrier plate 201 are arranged in a stacked relationship along the first direction. This embodiment of the application does not limit this arrangement.

[0077] A perovskite absorber layer 203 is formed on the surface of the carrier plate 201 away from the separation auxiliary layer 202.

[0078] After providing a carrier plate 201 and a separation auxiliary layer 202 sequentially stacked along a first direction, the battery generation apparatus forms a perovskite absorber layer 203 on the surface of the separation auxiliary layer 202 away from the carrier plate 201. The perovskite absorber layer 203 includes an adhesive substrate 2031 and a plurality of single-crystal perovskite particles 2032 arranged in the adhesive substrate 2031. Along the first direction, the adhesive substrate 2031 includes a first surface and a second surface opposite to each other. The first surface is away from the separation auxiliary layer 202. At least a portion of the single-crystal perovskite particles 2032 have a first convex surface and a second convex surface. The first convex surface protrudes relative to the first surface, and the second convex surface protrudes relative to the second surface. A functional layer 30 is formed on the surface of the single-crystal perovskite particles 2032.

[0079] The perovskite absorber layer 203 of the solar cell is constructed by using an adhesive substrate 2031 and multiple monocrystalline perovskite particles 2032 arranged in the adhesive substrate 2031. This ensures the stability of the perovskite absorber layer 203. The method of arranging the monocrystalline perovskite particles 2032 in the adhesive substrate 2031 avoids damage to the monocrystalline perovskite caused by the cutting process, thus ensuring the efficiency of the solar cell. At the same time, the method of arranging monocrystalline particles to construct the perovskite absorber layer 203 facilitates the formation of a large-area absorber layer and a monocrystalline perovskite solar cell, thereby improving production efficiency.

[0080] Among the multiple single-crystal perovskite particles 2032 arranged in the adhesive substrate 2031, at least a portion of the single-crystal perovskite particles 2032 have a first convex surface protruding relative to the first surface of the adhesive substrate 2031 and a second convex surface protruding relative to the second surface of the adhesive substrate 2031, respectively. By utilizing the single-crystal perovskite particles 2032 exposed on both opposite sides of the adhesive substrate 2031, the perovskite absorption layer 203 is constructed, giving the perovskite absorption layer 203 a textured structure, thereby exhibiting good light absorption capability. At the same time, the single-crystal perovskite particles 2032 exposed in the adhesive substrate 2031 enhance the ability of photogenerated carriers to be transported from the perovskite absorption layer 203 to the conductive layer or the carrier transport layer, thereby improving the photoelectric conversion efficiency and capability of the solar cell.

[0081] A functional layer 30 is formed on the surface of the monocrystalline perovskite particles 2032, which further reduces the probability of the monocrystalline perovskite particles 2032 decomposing during operation, thereby further improving the stability of the solar cell.

[0082] It is worth mentioning that the perovskite absorber layer 203 can be formed by first forming an adhesive substrate 2031 on the surface of the separation auxiliary layer 202 away from the carrier plate 201, and then arranging single-crystal perovskite particles 2032 in the adhesive substrate 2031. Forming the adhesive substrate 2031 first facilitates the arrangement and fixation of the single-crystal perovskite particles 2032. Alternatively, multiple single-crystal perovskite particles 2032 can be arranged on the surface of the separation auxiliary layer 202 away from the carrier plate 201 first, and then the adhesive substrate 2031 can be formed. Arranging the single-crystal perovskite particles 2032 first facilitates the accurate formation of the first and second convex surfaces. In addition, a complete perovskite absorber layer 203 can be pre-formed and then directly transferred to the surface of the separation auxiliary layer 202 away from the carrier plate 201. The embodiments of this application do not limit the specific formation method of the perovskite absorber layer 203.

[0083] In addition, the functional layer 30 can be a passivation layer obtained by passivation treatment, or a modification layer formed by deposition or growth. The embodiments of this application do not limit the specific type and formation method of the functional layer 30.

[0084] The first carrier transport layer 204 is formed.

[0085] After forming the perovskite absorber layer 203, the cell generation equipment forms a first carrier transport layer 204 on the surface of the perovskite absorber layer 203. The first carrier transport layer 204 is located on the surface of the perovskite absorber layer 203 away from the separation auxiliary layer 202. By forming the first carrier transport layer 204 on the surface of the perovskite absorber layer 203 away from the separation auxiliary layer 202, the solar cell has good collection and transport capabilities for a certain type of photogenerated carriers, and can reduce recombination between different carriers, thereby improving the photoelectric conversion efficiency of the finished solar cell.

[0086] The first conductive layer 205 is formed.

[0087] After forming the first carrier transport layer 204, the battery generation device forms a first conductive layer 205 on the surface of the first carrier transport layer 204. The first conductive layer 205 is located on the surface of the first carrier transport layer 204 away from the first surface of the perovskite absorber layer 203. By forming the first conductive layer 205 on the surface of the first carrier transport layer 204 away from the first surface of the perovskite absorber layer 203, it is easier to output electrical energy.

[0088] refer to Figure 2 and Figure 3 Remove the carrier plate 201 and the separation auxiliary layer 202, and form the second conductive layer 206.

[0089] After forming the first conductive layer 205, the battery generation equipment can flip the semi-finished battery and then sequentially remove the carrier plate 201 and the separation auxiliary layer 202, or directly remove the separation auxiliary layer 202 and the carrier plate 201 simultaneously along the boundary between the separation auxiliary layer 202 and the perovskite absorber layer 203. After removing the carrier plate 201 and the separation auxiliary layer 202, a second conductive layer 206 is formed on the surface of the perovskite absorber layer 203, located on the surface of the perovskite absorber layer 203 away from the first carrier transport layer 204. By forming the second conductive layer 206 on the surface of the perovskite absorber layer 203 away from the first carrier transport layer 204, the first conductive layer 205 and the second conductive layer 206 work together to efficiently output the electrical energy generated by the solar cell.

[0090] refer to Figure 2 and Figure 4 In some embodiments, the functional layer 30 can be formed by immersing the single-crystal perovskite particles 2032 in the functional layer growth mother solution, and forming a first functional layer 31 covering all surfaces of the single-crystal perovskite particles 2032 on the surface of the single-crystal perovskite particles 2032.

[0091] Figure 4 This is a cross-sectional view of a solar cell. During the solar cell fabrication process, before forming the perovskite absorber layer 203, the single-crystal perovskite particles 2032 are immersed in a functional layer growth solution. After a preset time or until a first functional layer 31 covering all surfaces of the single-crystal perovskite particles 2032 is formed, the single-crystal perovskite particles 2032 are removed. Then, the perovskite absorber layer 203 is formed using the single-crystal perovskite particles 2032 whose entire surface is covered by the first functional layer 31. The first functional layer 31 serves as the functional layer 30 on the surface of each single-crystal perovskite particle 2032 within the perovskite absorber layer 203.

[0092] By immersing the monocrystalline perovskite particles 2032 in the functional layer growth mother solution, a first functional layer 31 covering all surfaces is formed on the surface of the monocrystalline perovskite particles 2032, ensuring that the monocrystalline perovskite particles 2032 have good stability at any point during operation, thereby ensuring the stability of the solar cell.

[0093] The functional layer growth mother solution can be prepared by adding phenethylamine X salt (PEAX, X = I, Br, or Cl) or isobutylamine X salt (BAX, X = I, Br, or Cl) to indolepropionic acid (C 11 H 11 The mother liquor is formed by dissolving in NO2 (IPA). The embodiments of this application do not limit the preparation method of the growth mother liquor.

[0094] It is worth mentioning that the mother liquor for functional layer growth can be not only a liquid mother liquor formed by dissolving a specific salt in indolepropionic acid, but also a gaseous mother liquor composed of vaporized acetonitrile (C2H3N), indolepropionic acid, or water. Placing the single-crystal perovskite particles 2032 in vaporized acetonitrile (C2H3N), indolepropionic acid, or water can also form a functional layer 30 on the surface of the single-crystal perovskite particles 2032. The embodiments of this application do not limit the specific type and configuration of the mother liquor for functional layer growth.

[0095] refer to Figure 2 and Figure 5 In some embodiments, after forming the perovskite absorber layer 203, the method further includes removing the first functional layer 31 on the first convex surface.

[0096] In the process of fabricating solar cells, after forming the perovskite absorber layer 203, the first functional layer 31 on the first convex surface T1 of the single-crystal perovskite particles 2032 is removed by physical etching or chemical etching. The first convex surface T1 protrudes from the first surface of the bonding substrate 2031 away from the separation auxiliary layer 202. The first functional layer 31 remaining after removing the first functional layer 31 on the first convex surface T1 is used as the functional layer 30 on the surface of each single-crystal perovskite particle 2032.

[0097] By removing the first functional layer 31 on the first convex surface T1 after forming the perovskite absorption layer 203, and using the remaining first functional layer 31 as the functional layer 30 on the surface of each single-crystal perovskite particle 2032, the stability of the single-crystal perovskite particle 2032 during operation is ensured as much as possible, while reducing the light reflectivity of the first convex surface T1, ensuring that the single-crystal perovskite particle 2032 has good light absorption capability, thereby ensuring the carrier generation capability of the single-crystal perovskite particle 2032 and the photoelectric conversion capability of the solar cell.

[0098] It is worth mentioning that, during the process of removing the first functional layer 31 on the first convex surface T1, the first functional layer 31 on the first convex surface T1 can be completely removed, or the first functional layer 31 on the first convex surface T1 can be partially removed. The degree of removal can be adjusted according to the requirements of the stability and / or light absorption capacity of the single crystal perovskite particles 2032. This application embodiment does not limit this.

[0099] refer to Figure 2 and Figure 6 In some embodiments, after removing the first functional layer 31 on the first convex surface T1, the method further includes: forming a second functional layer 32, the second functional layer 32 covering the first surface of the adhesive substrate 2031 and the first convex surface T1; forming the first carrier transport layer 204 includes: forming the first carrier transport layer 204 on the surface of the second functional layer 32 away from the first surface of the adhesive substrate 2031.

[0100] After removing the first functional layer 31 on the first convex surface T1, the battery generation device forms a second functional layer 32 on the first surface of the adhesive substrate 2031 away from the separation auxiliary layer 202. The second functional layer 32 covers the first convex surface T1 of the single crystal perovskite particle 2032 and the first surface of the adhesive substrate 2031. The second functional layer 32 located on the first convex surface T1 and the first functional layer 31 remaining after removing the first functional layer 31 on the first convex surface T1 are used as the functional layer 30 on the surface of the single crystal perovskite particle 2032.

[0101] By preparing a second functional layer 32 located on the first convex surface T1 and the first surface of the bonding substrate 2031, the coverage area of ​​the functional layer 30 on the surface of the single crystal perovskite particles 2032 is increased, thereby improving the stability of the perovskite absorption layer 203. At the same time, the second functional layer 32 covering the first surface of the bonding substrate 2031 increases the reflectivity of light inside the bonding substrate 2031, enhances the light absorption capacity of the perovskite absorption layer 203, and improves the photoelectric conversion capacity of the solar cell.

[0102] It is worth mentioning that the second functional layer 32 can be formed integrally on the surface of the perovskite absorber layer 203, covering the first convex surface T1 of each single-crystal perovskite particle 2032, or it can be selectively formed on the surface of the perovskite absorber layer 203 according to a preset pattern, without covering all areas of the first convex surface T1 of all single-crystal perovskite particles 2032 and all areas of the first surface of the bonding substrate 2031. The second functional layer 32 can completely cover the entire first convex surface T1, or it can only cover a part of the first convex surface T1; this embodiment of the application does not impose any limitations on this.

[0103] refer to Figure 2 and Figure 7 In some embodiments, after removing the separation auxiliary layer 202 and the carrier plate 201, the method further includes removing the first functional layer 31 on the second convex surface T2.

[0104] After removing the separation auxiliary layer 202 and the carrier plate 201, the battery generation equipment removes the first functional layer 31 on the second convex surface T2 of the single-crystal perovskite particles 2032 by means of physical etching or chemical etching. The second convex surface T2 protrudes from the second surface of the bonding substrate 2031 away from the first carrier transport layer 204. The first functional layer 31 remaining after removing the first functional layer 31 on the second convex surface T2 is used as the functional layer 30 on the surface of each single-crystal perovskite particle 2032.

[0105] By removing the first functional layer 31 on the second convex surface T2 after forming the perovskite absorption layer 203, and using the remaining first functional layer 31 as the functional layer 30 on the surface of each single-crystal perovskite particle 2032, the stability of the single-crystal perovskite particle 2032 during operation is ensured as much as possible, while reducing the light reflectivity of the second convex surface T2. This ensures that the single-crystal perovskite particle 2032 has good light absorption capability, thereby ensuring the carrier generation capability of the single-crystal perovskite particle 2032 and the photoelectric conversion capability of the solar cell.

[0106] It is worth mentioning that, in order to completely remove the first functional layer 31 on the second convex surface T2 during the removal process, or not completely remove the first functional layer 31 on the second convex surface T2, the degree of removal can be adjusted according to the requirements of the stability and / or light absorption capacity of the single crystal perovskite particles 2032. This application embodiment does not limit this.

[0107] refer to Figure 2 and Figure 8 In some embodiments, after removing the first functional layer 31 on the second convex surface T2, the method further includes: forming a third functional layer 33, the third functional layer 33 covering the second surface of the adhesive substrate 2031 and the second convex surface T2; forming the second conductive layer 206 includes: forming the second conductive layer 206 on the surface of the third functional layer 33 away from the second surface of the adhesive substrate 2031.

[0108] After removing the first functional layer 31 on the second convex surface T2, the battery generation device forms a third functional layer 33 on the second surface of the bonding substrate 2031. The third functional layer 33 covers the second convex surface T2 of the monocrystalline perovskite particle 2032 and the second surface of the bonding substrate 2031. The third functional layer 33 located on the second convex surface T2 and the first functional layer 31 remaining after removing the first functional layer 31 on the second convex surface T2 are used as the functional layer 30 on the surface of the monocrystalline perovskite particle 2032.

[0109] By preparing a third functional layer 33 on the second convex surface T2 and the second surface of the bonding substrate 2031, the coverage area of ​​the functional layer 30 on the surface of the single crystal perovskite particles 2032 is increased, thereby improving the stability of the perovskite absorption layer 203. At the same time, the third functional layer 33 covering the second surface of the bonding substrate 2031 increases the reflectivity of light inside the bonding substrate 2031, enhances the light absorption capacity of the perovskite absorption layer 203, and improves the photoelectric conversion capacity of the solar cell.

[0110] It is worth mentioning that the third functional layer 33 can be formed integrally on the surface of the perovskite absorber layer 203, covering the second convex surface T2 of each single-crystal perovskite particle 2032, or it can be selectively formed on the surface of the perovskite absorber layer 203 according to a certain pattern, without covering all areas of the second convex surface T2 of all single-crystal perovskite particles 2032 and the second surface of the bonding substrate 2031. The third functional layer 33 can completely cover the entire second convex surface T2, or it can only cover a part of the second convex surface T2; this embodiment does not limit this.

[0111] Furthermore, during the fabrication of solar cells, a third functional layer 33 or a second functional layer 32 can be formed only on the surface of the perovskite absorber layer 203, or both can be formed in combination. This application does not limit this.

[0112] refer to Figure 2 and Figure 9 In some embodiments, the functional layer 30 may be formed in the following manner: after forming the perovskite absorber layer 203, a fourth functional layer 34 is formed on the surface of the perovskite absorber layer 203 away from the separation auxiliary layer 202, the fourth functional layer 34 covering the first surface and the first convex surface T1; forming the first carrier transport layer 204 includes: forming the first carrier transport layer 204 on the surface of the fourth functional layer 34 away from the first surface.

[0113] In the process of fabricating solar cells, after forming the perovskite absorber layer 203, regardless of whether the surface of the single-crystal perovskite particles 2032 has undergone passivation or modification treatment, a fourth functional layer 34 is directly formed on the surface of the perovskite absorber layer 203 away from the separation auxiliary layer 202. The fourth functional layer 34 covers the first surface of the bonding substrate 2031 and the first convex surface T1 of the single-crystal perovskite particles 2032, and the fourth functional layer 34 on the first convex surface T1 of the single-crystal perovskite particles 2032 serves as the functional layer 30 on the surface of the single-crystal perovskite particles 2032. Then, a first carrier transport layer 204 is formed on the surface of the fourth functional layer 34 away from the first surface of the bonding substrate 2031.

[0114] By preparing a fourth functional layer 34 covering the first surface of the bonding substrate 2031 and the first convex surface T1 of the single-crystal perovskite particle 2032, a functional layer 30 is formed on the surface of the first convex surface T1 of the single-crystal perovskite particle 2032, thereby improving the stability of the single-crystal perovskite particle 2032 during operation. At the same time, the fourth functional layer 34 covering the first surface of the bonding substrate 2031 increases the reflectivity of light inside the bonding substrate 2031, enhances the light absorption capacity of the perovskite absorption layer 203, and improves the photoelectric conversion capacity of the solar cell.

[0115] It is worth mentioning that the fourth functional layer 34 can be formed integrally on the surface of the perovskite absorber layer 203, covering the first convex surface T1 of each single-crystal perovskite particle 2032, or it can be selectively formed on the surface of the perovskite absorber layer 203 according to a certain pattern, without covering all areas of the first convex surface T1 of all single-crystal perovskite particles 2032 and the first surface of the bonding substrate 2031. The fourth functional layer 34 can completely cover the entire first convex surface T1, or it can only cover a part of the first convex surface T1; this embodiment of the application does not limit this.

[0116] refer to Figure 2 and Figure 10 In some embodiments, the functional layer 30 may be formed in the following manner: after removing the carrier plate 201 and separating the auxiliary layer 202, a fifth functional layer 35 is formed on the surface of the perovskite absorption layer 203 away from the first carrier transport layer 204, the fifth functional layer 35 covering the second surface and the second convex surface T2; forming the second conductive layer 206 includes forming the second conductive layer 206 on the surface of the fifth functional layer 35 away from the second surface.

[0117] In the process of fabricating solar cells, after removing the carrier plate 201 and the separation auxiliary layer 202, regardless of whether the surface of the single-crystal perovskite particles 2032 has undergone passivation or modification treatment, a fifth functional layer 35 is directly formed on the surface of the perovskite absorber layer 203 away from the first carrier transport layer 204. The fifth functional layer 35 covers the second surface of the bonding substrate 2031 and the second convex surface T2 of the single-crystal perovskite particles 2032, and the fifth functional layer 35 on the second convex surface T2 of the single-crystal perovskite particles 2032 serves as the functional layer 30 on the surface of the single-crystal perovskite particles 2032. Then, a second conductive layer 206 is formed on the surface of the fifth functional layer 35 away from the first surface of the bonding substrate 2031.

[0118] By preparing a fifth functional layer 35 covering the second surface of the bonding substrate 2031 and the second convex surface T2 of the single-crystal perovskite particles 2032, a functional layer 30 is formed on the surface of the second convex surface T2 of the single-crystal perovskite particles 2032, thereby improving the stability of the single-crystal perovskite particles 2032 during operation. At the same time, the fifth functional layer 35 covering the second surface of the bonding substrate 2031 increases the reflectivity of light inside the bonding substrate 2031, enhances the light absorption capacity of the perovskite absorption layer 203, and improves the photoelectric conversion capability of the solar cell.

[0119] It is worth mentioning that the fifth functional layer 35 can be formed integrally on the surface of the perovskite absorber layer 203, covering the second convex surface T2 of each single-crystal perovskite particle 2032, or it can be selectively formed on the surface of the perovskite absorber layer 203 according to a certain pattern, without covering all areas of the second convex surface T2 of all single-crystal perovskite particles 2032 and all areas of the second surface of the bonding substrate 2031. The fifth functional layer 35 can completely cover the entire second convex surface T2, or it can only cover a part of the second convex surface T2; this embodiment does not limit this.

[0120] Furthermore, during the fabrication of solar cells, a fifth functional layer 35 or a fourth functional layer 34 can be formed only on the surface of the perovskite absorber layer 203, or both can be formed in combination. This application does not limit this.

[0121] refer to Figure 2 and Figure 11In some embodiments, the solar cell fabrication method further includes: after removing the carrier plate 201 and the separation auxiliary layer 202, forming a second carrier transport layer 207, the second carrier transport layer 207 being located on the surface of the perovskite absorber layer 203 away from the first carrier transport layer 204; forming a second conductive layer 206 includes: forming a second conductive layer 206 on the surface of the second carrier transport layer 207 away from the second surface.

[0122] In the process of fabricating a solar cell, the battery generation equipment forms a second carrier transport layer 207 on the surface of the perovskite absorber layer 203. The second carrier transport layer 207 is located on the surface of the perovskite absorber layer 203 away from the first carrier transport layer 204. Then, a second conductive layer 206 is formed on the surface of the second carrier transport layer 207 away from the second surface of the bonding substrate 2031. By forming the second carrier transport layer 207 on the surface of the perovskite absorber layer 203 away from the first carrier transport layer 204, the solar cell, with the cooperation of the two carrier transport layers, has good collection and transport capabilities for different types of photogenerated carriers, and can minimize recombination between different carriers, thereby improving the photoelectric conversion efficiency of the finished solar cell.

[0123] In summary, in the solar cell fabrication method provided in one embodiment of this application, a bonding substrate 2031 and multiple monocrystalline perovskite particles 2032 arranged in the bonding substrate 2031 constitute the perovskite absorber layer 203 of the solar cell. The use of monocrystalline perovskite particles 2032 to construct the perovskite absorber layer 203 ensures the stability of the perovskite absorber layer 203. The arrangement of the monocrystalline perovskite particles 2032 in the bonding substrate 2031 avoids damage to the monocrystalline perovskite caused by the cutting process, thus ensuring the efficiency of the solar cell. Furthermore, the use of monocrystalline particle arrangement to construct the perovskite absorber layer 203 facilitates the fabrication of large-area monocrystalline perovskite solar cells. Among the multiple single-crystal perovskite particles 2032 arranged in the adhesive substrate 2031, at least a portion of the single-crystal perovskite particles 2032 have a first convex surface protruding relative to the first surface of the adhesive substrate 2031 and a second convex surface protruding relative to the second surface of the adhesive substrate 2031, respectively. The perovskite absorption layer 203 is constructed using single-crystal perovskite particles 2032 exposed on both opposite sides of the adhesive substrate 2031, giving the perovskite absorption layer 203 a textured surface structure, thus providing excellent light absorption capability. Simultaneously, it enhances the ability of photogenerated carriers to transport from the perovskite absorption layer 2033 to the conductive layer or carrier transport layer, thereby improving the photoelectric conversion efficiency and capability of the solar cell. A functional layer 30 is formed on the surface of the single-crystal perovskite particles 2032, which further reduces the probability of decomposition of the single-crystal perovskite particles 2032 during operation, thereby further improving the stability of the solar cell.

[0124] Correspondingly, another aspect of the embodiments of this application also provides a solar cell, as shown in the reference. Figures 12 to 14 ,in, Figure 12 This is a schematic diagram of the overall structure of a solar cell. Figure 13 This is a schematic diagram of the cross-sectional structure of a solar cell. Figure 14 This is a top view of the perovskite absorber layer 103, where the X direction is the first direction.

[0125] The solar cell includes: a first conductive layer 101, a first carrier transport layer 102, a perovskite absorber layer 103, and a second conductive layer 104, which are sequentially stacked along a first direction; the perovskite absorber layer 103 includes an adhesive substrate 1031 and a plurality of single-crystal perovskite particles 1032 arranged in the adhesive substrate 1031; along the first direction, the adhesive substrate 1031 includes a first surface and a second surface facing each other, the first surface facing the first conductive layer 101; at least a portion of the single-crystal perovskite particles 1032 have a first convex surface and a second convex surface, the first convex surface protruding relative to the first surface, the second convex surface protruding relative to the second surface, and a functional layer 30 is formed on the surface of the single-crystal perovskite particles 1032.

[0126] The adhesive substrate 1031 is used to accommodate and fix the single-crystal perovskite particles 1032 arranged within it. Therefore, a transparent, curable adhesive or other gel can be selected for construction. For example, acrylic adhesive, resin adhesive, or other UV-curable transparent adhesives or other types of curable transparent adhesives can be used to construct the adhesive substrate 1031. "Transparent" refers to good light transmittance to visible light, such as transmittance of over 80% for light above 400 nm, or over 75% for light above 450 nm.

[0127] The solar cell absorbs light irradiated onto it through the perovskite absorber layer 103, and then generates photogenerated carriers through the single-crystal perovskite particles 1032. Different photogenerated carriers are collected through the first carrier transport layer 102 and the second conductive layer 104, respectively, and finally the electrical energy generated by the solar cell is transmitted to the external component through the first conductive layer 101 and the second conductive layer 104.

[0128] During the operation of a solar cell, the photoelectric conversion efficiency is mainly affected by the ability to generate and utilize photogenerated carriers. In the construction of the perovskite absorber layer 103, a bonding substrate 1031 and multiple single-crystal perovskite particles 1032 arranged within the bonding substrate 1031 are used to complete the construction of the perovskite absorber layer 103. This ensures the integrity of the single-crystal perovskite particles 1032, avoids damage to the single-crystal perovskite material during the construction of the perovskite absorber layer 103, and guarantees that the photogenerated carrier generation capability of the perovskite absorber layer 103 is as good as possible.

[0129] Furthermore, by using single-crystal perovskite particles 1032 to construct the perovskite absorber layer 103, the rate at which the perovskite absorber layer 103 decomposes during battery operation is reduced, ensuring the stability of the perovskite absorber layer 103 and the solar cell. Moreover, the single-crystal perovskite particles 1032 have a longer carrier lifetime, higher carrier mobility, and longer diffusion, thus the solar cell has higher photoelectric conversion efficiency and longer lifespan.

[0130] Meanwhile, the perovskite absorber layer 103 is constructed by arranging single-crystal perovskite particles 1032 in the bonding substrate 1031. This facilitates the simple and efficient preparation of a large-area perovskite absorber layer 103, overcoming the limitation of the single-crystal perovskite raw material generation efficiency on the perovskite absorber layer 103 and the area of ​​the perovskite solar cell. This greatly improves the preparation efficiency of large-area perovskite solar cells with good stability, thus enhancing the application prospects of single-crystal perovskite solar cells.

[0131] A functional layer 30 is formed on the surface of the single-crystal perovskite particles 1032. The function of the functional layer 30 is to fill the defects of the single-crystal perovskite particles 1032 and / or inhibit the decomposition of the single-crystal perovskite particles 1032. Therefore, the setting of the functional layer 30 further reduces the probability of the single-crystal perovskite particles 1032 decomposing during operation, thereby improving the stability of the perovskite absorber layer 103 and the solar cell.

[0132] refer to Figure 13Along the first direction, the adhesive substrate 1031 includes opposing first and second surfaces; at least a portion of the single-crystal perovskite particles 1032 have a first convex surface and a second convex surface, the first convex surface protruding relative to the first surface and the second convex surface protruding relative to the second surface. During the construction of the perovskite absorption layer 103, at least a portion of the single-crystal perovskite particles 1032 are ensured to have a first convex surface and a second convex surface protruding from the two opposing surfaces of the adhesive substrate 1031, meaning that at least a portion of the single-crystal perovskite particles 1032 will penetrate the adhesive substrate 1031 and contact the first carrier transport layer 102 and the second conductive layer 104. Because at least a portion of the single-crystal perovskite particles 1032 have a first convex surface and a second convex surface, the two opposing surfaces of the perovskite absorption layer 103 are textured, improving the light absorption capability of the perovskite absorption layer 103. Meanwhile, since at least some of the single-crystal perovskite particles 1032 penetrate the bonding substrate 1031 and contact the first carrier transport layer 102 and the second conductive layer 104, the difficulty for photogenerated carriers to move to the first carrier transport layer 102 and the second conductive layer 104 after photogenerated carriers are generated is greatly reduced, thus improving the photogenerated carrier transport capability of the perovskite absorption layer 103. Consequently, the photoelectric conversion efficiency of the perovskite absorption layer 103 is improved in both light absorption and carrier transport capabilities.

[0133] It is worth mentioning that the shape of the single-crystal perovskite particles 1032 can be a regular polyhedron, including spheres, near-spheres, and cubes, or an irregular polyhedron. The size and shape of each single-crystal perovskite particle 1032 contained in the perovskite absorber layer 103 can be the same or different. This application embodiment does not limit this. In order to facilitate understanding and explanation, this application embodiment uses perovskite particles as spheres for illustration. In actual use, the shape of the single-crystal perovskite particles 1032 can be adjusted as needed. This application embodiment does not limit this.

[0134] Furthermore, the single-crystal perovskite particles 1032 included in the perovskite absorber layer 103 may all have a first convex surface and a second convex surface, or some particles may have both a first convex surface and a second convex surface, while the remaining particles may include one or more particles having only a first convex surface, only a second convex surface, or neither a first convex surface nor a second convex surface. This application embodiment does not impose any limitations on this. A functional layer 30 may be formed on the surface of each single-crystal perovskite particle 1032, or a functional layer 30 may be formed on the surface of some of the single-crystal perovskite particles 1032. This application embodiment does not impose any limitations on this.

[0135] Furthermore, the single-crystal perovskite particles 1032 in the perovskite absorption layer 103 can be arranged in an ordered array in the bonding substrate 1031 at fixed intervals, for example, arranged in a regular array of rectangular, near-rectangular, circular, or elliptical shapes, further improving the uniformity of light absorption and carrier output in the perovskite absorption layer 103. Alternatively, they can be freely arranged in the bonding substrate 1031 at irregular intervals and in any order; this embodiment does not impose any limitations on this arrangement.

[0136] refer to Figure 13 and Figure 15 In some embodiments, the functional layer 30 includes a first functional layer 31 covering all surfaces of the single-crystal perovskite particles 1032.

[0137] In the process of fabricating a solar cell, before forming the perovskite absorber layer 103, a first functional layer 31 is formed on the surface of the single-crystal perovskite particles 1032, covering all surfaces of the single-crystal perovskite particles 1032. Then, the perovskite absorber layer 103 is formed using the single-crystal perovskite particles 1032 whose entire surface is covered by the first functional layer 31, and the first functional layer 31 serves as the functional layer 30 on the surface of each single-crystal perovskite particle 1032 in the perovskite absorber layer 103.

[0138] By forming a first functional layer 31 covering all surfaces on the surface of the monocrystalline perovskite particles 1032, the monocrystalline perovskite particles 1032 are guaranteed to have good stability at any point during operation, thereby ensuring the stability of the solar cell.

[0139] refer to Figure 13 and Figure 16 In some embodiments, the functional layer 30 includes a second functional layer 32 covering all remaining surfaces of the single-crystal perovskite particle 1032 except for the first convex surface T1.

[0140] Figure 16 This is a cross-sectional view of a solar cell through the center of a single-crystal perovskite particle 1032. During the fabrication of the solar cell, a functional film layer covering all surfaces of the single-crystal perovskite particle 1032 can be formed first. Then, the functional film layer on the first convex surface T1 of the single-crystal perovskite particle 1032 is removed, resulting in a second functional layer 32 covering all remaining surfaces of the single-crystal perovskite particle 1032 except for the first convex surface T1. This second functional layer 32 is used as the functional layer 30 on the surface of the single-crystal perovskite particle 1032.

[0141] By forming a second functional layer 32 covering the remaining surface of the single-crystal perovskite particle 1032 except for the first convex surface T1, as a functional layer 30 on the surface of the single-crystal perovskite particle 1032, the stability of the single-crystal perovskite particle 1032 during operation is ensured as much as possible, while reducing the light reflectivity of the first convex surface T1, ensuring that the single-crystal perovskite particle 1032 has good light absorption capability, thereby ensuring the carrier generation capability of the single-crystal perovskite particle 1032 and the photoelectric conversion capability of the solar cell.

[0142] It is worth mentioning that the embodiments of this application are described with the example that the second functional layer 32 does not cover the first convex surface T1 at all. In specific applications, during the formation of the second functional layer 32, the second functional layer 32 can be made to not cover the first convex surface T1 at all, or the second functional layer 32 can be made to cover only a part of the first convex surface T1. The specific setting method can be adjusted according to the requirements of the stability and / or light absorption capacity of the single crystal perovskite particles 1032. The embodiments of this application do not limit this.

[0143] refer to Figure 13 and Figure 17 In some embodiments, the functional layer 30 includes a third functional layer 33 covering all remaining surfaces of the single-crystal perovskite particle 1032 except for the second convex surface T2.

[0144] Figure 17 This is a cross-sectional view of a solar cell through the center of a single-crystal perovskite particle 1032. During the fabrication of the solar cell, a functional film layer covering all surfaces of the single-crystal perovskite particle 1032 can be formed first. Then, the functional film layer on the second convex surface T2 of the single-crystal perovskite particle 1032 is removed, resulting in a third functional layer 33 covering all remaining surfaces of the single-crystal perovskite particle 1032 except for the second convex surface T2. This third functional layer 33 is used as the functional layer 30 on the surface of the single-crystal perovskite particle 1032.

[0145] By forming a third functional layer 33 covering the remaining surface of the single-crystal perovskite particle 1032 except for the second convex surface T2, as a functional layer 30 on the surface of the single-crystal perovskite particle 1032, the stability of the single-crystal perovskite particle 1032 during operation is ensured as much as possible, while reducing the light reflectivity of the second convex surface T2, ensuring that the single-crystal perovskite particle 1032 has good light absorption capability, thereby ensuring the carrier generation capability of the single-crystal perovskite particle 1032 and the photoelectric conversion capability of the solar cell.

[0146] It is worth mentioning that the embodiments of this application are described with the example that the third functional layer 33 does not cover the second convex surface T2 at all. In specific applications, during the formation of the third functional layer 33, the third functional layer 33 can be made to not cover the second convex surface T2 at all, or the third functional layer 33 can only cover a part of the second convex surface T2. The specific setting can be adjusted according to the requirements of the stability and / or light absorption capacity of the single crystal perovskite particles 1032. The embodiments of this application do not limit this.

[0147] refer to Figure 13 and Figure 18 In some embodiments, the functional layer 30 includes a fourth functional layer 34 covering all remaining surfaces of the single-crystal perovskite particles 1032 except for the first convex surface T1 and the second convex surface T2.

[0148] Figure 18 This is a cross-sectional view of a solar cell passing through the center of a single-crystal perovskite particle 1032. During the fabrication of the solar cell, a functional film layer covering all surfaces of the single-crystal perovskite particle 1032 can be formed first. Then, the functional film layer on the second convex surface T2 of the single-crystal perovskite particle 1032 is removed, resulting in a fourth functional layer 34 covering all remaining surfaces of the single-crystal perovskite particle 1032 except for the second convex surface T2. This fourth functional layer 34 is used as the functional layer 30 on the surface of the single-crystal perovskite particle 1032.

[0149] By forming a fourth functional layer 34 covering all remaining surfaces of the single-crystal perovskite particle 1032 except for the first convex surface T1 and the second convex surface T2, as a functional layer 30 on the surface of the single-crystal perovskite particle 1032, the stability of the single-crystal perovskite particle 1032 during operation is guaranteed to a certain extent, while reducing the light reflectivity of the first convex surface T1 and the second convex surface T2, ensuring that the single-crystal perovskite particle 1032 has good light absorption capability, thereby ensuring the carrier generation capability of the single-crystal perovskite particle 1032 and the photoelectric conversion capability of the solar cell.

[0150] refer to Figure 13 and Figure 19 In some embodiments, the functional layer 30 includes a fifth functional layer 35 covering the first convex surface T1 and the first surface.

[0151] Figure 19This is a cross-sectional view of a solar cell through the center of a single-crystal perovskite particle 1032. During the fabrication of the solar cell, regardless of whether the surface of the single-crystal perovskite particle 1032 has been passivated or modified beforehand, a fifth functional layer 35 is directly formed on the surface of the perovskite absorber layer 103 facing the first conductive layer 101. The fifth functional layer 35 covers the first surface of the bonding substrate 1031 and the first convex surface T1 of the single-crystal perovskite particle 1032. The fifth functional layer 35 on the first convex surface T1 of the single-crystal perovskite particle 1032 is used as the functional layer 30 on the surface of the single-crystal perovskite particle 1032.

[0152] By using the fifth functional layer 35 covering the first surface of the bonding substrate 1031 and the first convex surface T1 of the monocrystalline perovskite particle 1032 as the functional layer 30, the surface of the first convex surface T1 of the monocrystalline perovskite particle 1032 has the functional layer 30, which improves the stability of the monocrystalline perovskite particle 1032 during operation. At the same time, the fifth functional layer 35 covering the first surface of the bonding substrate 1031 increases the reflectivity of light inside the bonding substrate 1031, enhances the light absorption capacity of the perovskite absorption layer 103, and improves the photoelectric conversion capacity of the solar cell.

[0153] It is worth mentioning that the fifth functional layer 35 can be formed integrally on the surface of the perovskite absorber layer 103, covering the first convex surface T1 of each single-crystal perovskite particle 1032, or it can be selectively formed on the surface of the perovskite absorber layer 103 according to a certain pattern, without covering all areas of the first convex surface T1 of all single-crystal perovskite particles 1032 and the first surface of the bonding substrate 1031. The fifth functional layer 35 can completely cover the entire first convex surface T1, or it can only cover a part of the first convex surface T1; this embodiment of the application does not impose any limitations on this.

[0154] refer to Figure 13 and Figure 20 In some embodiments, the functional layer 30 includes a sixth functional layer 36 covering the second convex surface T2 and the second surface.

[0155] Figure 20 This is a cross-sectional view of a solar cell through the center of a single-crystal perovskite particle 1032. During the fabrication of the solar cell, regardless of whether the surface of the single-crystal perovskite particle 1032 has been passivated or modified beforehand, a sixth functional layer 36 is directly formed on the second surface of the perovskite absorber layer 103 along the first direction opposite to the first surface facing the first conductive layer 101. The sixth functional layer 36 covers the second surface of the bonding substrate 1031 and the second convex surface T2 of the single-crystal perovskite particle 1032. The sixth functional layer 36 on the second convex surface T2 of the single-crystal perovskite particle 1032 is used as the functional layer 30 on the surface of the single-crystal perovskite particle 1032.

[0156] By using the sixth functional layer 36 covering the second surface of the bonding substrate 1031 and the second convex surface T2 of the monocrystalline perovskite particle 1032 as the functional layer 30, the surface of the second convex surface T2 of the monocrystalline perovskite particle 1032 has the functional layer 30, which improves the stability of the monocrystalline perovskite particle 1032 during operation. At the same time, the sixth functional layer 36 covering the second surface of the bonding substrate 1031 increases the reflectivity of light inside the bonding substrate 1031, enhances the light absorption capacity of the perovskite absorption layer 103, and improves the photoelectric conversion capacity of the solar cell.

[0157] It is worth mentioning that the sixth functional layer 36 can be formed integrally on the surface of the perovskite absorber layer 103, covering the second convex surface T2 of each single-crystal perovskite particle 1032, or it can be selectively formed on the surface of the perovskite absorber layer 103 according to a certain pattern, without covering all areas of the second convex surface T2 of all single-crystal perovskite particles 1032 and all areas of the second surface of the bonding substrate 1031. The sixth functional layer 36 can completely cover the entire second convex surface T2, or it can only cover a part of the second convex surface T2; this embodiment does not limit this.

[0158] It should be understood that the above-mentioned functional layer 30 can be implemented not only independently, but also in combination with other functional layers. (Refer to...) Figures 13 to 21 , Figure 21 The diagrams show cross-sectional views of a solar cell where the functional layer 30 is composed of a fourth functional layer 34 covering only the remaining surfaces of the monocrystalline perovskite particles except for the first convex surface T1 and the second convex surface T2, a fifth functional layer 35 covering the first convex surface T1 and the first surface of the adhesive substrate 1031, and a sixth functional layer 36 covering the second convex surface T2 and the second surface of the adhesive substrate 1031; and cross-sectional views of a solar cell where the functional layer 30 is composed of a second functional layer 32 covering all remaining surfaces of the monocrystalline perovskite particles except for the first convex surface T1 and a sixth functional layer 36 covering the second convex surface T2 and the second surface of the adhesive substrate 1031. The functional layer 30 can be configured in the following ways: having only one of the first functional layers 31 to the sixth functional layer 36; having the first functional layer 31 and the fifth functional layer 35 and / or the sixth functional layer 36; having the second functional layer 32 and the fifth functional layer 35 and / or the sixth functional layer 36; having the third functional layer 33 and the fifth functional layer 35 and / or the sixth functional layer 36; having the fourth functional layer 34 and the fifth functional layer 35 and / or the sixth functional layer 36; or having the fifth functional layer 35 and the sixth functional layer 36. Cross-sectional views of solar cells using the remaining configurations of the functional layer 30 are not shown individually.

[0159] Furthermore, during the construction of the first functional layers 31 to the sixth functional layers 36, the selected construction materials can be adjusted according to the specific type of the carrier transport layer with the largest contact area. The carrier transport layer includes an electron transport layer and a hole transport layer. When the carrier transport layer with the largest contact area is an electron transport layer, lithium fluoride (LiF) or magnesium fluoride (MgF2) can be selected as the construction material. When the carrier transport layer with the largest contact area is a hole transport layer, poly[(9,9-bis(3'-(N,N-dimethylamino)propyl)fluorenyl-2,7-diyl)-alt-[(9,9-di-n-octylfluorenyl-2,7-diyl)bromo(PFN-Br) or poly[bis(4-phenyl)(4-butylphenyl)amine](TPD) can be selected as the construction material. When the contact area of ​​the two different carrier transport layers is not significantly different, trithio-s-triazine trisodium salt (TTTS) can be selected as the construction material. By selectively choosing appropriate materials to construct the functional layer 30 based on the contact area with different charge carrier transport layers, the accuracy of the functional layer 30 construction and its performance are improved. This application does not limit the specific construction method.

[0160] In some embodiments, the thickness of the functional layer 30 is from 0.1 nm to 1 μm.

[0161] refer to Figures 15 to 21 The thickness of the functional layer 30 is related to its configuration. When the functional layer 30 includes a fifth functional layer 35 and / or a sixth functional layer 36, the thickness of the functional layer 30 can be represented by the average or maximum spacing between two relative points on the fifth functional layer 35 and / or the sixth functional layer 36 along a first direction. When the functional layer 30 includes any one of the first to fourth functional layers 34, the thickness of the functional layer 30 can be represented by the average or maximum spacing between any point on the surface of the included first functional layer 31, second functional layer 32, third functional layer 33, or fourth functional layer 34 away from the surface of the single-crystal perovskite particle 1032 and the surface of the functional layer 30 adjacent to the single-crystal perovskite particle.

[0162] While excessively thick functional layer 30 can effectively improve the stability of monocrystalline perovskite particles 1032, it also leads to a decrease in the light absorption capacity of the particles, thereby reducing the photoelectric conversion efficiency of the solar cell. Conversely, while excessively thick functional layer 30 ensures the light absorption capacity of the monocrystalline perovskite particles 1032, it also increases the probability of decomposition, compromising the stability of the solar cell and limiting its overall improvement in light absorption capacity.

[0163] Therefore, the thickness of the functional layer 30 is set within the range of 0.1 nm to 1 μm, for example, 0.1 nm, 0.5 nm, 1 nm, 5 nm, 10 nm, 25 nm, 50 nm, 100 nm, 200 nm, 500 nm, 750 nm, or 900 nm. By setting the thickness of the functional layer 30, the single-crystal perovskite particles 1032 and the solar cell are ensured to have good light absorption capabilities, thus ensuring the photoelectric conversion efficiency of the solar cell while maximizing the stability of the solar energy.

[0164] In some embodiments, for any single-crystal perovskite particle 1032, the interval between the current single-crystal perovskite particle and the adjacent single-crystal perovskite particle 1032 is not greater than the maximum interval between any two points on the surface of the current single-crystal perovskite particle 1032.

[0165] refer to Figure 14 In the diagram, the two largest circles are formed along the horizontal direction, passing through the centers of two adjacent single-crystal perovskite particles 1032. The maximum distance between any two points on the surface of the current single-crystal perovskite particle is d, and the distance between the current single-crystal perovskite particle and its adjacent single-crystal perovskite particle 1032 is D. Here, D can represent the minimum distance between any point on the surface of the current single-crystal perovskite particle and any point on the surface of its adjacent single-crystal perovskite particle 1032. When the distance between two adjacent single-crystal perovskite particles 1032 is too large, the perovskite absorption layer 103 has extremely poor light absorption capacity for the region irradiated between the two adjacent single-crystal perovskite particles 1032, which leads to a decrease in the light absorption capacity of the perovskite absorption layer 103 and affects the photoelectric conversion capacity of the perovskite absorption layer.

[0166] The light absorption capacity of single-crystal perovskite particles 1032 gradually decreases as the distance between them and the light source increases. Therefore, it is necessary to limit the spacing D between two adjacent single-crystal perovskite particles 1032 in the perovskite absorption layer 103. The spacing D between the current single-crystal perovskite particle and its adjacent single-crystal perovskite particle 1032 should be set within a range smaller than the current size of the perovskite particle, i.e., smaller than the maximum spacing d between any two points on the surface of the current single-crystal perovskite particle. For example, D can be set to 0.1d, 0.2d, 0.35d, 0.45d, 0.5d, 0.75d, or 0.9d. By setting the spacing between the current single-crystal perovskite particle and its adjacent single-crystal perovskite particle 1032 within a range not exceeding the current size of the single-crystal perovskite particle, the perovskite absorption layer 103 can maintain good light absorption capacity, avoiding the problem of decreased solar cell photoelectric conversion efficiency due to reduced light absorption capacity.

[0167] In some embodiments, the distance between any point on the first convex surface and the first surface, and / or the distance between any point on the second convex surface and the second surface, along the first direction, is not greater than half the maximum length of the single-crystal perovskite particle 1032 along the first direction.

[0168] refer to Figure 13 and Figure 22 , Figure 22 This is a cross-sectional view of a perovskite absorption layer 103 formed along the vertical direction through the centers of three identical single-crystal perovskite particles 1032. In the perovskite absorption layer 103, along the first direction, the maximum distance between any point on the first convex surface of the single-crystal perovskite particle 1032 and the first surface of the bonding substrate 1031 is the distance *a* between point A, the point furthest from the first surface on the first convex surface, and the first surface. Similarly, the maximum distance between any point on the second convex surface of the single-crystal perovskite particle 1032 and the second surface of the bonding substrate 1031 is the distance *b* between point B, the point furthest from the second surface on the second convex surface, and the first surface. The maximum length of the single-crystal perovskite particle 1032 is *L*.

[0169] During the construction of the perovskite absorber layer 103, the bonding substrate 1031 serves to fix the single-crystal perovskite particles 1032. To ensure the fixing effect, the bonding substrate 1031 has a certain thickness. During the generation of charge carriers by the single-crystal perovskite particles 1032, different charge carriers converge and move towards both ends of the single-crystal perovskite particles 1032. If the distance a between point A on the first convex surface of the single-crystal perovskite particle 1032 and the first surface is greater than or equal to half a L, and / or the distance b between point B on the second convex surface and the second surface is greater than or equal to half a L, the charge carriers converged on the first charge carrier transport layer 102 or the second conductive layer 104 may recombine with opposite charge carriers, leading to a decrease in the photoelectric conversion efficiency of the perovskite absorber layer 103.

[0170] Therefore, during the construction of the perovskite absorber layer 103, for the single-crystal perovskite particles 1032 containing a first convex surface and a second convex surface, along the first direction, the distance between any point on the first convex surface of the single-crystal perovskite particle 1032 and the first surface, and / or the distance between any point on the second convex surface and the second surface, is ensured to be no greater than half the maximum length of the single-crystal perovskite particle 1032 along the first direction. For example, the distance a and / or the distance b can be set to 0.1L, 0.15L, 0.2L, 0.25L, 0.35L, 0.45L, or 0.49L, etc. By limiting the distance between any point on the first convex surface of the single-crystal perovskite particle 1032 and the first surface, and / or the distance between any point on the second convex surface and the second surface, the probability of recombination between opposite charge carriers is minimized, thus ensuring the photoelectric conversion efficiency of the solar cell.

[0171] In some embodiments, the maximum spacing between any two points on the surface of the single-crystal perovskite particle 1032 is 5 μm to 100 μm.

[0172] During the construction of the perovskite absorber layer 103, if the size of the selected monocrystalline perovskite particles 1032 is too large (i.e., the maximum distance d between any two points on the particle surface is too large), after the perovskite absorber layer is constructed using the monocrystalline perovskite particles 1032, the distance that the charge carriers need to travel to migrate to the first charge carrier transport layer 102 or the second conductive layer 104 after absorbing light energy and generating charge carriers is too large, making it difficult to complete the carrier migration and thus reducing the photoelectric conversion efficiency of the solar cell. If the size of the monocrystalline perovskite particles 1032 is too small (i.e., the maximum distance d between any two points on the particle surface is too small), the spacing between different charge carriers is very small during the migration process, making it easy for charge carrier recombination to occur, leading to a decrease in the photoelectric conversion efficiency of the solar cell. Furthermore, when the size of the monocrystalline perovskite particles 1032 is too small, the thickness of the perovskite absorber layer 103 is also very small. Under the influence of the potential difference on both sides, the probability of the monocrystalline perovskite particles 1032 decomposing is greatly increased, leading to a decrease in the stability of the solar cell.

[0173] Therefore, in constructing the perovskite absorber layer 103, single-crystal perovskite particles 1032 with a maximum distance of 5-100 micrometers between any two points on the particle surface are selected for construction. For example, single-crystal perovskite particles 1032 with a maximum distance of 5 μm, 7.5 μm, 10 μm, 15 μm, 25 μm, 60 μm, 80 μm, 85 μm, or 95 μm between any two points on the particle surface are selected for constructing the perovskite absorber layer 103. This ensures that charge carriers can migrate relatively easily in the perovskite absorber layer 103, while reducing the probability of recombination between different charge carriers and the probability of decomposition of the single-crystal perovskite particles 1032, thus ensuring the photoelectric conversion efficiency and stability of the solar cell.

[0174] In some embodiments, the area of ​​the perovskite absorber layer 103 projected onto the first conductive layer 101 is a first area, and the area of ​​the plurality of single-crystal perovskite particles 1032 projected onto the first conductive layer 101 is a second area, with the ratio of the second area to the first area being 0.3 to 0.9.

[0175] During the construction of the perovskite absorber layer 103, the light absorption area of ​​the perovskite absorber layer 103 during photoelectric conversion can be considered as the sum of the orthogonal projection areas of all single-crystal perovskite particles 1032 on the first conductive layer 101, i.e., the second area. The area of ​​the perovskite absorber layer 103 that receives light can be considered as the orthogonal projection area of ​​the perovskite absorber layer 103 on the first conductive layer 101, i.e., the first area. When the ratio of the second area to the first area is too small, the absorption and utilization rate of light irradiated onto the perovskite absorber layer 103 is very low, resulting in a weak photoelectric conversion capability of the solar cell, making effective photoelectric conversion difficult. Due to the inherent limitations in photoelectric conversion capability of the single-crystal perovskite particles 1032, there is an upper limit to the absorption and utilization rate of light irradiated onto the perovskite absorption layer 103. When the ratio of the second area to the first area is too large, there are single-crystal perovskite particles 1032 in the perovskite absorption layer 103 whose photoelectric conversion capability is not fully utilized, resulting in a low cost-performance ratio between the manufacturing cost and photoelectric conversion capability of the solar cell.

[0176] Therefore, during the construction of the perovskite absorber layer 103, it is necessary to limit the ratio of the area of ​​the orthographic projection of each single-crystal perovskite particle 1032 on the first conductive layer 101 to the area of ​​the orthographic projection of the perovskite absorber layer 103 on the first conductive layer 101. The ratio of the second area to the first area is controlled within the range of 0.3 to 0.9, for example, 0.3, 0.35, 0.45, 0.5, 0.65, 0.7, 0.75, 0.8, or 0.85. By limiting the sum of the areas of the orthographic projection of each single-crystal perovskite particle 1032 on the first conductive layer 101 to the area of ​​the orthographic projection of the perovskite absorber layer 103 on the first conductive layer 101 within a certain range, the light absorption and utilization rate of the perovskite absorber layer 103 is ensured while minimizing the fabrication cost of the solar cell.

[0177] Furthermore, during the construction of the perovskite absorber layer 103, the light transmittance requirements of the top cell when using a perovskite solar cell as the top cell in a tandem solar cell construction can be referenced. Based on the type of the bottom cell and the optimal photoelectric conversion efficiency of the tandem solar cell, the ratio of the required illumination area of ​​the bottom cell to the area of ​​its light-receiving surface is determined when the tandem solar cell achieves optimal or good photoelectric conversion efficiency. Based on the determined area ratio, the ratio of the second area to the first area in the perovskite absorber layer 103 is set. For example, when the light-receiving surface areas of the bottom and top cells are the same, and the tandem solar cell requires 30%, 50%, or 70% of the light transmitted from the top cell to the bottom cell to achieve optimal photoelectric conversion efficiency, the ratio of the second area to the first area in the perovskite absorber layer 103 can be set to 0.7, 0.5, and 0.3 respectively.

[0178] Furthermore, to ensure the photoelectric conversion efficiency of the solar cell, monocrystalline perovskite particles 1032 with a band gap of 1 eV to 2 eV can be selected for constructing the perovskite solar cell. When using a perovskite cell as the top cell to construct a tandem solar cell, the photoelectric conversion efficiency of the tandem solar cell is also related to the band gap of the monocrystalline perovskite particles 1032 in the top cell. During the construction of the tandem solar cell, monocrystalline perovskite particles 1032 with a band gap of 1.4 eV to 1.8 eV can be selected for constructing the perovskite cell, depending on the type of bottom cell. In the selection of monocrystalline perovskite particles 1032, the goal is to achieve good photoelectric conversion efficiency in the tandem solar cell; the specific band gap of the selected monocrystalline perovskite particles 1032 is not limited in this embodiment.

[0179] Therefore, during the construction of tandem solar cells, the ratio of the second area to the first area in the perovskite absorber layer 103 and the band gap of the single-crystal perovskite particles 1032 can be controlled according to the requirements for achieving good photoelectric conversion efficiency of tandem solar cells, so as to maximize the photoelectric conversion efficiency of tandem solar cells.

[0180] It is worth noting that the plurality of single-crystal perovskite particles 1032 may include perovskite particles that do not have a first convex surface and / or a second convex surface. The photogenerated carriers generated in single-crystal perovskite particles 1032 that do not have a first convex surface and a second convex surface are difficult to migrate due to the limitations of the bonding substrate 1031. To further ensure the light utilization rate of the perovskite absorption layer 103, during the second area calculation, only the sum of the areas of the orthogonal projections of each single-crystal perovskite particle 1032 containing both the first and second convex surfaces on the first conductive layer 101 can be counted. Alternatively, the orthogonal projections of all single-crystal perovskite particles 1032 with both the first and / or second convex surfaces on the first conductive layer 101 can be counted; this embodiment of the application does not impose any limitations on this.

[0181] In some embodiments, the thickness of the adhesive substrate 1031 is not less than 100 nm.

[0182] refer to Figure 13 and Figure 22The thickness h of the adhesive substrate 1031 can be represented by the interval between two opposite points on the first and second surfaces of the adhesive substrate 1031 along the first direction. A key function of the adhesive substrate 1031 is to fix the single-crystal perovskite particles 1032 arranged within it. Therefore, if the thickness h of the adhesive substrate 1031 along the first direction is too small, it is difficult to achieve stable fixation of the single-crystal perovskite particles 1032, which may lead to problems such as microcracks and a decrease in the stability of the solar cell. Simultaneously, it may also result in excessively small spacing between different charge carriers, leading to recombination between them and a decrease in the photoelectric conversion efficiency of the solar cell.

[0183] Therefore, during the fabrication of the bonding substrate 1031, it is necessary to ensure that the thickness h of the bonding substrate 1031 along the first direction is not less than 100 nm, for example, 100 nm, 200 nm, 350 nm, 500 nm, 800 nm, 1 μm, 5 μm, 20 μm, or 50 μm. By setting the thickness of the bonding substrate 1031 along the first direction to be sufficiently large, it is ensured that the bonding substrate 1031 can stably fix the single-crystal perovskite particles 1032, preventing the perovskite absorber layer 103 from malfunctioning, improving the stability of the solar cell, and at the same time ensuring that the spacing between different charge carriers is large enough to prevent recombination of different charge carriers, thus ensuring the photoelectric conversion efficiency of the solar cell.

[0184] Furthermore, if the thickness h of the bonding substrate 1031 along the first direction is too large, in order to have the first convex surface and the second convex surface, the size of the single crystal perovskite particle 1032, that is, the maximum distance between any two points on the particle surface, will also increase. This will increase the difficulty of the migration of photogenerated carriers generated by the single crystal perovskite particle 1032, thereby causing a decrease in the photoelectric conversion efficiency of the solar cell.

[0185] Therefore, in setting the adhesive substrate 1031, it is necessary to consider not only the fixing effect and carrier isolation effect of the adhesive substrate 1031 on the single-crystal perovskite particles 1032, but also the influence of the adhesive substrate 1031 on the photoelectric conversion capability of the selected single-crystal perovskite particles 1032. The thickness h of the adhesive substrate 1031 along the first direction is set within a range smaller than the size of the single-crystal perovskite particles 1032 with good photoelectric conversion efficiency, so as to ensure that the perovskite absorption layer 103 has the best possible photoelectric conversion efficiency.

[0186] refer to Figure 13 , Figures 23 to 25 In some embodiments, the adhesive substrate 1031 includes a light-trapping surface 1033 facing the first carrier transport layer 102 and / or facing the second conductive layer 104.

[0187] Figures 23 to 25 All of these are cross-sectional views of solar cells along the vertical direction. Figure 23 The recessed smooth surface 1033 includes only the surface of the adhesive substrate 1031 facing the first carrier transport layer 102. Figure 24 The recessed smooth surface 1033 includes only the surface of the adhesive substrate 1031 facing the second conductive layer 104. Figure 25 The light-trapping surface 1033 includes the surface of the adhesive substrate 1031 facing the first carrier transport layer 102 and the surface facing the second conductive layer 104. Another important function of the adhesive substrate 1031 is to ensure the light absorption capability of the perovskite absorption layer 103. Therefore, during the fabrication of the adhesive substrate 1031, a light-trapping surface 1033 to enhance the light absorption capability of the perovskite absorption layer 103 can also be fabricated on the adhesive substrate 1031. During the fabrication process, the light-trapping surface 1033 may only include the surface of the adhesive substrate 1031 facing the first carrier transport layer 102, or only include the surface of the adhesive substrate 1031 facing the second conductive layer 104, or simultaneously include both the surface of the adhesive substrate 1031 facing the first carrier transport layer 102 and the surface facing the second conductive layer 104.

[0188] By forming a light-trapping surface 1033 on the adhesive substrate 1031 that faces the first carrier transport layer 102 and / or the second conductive layer 104, the optical path of the light irradiated onto the perovskite absorption layer 103 is increased in the perovskite absorption layer 103, thereby improving the light absorption capacity of the perovskite absorption layer 103 and thus improving the photoelectric conversion efficiency of the perovskite absorption layer 103 and the solar cell.

[0189] refer to Figure 13 and Figure 26 In some embodiments, the light-trapping surface 1033 includes a first light-trapping structure 311, which extends outward from the adhesive substrate 1031 along a first direction.

[0190] Figure 26The light-trapping surface 1033 includes both the surface of the adhesive substrate 1031 facing the first carrier transport layer and the surface facing the second conductive layer 104, and the light-trapping surface 1033 includes a first light-trapping structure 311 in a cross-sectional view of a solar cell. During the fabrication of the light-trapping surface 1033 on the adhesive substrate 1031, the first light-trapping structure 311 can be formed on the surface of the adhesive substrate 1031 facing the first carrier transport layer 102 and / or facing the second conductive layer 104, that is, one or more protrusions extending away from the adhesive substrate 1031 are formed on the first or second surface. The first light-trapping structure 311 is located on the first surface and / or the second surface, and the positional relationship between any side of the first light-trapping structure 311 and the first convex surface and / or the second convex surface of each single crystal perovskite particle 1032 in the perovskite absorption layer 103 is tangential or disjoint, and the first light-trapping structure 311 does not affect the contact area between the first convex surface and the first carrier transport layer 102 or the contact area between the second convex surface and the second conductive layer 104.

[0191] By forming one or more protrusions extending away from the adhesive substrate 1031 on the first surface and / or the second surface as a first light-trapping structure 311, the first surface and / or the second surface are transformed into a light-trapping surface 1033 with the ability to extend the optical path of incident light in the perovskite absorption layer 103, thereby improving the absorption and utilization capability of the perovskite absorption layer 103 for incident light, and thus improving the photoelectric conversion capability and efficiency of the perovskite absorption layer 103.

[0192] It is worth mentioning that the shape and size of each first light-trapping structure 311 can be the same or different, and this application embodiment does not limit this.

[0193] refer to Figure 13 and reference Figure 27 In some embodiments, the light-trapping surface 1033 includes a second light-trapping structure 312, which is recessed into the adhesive substrate 1031 along the first direction.

[0194] Figure 27The light-trapping surface 1033 includes both the surface of the adhesive substrate 1031 facing the first carrier transport layer and the surface facing the second conductive layer 104, and the light-trapping surface 1033 includes a second light-trapping structure 312 in a cross-sectional view of a solar cell. During the fabrication of the light-trapping surface 1033 on the adhesive substrate 1031, the second light-trapping structure 312 can be formed on the surface of the adhesive substrate 1031 facing the first carrier transport layer 102 and / or facing the second conductive layer 104, that is, one or more recesses extending into the interior of the adhesive substrate 1031 are formed on the first or second surface. The second light-trapping structure 312 is located on the first surface and / or the second surface, and the positional relationship between any side of the second light-trapping structure 312 and the surface of each single crystal perovskite particle 1032 in the perovskite absorption layer 103 located inside the adhesive substrate 1031 is tangential or disjoint, and the second light-trapping structure 312 does not affect the contact area between the single crystal perovskite particle 1032 and the adhesive substrate 1031.

[0195] By forming one or more recesses extending into the adhesive substrate 1031 on the first or second surface as a second light-trapping structure 312, the first and / or second surfaces are transformed into light-trapping surfaces 1033 with the ability to extend the optical path of incident light in the perovskite absorption layer 103, thereby enhancing the absorption and utilization capability of the perovskite absorption layer 103 for incident light, and thus improving the photoelectric conversion capability and efficiency of the perovskite absorption layer 103.

[0196] It is worth mentioning that the light-trapping surface 1033 may include only one or more first light-trapping structures 311, or only one or more second light-trapping structures 312, or both. The light-trapping surface 1033 may include only the surface of the adhesive substrate 1031 facing the first carrier transport layer 102, or only the surface of the adhesive substrate 1031 facing the second conductive layer 104, or both. The embodiments of this application do not limit the specific configuration of the light-trapping surface 1033, nor the type and number of light-trapping structures included on the light-trapping surface 1033.

[0197] It is worth mentioning that the shape and size of each second light-trapping structure 312 can be the same or different, and this application embodiment does not limit this.

[0198] In some embodiments, the first carrier transport layer 102 is an electron transport layer or a hole transport layer.

[0199] The function of the first carrier transport layer 102 is to collect and transport the carriers generated in the perovskite absorber layer 103. Based on the working mechanism of the solar cell, the first carrier transport layer 102 can be either a hole transport layer or an electron transport layer. When the first carrier transport layer 102 is an electron transport layer, its function includes collecting electrons and transporting them to the first conductive layer 101 for power output, while also blocking holes from flowing directly to the first conductive layer 101. When the first carrier transport layer 102 is a hole transport layer, its function includes blocking electrons from entering the first conductive layer 101 and enhancing hole transport, preventing direct contact between the perovskite absorber layer 103 and the first conductive layer 101. This ensures the photoelectric conversion capability and power output of the solar cell.

[0200] It is worth mentioning that the electron transport layer can be composed of materials such as tin oxide (SnOx), titanium dioxide (TiO2), C60, and fullerenes and their derivatives including PCBM, while the hole transport layer can be composed of materials such as poly[bis(4-phenyl)(2,4,6-trimethylphenyl)amine] (PTAA), 2,2',7,7'-tetratetra[N,N-di(4-methoxyphenyl)amino]-9,9'-spirodifluorene (spiro-OMeTAD), nickel oxide (NiOx), or cuprous thiocyanate (CuSCN).

[0201] In some embodiments, the thickness of the first carrier transport layer 102 along the first direction includes 1 nm to 1 μm.

[0202] The core function of the first carrier transport layer 102 is to enhance the collection and transport capacity of one type of carrier while isolating another type of carrier from contact with the first conductive layer 101. Therefore, if the thickness of the first carrier transport layer 102 along the first direction is too large, the migration distance of carriers to the first conductive layer 101 will be too long, potentially leading to carrier recombination and significant carrier loss, thus reducing the photoelectric conversion efficiency of the solar cell. Conversely, if the thickness of the first carrier transport layer 102 along the first direction is too small, its capacity for collecting and transporting carriers will be limited, potentially failing to collect and transport all carriers of a certain type generated by the perovskite absorber layer 103 in a timely manner, resulting in significant carrier loss and affecting the photoelectric conversion efficiency of the solar cell. Furthermore, a thinner layer will also reduce its isolation capacity for another type of carrier, potentially leading to recombination of different types of carriers, further impacting the photoelectric conversion efficiency of the solar cell.

[0203] Therefore, during the construction of the first carrier transport layer 102, the thickness of the first carrier transport layer 102 along the first direction is set between 1 nm and 1 μm, for example, set to 1 nm, 5 nm, 10 nm, 50 nm, 100 nm, 200 nm, 250 nm, 400 nm, 500 nm, 650 nm, 750 nm, 800 nm, or 950 nm, etc. This ensures that the first carrier transport layer 102 has a sufficiently large collection and transport capacity for one type of carrier and a sufficiently large isolation capacity for another type of carrier, reducing carrier loss caused by carrier recombination and migration, and ensuring the photoelectric conversion efficiency of the solar cell.

[0204] refer to Figure 28 In some embodiments, the solar cell further includes a second carrier transport layer 105, which is located between the perovskite absorber layer 103 and the second conductive layer 104, and is in contact with the perovskite absorber layer 103 and the second conductive layer 104, respectively.

[0205] The second carrier transport layer 105 is similar to the first carrier transport layer 102, and its function is to collect and transport carriers generated in the perovskite absorber layer 103. Based on the working mechanism of the solar cell, the second carrier transport layer 105 can be either a hole transport layer or an electron transport layer. When the second carrier transport layer 105 is an electron transport layer, its function includes collecting electrons and transporting them to the first conductive layer 101 for power output, while also blocking holes from flowing directly to the first conductive layer 101. When the second carrier transport layer 105 is a hole transport layer, its function includes blocking electrons from entering the first conductive layer 101 and enhancing hole transport, preventing direct contact between the perovskite absorber layer 103 and the first conductive layer 101. This ensures the photoelectric conversion capability and power output of the solar cell.

[0206] In some embodiments, the thickness of the second carrier transport layer 105 along the first direction includes 1 nm to 1 μm.

[0207] The core function of the second carrier transport layer 105 is to enhance the collection and transport capacity of one type of carrier while isolating another type of carrier from contact with the first conductive layer 101. Therefore, if the thickness of the second carrier transport layer 105 along the first direction is too large, the migration distance of carriers to the second conductive layer 104 will be too long, potentially leading to carrier recombination and significant carrier loss, thus reducing the photoelectric conversion efficiency of the solar cell. Conversely, if the thickness of the second carrier transport layer 105 along the first direction is too small, its capacity for collecting and transporting carriers will be limited, potentially failing to collect and transport all carriers of a certain type generated by the perovskite absorber layer 103 in a timely manner, resulting in significant carrier loss and affecting the photoelectric conversion efficiency of the solar cell. Furthermore, a thinner layer will also reduce its isolation capacity for another type of carrier, potentially leading to recombination of different types of carriers, further impacting the photoelectric conversion efficiency of the solar cell.

[0208] Therefore, during the construction of the second carrier transport layer 105, the thickness of the second carrier transport layer 105 along the first direction is set between 1 nm and 1 μm, for example, set to 1 nm, 5 nm, 10 nm, 50 nm, 100 nm, 200 nm, 250 nm, 400 nm, 500 nm, 650 nm, 750 nm, 800 nm, or 950 nm, etc. This ensures that the second carrier transport layer 105 has a sufficiently large collection and transport capacity for one type of carrier and a sufficiently large isolation capacity for another type of carrier, reducing carrier loss caused by carrier recombination and migration, and ensuring the photoelectric conversion efficiency of the solar cell.

[0209] In some embodiments, when the first carrier transport layer 102 is a hole transport layer, the second carrier transport layer 105 is an electron transport layer; when the first carrier transport layer 102 is an electron transport layer, the second carrier transport layer 105 is a hole transport layer.

[0210] To further improve the efficiency of solar cells, carrier transport layers for collecting and transporting different charge carriers can be respectively provided on opposite sides of the perovskite absorber layer 103 along the first direction, thereby maximizing the photoelectric conversion efficiency and stability of the solar cells.

[0211] In summary, in the solar cell provided by one embodiment of this application, a perovskite absorber layer 103 of the solar cell is constituted by an adhesive substrate 1031 and multiple monocrystalline perovskite particles 1032 arranged in the adhesive substrate 1031. The use of monocrystalline perovskite particles 1032 to construct the perovskite absorber layer 103 ensures the stability of the perovskite absorber layer 103. The arrangement of monocrystalline perovskite particles 1032 in the adhesive substrate 1031 avoids damage to the monocrystalline perovskite caused by the cutting process, thus ensuring the efficiency of the solar cell. At the same time, the use of monocrystalline particle arrangement to construct the perovskite absorber layer 103 facilitates the fabrication of large-area monocrystalline perovskite solar cells. Among the multiple single-crystal perovskite particles 1032 arranged in the adhesive substrate 1031, at least a portion of the single-crystal perovskite particles 1032 have a first convex surface protruding relative to a first surface of the adhesive substrate 1031 and a second convex surface protruding relative to a second surface of the adhesive substrate 1032. The perovskite absorber layer 103 is constructed using single-crystal perovskite particles 1032 exposed on both opposite sides of the adhesive substrate 1031, giving the perovskite absorber layer 103 a textured surface structure, thus providing excellent light absorption capability. Simultaneously, it enhances the ability of photogenerated carriers to transport from the perovskite absorber layer 103 to the conductive layer or carrier transport layer, thereby improving the photoelectric conversion efficiency and capability of the solar cell. A functional layer 30 is formed on the surface of the single-crystal perovskite particles 1032, improving the stability of the perovskite absorber layer 103 and the solar cell.

[0212] It is not difficult to see that this embodiment is a solar cell structure embodiment corresponding to the solar cell fabrication method embodiment. The details in this embodiment are also applicable to the solar cell fabrication method embodiment, and similarly, the details in the solar cell fabrication method embodiment are also applicable to this embodiment.

[0213] Accordingly, another embodiment of this application also provides a tandem solar cell, the structural schematic diagram of which can be referred to. Figure 29 It includes: a top cell 1001, an adhesive layer 1002 and a bottom cell 1003 stacked in sequence, wherein the top cell 1001 is the aforementioned solar cell.

[0214] In some embodiments, the type of the bottom cell 1003 includes crystalline silicon solar cells, CIGS thin-film solar cells, cadmium telluride thin-film solar cells, III-V thin-film solar cells, or narrow bandgap perovskite thin-film solar cells, wherein the narrow bandgap perovskite thin-film solar cells can be narrow bandgap monocrystalline perovskite thin-film solar cells or narrow bandgap polycrystalline perovskite thin-film solar cells.

[0215] In some embodiments, the bonding layer 1002 includes a mechanical bonding layer engineered with conductive adhesive. The conductive adhesive can be formed by adding conductive particles to a transparent adhesive with good light transmittance, for example, by adding conductive particles to an adhesive with transmittance of 80% or more for light above 400 nm or light above 450 nm. The conductive adhesive can also be a transparent thin adhesive whose constituent particles have a certain degree of conductivity; the degree of transparency can be similar to that of the aforementioned adhesives, and will not be further elaborated upon. This application does not limit the specific type of conductive adhesive.

[0216] Although this application discloses preferred embodiments as described above, it is not intended to limit the claims. Any person skilled in the art can make several possible changes and modifications without departing from the concept of this application. Therefore, the scope of protection of this application should be determined by the scope defined in the claims of this application.

[0217] Those skilled in the art will understand that the above embodiments are specific examples of implementing this application, and in practical applications, various changes in form and detail can be made without departing from the spirit and scope of this application. Any person skilled in the art can make various alterations and modifications without departing from the spirit and scope of this application; therefore, the scope of protection of this application should be determined by the scope defined in the claims.

Claims

1. A method for producing a solar cell, characterized by, include: A carrier plate and a separation auxiliary layer are provided, which are stacked sequentially along a first direction; A perovskite absorber layer is formed on the surface of the carrier plate away from the separation auxiliary layer. The perovskite absorber layer includes an adhesive matrix and a plurality of single-crystal perovskite particles arranged in the adhesive matrix. Along the first direction, the adhesive matrix includes opposing first and second surfaces. The first surface is away from the separation auxiliary layer. At least a portion of the single-crystal perovskite particles have a first convex surface and a second convex surface. The first convex surface protrudes relative to the first surface, and the second convex surface protrudes relative to the second surface. A functional layer is formed on the surface of the single-crystal perovskite particles. The functional layer is a passivation layer or a modification layer. The adhesive matrix is ​​constructed from a transparent curable adhesive or glue. A first carrier transport layer is formed, which is located on the surface of the perovskite absorber layer away from the separation aid layer. A first conductive layer is formed on the surface of the first carrier transport layer that is away from the first surface; The carrier plate and the separation auxiliary layer are removed, and a second conductive layer is formed. The second conductive layer is located on the surface of the perovskite absorption layer away from the first carrier transport layer.

2. The solar cell manufacturing method according to claim 1, wherein The functional layer is formed in the following manner: The single-crystal perovskite particles are immersed in a functional layer growth mother solution to form a first functional layer covering all surfaces of the single-crystal perovskite particles.

3. The method for preparing a solar cell according to claim 2, characterized in that, After forming the perovskite absorber layer, the method further includes: Remove the first functional layer from the first convex surface.

4. The solar cell manufacturing method according to claim 3, wherein After removing the first functional layer on the first convex surface, the method further includes: A second functional layer is formed, which covers the first surface and the first convex surface; The formation of the first carrier transport layer includes: forming the first carrier transport layer on the surface of the second functional layer away from the first surface.

5. The method for preparing a solar cell according to claim 2, characterized in that, After removing the separation auxiliary layer and the carrier plate, the method further includes: Remove the first functional layer from the second convex surface.

6. The solar cell manufacturing method according to claim 5, wherein After removing the first functional layer on the second convex surface, the method further includes: A third functional layer is formed, which covers the second surface and the second convex surface; The formation of the second conductive layer includes: forming the second conductive layer on the surface of the third functional layer away from the second surface.

7. The method of claim 1, wherein the method further comprises: The functional layer is formed in the following manner: After the perovskite absorber layer is formed, a fourth functional layer is formed on the surface of the perovskite absorber layer away from the separation aid layer, and the fourth functional layer covers the first surface and the first convex surface. The formation of the first carrier transport layer includes: forming the first carrier transport layer on the surface of the fourth functional layer away from the first surface.

8. The solar cell manufacturing method according to claim 1, wherein The functional layer is formed in the following manner: After removing the carrier plate and the separation auxiliary layer, a fifth functional layer is formed on the surface of the perovskite absorption layer away from the first carrier transport layer, and the fifth functional layer covers the second surface and the second convex surface. The formation of the second conductive layer includes: forming the second conductive layer on the surface of the fifth functional layer away from the second surface.

9. The solar cell production method according to any one of claims 1 to 8, wherein Also includes: After removing the carrier plate and the separation auxiliary layer, a second carrier transport layer is formed, which is located on the surface of the perovskite absorber layer away from the first carrier transport layer. The formation of the second conductive layer includes: forming the second conductive layer on the surface of the second carrier transport layer away from the second surface.

10. A solar cell, characterized by, include: A first conductive layer, a first carrier transport layer, a perovskite absorption layer, and a second conductive layer are sequentially stacked along a first direction. The perovskite absorber layer includes an adhesive matrix and a plurality of single-crystal perovskite particles arranged in the adhesive matrix. Along the first direction, the adhesive matrix includes a first surface and a second surface opposite to each other, the first surface facing the first conductive layer. At least a portion of the single-crystal perovskite particles have a first convex surface and a second convex surface, the first convex surface protruding relative to the first surface and the second convex surface protruding relative to the second surface. A functional layer is formed on the surface of the single-crystal perovskite particles. The functional layer is a passivation layer or a modification layer. The adhesive matrix is ​​constructed from a transparent curable adhesive or glue.

11. The solar cell of claim 10, wherein, The functional layer includes a first functional layer covering all surfaces of the single-crystal perovskite particles.

12. The solar cell of claim 10, wherein, The functional layer includes a second functional layer covering all remaining surfaces of the single-crystal perovskite particle except for the first convex surface.

13. The solar cell of claim 10, wherein, The functional layer includes a third functional layer covering all remaining surfaces of the single-crystal perovskite particle except for the second convex surface.

14. The solar cell of claim 10, wherein, The functional layer includes a fourth functional layer that covers all remaining surfaces of the single-crystal perovskite particle except for the first convex surface and the second convex surface.

15. The solar cell of claim 10, wherein, The functional layer includes a fifth functional layer that covers the first convex surface and the first surface.

16. The solar cell of claim 10, wherein, The functional layer includes a sixth functional layer that covers the second convex surface and the second surface.

17. The solar cell of claim 10, wherein, The thickness of the functional layer is from 0.1 nm to 1 μm.

18. The solar cell of claim 10, wherein, For any of the single-crystal perovskite particles, the interval between the single-crystal perovskite particles and the adjacent single-crystal perovskite particles is no greater than the maximum interval between any two points on the surface of the single-crystal perovskite particle.

19. The solar cell of claim 10, wherein, The maximum spacing between any two points on the surface of the single-crystal perovskite particle ranges from 5 μm to 100 μm.

20. The solar cell of claim 10, wherein, The area of ​​the perovskite absorber layer projected onto the first conductive layer is the first area, and the area of ​​all the multiple single-crystal perovskite particles projected onto the first conductive layer is the second area. The ratio of the second area to the first area is 0.3 to 0.

9.

21. The solar cell of claim 10, wherein, Along the first direction, the distance between any point on the first convex surface and the first surface, and / or the distance between any point on the second convex surface and the second surface, is no greater than half the maximum length of the single-crystal perovskite particle along the first direction.

22. The solar cell of claim 10, wherein, Along the first direction, the thickness of the adhesive substrate is not less than 100 nm.

23. The solar cell of claim 10, wherein, The adhesive substrate includes a light-trapping surface facing the first carrier transport layer and / or facing the second conductive layer.

24. The solar cell of claim 23, wherein, The light-trapping surface includes a first light-trapping structure that extends outward from the adhesive substrate along the first direction.

25. The solar cell of claim 23, wherein, The light-trapping surface includes a second light-trapping structure, which is recessed into the adhesive substrate along the first direction.

26. The solar cell of claim 10, wherein, The first carrier transport layer is either an electron transport layer or a hole transport layer.

27. The solar cell of claim 10, wherein, Also includes: The second carrier transport layer is located between the perovskite absorber layer and the second conductive layer, and is in contact with both the perovskite absorber layer and the second conductive layer.

28. The solar cell of claim 27, wherein, When the first carrier transport layer is a hole transport layer, the second carrier transport layer is an electron transport layer; When the first carrier transport layer is an electron transport layer, the second carrier transport layer is a hole transport layer.

29. A tandem solar cell, characterized by include: A top cell, an adhesive layer, and a bottom cell are stacked in sequence, wherein the top cell is a solar cell as described in any one of claims 11 to 28.

30. The laminated solar cell of claim 29, wherein, The base cell includes crystalline silicon solar cells, CIGS thin-film solar cells, cadmium telluride thin-film solar cells, III-V thin-film solar cells, or narrow bandgap perovskite thin-film solar cells.

31. The laminated solar cell of claim 29, wherein, The bonding layer includes a mechanical bonding layer made of conductive adhesive.

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