Perovskite laminated solar cell and preparation method thereof

Abstract

The invention relates to a perovskite laminated solar cell and a preparation method thereof. The perovskite laminated solar cell comprises a top cell (10), a composite layer (20), a bottom cell (30) and a packaging layer (40), the composite layer (20) is arranged between the top cell (10) and the bottom cell (30), and the packaging layer (40) covers the area, except a front electrode (105), of the front face of the top cell (10) and covers the side face of the top cell (10). Therefore, the perovskite top cell is prevented from being eroded by moisture and oxygen, and the storage life of the perovskite laminated solar cell is prolonged. Therefore, the perovskite laminated solar cells cannot be eroded by moisture and oxygen due to the protection of the encapsulation layer even if the perovskite laminated solar cells are exposed in the air for a long time before the plurality of perovskite laminated solar cells are subjected to assembly encapsulation and in the processes of storage, transportation and assembly preparation, so that the effective use of the cell assembly is ensured.

Description

Technical Field

[0001] The present disclosure relates to the technical field of semiconductor devices, and in particular, to a perovskite tandem solar cell and a preparation method thereof. Background Art

[0002] Perovskite solar cells are solar cells that use perovskite-type organic metal halide semiconductors as light-absorbing materials, also known as new concept solar cells. As crystalline silicon single-junction solar cell technology gradually reaches a bottleneck, perovskite tandem solar cells will become a new technology trend in the future. Perovskite tandem solar cells are composed of a top cell, a composite layer, and a bottom cell. Summary of the invention

[0003] The purpose of the present disclosure is to provide a perovskite tandem solar cell and a preparation method thereof that can prevent the top cell from being corroded by moisture and oxygen.

[0004] In order to achieve the above-mentioned objectives, the present disclosure provides a perovskite tandem solar cell, which includes a top cell, a composite layer, a bottom cell and an encapsulation layer, wherein the composite layer is arranged between the top cell and the bottom cell, and the encapsulation layer covers the front area of ​​the top cell except the front electrode, and covers the side surfaces of the top cell.

[0005] Optionally, the encapsulation layer also covers side surfaces of the composite layer.

[0006] Optionally, the encapsulation layer also covers the side surfaces of the bottom battery.

[0007] Optionally, in the horizontal direction, the side surface of the bottom battery extends outward by a first distance based on the side surface of the top battery.

[0008] Optionally, in the horizontal direction, the side surface of the top battery and the side surface of the composite layer are aligned.

[0009] Optionally, the material of the encapsulation layer is ultraviolet curing glue.

[0010] The present invention also provides a method for preparing a perovskite tandem solar cell, the method comprising: preparing a bottom battery; preparing a composite layer on the bottom cell; preparing a top cell on the composite layer; An encapsulation layer is prepared on the front surface of the top cell except the front electrode and on the side surface of the top cell.

[0011] Optionally, before the step of preparing an encapsulation layer on the front area of ​​the top cell except the front electrode and on the side of the top cell, the method further comprises: The side surface of the top battery is cleared so that in a horizontal direction, the side surface of the bottom battery extends outward by a first distance based on the side surface of the top battery.

[0012] Optionally, the cleaning of the side surface of the top battery includes: The side surfaces of the top battery and the composite layer are cleared so that in a horizontal direction, the side surfaces of the bottom battery extend outward by the first distance based on the side surfaces of the top battery and the composite layer.

[0013] Optionally, the step of preparing an encapsulation layer on the front side of the top battery except for the front electrode and on the side of the top battery comprises: The encapsulation layer is prepared on the front surface of the top cell except the front electrode, the side surface of the top cell, and the side surface of the composite layer.

[0014] Optionally, the step of preparing an encapsulation layer on the front side of the top battery except for the front electrode and on the side of the top battery comprises: The encapsulation layer is prepared on the front surface of the top cell except the front electrode, the side surface of the top cell, the side surface of the composite layer, and the side surface of the bottom cell.

[0015] Through the above technical solution, the encapsulation layer covers the front area of ​​the top cell except the front electrode, and covers the side of the top cell. In this way, the perovskite top cell is prevented from being corroded by water vapor and oxygen, and the storage life of the perovskite tandem solar cell is extended. Therefore, before the multiple perovskite tandem solar cells are packaged, during storage, transportation and component preparation, even if they are exposed to the air for a long time, due to the protection of the encapsulation layer, the perovskite tandem solar cell will not be corroded by water vapor and oxygen, thereby ensuring the effective use of the battery component.

[0016] Other features and advantages of the present disclosure will be described in detail in the following detailed description. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] The accompanying drawings are used to provide a further understanding of the present disclosure and constitute a part of the specification. Together with the following specific embodiments, they are used to explain the present disclosure but do not constitute a limitation of the present disclosure. In the accompanying drawings: Figure 1 It is a schematic structural diagram of a perovskite tandem solar cell provided by an exemplary embodiment.

[0018] Figure 2 It is a schematic structural diagram of a perovskite tandem solar cell provided by another exemplary embodiment.

[0019] Figure 3It is a schematic structural diagram of a perovskite tandem solar cell provided by another exemplary embodiment.

[0020] Figure 4 It is a schematic structural diagram of a perovskite tandem solar cell provided by another exemplary embodiment.

[0021] Figure 5 It is a flow chart of a method for preparing a perovskite tandem solar cell provided by an exemplary embodiment.

[0022] Figure 6-8 It is a schematic diagram of a process for preparing a perovskite tandem solar cell provided by an exemplary embodiment.

[0023] Description of Reference Numerals DETAILED DESCRIPTION

[0024] The specific implementation of the present disclosure is described in detail below in conjunction with the accompanying drawings. It should be understood that the specific implementation described herein is only used to illustrate and explain the present disclosure, and is not used to limit the present disclosure.

[0025] When growing a perovskite top cell on a bottom cell, due to the limitations of the actual production process precision, there are problems such as unevenness, discontinuity, and too many holes in the edge area of ​​the perovskite cell, which will cause edge recombination to seriously reduce the overall efficiency of the stacked cell. At the same time, water and oxygen are more likely to corrode from the edge to the inside, affecting the overall stability of the stack, further reducing the performance of the cell. That is, in perovskite stacked solar cells, due to its inherent properties, the perovskite top cell is more sensitive to water and oxygen during the production and storage process, and is easily decomposed in humid air, forming a large number of defects, and may even cause the perovskite structure to collapse, ultimately causing the cell to lose its original function. Since the top cell of the two-terminal and three-terminal stacked solar cells is directly prepared on the crystalline silicon bottom cell substrate, it cannot be directly prepared into a module like a single-junction perovskite solar cell. Instead, multiple perovskite stacked solar cells need to be packaged in the module factory. The perovskite stacked solar cells will be exposed to the air for a long time during storage, transportation and module preparation.

[0026] In view of this, the present invention provides a perovskite tandem solar cell and a preparation method thereof. By performing special front-end packaging treatment on the tandem cells, it can be ensured that the perovskite top cell will not be corroded by moisture and oxygen during this process.

[0027] Figure 1 FIG. 1 is a schematic diagram of the structure of a perovskite tandem solar cell provided by an exemplary embodiment. Figure 1As shown, the perovskite tandem solar cell includes a top cell 10, a composite layer 20, a bottom cell 30 and an encapsulation layer 40. The top cell 10 includes a front electrode 105. The composite layer 20 is disposed between the top cell 10 and the bottom cell 30. The encapsulation layer 40 covers the front area of ​​the top cell 10 except the front electrode 105, and covers the side of the top cell 10.

[0028] Among them, after the top battery 10, the composite layer 20 and the bottom battery 30 are prepared, the side of the top battery 10 can be cleaned. For example, the range and depth of the cleaning can be accurately controlled by laser to prevent damage to the bottom battery 30.

[0029] The encapsulation layer 40 can be patterned based on the position and size of the front electrode 105 of the top battery 10, avoiding the area of ​​the front electrode 105, and the encapsulation layer is covered based on the patterning, for example, by inkjet printing. The patterned encapsulation avoids the subsequent electrode conduction and string welding metal contact problems caused by the encapsulation film covering the battery electrode surface.

[0030] The front electrode 105 of the top cell 10 may include a fine grid and a main grid, and the above patterning may avoid all the front electrodes 105, or only avoid the main grid, thereby reducing the difficulty of patterning and improving the efficiency of preparing the encapsulation layer. At this time, the encapsulation layer 40 covers the front area of ​​the top cell 10 except the main grid of the front electrode 105.

[0031] The material of the encapsulation layer 40 can be ultraviolet curing glue, that is, UV (Ultraviolet Rays) glue. Preferably, it can be acrylic UV glue or metal compound, or a thin film prepared by atomic layer deposition (ALD), which can play the role of water and oxygen barrier. At the same time, the ultraviolet curing glue has good thermal stability and can withstand the heat generated by the battery during transportation, component string welding and lamination, and component operation, and will not cause thermal decomposition or thermal deformation during the encapsulation process.

[0032] Through the above technical solution, the encapsulation layer covers the front area of ​​the top cell except the front electrode, and covers the side of the top cell. In this way, the perovskite top cell is prevented from being corroded by water vapor and oxygen, and the storage life of the perovskite tandem solar cell is extended. Therefore, before the multiple perovskite tandem solar cells are packaged, during storage, transportation and component preparation, even if they are exposed to the air for a long time, due to the protection of the encapsulation layer, the perovskite tandem solar cell will not be corroded by water vapor and oxygen, thereby ensuring the effective use of the battery assembly. At the same time, this embodiment uses the perovskite cell edge cleaning process to form a space for accommodating the packaging material without adding the original process. It is suitable for the preparation of 2T, 3T, and 4T perovskite crystalline silicon tandem cells, is easy to implement, and is conducive to industrial promotion.

[0033] Figure 2 FIG. 1 is a schematic diagram of the structure of a perovskite tandem solar cell provided by another exemplary embodiment. Figure 1 Compared with the perovskite tandem solar cells, Figure 2 In the embodiment, the encapsulation layer 40 also covers the side of the composite layer 20, which can further improve the isolation effect of the perovskite top cell from the outside world and avoid Figure 1 The intrusion of water and oxygen at the interface between the encapsulation layer 40 and the composite layer 20 causes the performance of the perovskite top cell to decay.

[0034] Figure 3 FIG. 1 is a schematic diagram of the structure of a perovskite tandem solar cell provided by another exemplary embodiment. Figure 2 Compared with the perovskite tandem solar cells, Figure 3 In the embodiment of the present invention, the encapsulation layer 40 also covers the side of the bottom battery 30, which can further improve the isolation effect of the perovskite top battery from the outside world and avoid Figure 2 The intrusion of water and oxygen at the interface between the encapsulation layer 40 and the bottom cell 30 causes the performance of the perovskite top cell to decay.

[0035] In yet another embodiment, in the horizontal direction, the side surface of the bottom cell 30 extends outward by a first distance on the basis of the side surface of the top cell 10 . Figure 1-Figure 3 is a schematic diagram of a cross section of a perovskite tandem solar cell. When cleaning the edges, for example, the range and depth of the cleaning edges can be precisely controlled by a laser process to etch away the edge of the perovskite top cell 10 while preventing damage to the bottom cell. Preferably, in the horizontal direction, the side of the top cell 10 and the side of the bottom cell may have a first distance d, such as Figure 2 As shown in . The value of the first distance d can be less than or equal to 0.5 mm. When looking down at the stacked battery, in the horizontal direction, the side of the bottom battery extends the first distance d beyond the side of the top battery. The thickness of the encapsulation layer 40 can be the first distance d.

[0036] exist Figure 1 In the embodiment, the side of the top battery 10 is indented a certain distance from the side of the composite layer 20 and the bottom battery 30 to prevent the packaging glue from overflowing and flowing to the side of the composite layer 20 and the side and back of the bottom battery 30 during the gluing and packaging.

[0037] exist Figure 2 In the figure, the side surfaces of the top battery 10 and the composite layer 20 are indented a certain distance from the side surfaces of the bottom battery 30 to prevent the encapsulation glue from overflowing and flowing onto the side surfaces and back surface of the bottom battery 30 during the encapsulation.

[0038] exist Figure 3In the figure, the sides of the top battery 10 and the composite layer 20 are indented a distance from the sides of the bottom battery 30. When gluing and packaging, the packaging layer on the sides of the bottom battery 30 is thinner to prevent the packaging glue from overflowing and flowing to the back of the bottom battery 30.

[0039] like Figure 2 , Figure 3 As shown, in the horizontal direction, the side of the top battery 10 is aligned with the side of the composite layer 20. In this way, it is convenient to perform edge cleaning treatment on the top battery 10 and the composite layer 20 at the same time.

[0040] Figure 4 FIG. 1 is a schematic diagram of the structure of a perovskite tandem solar cell provided by another exemplary embodiment. Figure 4 As shown, in the perovskite tandem solar cell, in the direction from the composite layer 20 to the front electrode 105, the top cell 10 may include a hole transport layer 101, a perovskite layer 102, an electron transport layer 103, a conductive layer 104 and a front electrode 105 in sequence.

[0041] Among them, the hole transport layer 101 can be a double-layer structure of nickel oxide and self-assembled monolayer (Self-AssembledMonolayer, SAM) molecules, with nickel oxide deposited first and then the SAM layer. The specific process can be spin coating nickel oxide nanoparticles or forming a nickel oxide film by magnetron sputtering, and the thickness is controlled between 10-50nm. The hole transport layer can also be a pure SAM structure, and the material can include Me-4PACZ and related derivative materials. The specific process can be prepared by spin coating, vacuum method or spraying method, such as physical vapor deposition (Physical Vapor Deposition, PVD), and the final film thickness can be 0.5-2nm.

[0042] The structure of the perovskite layer 102 is a wide bandgap perovskite material, and the optional processes are a one-step method and a two-step method. In the one-step method, a precursor solution (a mixed solution of organic and inorganic) is prepared first, and the perovskite layer is prepared by spin coating, slit coating or spraying, and the perovskite layer 102 is formed by VCD and heating annealing processes; in the two-step method, an inorganic salt film is prepared by vacuum evaporation, and the main component is PbI2, and other components may include CsI, PbBr2, etc., and then an organic salt solution is coated on the surface of the inorganic salt film. The solute material may include FAI, FABr, MAI, MABr and additives, including organic ammonium salts, halide ammonium salts, organic small molecules, polymer molecules, etc.

[0043] The electron transport layer 103 can be divided into two layers. The first layer is preferably a C60 layer, which can be prepared by vacuum evaporation coating technology, and the film thickness is controlled within the range of 5-20nm. The second layer structure is preferably SnO2, which can be prepared by atomic deposition (ALD), and the film thickness is controlled within the range of 15-20nm.

[0044] The conductive layer 104 may be a conductive oxide coating (Transparent Conductive Oxides, TCO) conductive layer, and the structure may be a transparent metal oxide conductive layer. The coating may be made by magnetron sputtering process, and the structural material may include indium tin oxide (Indium Tin Oxide, ITO), indium oxide with tungsten (Indium Oxide with Tungsten, IWO), indium carbonate oxide (Indium Carbonate Oxide, ICO), indium zinc oxide (Indium Zinc Oxide, IZO), aluminum-doped zinc oxide (Aluminum-Doped Zinc Oxide, AZO), etc.

[0045] The material of the front electrode 105 is preferably metallic silver. The electrode process can be vacuum evaporated or screen printed. The raw material can be high-purity metallic silver or low-temperature silver paste, wherein the curing temperature of the low-temperature silver paste is lower than 150 degrees Celsius.

[0046] In the direction from the back side of the bottom cell 30 to the composite layer 20 , the bottom cell 30 may include a back electrode 306 , a silicon nitride layer 301 , an aluminum oxide layer 302 , a P-type passivation layer 303 , a substrate 304 and an N-type passivation layer 305 in sequence.

[0047] The N-type passivation layer 305 may be composed of a stack of N-poly and silicon oxide, and the thin silicon oxide layer is located between the N-type crystalline silicon substrate 304 and the N-poly. A tunneling layer (not shown) may be provided between the N-type crystalline silicon substrate 304 and the N-type passivation layer 305, and a tunneling layer (not shown) may also be provided between the N-type crystalline silicon substrate 304 and the P-type passivation layer 303.

[0048] The stack of silicon nitride layer 301 and aluminum oxide layer 302 may constitute a passivation layer. It is understood that the silicon nitride layer 301 and aluminum oxide layer 302 may be multiple layers.

[0049] The back electrode 306 can form a back-patterned electrode distribution through a screen printing silver paste process, and then burn through the passivation layer composed of the silicon nitride layer 301 and the aluminum oxide layer 302 at a high temperature to form an ohmic contact with the p-poly in the P-type passivation layer 303, and collect and transmit photogenerated carriers through the back electrode.

[0050] The back of the bottom battery 30 may adopt a BC structure. The BC structure means that the back of the bottom battery includes a P region and an N region that are spaced apart, so that the electrons and holes of the photogenerated carriers generated inside the bottom battery are separated and collected on the back of the bottom battery. The BC structure may include a TBC, HBC or hybrid BC structure. TBC means that the P and N regions on the back of the bottom battery are both TOPCON structures, HBC means that the P and N regions on the back of the bottom battery are both HJT structures, and hybrid BC means that the structures of the P and N regions are different, for example, the P region is an HJT structure and the N region is a TOPCON structure, or the N region is an HJT structure and the P region is a TOPCON structure. In addition, the above-mentioned BC structure may also be other types of BC structures.

[0051] Figure 4 The perovskite top cell 10 in the embodiment adopts a trans structure, and in other embodiments, a regular structure may also be adopted.

[0052] The encapsulation layer can be formed on the top surface and side surfaces of the top battery 10 by inkjet printing, coating, deposition, etc., or by other gluing methods.

[0053] The composite layer 20 may be a transparent conductive oxide (TCO) layer, which may be deposited by a PVD method, for example.

[0054] Figure 5 FIG. 1 is a flow chart of a method for preparing a perovskite tandem solar cell provided by an exemplary embodiment. Figure 5 As shown, the method includes steps S101-S104.

[0055] S101 , preparing the bottom cell 30 .

[0056] S102 , preparing a composite layer 20 on the bottom cell 30 .

[0057] S103 , preparing a top cell 10 on the composite layer 20 .

[0058] S104 , preparing an encapsulation layer 40 on the front surface of the top cell 10 except the front electrode 105 and on the side surface of the top cell 10 .

[0059] For example, preparation Figure 1 In the perovskite tandem solar cell, after the bottom cell 30, the composite layer 20 and the top cell 10 are prepared in sequence, the encapsulation layer 40 is prepared on the front area of ​​the top cell 10 except the front electrode 105 and on the side of the top cell 10.

[0060] In one embodiment, the following can be prepared: Figure 4The perovskite tandem solar cell shown in the figure. The preparation of the bottom cell 30 may include: arranging a silicon nitride layer 301 , an aluminum oxide layer 302 , a P-type passivation layer 303 , a substrate 304 , an N-type passivation layer 305 and a back electrode 306 in the bottom cell 30 .

[0061] The preparation of the composite layer 20 on the bottom cell 30 may include: depositing a transparent TCO layer by a PVD method.

[0062] Preparing the top cell 10 on the composite layer 20 may include: A pure SAM structure is prepared as the hole transport layer 101 by spin coating, vacuum coating or spray coating, and the material may include Me-4PACZ and related derivative materials; An inorganic salt film is prepared by vacuum evaporation, and then an organic salt solution is coated on the surface of the inorganic salt film to form a perovskite layer 102; A C60 layer of SnO2 is deposited by vacuum evaporation coating process, and then a SnO2 thin film is prepared by atomic deposition (ALD) to generate an electron transport layer 103; A magnetron sputtering process is used to deposit a transparent metal oxide conductive layer to generate a conductive layer 104; The front electrode 105 is arranged by vacuum evaporation or screen printing, and the raw material can be high-purity metallic silver (vacuum evaporation) or low-temperature silver paste (screen printing).

[0063] Finally, an ultraviolet curing adhesive is deposited on the front surface of the top cell 10 except the front electrode 105 and the side surface of the top cell 10 by using ALD to form an encapsulation layer 40 .

[0064] Through the above technical solution, the encapsulation layer covers the front area of ​​the top cell except the front electrode, and covers the side of the top cell. In this way, the perovskite top cell is prevented from being corroded by water vapor and oxygen, and the storage life of the perovskite tandem solar cell is extended. Therefore, before the multiple perovskite tandem solar cells are packaged, during storage, transportation and component preparation, even if they are exposed to the air for a long time, due to the protection of the encapsulation layer, the perovskite tandem solar cell will not be corroded by water vapor and oxygen, thereby ensuring the effective use of the battery component.

[0065] In one embodiment, before step S104 of preparing the encapsulation layer 40 on the front area of ​​the top battery 10 except the front electrode 105 and the side of the top battery 10, the method further includes: The side surface of the top battery 10 is cleaned so that in the horizontal direction, the side surface of the bottom battery 30 extends outward by a first distance based on the side surface of the top battery 10 .

[0066] After step S103 of preparing the top cell 10 on the composite layer 20 , the side of the top cell 10 is cleaned. For example, the range and depth of the cleaning can be precisely controlled by laser to prevent damage to the bottom cell 30 .

[0067] The encapsulation layer 40 may be patterned based on the position and size of the front electrode 105 of the top cell 10 to avoid the area of ​​the front electrode 105 , and the encapsulation layer may be covered based on the patterning, for example, by inkjet printing.

[0068] In the horizontal direction, the side of the top battery 10 and the side of the bottom battery may have a first distance, and the value of the first distance may be less than or equal to 0.5 mm. From the perspective of looking down at the stacked battery, in the horizontal direction, the side of the bottom battery extends the first distance from the side of the top battery. The thickness of the encapsulation layer 40 may be the first distance.

[0069] This implementation example Figure 1-Figure 3 As shown, the side of the top cell 10 is cleaned to clean up the unevenness, discontinuity, excessive holes and other problems in the edge area of ​​the perovskite top cell. At the same time, the top cell is indented relative to the bottom cell to facilitate the glue application and packaging, so that the packaging glue overflows and flows to the side of the composite layer 20 and the side and back of the bottom cell 30.

[0070] This embodiment uses the perovskite battery edge cleaning process to form a space for accommodating packaging materials without adding to the original process. It is suitable for the preparation of 2T, 3T, and 4T perovskite crystalline silicon stacked batteries, is easy to implement, and is conducive to industrial promotion.

[0071] In another embodiment, the side of the top battery 10 is cleaned, including: cleaning the side of the top battery 10 and the side of the composite layer 20, so that in the horizontal direction, the side of the bottom battery 30 extends outward by a first distance based on the side of the top battery 10 and the side of the composite layer 20.

[0072] This implementation example Figure 2 , Figure 3 As shown, the sides of the top cell 10 and the sides of the composite layer 20 are cleaned, so that the unevenness, discontinuity, excessive holes and other problems in the edge areas of the perovskite top cell and the composite layer 20 can be cleaned. At the same time, the top cell 10 and the composite layer 20 are indented relative to the bottom cell 30 to prevent the packaging glue from overflowing and flowing to the back of the bottom cell 30 during gluing and packaging.

[0073] In another embodiment, an encapsulation layer 40 is prepared on the front area of ​​the top battery 10 except the front electrode 105 and the side of the top battery 10, including: preparing an encapsulation layer 40 on the front area of ​​the top battery 10 except the front electrode 105, the side of the top battery 10 and the side of the composite layer 20.

[0074] This implementation example Figure 2 As shown, the sides of the top battery 10 and the composite layer 20 are indented a certain distance from the sides of the bottom battery 30, so as to prevent the packaging glue from overflowing and flowing to the sides and back of the bottom battery 30 during the packaging.

[0075] In another embodiment, an encapsulation layer 40 is prepared on the front area of ​​the top battery 10 except the front electrode 105 and the side of the top battery 10, including: preparing an encapsulation layer 40 on the front area of ​​the top battery 10 except the front electrode 105, the side of the top battery 10, the side of the composite layer 20 and the side of the bottom battery 30.

[0076] This implementation example Figure 3 As shown, the sides of the top battery 10 and the composite layer 20 are indented a distance from the sides of the bottom battery 30 . During the gluing and packaging process, the packaging layer on the sides of the bottom battery 30 is thinner to prevent the packaging glue from overflowing and flowing to the back of the bottom battery 30 .

[0077] Figure 6-8 It is a schematic diagram of a process for preparing a perovskite tandem solar cell provided by an exemplary embodiment. Figure 6 In the embodiment, the top cell 10, the composite layer 20 and the bottom cell 30 have been prepared. Figure 7 In the process, the top cell 10 and the composite layer 20 are cleaned by laser, so that the top cell 10 and the composite layer 20 are retracted a certain distance relative to the bottom cell 30 in the horizontal direction. Figure 8 In the process, the encapsulation layer 40 is formed on the top surface and the side surface of the top battery 10 by inkjet printing, coating, deposition, etc. The encapsulation layer 40 can be patterned based on the position and size of the front electrode 105 of the top battery 10, avoiding the area of ​​the front electrode 105, and covering the encapsulation layer based on the patterning.

[0078] The preferred embodiments of the present disclosure are described in detail above in conjunction with the accompanying drawings; however, the present disclosure is not limited to the specific details in the above embodiments. Within the technical concept of the present disclosure, a variety of simple modifications can be made to the technical solution of the present disclosure, and these simple modifications all fall within the protection scope of the present disclosure.

[0079] It should also be noted that the various specific technical features described in the above specific embodiments can be combined in any suitable manner without contradiction. In order to avoid unnecessary repetition, the present disclosure will not further describe various possible combinations.

[0080] In addition, various embodiments of the present disclosure may be arbitrarily combined, and as long as they do not violate the concept of the present disclosure, they should also be regarded as the contents disclosed by the present disclosure.

Claims

1. A perovskite tandem solar cell, characterized in that: The perovskite tandem solar cell comprises a top cell (10), a composite layer (20), a bottom cell (30) and an encapsulation layer (40), wherein the composite layer (20) is arranged between the top cell (10) and the bottom cell (30), and the encapsulation layer (40) covers the front area of ​​the top cell (10) except the front electrode (105), and covers the side surfaces of the top cell (10).

2. The perovskite tandem solar cell according to claim 1, characterized in that: The encapsulation layer (40) also covers the side surfaces of the composite layer (20).

3. The perovskite tandem solar cell according to claim 2, characterized in that: The encapsulation layer (40) also covers the side surfaces of the bottom battery (30).

4. The perovskite tandem solar cell according to claim 1, characterized in that: In the horizontal direction, the side surface of the bottom battery (30) extends outwards by a first distance based on the side surface of the top battery (10).

5. The perovskite tandem solar cell according to claim 4, characterized in that: In the horizontal direction, the side surface of the top battery (10) and the side surface of the composite layer (20) are aligned.

6. The perovskite tandem solar cell according to any one of claims 1 to 5, characterized in that: The material of the packaging layer (40) is ultraviolet curing glue.

7. A method for preparing a perovskite tandem solar cell, characterized in that: The method comprises: preparing a bottom cell (30); Preparing a composite layer (20) on the bottom battery (30); Preparing a top battery (10) on the composite layer (20); An encapsulation layer (40) is prepared on the front area of ​​the top battery (10) except the front electrode (105) and on the side of the top battery (10).

8. The method according to claim 7, characterized in that Before the step of preparing an encapsulation layer (40) on the front area of ​​the top battery (10) except the front electrode (105) and on the side of the top battery (10), the method further comprises: The side surface of the top battery (10) is cleaned so that, in a horizontal direction, the side surface of the bottom battery (30) extends outward by a first distance based on the side surface of the top battery (10).

9. The method according to claim 8, characterized in that The step of cleaning the side surface of the top battery (10) comprises: The side surfaces of the top battery (10) and the side surfaces of the composite layer (20) are cleaned so that, in a horizontal direction, the side surfaces of the bottom battery (30) extend outwardly by the first distance based on the side surfaces of the top battery (10) and the side surfaces of the composite layer (20).

10. The method according to claim 7, characterized in that The step of preparing an encapsulation layer (40) on the front side of the top battery (10) except for the front electrode (105) and on the side of the top battery (10) comprises: The encapsulation layer (40) is prepared on the front area of ​​the top battery (10) except the front electrode (105), the side of the top battery (10), and the side of the composite layer (20).

11. The method according to claim 7, characterized in that The step of preparing an encapsulation layer (40) on the front side of the top battery (10) except for the front electrode (105) and on the side of the top battery (10) comprises: The encapsulation layer (40) is prepared on the front area of ​​the top battery (10) except the front electrode (105), the side of the top battery (10), the side of the composite layer (20), and the side of the bottom battery (30).

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