Crystalline silicon / perovskite laminated solar cell edge passivation method and device

Abstract

The invention provides a crystalline silicon / perovskite laminated solar cell edge passivation method and device, and belongs to the technical field of perovskite and crystalline silicon lamination. The edge of the cut laminated solar cell is passivated in a mode of combining laser cutting and a low-temperature breaking process, so that the carrier recombination rate of a laser cutting surface and the edge of a cell piece is effectively reduced, and the conversion efficiency and the stability of a laminated cell assembly are improved.

Description

Technical Field

[0001] The present invention relates to the technical field of perovskite tandem solar cells, and in particular to a method and device for edge passivation of a crystalline silicon / perovskite tandem solar cell. Background Art

[0002] Crystalline silicon solar cells are currently the dominant technology in the photovoltaic market, accounting for more than 90% of the global market. However, the photoelectric conversion efficiency of crystalline silicon cells has a theoretical limit (Shockley-Queisser limit), which is about 29%. Currently, the efficiency of commercial crystalline silicon cells is usually around 20%, and the efficiency of top laboratory cells is only around 26%, which is relatively close to the theoretical limit. In order to break through this efficiency bottleneck, researchers began to explore stacked cell technology. Perovskite materials have attracted widespread attention in the photovoltaic field in recent years due to their excellent photoelectric properties, such as high absorption coefficient, adjustable band gap and simple manufacturing process.

[0003] Perovskite-crystalline silicon tandem cells combine a perovskite absorption layer with a crystalline silicon solar cell. The perovskite absorption layer absorbs ultraviolet and visible light, while the crystalline silicon material absorbs infrared light, which improves spectral utilization, reduces thermal relaxation losses, and improves device performance. In order to further improve the performance of perovskite-crystalline silicon tandem cells, an edge passivation process is introduced during the cell preparation process. By adding a passivation layer to the edge area of ​​the cell, the recombination loss at the edge is reduced, thereby improving the efficiency of the cell. Specifically, edge passivation has the following principles and necessity:

[0004] 1. Reduce surface recombination: Due to the manufacturing process and surface unevenness, the edge area of ​​the solar cell often has a higher surface recombination rate, which causes electrons and holes to recombine before reaching the electrode, reducing the photoelectric conversion efficiency of the cell. By adding a passivation layer to the edge area, the number of surface defect states can be reduced, thereby reducing the recombination rate.

[0005] 2. Improve battery performance: The passivation layer can reduce carrier loss in the edge area, increase the open circuit voltage and fill factor of the battery, and ultimately improve the conversion efficiency of the battery.

[0006] 3. Increase photogenerated current: The introduction of the passivation layer reduces non-radiative recombination losses, allowing more photogenerated carriers to participate in the generation of current, thereby increasing the photogenerated current of the battery.

[0007] 4. Prevent battery degradation: Edge passivation can also protect the edge area from the influence of the external environment to a certain extent, reducing the degradation of the battery during long-term use.

[0008] Patent application CN119029054A discloses an edge-passivated crystalline silicon cell and a perovskite crystalline silicon stacked cell and their preparation. The crystalline silicon cell provided by the present invention is a cut cell, and the cut end face is covered with a GeSe2 passivation layer. The photogenerated carriers will be confined inside the crystalline silicon cell, preventing the non-radiative recombination of the photogenerated carriers at the cut end face, reducing the charge accumulation at the edge of the crystalline silicon cell, thereby reducing the surface recombination rate of the crystalline silicon cell, and thus improving the photoelectric conversion efficiency of the crystalline silicon cell. However, this invention is to passivate the edges of the single-junction cell after cutting. Compared with the single-junction cell, the stacked cell adds multiple steps (several more layers of film), and the superposition of multiple layers of film often leads to more serious edge recombination, reducing the service life of the cell. At present, the efficiency records of stacked cells are often smaller laboratory areas, such as 1cm 2 , the edge recombination phenomenon is not particularly obvious. However, at commercial sizes, edge recombination often leads to very serious device performance loss. At the same time, in the aging test of stacked cells, it was also found that perovskite often starts to degrade from the edge.

[0009] Therefore, an edge passivation process is urgently needed to solve the edge recombination and large-size commercialization problems of stacked solar cells. Summary of the invention

[0010] In order to solve the problem that traditional edge passivation processes are difficult to apply to stacked solar cells, the present invention provides a method and device for edge passivation of crystalline silicon / perovskite stacked solar cells. By combining laser cutting and low-temperature breaking processes, the cut stacked solar cells are edge passivated, which effectively reduces the carrier recombination rate on the laser cutting surface and the edge of the battery cell, and improves the conversion efficiency and stability of the battery component.

[0011] To achieve the above object, the specific scheme provided by the present invention is as follows:

[0012] A method for edge passivation of a crystalline silicon / perovskite tandem solar cell comprises the following steps:

[0013] A crystalline silicon / perovskite stacked solar cell is provided, wherein the stacked cell comprises a crystalline silicon bottom cell and a perovskite top cell thereon, laser cutting is performed on the surface of the stacked cell where the crystalline silicon bottom cell is located, a groove is formed on the crystalline silicon bottom cell, the stacked cell after the cutting is then placed in a low temperature environment for breaking, a plurality of broken stacked cells are stacked with the broken surfaces facing the same direction and placed in a carrier, the carrier is placed in a deposition device, an edge passivation layer is formed on the broken surfaces of the plurality of stacked cells, and the stacked cells are split to obtain a plurality of edge-passivated stacked cells.

[0014] Furthermore, the crystalline silicon bottom cell can be selected from one of the crystalline silicon cell structures such as PERC cell, topcon cell or HJT.

[0015] Specifically, the crystalline silicon bottom cell includes, from bottom to top, a first metal electrode layer, a first transparent electrode layer, a P-type base doping layer, a base passivation layer, a silicon substrate, a base surface passivation layer, an N-type base doping layer and a tunneling layer; the perovskite top cell includes a hole transport layer, a perovskite layer, a perovskite passivation layer, an electron transport layer, a second transparent electrode layer, a second metal electrode layer and an anti-reflection layer, which are sequentially arranged on the crystalline silicon bottom cell.

[0016] In another embodiment, the edge passivation method can also be applied to multi-layer cells, that is, a plurality of perovskite middle cells are arranged between the crystalline silicon bottom cell and the perovskite top cell, and the perovskite middle cell may include a middle cell hole transport layer, a middle cell perovskite layer, a middle cell perovskite passivation layer, and a middle cell electron transport layer.

[0017] In this embodiment, when the stacked battery is laser cut, a groove is formed by cutting from the surface of the crystalline silicon bottom battery. By controlling the laser power to 10~120W, the groove depth does not exceed the thickness of the crystalline silicon bottom battery. In this embodiment, the purpose of laser cutting is mainly to form a line on the crystalline silicon bottom battery, and the etching depth can be accurately controlled to reduce the ablation of the perovskite top battery.

[0018] Preferably, the groove depth is 30-90% of the thickness of the crystalline silicon bottom cell.

[0019] In this embodiment, the stacked battery after cutting is cooled to a temperature of -15 to 15° C. in a low temperature environment for 2 to 30 minutes, and is broken after cooling.

[0020] Furthermore, the cut laminated battery is moved to a low temperature environment for cooling, and then the laminated battery falls on a conical dividing table at a certain height due to gravity, and is divided into two half-sheet laminated batteries along the path where the grooves are located. In this embodiment, cooling the cut laminated battery can, on the one hand, reduce the heat conduction diffusion remaining on the crystalline silicon bottom battery after cutting, and avoid excessive temperature from damaging the crystal structure of the perovskite film; on the other hand, it can reduce the elastic strain of the perovskite thin film battery, increase its rigidity, and prevent the formation of irregular sections.

[0021] In this embodiment, several single stacked cells obtained by cutting are stacked so that the laser cut sections are on the same plane, and the stacked solar cells are placed on a carrier, clamped and blocked by a baffle, and then an edge passivation layer is formed on the laser cut section. The edge passivation layer can be prepared by atomic layer deposition, evaporation, chemical vapor deposition, magnetron sputtering and other deposition methods. The edge passivation layer can be selected from thin films such as aluminum oxide, silicon oxide, aluminum nitride, etc., with a thickness of 5-100nm.

[0022] Optionally, when atomic layer deposition is used for deposition, the deposition temperature is controlled to be 200°C; the deposition pressure is 1 torr; the flow rate of TMA is 15000 sccm, the flow rate of water vapor is 15000 sccm, and the flow rate of nitrogen is 30000 sccm, to form an edge passivation layer on the cross section.

[0023] Optionally, when magnetron sputtering is used for deposition, the chamber pressure is controlled at 0.3-0.6 Pa, the deposition power is 2000 W, and Ar 1000 sccm is introduced to form an edge passivation layer on the cross section.

[0024] In this embodiment, the stacked battery with edge passivation layer plated is placed in an annealing device for annealing, the temperature is set to 80-200°C, the annealing time is 10min~30min, and after the annealing is completed, it is disassembled and subsequently packaged into a complete battery assembly after testing.

[0025] The present invention also provides a crystalline silicon / perovskite stacked solar cell edge passivation device, which is applied to the above passivation method, including a laser cutting machine, a low-temperature breaking machine, a deposition device, and a transmission device, wherein the laser cutting machine and the low-temperature breaking machine are sequentially arranged on the transmission device.

[0026] In this embodiment, the laser cutting machine is composed of a laser system, a cutting platform, a cooling system, a positioning system and other components. The cutting platform is arranged on the transmission device, and the laser system is arranged above the cutting platform and fixed on the laser cutting machine. The laser system is used to emit high-power laser and adjust the running direction and height of the laser; the cutting platform is used to place the battery samples to be cut, which can play a role in fixing the position of the battery samples; the positioning system can assist the laser system to accurately cut the samples and determine the laser cutting path. During the cutting process, the cooling system can be used to control the laser cutting machine to maintain a low temperature environment to reduce the damage to the battery caused by excessive cutting temperature.

[0027] In this embodiment, the low temperature breaking machine includes a cooling system, a gantry transport system, and a conical dividing table. The cooling system controls the interior of the low temperature breaking machine to be in a low temperature environment of -15~15°C, and the battery sample is clamped by the gantry transport system and moved to the upper position of the conical dividing table, and the laminated battery falls to obtain two laminated batteries.

[0028] In this embodiment, the transmission device is composed of a plurality of conveyor belts and a control system. The control system independently controls the plurality of conveyor belts to transport the samples. Specifically, the plurality of conveyor belts include a feed conveyor belt, a first conveyor belt and a discharge conveyor belt. The feed conveyor belt is connected and fixed under the laser cutting machine. The battery sample can be moved to the laser cutting machine for cutting through the feed conveyor belt. After cutting, it is moved to the low-temperature breaking machine for cooling through the first conveyor belt. Then, the battery sample is moved to the conical cutting table for breaking through the gantry transportation system. The conical cutting table is transported out through the discharge conveyor belt. The collected cut laminated solar cells are stacked and placed in a carrier, and placed in a deposition device for edge passivation deposition of the cross section.

[0029] In this embodiment, the deposition equipment includes a deposition equipment gas system, a vacuum system, and a reaction chamber. The vacuum system and the deposition equipment gas system are both connected to the reaction chamber. The vacuum system controls the air pressure in the reaction chamber to maintain the vacuum environment inside the chamber, and the deposition equipment gas system is used to inject gas required for the reaction into the reaction chamber, or to extract useless gas after the reaction.

[0030] In this embodiment, the carrier includes a support frame, at least two fixing rods and at least two baffles, the fixing rod is provided with at least one fixing notch and is fixed to the support frame, the at least two baffles are parallel, each fixing notch is engaged with two baffles, and the gap between each two baffles is controlled by the fixing rod to fix the stacked batteries between each two baffles.

[0031] Preferably, the number of the baffles is an even number, the plurality of fixing rods are arranged in parallel, and each fixing rod is fixed to the edges of every two baffles in a bite-engaged manner through a fixing notch.

[0032] The present application provides a method for edge passivation of a crystalline silicon / perovskite tandem solar cell, comprising laser cutting the tandem cell, then placing the cut tandem cell in a low temperature environment for breaking, stacking a number of broken tandem cells with the broken surfaces facing the same direction and placing them in a carrier, placing the carrier in a deposition device, and forming an edge passivation layer on the broken surfaces of the several tandem cells. By providing the edge passivation layer on the tandem cell, the edge film of the perovskite cell can be effectively protected, the defects of the edge film and the cutting damage can be reduced, and the carrier recombination rate of the cut surface of the tandem cell and the edge of the cell can be effectively reduced, thereby improving the photoelectric conversion efficiency and stability of the tandem cell. The present application also uses a passivation device to automatically design the passivation step, reduce human interference, and improve production quality and efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] Figure 1 This is a step diagram of the edge passivation method of the crystalline silicon / perovskite tandem solar cell described in the present invention;

[0034] Figure 2 This is a flow chart of edge passivation of the crystalline silicon / perovskite tandem solar cell described in the present invention;

[0035] Figure 3 A schematic diagram of the structure of a crystalline silicon / perovskite tandem solar cell prepared by the method of the present invention;

[0036] Figure 4 A schematic diagram of the structure of a multi-layer solar cell prepared by the method of the present invention;

[0037] Figure 5 This is a schematic diagram of the structure of the edge passivation device of the crystalline silicon / perovskite tandem solar cell described in the present invention;

[0038] Figure 6 is a schematic structural diagram of the deposition device described in the present invention;

[0039] Figure 7 is a schematic structural diagram of the carrier of the present invention when no laminated battery is loaded;

[0040] Figure 8 It is a schematic diagram of the structure of the carrier of the present invention when loading the laminated battery.

[0041] The labels in the figure are:

[0042] 10. Crystalline silicon bottom cell; 101. First metal electrode layer; 102. First transparent electrode layer; 103. P-type base doping layer; 104. Base passivation layer; 105. Silicon substrate; 106. Base surface passivation layer; 107. N-type base doping layer; 108. Tunneling layer;

[0043] 20, perovskite top cell; 201, hole transport layer; 202, perovskite layer; 203, perovskite passivation layer; 204, electron transport layer; 205, second transparent electrode layer; 206, second metal electrode layer; 207, anti-reflection layer;

[0044] 21. Perovskite mid-cell; 211. Mid-cell hole transport layer; 212. Mid-cell perovskite layer; 213. Mid-cell perovskite passivation layer; 214. Mid-cell electron transport layer;

[0045] L1, groove;

[0046] 30. Edge passivation layer;

[0047] 40. Edge passivation device; 401. Laser cutting machine; 4011. Laser system; 4012. Cutting platform; 403. Low-temperature breaking machine; 4031. Gantry transportation system; 4032. Conical dividing table; 404. Transmission device; 405. Deposition equipment; 4051. Deposition equipment gas path system; 4052. Vacuum system; 4053. Reaction chamber;

[0048] 50. carrier; 501. support frame; 502. fixing rod; 5021. fixing notch; 503. baffle. DETAILED DESCRIPTION

[0049] The technical solutions in the embodiments of the present invention will be described clearly and completely below. Obviously, the described embodiments are only part of the embodiments of the present invention, rather than all the embodiments.

[0050] In the description of the present invention, unless otherwise specified, "multiple" means two or more; the terms "center", "longitudinal", "lateral", "up", "down", "left", "right", "inside", "outside", "front end", "rear end", "head", "tail", "vertical", "horizontal", "top", "bottom", "inside", "outside" and the like indicate the orientation or position relationship based on the orientation or position relationship shown in the drawings, which is only for the convenience of describing the present invention and simplifying the description, and does not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operate in a specific orientation, and therefore cannot be understood as limiting the present invention. In addition, the terms "first", "second", "third" and the like are used for descriptive purposes only and cannot be understood as indicating or implying relative importance.

[0051] In the commercial production of stacked cells, large-area preparation processes are often used to make stacked cells. After slicing, the edges of the cells are exposed to the air, resulting in very serious device defects in the edge areas, reducing the photoelectric conversion efficiency and stability of the device. Figure 1, the embodiment of the present application provides a crystalline silicon / perovskite tandem solar cell edge passivation method, which is applied to the production of large-area tandem solar cells. A groove L1 is cut on the surface of the crystalline silicon bottom cell 10 of the tandem cell by laser cutting. After cutting, low-temperature breaking is performed to obtain two tandem cells of half the size of the original cell. Several broken tandem cells are stacked and then batch edge passivation is performed, and several tandem cells with edge passivation layers are finally obtained. In the present application, the process of combining laser cutting and low-temperature breaking can well protect the perovskite top cell 20 of the tandem cell, and cool the tandem cell after cutting. On the one hand, it can reduce the heat conduction diffusion remaining on the crystalline silicon bottom cell 10 after cutting, and avoid excessive temperature from destroying the crystal structure of the perovskite film; on the other hand, it can reduce the film elastic strain of the perovskite top cell 20, increase its rigidity, and prevent the formation of irregular cross-sections, thereby reducing the surface recombination of the edge area of ​​the device, and improving the photoelectric conversion efficiency and stability of the device.

[0052] See also Figures 1 to 4 The embodiment of the present application provides a method for edge passivation of a crystalline silicon / perovskite tandem solar cell, comprising:

[0053] A crystalline silicon / perovskite tandem solar cell is provided, wherein the tandem cell comprises a crystalline silicon bottom cell 10 and a perovskite top cell 20 thereon, the surface of the crystalline silicon bottom cell 10 of the tandem cell is laser cut to form a groove L1 on the crystalline silicon bottom cell 10, and then the cut tandem cell is placed in a low temperature environment to be broken, and a plurality of broken tandem cells are stacked with the broken surfaces facing the same direction and placed in a carrier, and the carrier is placed in a deposition device, and an edge passivation layer 30 is formed on the broken surfaces of the plurality of tandem cells, and the tandem cells are split to obtain a plurality of edge-passivated tandem cells.

[0054] Furthermore, the crystalline silicon bottom cell 10 can be selected from one of the crystalline silicon cell structures such as PERC cell, topcon cell or HJT.

[0055] Specifically, the crystalline silicon bottom cell 10 includes, from bottom to top, a first metal electrode layer 101, a first transparent electrode layer 102, a P-type base doping layer 103, a base passivation layer 104, a silicon substrate 105, a base surface passivation layer 106, an N-type base doping layer 107 and a tunneling layer 108; the perovskite top cell 20 includes a hole transport layer 201, a perovskite layer 202, a perovskite passivation layer 203, an electron transport layer 204, a second transparent electrode layer 205, a second metal electrode layer 206 and an anti-reflection layer 207, which are sequentially arranged on the crystalline silicon bottom cell 10.

[0056] In another embodiment, the edge passivation method can also be applied to multi-layer cells, that is, a plurality of perovskite middle cells 21 are arranged between the crystalline silicon bottom cell 10 and the perovskite top cell 20, and the perovskite middle cell 21 may include a middle cell hole transport layer 211, a middle cell perovskite layer 212, a middle cell perovskite passivation layer 213, and a middle cell electron transport layer 214.

[0057] In this embodiment, when the stacked cell is laser cut, the groove L1 is cut from the surface of the crystalline silicon bottom cell 10. By controlling the laser power to 10~120W, the groove depth does not exceed the thickness of the crystalline silicon bottom cell 10. In this embodiment, the purpose of laser cutting is mainly to form a scribed line on the crystalline silicon bottom cell 10, and the etching depth can be accurately controlled to reduce the ablation of the perovskite top cell 20. Since the perovskite film is more susceptible to damage caused by high-temperature thermal cutting, laser cutting can be performed in a low-temperature environment. The stacked cell is placed on a low-temperature cutting platform and the temperature is controlled to be -15℃~5℃, which can reduce the impact of laser ablation on the perovskite film.

[0058] Preferably, the depth of the groove L1 is 30-90% of the thickness of the crystalline silicon bottom cell 10 .

[0059] In this embodiment, the stacked battery after cutting is cooled to a temperature of -15 to 15° C. in a low temperature environment for 2 to 30 minutes, and is broken after cooling.

[0060] Furthermore, the stacked battery after cutting is moved to a low temperature environment for cooling, and then the stacked battery falls on the conical dividing table at a certain height due to gravity, and is divided into two half-sheet stacked batteries along the path where the groove L1 is located. The height can be controlled at 10cm~60cm. In this embodiment, cooling the stacked battery after cutting can reduce the heat conduction diffusion remaining on the crystalline silicon bottom battery 10 after cutting, and avoid excessive temperature from destroying the crystal structure of the perovskite film; on the other hand, it can reduce the elastic strain of the perovskite thin film battery, increase its rigidity, and prevent the formation of irregular sections.

[0061] In this embodiment, several single stacked cells obtained by cutting are stacked so that the laser cut sections are on the same plane, and the stacked solar cells are placed on a carrier, clamped and blocked by a baffle, and then an edge passivation layer 30 is formed on the laser cut section. The edge passivation layer 30 can be prepared by atomic layer deposition, evaporation, chemical vapor deposition, magnetron sputtering and other deposition methods. The edge passivation layer 30 can be selected from thin films such as aluminum oxide, silicon oxide, aluminum nitride, etc., with a thickness of 5-100nm.

[0062] Optionally, when atomic layer deposition is used for deposition, the deposition temperature is controlled to be 200° C., the deposition pressure is 1 torr, the flow rate of TMA is 15000 sccm, the flow rate of water vapor is 15000 sccm, and the flow rate of nitrogen is 30000 sccm, and an edge passivation layer 30 is formed on the cross section.

[0063] Optionally, when magnetron sputtering is used for deposition, the chamber pressure is controlled at 0.3-0.6 Pa, the deposition power is 2000 W, and Ar is introduced at 1000 sccm to form an edge passivation layer 30 on the cross section.

[0064] In this embodiment, the stacked battery with the edge passivation layer 30 plated is placed in an annealing device for annealing, the temperature is set to 80-200°C, the annealing time is 10min~30min, and after the annealing is completed, it is disassembled and subsequently packaged into a complete battery assembly after testing.

[0065] The above passivation method is mainly used for edge passivation of crystalline silicon / perovskite tandem solar cells. The use of laser etching and low-temperature breaking methods can reduce the ablation damage and flexible damage of the sub-cells in the tandem cells caused by high-power lasers in the traditional edge passivation process, thereby improving the performance of the tandem cells.

[0066] See also Figure 3 An embodiment of the present application provides a crystalline silicon / perovskite stacked solar cell, which is prepared by the above-mentioned edge passivation method, including: a crystalline silicon bottom cell 10 and a perovskite top cell 20 thereon, and an edge passivation layer 30 arranged on the sides of the crystalline silicon bottom cell 10 and the perovskite top cell 20.

[0067] Furthermore, the crystalline silicon bottom cell 10 can be selected from one of the crystalline silicon cell structures such as PERC cell, topcon cell or HJT.

[0068] When applied to a PERC cell, the crystalline silicon bottom cell 10 includes an aluminum back surface field, a passivation film, a P-type silicon wafer, and an N+ emitter from bottom to top.

[0069] When applied to a TOPcon cell, the crystalline silicon bottom cell 10 includes, from bottom to top, a metal gate line, a p+ emitter passivation film, a p+ emitter, an N-type silicon substrate, an ultra-thin tunneling oxide layer, and a phosphorus-doped polysilicon layer.

[0070] In this embodiment, taking HJT as an example, the crystalline silicon bottom cell 10 includes, from bottom to top, a first metal electrode layer 101, a first transparent electrode layer 102, a P-type base doping layer 103, a base passivation layer 104, a silicon substrate 105, a base surface passivation layer 106, an N-type base doping layer 107 and a tunneling layer 108; the perovskite top cell 20 includes a hole transport layer 201, a perovskite layer 202, a perovskite passivation layer 203, an electron transport layer 204, a second transparent electrode layer 205, a second metal electrode layer 206 and an anti-reflection layer 207, which are sequentially arranged on the crystalline silicon bottom cell 10.

[0071] In this embodiment, the crystalline silicon bottom cell 10 is prepared in the following manner: a base passivation layer 104 is prepared on the back side of a silicon substrate 105, and a phosphorus source is diffused into the base passivation layer 104 to form a P-type base doping layer 103; a base surface passivation layer 106 is prepared on the surface of the silicon substrate 105, and a nitrogen source is diffused into the base surface passivation layer 106 to form an N-type base doping layer 107 and a tunneling layer 108, and a first transparent electrode layer 102 and a first metal electrode layer 101 are sequentially formed on the surface of the P-type base doping layer 103, and finally the crystalline silicon bottom cell 10 is obtained.

[0072] In this embodiment, each film layer of the perovskite top cell 20 is formed on the crystalline silicon bottom cell 10 in sequence.

[0073] In this embodiment, the hole transport layer 201 is one or more of poly[bis(4-phenyl)(2,4,6-trimethylphenyl)amine] (PTAA), poly-3-hexylthiophene (P3HT), nickel oxide (NiOx), molybdenum trioxide (MoO3), cuprous iodide (CuI), and cuprous thiocyanate (CuSCN).

[0074] In this embodiment, the composition of the perovskite layer 202 may be an ABX3 structure, wherein:

[0075] A position is an organic cation, including CH3NH3 + (MA+), NH2CH=NH2 + (FA+), CH3CH2NH3 + or Cs + One or more of the following;

[0076] The B position is a metal cation, including Pb 2+ Sn 2+ One or more of the following;

[0077] The X position is a halogen anion, including F - , Cl - Br - ,I - One or more of the .

[0078] In this embodiment, the components of the perovskite passivation layer 203 include one or more of propylenediamine iodide, propylenediamine bromide (PDADBr), butylammonium chloride (BACl), butylammonium bromide (BABr), butylammonium iodide (BAI), N,N-dimethyl-1,3-propylenediamine hydrochloride (DMePDADCl), dodecanediaminium bromide (DDDADBr), magnesium fluoride, lithium fluoride (LiF), and sodium fluoride (NaF).

[0079] In this embodiment, the components of the electron transport layer 204 are zinc oxide (ZnO), tin dioxide (SnO2), titanium dioxide (TiO2), [6,6]-phenyl C 61 Methyl butyrate (PC 61 BM), carbon 60 (C 60 ), 2,9-dimethyl-4,7-diphenyl-1,10-phenanthroline (BCP) or more thereof.

[0080] In this embodiment, the anti-reflection layer 207 is made of one or more of magnesium fluoride, lithium fluoride (LiF), sodium fluoride (NaF), and silicon oxide (SiO 2 ).

[0081] In this embodiment, the first metal electrode layer 101 and the second metal electrode layer 206 are made of one or more of silver, gold, copper, aluminum, and carbon.

[0082] In this embodiment, the first transparent electrode layer 102 and the second transparent electrode layer 205 are made of a transparent material such as ITO and IZO.

[0083] See also Figure 4 In another embodiment, the above-mentioned edge passivation method can also be applied to the production of multi-layer solar cells, wherein the multi-layer solar cell structure includes: a crystalline silicon bottom cell 10 and a plurality of perovskite middle cells 21 and a perovskite top cell 20 thereon, and an edge passivation layer 30 arranged on the sides of the crystalline silicon bottom cell 10, the plurality of perovskite middle cells 21 and the perovskite top cell 20.

[0084] See also Figures 5 to 8 The present invention also provides a crystalline silicon / perovskite stacked solar cell edge passivation device 40, which is applied to the above passivation method, including a laser cutting machine 401, a low-temperature breaking machine 403, a deposition device 405, and a transmission device 404, wherein the laser cutting machine 401 and the low-temperature breaking machine 403 are sequentially arranged on the transmission device 404.

[0085] In this embodiment, the laser cutting machine 401 is composed of a laser system 4011, a cutting platform 4012, a cooling system, a positioning system and other components. The cutting platform 4012 is arranged on the transmission device 404, and the laser system 4011 is arranged above the cutting platform 4012 and fixed on the laser cutting machine 401. The laser system 4011 is used to emit high-power laser and adjust the running direction and height of the laser; the cutting platform 4012 is used to place the battery sample to be cut, which can play a role in fixing the position of the battery sample; the positioning system can assist the laser system to accurately cut the sample and determine the laser cutting path. During the cutting process, the cooling system can be used to control the laser cutting machine 401 to maintain a low temperature environment to reduce the damage to the battery caused by excessive cutting temperature.

[0086] In this embodiment, the low temperature breaking machine 403 includes a cooling system, a gantry transport system 4031, and a conical dividing table 4032. The cooling system controls the interior of the low temperature breaking machine to be in a low temperature environment of -15~15°C, and the battery sample is clamped by the gantry transport system 4031, and the sample is moved to the upper position of the conical dividing table 4032, and the laminated battery falls to obtain two laminated batteries.

[0087] In this embodiment, the transmission device 404 is composed of a plurality of conveyor belts and a control system. The control system independently controls the plurality of conveyor belts to transport the samples. Specifically, the plurality of conveyor belts include a feed conveyor belt, a first conveyor belt and a discharge conveyor belt. The feed conveyor belt is connected and fixed to the bottom of the laser cutting machine 401. The battery sample can be moved to the laser cutting machine 401 through the feed conveyor belt for cutting. After cutting, it is moved to the low-temperature breaking machine 403 through the first conveyor belt for cooling. Then, the battery sample is moved to the conical cutting table 4032 for breaking through the gantry transportation system 4031. The conical cutting table 4032 is transported out through the discharge conveyor belt. The collected cut laminated solar cells are stacked and placed in the carrier 50, and placed in the deposition equipment 405 for edge passivation deposition of the cross section.

[0088] In this embodiment, the deposition device 405 includes a deposition device gas system 4051, a vacuum system 4052, and a reaction chamber 4053. The vacuum system 4052 and the deposition device gas system 4051 are both connected to the reaction chamber 4053. The gas pressure of the reaction chamber 4053 is controlled by the vacuum system 4052 to maintain the vacuum environment inside the chamber, and the gas required for the reaction is injected into the reaction chamber 4053 through the deposition device gas system 4051, or useless gas after the reaction is extracted.

[0089] In another optional embodiment, the deposition device 405 can not only passivate the broken surface of the stacked battery, but also passivate the other three sides of the battery including the broken surface, so as to further improve the passivation effect of the battery.

[0090] In this embodiment, the carrier 50 includes a support frame 501, at least two fixing rods 502 and at least two baffles 503. The fixing rod 502 is provided with at least one fixing notch 5021 and is fixed on the support frame 501. The at least two baffles 503 are parallel, and each fixing notch 5021 is engaged with two baffles 503. The gap between each two baffles 503 is controlled by the fixing rod 502 to fix the stacked batteries between each two baffles 503.

[0091] Preferably, the number of the baffles 503 is an even number, and the plurality of fixing rods 502 are arranged in parallel, and each fixing rod 502 is fixed to the edge of every two baffles 503 in a bite-engaged manner through a fixing notch 5021 .

[0092] In an optional embodiment, the carrier 50 can clamp at least two broken laminated batteries, and if conditions permit, can also clamp more than 1000 broken laminated batteries.

[0093] The following specific embodiments and comparative examples are provided to clearly and completely describe the technical solution of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, rather than all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0094] Example 1

[0095] Step 1: Prepare a number of large-area crystalline silicon / perovskite stacked solar cells. A cell with an area of ​​M6 can be selected according to production needs. The cell includes a crystalline silicon bottom cell 10 and a perovskite top cell 20. The cell is placed on a conveyor belt with the crystalline silicon bottom cell 10 facing upward, and moved to a laser cutting machine 401 for cutting. The power of the laser cutting is controlled to be 100w, and a groove L1 is formed on the surface of the crystalline silicon bottom cell 10 on the stacked solar cell. The depth of the groove L1 is 40% of the thickness of the crystalline silicon bottom cell.

[0096] Step 2: Move the cut stacked solar cell to the low-temperature breaking machine 403 for cooling, control the internal temperature of the low-temperature breaking machine 403 to -10°C, and cool for 15 minutes. After cooling, clamp it to the upper position of the conical dividing table 4032 through the gantry transportation system 4031, align the cutting groove L1 with the dividing line of the conical dividing table 4032, and drop it to obtain two stacked solar cells.

[0097] Step three: stack several broken single stacked solar cells so that their laser cut sections are on the same plane, and place the stacked solar cells on a carrier 50, clamp and block them with a baffle 503, and then form an aluminum oxide passivation layer with a thickness of 20nm on the laser cut section; when the aluminum oxide passivation layer is deposited by atomic layer deposition, the deposition temperature is controlled to be 200°C; the deposition pressure is 1torr; the flow rate of TMA is 15000sccm, the flow rate of water vapor is 15000sccm, and the flow rate of nitrogen is 30000sccm.

[0098] Step 4: Place the solar cell with edge passivation and aluminum oxide film into the annealing equipment for annealing. The temperature is set to 200°C and the process time is 20 minutes. After the annealing is completed, the half-cell is sorted and tested, and then packaged into a half-cell module.

[0099] Example 2

[0100] The steps of this embodiment are consistent with those of the embodiment 1, except that the cutting depth of the groove L1 in step 1 is 60% of the thickness of the crystalline silicon bottom cell 10 .

[0101] Example 3

[0102] The steps of this embodiment are consistent with those of the embodiment 1, except that the cutting depth of the groove L1 in step 1 is 80% of the thickness of the crystalline silicon bottom cell 10 .

[0103] Example 4

[0104] The steps of this embodiment are consistent with those of embodiment 2, except that the cooling temperature of the cut stacked solar cell in step 3 is -15°C.

[0105] Example 5

[0106] The steps of this embodiment are consistent with those of embodiment 2, except that the cooling temperature of the cut stacked solar cell in step 3 is -5°C.

[0107] Example 6

[0108] The steps of this embodiment are consistent with those of embodiment 2, except that the cooling temperature of the cut stacked solar cell in step 3 is 0°C.

[0109] Comparative Example 1

[0110] Step 1: Prepare several large-area crystalline silicon-perovskite stacked solar cells. Cells with an area of ​​M6 can be selected according to production needs. The cells include a crystalline silicon bottom cell 10 and a perovskite top cell 20. Place the cells on a conveyor belt with the crystalline silicon bottom cell 10 facing upward, move them to a laser cutting machine for cutting, control the laser cutting power to 100w, cut the stacked solar cells, and obtain two solar cells.

[0111] Step 2: Stack several single stacked solar cells after cutting so that their laser cut sections are on the same plane, and place the stacked solar cells on a carrier 50, clamp and block them with a baffle 503, and then form an aluminum oxide passivation layer with a thickness of 20nm on the laser cut section; when the aluminum oxide passivation layer is deposited by atomic layer deposition, the deposition temperature is controlled to be 200°C; the deposition pressure is 1torr; the flow rate of TMA is 15000sccm, the flow rate of water vapor is 15000sccm, and the flow rate of nitrogen is 30000sccm.

[0112] Step 3: Place the solar cell with edge passivation and aluminum oxide film into the annealing equipment for annealing. The temperature is set to 200°C and the process time is 20 minutes. After the annealing is completed, the half-cell is sorted and tested, and then packaged into a half-cell module.

[0113] Comparative Example 2

[0114] The steps of this comparative example are consistent with those of Example 2, except that in step 2, the cut stacked solar cell is not cooled but broken at room temperature.

[0115] Comparative Example 3

[0116] The steps of this comparative example are the same as those of comparative example 1, except that the edge passivation process in step 2 is removed, and annealing, packaging and testing are directly performed. The comparative example directly uses solar cells cut by laser without any repair treatment.

[0117] The laminated solar cells obtained in Examples 1-3 and the comparative example were tested under the following test conditions: a standard solar intensity calibration was performed using a solar simulator, and a solar cell with an area of ​​1.0 cm 2 The device of the embodiment of the present invention is subjected to a long-term IV test, with the starting voltage set to 1.95V, the cut-off voltage set to 0V, the range set to 100mA, and the result is rounded to one decimal place. The test results are shown in Table 1 below.

[0118] Table 1. Performance test results of solar cells obtained in Examples 1 to 6 and Comparative Examples

[0119] Performance Indicators EFF(%) Voc(V) <![CDATA[ Isc(mA / cm 2 )]]> FF(%) Example 1 24.35 1.811 18.321 73.2 Example 2 24.75 1.815 18.331 74.4 Example 3 24.42 1.813 18.328 73.5 Example 4 24.32 1.806 18.326 73.5 Example 5 24.53 1.814 18.328 73.8 Example 6 24.27 1.807 18.323 73.3 Comparative Example 1 22.51 1.731 18.213 71.4 Comparative Example 2 23.65 1.786 18.248 72.6 Comparative Example 3 23.56 1.783 18.229 72.5

[0120] In Table 1, EFF refers to the battery conversion efficiency, Voc is the open circuit voltage of the battery cell, Isc is the short circuit current of the battery cell, and FF refers to the fill factor.

[0121] It can be seen from the table that the edge-passivated perovskite crystalline silicon laminated solar cell effectively protects the thin film along the edge of the perovskite solar cell, improves stability, effectively reduces the carrier recombination rate of the laser cutting surface of the battery and the edge of the battery cell, and effectively improves the conversion efficiency of the battery assembly. It can be shown in Examples 1-3 that different cutting depths have different effects on the performance of the battery. This is because the cutting depth is too high, and the high temperature during cutting will affect the structure of the perovskite film layer, thereby reducing the overall battery performance; if the cutting depth is too low, on the one hand, it will affect the structure of the silicon-based battery, and on the other hand, due to the insufficient breaking force required for the perovskite top battery to form a regular cross-section, the resulting battery cross-section structure has defects. In Examples 4-5 and Comparative Example 2, breaking at different temperatures will affect the cross-sectional regularity of the laminated battery. Cooling the laminated battery after cutting can reduce the heat conduction diffusion remaining on the crystalline silicon bottom battery after cutting, and avoid excessive temperature from destroying the crystal structure of the perovskite film; on the other hand, it can reduce the elastic strain of the perovskite thin film battery, increase its rigidity, and prevent the formation of irregular cross-sections.

[0122] Comparative Example 1 shows that only using laser to cut the entire perovskite-crystalline silicon stacked cell will seriously damage the perovskite film structure and reduce the photoelectric conversion efficiency and stability of the cell. Comparative Example 3 shows that when the passivation process is not performed after cutting, the defects of the cross section lead to serious composite loss on the cell surface.

[0123] The above embodiments are only preferred implementation modes of the present invention. It should be pointed out that for ordinary technicians in this technical field, various changes, modifications, substitutions and deformations can be made to these embodiments without departing from the principles of the present invention. These technical solutions that are equivalent to the claims of the present invention all fall within the protection scope of the present invention, and the protection scope of the present invention is limited by the attached claims and their equivalents.

Claims

1. A method for edge passivation of a crystalline silicon / perovskite tandem solar cell, characterized in that: The following steps are involved: A crystalline silicon / perovskite stacked solar cell is provided, wherein the stacked cell comprises a crystalline silicon bottom cell and a perovskite top cell thereon, laser cutting is performed on the surface of the stacked cell where the crystalline silicon bottom cell is located, a groove is formed on the crystalline silicon bottom cell, the stacked cell after the cutting is then placed in a low temperature environment for breaking, a plurality of broken stacked cells are stacked with the broken surfaces facing the same direction and placed in a carrier, the carrier is placed in a deposition device, an edge passivation layer is formed on the broken surfaces of the plurality of stacked cells, and the stacked cells are split to obtain a plurality of edge-passivated stacked cells.

2. The edge passivation method of crystalline silicon / perovskite tandem solar cell according to claim 1, characterized in that: When the stacked battery is laser cut, the groove is cut from the surface where the crystalline silicon bottom battery is located, and the groove depth does not exceed the thickness of the crystalline silicon bottom battery by controlling the laser power to 10-120W.

3. The edge passivation method of crystalline silicon / perovskite tandem solar cell according to claim 2, characterized in that: The groove depth is 30-90% of the thickness of the crystalline silicon bottom cell.

4. The edge passivation method of crystalline silicon / perovskite tandem solar cell according to claim 1, characterized in that: The stacked battery after cutting is cooled to a temperature of -15 to 15° C. in a low temperature environment for 2 to 30 minutes, and is broken after cooling.

5. The edge passivation method of crystalline silicon / perovskite tandem solar cell according to claim 1, characterized in that: After cutting, the stacked battery is moved to a low-temperature environment to cool down, and then the stacked battery falls on a conical dividing table at a height of 10cm~60cm due to gravity, and is divided into two half-sheets of stacked battery along the path where the grooves are located.

6. The edge passivation method of crystalline silicon / perovskite tandem solar cell according to claim 1, characterized in that: The edge passivation layer is prepared by one of the deposition methods of atomic layer deposition, evaporation, chemical vapor deposition, and magnetron sputtering. The edge passivation layer is selected from one or more thin films of aluminum oxide, silicon oxide, and aluminum nitride, and has a thickness of 5 to 100 nm.

7. The edge passivation method of crystalline silicon / perovskite tandem solar cell according to claim 1, characterized in that: The stacked battery with edge passivation layer plated is placed in an annealing device for annealing, the temperature is set to 80-200°C, the annealing time is 10min~30min, and after the annealing is completed, it is split.

8. The edge passivation method of crystalline silicon / perovskite tandem solar cell according to claim 1, characterized in that: The crystalline silicon bottom cell is selected from one of the crystalline silicon cell structures of PERC cell, topcon cell or HJT; the perovskite top cell includes a hole transport layer, a perovskite layer, a perovskite passivation layer, an electron transport layer, a second transparent electrode layer, a second metal electrode layer and an anti-reflection layer which are sequentially arranged on the crystalline silicon bottom cell.

9. A crystalline silicon / perovskite tandem solar cell edge passivation device, applied to the crystalline silicon / perovskite tandem solar cell edge passivation method according to any one of claims 1 to 8, characterized in that: It comprises a laser cutting machine, a low temperature breaking machine, a deposition device and a transmission device, wherein the laser cutting machine and the low temperature breaking machine are arranged on the transmission device in sequence.

10. The edge passivation device for crystalline silicon / perovskite tandem solar cell according to claim 9, characterized in that: The laser cutting machine is composed of a laser system, a cutting platform, a cooling system, and a positioning system. The cutting platform is arranged on the transmission device, and the laser system is arranged above the cutting platform and fixed on the laser cutting machine.

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