Solar laminated cell, solar module and solar cell manufacturing method

Abstract

The present invention is applicable to the field of solar cell technology and provides a solar tandem cell, a solar module, and a method for manufacturing a solar cell. The solar tandem cell sequentially comprises a perovskite top cell, a P-type microcrystalline silicon bonding layer, and an N-type crystalline silicon bottom cell. The P-type microcrystalline silicon bonding layer serves to conduct electricity between the perovskite top cell and the N-type crystalline silicon bottom cell. Thus, the P-type microcrystalline silicon bonding layer serves as a tunneling layer. Because the P-type microcrystalline silicon bonding layer has lower crystallinity than the N-type doped polycrystalline silicon layer, and has a higher defect state density and more carrier recombination centers, it can increase the open-circuit voltage and thus improve the conversion efficiency of the solar tandem cell.

Description

Technical Field

[0001] The present invention belongs to the technical field of solar cells, and in particular relates to a solar laminate cell, a solar module and a method for manufacturing a solar cell. Background Art

[0002] In related technologies, perovskite tandem cells are constructed by connecting the positive and negative electrodes of a perovskite cell and a topcon crystalline silicon cell in series. However, connecting these two different cell materials in series creates lattice mismatch and hinders tunneling, leading to a significant decrease in the fill factor (FF) and low cell conversion efficiency. Consequently, improving the conversion efficiency of solar tandem cells has become a pressing technical challenge. Summary of the Invention

[0003] The present invention provides a solar tandem cell, a solar module and a method for manufacturing a solar cell, aiming to solve the problem of how to improve the conversion efficiency of the solar tandem cell.

[0004] In a first aspect, the solar tandem cell provided by the present invention is provided with a perovskite top cell, a P-type microcrystalline silicon bonding layer and an N-type crystalline silicon bottom cell in sequence, and the P-type microcrystalline silicon bonding layer is used to conduct the perovskite top cell and the N-type crystalline silicon bottom cell.

[0005] Optionally, the thickness of the P-type microcrystalline silicon bonding layer is in the range of 5 nm to 20 nm.

[0006] Optionally, the P-type microcrystalline silicon bonding layer includes at least two layers of a P-type microcrystalline silicon layer, a hydrogen-doped P-type microcrystalline silicon oxide layer, and a hydrogen-doped P-type microcrystalline silicon layer.

[0007] Optionally, the P-type microcrystalline silicon bonding layer includes the P-type microcrystalline silicon layer, the hydrogen-doped P-type microcrystalline silicon oxide layer, and the hydrogen-doped P-type microcrystalline silicon layer, which are sequentially arranged from top to bottom.

[0008] Optionally, the thickness of the P-type microcrystalline silicon layer is in the range of 2 to 10 nm, the thickness of the hydrogen-doped P-type microcrystalline silicon oxide layer is in the range of 2 to 10 nm, and the thickness of the hydrogen-doped P-type microcrystalline silicon layer is in the range of 2 to 10 nm.

[0009] Optionally, the N-type crystalline silicon bottom cell includes topcon, HJT, IBC or HBC.

[0010] Optionally, the N-type crystalline silicon bottom cell includes a topcon, which is provided with an N-type doped polysilicon layer, a silicon dioxide layer, an N-type silicon wafer, a boron diffusion layer and a passivation layer from top to bottom.

[0011] Optionally, the perovskite top cell includes a transparent conductive layer, an electron transport layer, a perovskite absorption layer and a hole transport layer.

[0012] In a second aspect, the present invention provides a solar module comprising any one of the solar tandem cells described above.

[0013] In a third aspect, the present invention provides a method for manufacturing a solar cell, which is used to manufacture any of the above-mentioned solar cell tandem cells, and the method for manufacturing a solar cell comprises the following steps:

[0014] Making the N-type crystalline silicon bottom cell;

[0015] Depositing the P-type microcrystalline silicon bonding layer on the N-type crystalline silicon bottom cell;

[0016] A perovskite top cell is manufactured on the P-type microcrystalline silicon bonding layer.

[0017] The step of depositing the P-type microcrystalline silicon bonding layer on the N-type crystalline silicon bottom cell includes at least two of the following three steps:

[0018] B2H6 and SiH4 are introduced into the interior of the PECVD equipment to form a P-type microcrystalline silicon layer; or

[0019] Introducing H2, CO2, B2H6 and SiH4 into the PECVD equipment to form a hydrogen-doped P-type microcrystalline silicon oxide layer; or

[0020] H2, B2H6 and SiH4 are introduced into the PECVD equipment to form a hydrogen-doped P-type microcrystalline silicon layer.

[0021] Optionally, in the step of introducing B2H6 and SiH4 into the interior of the PECVD device to form the P-type microcrystalline silicon layer, the temperature is controlled within a range of 170° C. to 200° C., the ratio of B2H6 to SiH4 is 1 to 2:1, the power of the PECVD device is within a range of 2000 to 4000 W, and the thickness of the P-type microcrystalline silicon layer is within a range of 2 to 10 nm;

[0022] In the step of introducing H2, CO2, B2H6 and SiH4 into the interior of the PECVD device to form a hydrogen-doped P-type microcrystalline silicon oxide layer, the temperature is controlled within the range of 170° C. to 200° C., the ratio of H2, CO2, B2H6 and SiH4 is 200-300:100-200:1-2:1, the power of the PECVD device is within the range of 2000-4000 W, and the thickness of the hydrogen-doped P-type microcrystalline silicon oxide layer is within the range of 2-10 nm;

[0023] In the step of introducing H2, B2H6 and SiH4 into the interior of the PECVD equipment to form a hydrogen-doped P-type microcrystalline silicon layer, the temperature is controlled in the range of 170°C to 200°C, the ratio of H2, B2H6 and SiH4 is 200-300:1-2:1, the power of the PECVD equipment is in the range of 2000 to 4000W, and the thickness of the hydrogen-doped P-type microcrystalline silicon layer is in the range of 2 to 10nm.

[0024] In the manufacturing method of the solar tandem cell, solar module and solar cell of the embodiments of the present invention, a P-type microcrystalline silicon bonding layer is used as a tunneling layer. Since the P-type microcrystalline silicon bonding layer has lower crystallinity than the N-type doped polycrystalline silicon layer, and has a higher defect state density and more carrier recombination centers, the open circuit voltage can be superimposed, thereby improving the conversion efficiency of the solar tandem cell. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 Schematic diagram of the structure of a solar tandem cell according to an embodiment of the present invention;

[0026] Figure 2 Schematic diagram of the morphology of the P-type microcrystalline silicon bonding layer in the solar tandem cell according to an embodiment of the present invention;

[0027] Figure 3 is another structural schematic diagram of a solar tandem cell according to an embodiment of the present invention;

[0028] Figure 4 It is a schematic flow chart of a method for manufacturing a solar cell according to an embodiment of the present invention.

[0029] Description of main component symbols:

[0030] Solar stack cell 10, perovskite top cell 12, top electrode 121, transparent conductive layer 122, electron transport layer 124, perovskite absorption layer 126, hole transport layer 128, P-type microcrystalline silicon bonding layer 14, N-type crystalline silicon bottom cell 16, N-type doped polysilicon layer 162, silicon dioxide layer 164, N-type silicon wafer 166, boron diffusion layer 168, passivation layer 169, bottom electrode 161. DETAILED DESCRIPTION

[0031] In order to make the purpose, technical solutions and advantages of the present invention more clearly understood, the present invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not intended to limit the present invention.

[0032] Existing perovskite tandem cells connect two different materials in series, resulting in low cell efficiency. However, the solar tandem cell of the present invention uses a P-type microcrystalline silicon bonding layer as a tunneling layer to connect the perovskite top cell and the N-type crystalline silicon bottom cell, which can improve the conversion efficiency of the solar tandem cell.

[0033] See also Figure 1 The solar tandem cell 10 provided in an embodiment of the present invention is provided with a perovskite top cell 12, a P-type microcrystalline silicon bonding layer 14 and an N-type crystalline silicon bottom cell 16 in sequence, and the P-type microcrystalline silicon bonding layer 14 is used to conduct the perovskite top cell 12 and the N-type crystalline silicon bottom cell 16.

[0034] The solar tandem cell 10 of the embodiment of the present invention utilizes a P-type microcrystalline silicon bonding layer as a tunneling layer. Since the P-type microcrystalline silicon bonding layer has lower crystallinity than the N-type doped polycrystalline silicon layer, and has a higher defect state density and more carrier recombination centers, the open circuit voltage can be superimposed, thereby improving the conversion efficiency of the solar tandem cell 10.

[0035] Please note that the embodiment of the present invention utilizes the P-type microcrystalline silicon bonding layer as a tunneling layer, so the P-type microcrystalline silicon bonding layer connecting the perovskite top cell 12 and the N-type crystalline silicon bottom cell 16 does not include a tunneling layer.

[0036] Specifically, the perovskite top cell 12 includes a transparent conductive layer 122, an electron transport layer 124, a perovskite absorber layer 126, and a hole transport layer 128. The perovskite top cell 12 may also include a top electrode 121. The top electrode 121 may be a silver electrode. Silver has good conductivity, and using silver as an electrode can improve the performance of the perovskite top cell 12.

[0037] See also Figure 2 , Figure 2 FIG2 is a schematic diagram of the morphology of the P-type microcrystalline silicon bonding layer 14 in the solar tandem cell 10 according to an embodiment of the present invention, as measured using a transmission electron microscope (TEM). The lattice arrangement of the P-type microcrystalline silicon bonding layer 14 is partially long-range ordered and partially disordered.

[0038] Optionally, the P-type microcrystalline silicon bonding layer 14 includes at least two layers of a P-type microcrystalline silicon layer, a hydrogen-doped P-type microcrystalline silicon oxide layer, and a hydrogen-doped P-type microcrystalline silicon layer.

[0039] In this way, the P-type microcrystalline silicon bonding layer 14 further improves the lattice matching, reduces grain boundary defects, and enhances the interface contact performance, which is beneficial to improving the conversion efficiency of the solar tandem cell 10 .

[0040] In one example, the P-type microcrystalline silicon bonding layer 14 is composed of a P-type microcrystalline silicon layer and a hydrogen-doped P-type microcrystalline silicon oxide layer; in another example, the P-type microcrystalline silicon bonding layer 14 is composed of a P-type microcrystalline silicon layer and a hydrogen-doped P-type microcrystalline silicon layer; in yet another example, the P-type microcrystalline silicon bonding layer 14 is composed of a hydrogen-doped P-type microcrystalline silicon oxide layer and a hydrogen-doped P-type microcrystalline silicon layer; in yet another example, the P-type microcrystalline silicon bonding layer 14 is composed of a P-type microcrystalline silicon layer, a hydrogen-doped P-type microcrystalline silicon oxide layer and a hydrogen-doped P-type microcrystalline silicon layer.

[0041] In the example where the P-type microcrystalline silicon bonding layer 14 is composed of a P-type microcrystalline silicon layer and a hydrogen-doped P-type microcrystalline silicon oxide layer, the P-type microcrystalline silicon layer and the hydrogen-doped P-type microcrystalline silicon oxide layer can be stacked in sequence along the direction from the perovskite top cell 12 to the N-type crystalline silicon bottom cell 16, or the hydrogen-doped P-type microcrystalline silicon oxide layer and the P-type microcrystalline silicon layer can be stacked in sequence.

[0042] In the example where the P-type microcrystalline silicon bonding layer 14 is composed of a P-type microcrystalline silicon layer and a hydrogen-doped P-type microcrystalline silicon layer, along the direction from the perovskite top cell 12 to the N-type crystalline silicon bottom cell 16, the P-type microcrystalline silicon layer and the hydrogen-doped P-type microcrystalline silicon layer can be stacked in sequence, or the hydrogen-doped P-type microcrystalline silicon layer and the P-type microcrystalline silicon layer can be stacked in sequence.

[0043] In the example where the P-type microcrystalline silicon bonding layer 14 is composed of a hydrogen-doped P-type microcrystalline silicon oxide layer and a hydrogen-doped P-type microcrystalline silicon layer, the hydrogen-doped P-type microcrystalline silicon oxide layer and the hydrogen-doped P-type microcrystalline silicon layer can be stacked in sequence along the direction from the perovskite top cell 12 to the N-type crystalline silicon bottom cell 16, or the hydrogen-doped P-type microcrystalline silicon layer and the hydrogen-doped P-type microcrystalline silicon oxide layer can be stacked in sequence.

[0044] In the example where the P-type microcrystalline silicon bonding layer 14 is composed of a P-type microcrystalline silicon layer, a hydrogen-doped P-type microcrystalline silicon oxide layer, and a hydrogen-doped P-type microcrystalline silicon layer, along the direction from the perovskite top cell 12 to the N-type crystalline silicon bottom cell 16, the P-type microcrystalline silicon layer, the hydrogen-doped P-type microcrystalline silicon oxide layer, and the hydrogen-doped P-type microcrystalline silicon layer may be stacked in sequence, or the P-type microcrystalline silicon layer, the hydrogen-doped P-type microcrystalline silicon layer, and the hydrogen-doped P-type microcrystalline silicon oxide layer may be stacked in sequence, or the hydrogen-doped P-type microcrystalline silicon oxide layer, the P-type microcrystalline silicon layer, and the hydrogen-doped P-type microcrystalline silicon layer may be stacked in sequence, or the hydrogen-doped P-type microcrystalline silicon oxide layer, the P-type microcrystalline silicon layer, and the hydrogen-doped P-type microcrystalline silicon layer may be stacked in sequence, or the hydrogen-doped P-type microcrystalline silicon layer, the hydrogen-doped P-type microcrystalline silicon oxide layer, and the P-type microcrystalline silicon layer may be stacked in sequence, or the hydrogen-doped P-type microcrystalline silicon layer, the hydrogen-doped P-type microcrystalline silicon oxide layer, and the P-type microcrystalline silicon layer may be stacked in sequence.

[0045] The specific structure and stacking sequence of the P-type microcrystalline silicon bonding layer 14 are not limited here.

[0046] In this embodiment, the P-type microcrystalline silicon bonding layer 14 includes a P-type microcrystalline silicon layer, a hydrogen-doped P-type microcrystalline silicon oxide layer, and a hydrogen-doped P-type microcrystalline silicon layer, which are arranged in sequence from top to bottom. In this way, the hydrogen-doped P-type microcrystalline silicon layer can achieve lattice matching with the bottom cell by controlling the crystallization rate and hydrogen passivation, and can further enhance the passivation effect at the interface. The addition of a hydrogen-doped P-type microcrystalline silicon oxide layer between the P-type microcrystalline silicon layer and the hydrogen-doped P-type microcrystalline silicon layer can achieve good energy level matching between the layers, allowing for more selective carrier passage, reducing interface recombination, increasing the effective area of ​​the perovskite, and improving the conversion efficiency of the solar tandem cell 10.

[0047] Optionally, the thickness of the P-type microcrystalline silicon bonding layer 14 is in the range of 5 to 20 nm. For example, it is 5 nm, 5.1 nm, 6.2 nm, 6.8 nm, 7.3 nm, 8.5 nm, 9.7 nm, 10 nm, 10.1 nm, 11 nm, 12.2 nm, 13.8 nm, 14.3 nm, 15.5 nm, 16.7 nm, 17 nm, 18.3 nm, 19.6 nm, or 20 nm. This improves the performance of the P-type microcrystalline silicon bonding layer 14 and helps improve the conversion efficiency of the solar tandem cell 10.

[0048] Specifically, the thickness of the P-type microcrystalline silicon bonding layer 14 can be controlled by controlling the deposition time and ventilation volume. In this way, the thickness of the P-type microcrystalline silicon bonding layer 14 can be conveniently and accurately controlled, thereby improving production efficiency and ensuring conversion efficiency.

[0049] Preferably, the thickness of the P-type microcrystalline silicon bonding layer 14 is in the range of 5 to 10 nm. For example, it is 5 nm, 5.1 nm, 6.2 nm, 6.8 nm, 7.3 nm, 8.5 nm, 9.7 nm, and 10 nm. This improves the performance of the P-type microcrystalline silicon bonding layer 14, which is conducive to further improving the conversion efficiency of the solar tandem cell 10. Moreover, experiments have shown that when the thickness of the P-type microcrystalline silicon bonding layer 14 is between 5 and 10 nm, the effect of improving conversion efficiency is relatively good, and the conversion efficiency is the highest.

[0050] Optionally, the conversion efficiency can be further improved by controlling the thickness of each layer in the P-type microcrystalline silicon bonding layer 14. Specifically, the thickness of the P-type microcrystalline silicon layer is within a range of 2 to 10 nm, the thickness of the hydrogen-doped P-type microcrystalline silicon oxide layer is within a range of 2 to 10 nm, and the thickness of the hydrogen-doped P-type microcrystalline silicon layer is within a range of 2 to 10 nm. This helps improve the conversion efficiency of the solar tandem cell 10.

[0051] Specifically, the thickness of the P-type microcrystalline silicon layer is, for example, 2 nm, 2.1 nm, 3.2 nm, 4.5 nm, 5.3 nm, 6.8 nm, 7.3 nm, 8.5 nm, 9.7 nm, and 10 nm. The thickness of the hydrogen-doped P-type microcrystalline silicon oxide layer is, for example, 2 nm, 2.1 nm, 3.2 nm, 4.5 nm, 5.3 nm, 6.8 nm, 7.3 nm, 8.5 nm, 9.7 nm, and 10 nm. The thickness of the hydrogen-doped P-type microcrystalline silicon layer is, for example, 2 nm, 2.1 nm, 3.2 nm, 4.5 nm, 5.3 nm, 6.8 nm, 7.3 nm, 8.5 nm, 9.7 nm, and 10 nm. The specific values ​​of the thicknesses of the P-type microcrystalline silicon layer, the hydrogen-doped P-type microcrystalline silicon oxide layer, and the hydrogen-doped P-type microcrystalline silicon layer are not limited herein, as long as they are within the aforementioned ranges.

[0052] Preferably, the thickness of the P-type microcrystalline silicon layer is within the range of 2 to 5 nm, the thickness of the hydrogen-doped P-type microcrystalline silicon oxide layer is within the range of 2 to 5 nm, and the thickness of the hydrogen-doped P-type microcrystalline silicon layer is within the range of 2 to 5 nm. This helps further improve the conversion efficiency of the solar tandem cell 10. Furthermore, experiments have shown that when the thickness of each layer of the P-type microcrystalline silicon bonding layer 14 is within the aforementioned ranges, the effect of improving conversion efficiency is relatively good, with the highest conversion efficiency improvement achieved.

[0053] Specifically, the thickness of the P-type microcrystalline silicon layer is, for example, 2 nm, 2.1 nm, 2.8 nm, 3.2 nm, 3.7 nm, 4.5 nm, 4.8 nm, and 5 nm. The thickness of the hydrogen-doped P-type microcrystalline silicon oxide layer is, for example, 2 nm, 2.1 nm, 2.8 nm, 3.2 nm, 3.7 nm, 4.5 nm, 4.8 nm, and 5 nm. The thickness of the hydrogen-doped P-type microcrystalline silicon layer is, for example, 2 nm, 2.1 nm, 2.8 nm, 3.2 nm, 3.7 nm, 4.5 nm, 4.8 nm, and 5 nm. The specific values ​​of the thicknesses of the P-type microcrystalline silicon layer, the hydrogen-doped P-type microcrystalline silicon oxide layer, and the hydrogen-doped P-type microcrystalline silicon layer are not limited herein, as long as they are within the aforementioned ranges.

[0054] Preferably, the thickness of the P-type microcrystalline silicon layer is within a range of 2 to 5 nm, the thickness of the hydrogen-doped P-type microcrystalline silicon oxide layer is within a range of 2 to 5 nm, and the thickness of the hydrogen-doped P-type microcrystalline silicon layer is within a range of 2 to 5 nm. Furthermore, the thickness of the P-type microcrystalline silicon bonding layer 14 is within a range of 5 to 10 nm. In this way, the conversion efficiency of the solar tandem cell 10 is improved from two aspects: the total thickness of the P-type microcrystalline silicon bonding layer 14 and the thickness of each layer in the P-type microcrystalline silicon bonding layer 14, thereby further enhancing the conversion efficiency.

[0055] Optionally, the N-type crystalline silicon bottom cell 16 includes topcon, HJT, IBC or HBC. Thus, the N-type crystalline silicon bottom cell 16 can be in various forms and can be selected according to actual conditions.

[0056] Specifically, a TOPCon (Tunnel Oxide Passivated Contact) cell includes a tunnel oxide layer and a thin layer of polysilicon, which together form a passivated contact structure. This structure can passivate the cell surface and increase the open-circuit voltage.

[0057] Specifically, an HJT (Heterojunction with Intrinsic Thinfilm) cell can include an N-type doped amorphous silicon layer, an intrinsic amorphous silicon layer, an N-type silicon wafer 166, an intrinsic amorphous silicon layer, a P-type doped amorphous silicon layer, and a transparent conductive film. Thus, the intrinsic amorphous silicon layer, disposed between the N-type silicon wafer 166 and the P-type doped amorphous silicon layer, provides surface passivation for the cell, thereby improving the cell's conversion efficiency.

[0058] Specifically, the metal grid electrode of an IBC (Interdigitated back contact) battery is located on the back side, so that the front surface is not blocked, which can reduce optical loss and help improve the conversion efficiency of the battery.

[0059] Specifically, HBC (interdigitated back contact heterojunction) cells combine the advantages of IBC cells and HJT cells, which can further improve the conversion efficiency of cells.

[0060] See also Figure 3 In this embodiment, the N-type crystalline silicon bottom cell 16 includes a topcon, which comprises, from top to bottom, an N-type doped polysilicon layer 162, a silicon dioxide layer 164, an N-type silicon wafer 166, a boron diffusion layer 168, and a passivation layer 169. Thus, the silicon dioxide layer 164 and the N-type doped polysilicon layer 162 form a passivation contact structure, which can passivate the cell surface and help improve the cell's conversion efficiency.

[0061] It is understood that the silicon dioxide layer 164 in this embodiment is a tunneling layer. That is, in this embodiment, the tunneling layer is located in the N-type crystalline silicon bottom cell 16, while the P-type microcrystalline silicon bonding layer does not include a tunneling layer.

[0062] Specifically, the N-type crystalline silicon bottom cell 16 may include a bottom electrode 161. The bottom electrode 161 may be a silver electrode. Silver has good conductivity, and using silver as an electrode is beneficial to the performance of the N-type crystalline silicon bottom cell 16.

[0063] The solar module provided by the embodiment of the present invention includes any one of the above-mentioned solar tandem cells 10 .

[0064] In the solar module of the embodiment of the present invention, a P-type microcrystalline silicon bonding layer is used as a tunneling layer. Since the P-type microcrystalline silicon bonding layer has lower crystallinity than the N-type doped polycrystalline silicon layer, and has a higher defect state density and more carrier recombination centers, the open circuit voltage can be superimposed, thereby improving the conversion efficiency of the solar tandem cell 10.

[0065] See also Figure 4 The solar cell manufacturing method provided in the embodiment of the present invention is used to manufacture any of the above-mentioned solar tandem cells 10, and the solar cell manufacturing method includes the following steps:

[0066] Step S12: making an N-type crystalline silicon bottom cell 16;

[0067] Step S14: depositing a P-type microcrystalline silicon bonding layer 14 on the N-type crystalline silicon bottom cell 16;

[0068] Step S16 : fabricating a perovskite top cell 12 on the P-type microcrystalline silicon bonding layer 14 .

[0069] In the solar cell manufacturing method of the embodiment of the present invention, a P-type microcrystalline silicon bonding layer is used as a tunneling layer. Since the P-type microcrystalline silicon bonding layer has lower crystallinity than the N-type doped polycrystalline silicon layer, and has a higher defect state density and more carrier recombination centers, the open circuit voltage can be superimposed, thereby improving the conversion efficiency of the solar stack cell 10.

[0070] Please note that the embodiment of the present invention utilizes the P-type microcrystalline silicon bonding layer as a tunneling layer, so the P-type microcrystalline silicon bonding layer connecting the perovskite top cell 12 and the N-type crystalline silicon bottom cell 16 does not include a tunneling layer.

[0071] Specifically, in step S12, a boron diffusion layer 168 can be formed on an N-type silicon wafer 166 by using a laser grooving and local diffusion process; borosilicate glass (BSG) removal; cleaning the silicon wafer; depositing a silicon dioxide layer 164 (SiOx) by PECVD or LPCVD; depositing an N-type layer (N layer) by PECVD; high-temperature annealing and diffusion to form an N-type doped polycrystalline silicon layer 162 (Npolycrystal); wet cleaning the silicon wafer; depositing Al2O3 and SiN by PECVD. x A passivation layer 169 is formed, and a silver electrode is formed by screen printing and high-temperature sintering. In this way, an N-type crystalline silicon bottom cell 16 is manufactured.

[0072] Specifically, in step S14, the prepared N-type crystalline silicon bottom cell 16 can be placed in PECVD, with the N-type doped polysilicon layer 162 of the N-type crystalline silicon bottom cell 16 facing upward, and H2, B2H6 and SiH4 are introduced. The temperature is controlled in the range of 170 to 200°C, the ratio of H2, B2H6 and SiH4 is 200 to 300:1:1, the power of the PECVD equipment is in the range of 2000 to 4000W, and the thickness of the P-type microcrystalline silicon bonding layer 14 is in the range of 5 to 20nm.

[0073] Furthermore, the temperature is, for example, 170° C., 173° C., 182° C., 195° C., 198° C., or 200° C. The ratio of H2, B2H6, and SiH4 is, for example, 200:1:1, 210:1:1, 230:1:1, 250:1:1, 280:1:1, 290:1:1, or 300:1:1. The power of the PECVD equipment is, for example, 2000 W, 2100 W, 2250 W, 2600 W, 3000 W, 3200 W, 3600 W, 3800 W, or 4000 W. The thickness of the P-type microcrystalline silicon bonding layer 14 is, for example, 5 nm, 5.1 nm, 6.2 nm, 6.8 nm, 7.3 nm, 8.5 nm, 9.7 nm, 10 nm, 10.1 nm, 11 nm, 12.2 nm, 13.8 nm, 14.3 nm, 15.5 nm, 16.7 nm, 17 nm, 18.3 nm, 19.6 nm, or 20 nm.

[0074] Preferably, the thickness of the P-type microcrystalline silicon bonding layer 14 is in the range of 5 to 10 nm, for example, 5 nm, 5.3 nm, 6.8 nm, 7.3 nm, 8.5 nm, 9.7 nm, or 10 nm.

[0075] It can be understood that since a low-temperature process of less than 200°C is used and the plated silver electrode is located on the back, the impact on subsequent coating is limited, so the process steps can be effectively reduced and the production efficiency can be improved. After the P-type microcrystalline silicon bonding layer 14 is plated, the perovskite top cell 12 can continue to be produced.

[0076] Specifically, in step S16, a hole transport layer 128 (Spiro) is fabricated; a perovskite absorption layer 126 is fabricated; lithium fluoride (LiF), carbon 60 (C60), and tin oxide (SnO2) are fabricated to form an electron transport layer 124; a transparent conductive oxide (TCO) layer 122 is fabricated; and a silver electrode is fabricated. Thus, the perovskite top cell 12 is fabricated.

[0077] Optionally, step S14 includes at least two of the following three steps:

[0078] B2H6 and SiH4 are introduced into the interior of the PECVD equipment to form a P-type microcrystalline silicon layer; or

[0079] Introducing H2, CO2, B2H6 and SiH4 into the PECVD equipment to form a hydrogen-doped P-type microcrystalline silicon oxide layer; or

[0080] H2, B2H6 and SiH4 are introduced into the PECVD equipment to form a hydrogen-doped P-type microcrystalline silicon layer.

[0081] In this manner, a P-type microcrystalline silicon bonding layer 14 is deposited on the N-type crystalline silicon bottom cell 16, such that the P-type microcrystalline silicon bonding layer 14 is composed of at least two layers: a P-type microcrystalline silicon layer, a hydrogen-doped P-type microcrystalline silicon oxide layer, and a hydrogen-doped P-type microcrystalline silicon layer. This further improves lattice matching, reduces grain boundary defects, and enhances interface contact performance, thereby increasing the conversion efficiency of the solar tandem cell 10.

[0082] Specifically, in one example, step S14 includes introducing B2H6 and SiH4 into the PECVD apparatus to form a P-type microcrystalline silicon layer; and introducing H2, CO2, B2H6, and SiH4 into the PECVD apparatus to form a hydrogen-doped P-type microcrystalline silicon oxide layer. Please note that the order of these two steps is interchangeable and is not limited herein.

[0083] In another example, step S14 includes introducing B2H6 and SiH4 into the PECVD apparatus to form a P-type microcrystalline silicon layer; and introducing H2, B2H6, and SiH4 into the PECVD apparatus to form a hydrogen-doped P-type microcrystalline silicon layer. Please note that the order of these two steps is interchangeable and is not limited herein.

[0084] In another example, step S14 includes introducing H2, CO2, B2H6, and SiH4 into the PECVD apparatus to form a hydrogen-doped P-type microcrystalline silicon oxide layer; and introducing H2, B2H6, and SiH4 into the PECVD apparatus to form a hydrogen-doped P-type microcrystalline silicon layer. Please note that the order of these two steps is interchangeable and is not limited herein.

[0085] In another example, step S14 at least includes introducing B2H6 and SiH4 into the PECVD apparatus to form a P-type microcrystalline silicon layer; introducing H2, CO2, B2H6, and SiH4 into the PECVD apparatus to form a hydrogen-doped P-type microcrystalline silicon oxide layer; and introducing H2, B2H6, and SiH4 into the PECVD apparatus to form a hydrogen-doped P-type microcrystalline silicon layer. Please note that the order of these three steps is interchangeable and is not limited herein.

[0086] Optionally, in the step of introducing B2H6 and SiH4 into the PECVD equipment to form a P-type microcrystalline silicon layer, the temperature is controlled in the range of 170°C to 200°C, the ratio of B2H6 to SiH4 is 1 to 2:1, the power of the PECVD equipment is in the range of 2000 to 4000W, and the thickness of the P-type microcrystalline silicon layer is in the range of 2 to 10nm.

[0087] In this way, the production of a P-type microcrystalline silicon layer is achieved. Moreover, since a low-temperature process of less than 200°C is used and the plated silver electrode is located on the back, the impact on subsequent coating is limited, thus effectively reducing the number of process steps and improving production efficiency.

[0088] Specifically, the temperature is, for example, 170° C., 173° C., 182° C., 195° C., 198° C., or 200° C. The ratio of B2H6 to SiH4 is, for example, 1:1, 1.2:1, 1.5:1, 1.8:1, or 2:1. The power of the PECVD equipment is, for example, 2000 W, 2100 W, 2250 W, 2600 W, 3000 W, 3200 W, 3600 W, 3800 W, or 4000 W. The thickness of the P-type microcrystalline silicon layer is, for example, 2 nm, 2.1 nm, 3.2 nm, 4.5 nm, 5.3 nm, 6.8 nm, 7.3 nm, 8.5 nm, 9.7 nm, or 10 nm.

[0089] Preferably, the thickness of the P-type microcrystalline silicon layer is in the range of 2 to 5 nm, for example, 2 nm, 2.1 nm, 2.8 nm, 3.2 nm, 3.7 nm, 4.5 nm, 4.8 nm, or 5 nm.

[0090] Optionally, in the step of introducing H2, CO2, B2H6 and SiH4 into the interior of the PECVD equipment to form a hydrogen-doped P-type microcrystalline silicon oxide layer, the temperature is controlled to be in the range of 170°C to 200°C, the ratio of H2, CO2, B2H6 and SiH4 is 200-300:100-200:1-2:1, the power of the PECVD equipment is in the range of 2000 to 4000W, and the thickness of the hydrogen-doped P-type microcrystalline silicon oxide layer is in the range of 2 to 10nm.

[0091] In this way, the hydrogen-doped P-type microcrystalline silicon oxide layer is produced. Moreover, since a low-temperature process of less than 200°C is used and the plated silver electrode is located on the back, the impact on subsequent coating is limited, thus effectively reducing the number of process steps and improving production efficiency.

[0092] Specifically, the temperatures are, for example, 170° C., 173° C., 182° C., 195° C., 198° C., and 200° C. The ratios of H 2 , CO 2 , B 2 H 6 , and SiH 4 are, for example, 200:100:1:1, 225:100:1:1, 250:100:1:1, 280:100:1:1, 200:110:1:1, 200:150:1:1, 200:180:1:1, 200:100:1.2:1, 200:100:1.5:1, 200:100:1.8:1, and 300:200:2:1. The power of the PECVD equipment is, for example, 2000 W, 2100 W, 2250 W, 2600 W, 3000 W, 3200 W, 3600 W, 3800 W, or 4000 W. The thickness of the hydrogen-doped P-type microcrystalline silicon oxide layer is, for example, 2 nm, 2.1 nm, 3.2 nm, 4.5 nm, 5.3 nm, 6.8 nm, 7.3 nm, 8.5 nm, 9.7 nm, or 10 nm.

[0093] Preferably, the thickness of the hydrogen-doped P-type microcrystalline silicon oxide layer is in the range of 2 to 5 nm, for example, 2 nm, 2.1 nm, 2.8 nm, 3.2 nm, 3.7 nm, 4.5 nm, 4.8 nm, or 5 nm.

[0094] In the step of introducing H2, B2H6 and SiH4 into the PECVD equipment to form a hydrogen-doped P-type microcrystalline silicon layer, the temperature is controlled in the range of 170°C to 200°C, the ratio of H2, B2H6 and SiH4 is 200-300:1-2:1, the power of the PECVD equipment is in the range of 2000 to 4000W, and the thickness of the hydrogen-doped P-type microcrystalline silicon layer is in the range of 2 to 10nm.

[0095] In this way, the production of hydrogen-doped P-type microcrystalline silicon layers is achieved. Moreover, since a low-temperature process of less than 200°C is used and the plated silver electrode is located on the back, the impact on subsequent coating is limited, thus effectively reducing the number of process steps and improving production efficiency.

[0096] Specifically, the temperature is, for example, 170° C., 173° C., 182° C., 195° C., 198° C., or 200° C. The ratio of H 2 , B 2 H 6 , and SiH 4 is, for example, 200:1:1, 220:1:1, 250:1:1, 280:1:1, 200:1.2:1, 200:1.5:1, 200:1.8:1, or 300:2:1. The power of the PECVD equipment is, for example, 2000 W, 2100 W, 2250 W, 2600 W, 3000 W, 3200 W, 3600 W, 3800 W, or 4000 W. The thickness of the hydrogen-doped P-type microcrystalline silicon layer is, for example, 2 nm, 2.1 nm, 3.2 nm, 4.5 nm, 5.3 nm, 6.8 nm, 7.3 nm, 8.5 nm, 9.7 nm, or 10 nm.

[0097] Preferably, the thickness of the hydrogen-doped P-type microcrystalline silicon layer is in the range of 2 to 5 nm, for example, 2 nm, 2.1 nm, 2.8 nm, 3.2 nm, 3.7 nm, 4.5 nm, 4.8 nm, or 5 nm.

[0098] For other explanations and descriptions of the solar cell manufacturing method according to the embodiment of the present invention, please refer to the above text, which will not be repeated here to avoid redundancy.

[0099] Table 1 below compares the cell characteristics of conventional solar cells and a solar tandem cell 10 according to an embodiment of the present invention. Comparative Example 1 shows a high-efficiency tunneling perovskite tandem solar cell according to conventional technology, while Comparative Example 2 shows a perovskite tandem solar cell with only one microcrystalline silicon layer. The bottom cell used in both examples is an N-type topcon cell.

[0100]

[0101] Obviously, the solar tandem cell 10 according to the embodiment of the present invention has a higher open circuit voltage, a lower short circuit current, a smaller decrease in fill factor, and a higher conversion efficiency.

[0102] The above are only preferred embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.

Claims

1. A solar tandem cell, characterized in that: A perovskite top cell, a P-type microcrystalline silicon bonding layer and an N-type crystalline silicon bottom cell are sequentially provided, wherein the P-type microcrystalline silicon bonding layer is used to conduct the perovskite top cell and the N-type crystalline silicon bottom cell; The P-type microcrystalline silicon bonding layer includes a P-type microcrystalline silicon layer, a hydrogen-doped P-type microcrystalline silicon oxide layer, and a hydrogen-doped P-type microcrystalline silicon layer arranged in sequence from top to bottom; The thickness of the P-type microcrystalline silicon layer is in the range of 2.1 to 4.8 nm, the thickness of the hydrogen-doped P-type microcrystalline silicon oxide layer is in the range of 2.1 to 4.8 nm, and the thickness of the hydrogen-doped P-type microcrystalline silicon layer is in the range of 2.1 to 5 nm.

2. The solar tandem cell according to claim 1, characterized in that: The N-type crystalline silicon bottom cell includes topcon, HJT, IBC or HBC.

3. The solar tandem cell according to claim 1, characterized in that: The N-type crystalline silicon bottom cell includes a topcon, which is provided with an N-type doped polysilicon layer, a silicon dioxide layer, an N-type silicon wafer, a boron diffusion layer and a passivation layer from top to bottom.

4. The solar tandem cell according to claim 1, characterized in that: The perovskite top cell includes a transparent conductive layer, an electron transport layer, a perovskite absorption layer and a hole transport layer.

5. A solar module, characterized in that: The solar cell comprises the solar tandem cell according to any one of claims 1 to 4.

6. A method for manufacturing a solar cell, characterized in that: For manufacturing the solar cell stack according to any one of claims 1 to 5, the solar cell manufacturing method comprises the following steps: Making the N-type crystalline silicon bottom cell; Depositing the P-type microcrystalline silicon bonding layer on the N-type crystalline silicon bottom cell; wherein the P-type microcrystalline silicon bonding layer comprises a P-type microcrystalline silicon layer, a hydrogen-doped P-type microcrystalline silicon oxide layer, and a hydrogen-doped P-type microcrystalline silicon layer arranged in sequence from top to bottom; the thickness of the P-type microcrystalline silicon layer is in the range of 2.1 to 4.8 nm, the thickness of the hydrogen-doped P-type microcrystalline silicon oxide layer is in the range of 2.1 to 4.8 nm, and the thickness of the hydrogen-doped P-type microcrystalline silicon layer is in the range of 2.1 to 5 nm; A perovskite top cell is manufactured on the P-type microcrystalline silicon bonding layer.

7. The method for manufacturing a solar cell according to claim 6, wherein: The step of depositing the P-type microcrystalline silicon bonding layer on the N-type crystalline silicon bottom cell comprises: B2H6 and SiH4 are introduced into the PECVD device to form the P-type microcrystalline silicon layer; introducing H2, CO2, B2H6 and SiH4 into the interior of the PECVD device to form the hydrogen-doped P-type microcrystalline silicon oxide layer; H2, B2H6 and SiH4 are introduced into the PECVD equipment to form the hydrogen-doped P-type microcrystalline silicon layer.

8. The method for manufacturing a solar cell according to claim 7, wherein: In the step of introducing B2H6 and SiH4 into the PECVD device to form the P-type microcrystalline silicon layer, the temperature is controlled within the range of 170°C to 200°C, the ratio of B2H6 to SiH4 is 1-2:1, and the power of the PECVD device is within the range of 2000 to 4000W; In the step of introducing H2, CO2, B2H6 and SiH4 into the interior of the PECVD device to form the hydrogen-doped P-type microcrystalline silicon oxide layer, the temperature is controlled within the range of 170°C to 200°C, the ratio of H2, CO2, B2H6 and SiH4 is 200-300:100-200:1-2:1, and the power of the PECVD device is within the range of 2000-4000W; In the step of introducing H2, B2H6 and SiH4 into the interior of the PECVD equipment to form the hydrogen-doped P-type microcrystalline silicon layer, the temperature is controlled in the range of 170°C to 200°C, the ratio of H2, B2H6 and SiH4 is 200~300:1~2:1, and the power of the PECVD equipment is in the range of 2000 to 4000W.

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