TOPCon composite perovskite laminated cell and preparation method thereof

Abstract

The invention belongs to the field of solar photovoltaics, and provides a TOPCon composite perovskite laminated cell and a preparation method thereof.According to the laminated cell, on the basis that a polycrystalline silicon layer is thinned, hydrogen passivation of the polycrystalline silicon layer is achieved by arranging a hydrogenated PN junction, the polycrystalline silicon layer can also be effectively used as a middle connecting layer, and therefore the performance of the polycrystalline silicon layer is improved. Therefore, tunneling recombination of carriers in the laminated device is realized. According to the laminated cell, the traditional tedious steps and process dependence of back SiNx manufacturing and hydrogen passivation and fine removal are abandoned, the bad influence caused by HF acid post-treatment is eliminated, meanwhile, the traditional scheme of forming a middle connecting layer by ITO sputtering is abandoned, the influence of sputtering damage on a device is avoided, and the production efficiency is improved. And the performance of the bottom cell and the laminated cell and the repeatability and expandability of production and manufacturing are ensured.

Description

Technical Field

[0001] This invention belongs to the field of solar photovoltaics and relates to a perovskite / crystalline silicon tandem cell, and more particularly to a TOPCon composite perovskite tandem cell and its preparation method. Background Technology

[0002] Solar energy is inexhaustible and an ideal energy choice for the future. Solar energy is converted into electrical energy through the photovoltaic effect, using semiconductor photovoltaic materials as carriers. Since the first silicon solar cell appeared in 1953, silicon solar cells have occupied more than 90% of the photovoltaic market, becoming the mainstream solution in the photovoltaic field.

[0003] Recently, LONGi Green Energy, a leading Chinese photovoltaic company, reported that its silicon solar cells achieved a certified efficiency of 27.09%, very close to the Shockley-Queisser limit (29.2%) for crystalline silicon cells. This indicates that further cost reduction through efficiency improvements has essentially reached a point where there is no longer any feasible option. Therefore, exploring the combination of silicon solar cells with other types of wide-bandgap (near-infrared transparent) cells to fabricate tandem cells at both ends, thereby broadening the spectral range, reducing thermal losses, and further improving photoelectric conversion efficiency, has gradually become an important direction for the future development of silicon photovoltaic cells.

[0004] Organic-inorganic hybrid perovskite materials possess excellent photoelectric properties, with tunable band gaps and diverse and simple fabrication methods. Since their initial report in 2009, they have received widespread attention from academia and industry. In just over a decade, the efficiency of perovskite solar cells has rapidly increased from 3.8% to 26.1%. While the theoretical efficiency limit of perovskite / silicon tandem solar cells is 46%, LONGi Green Energy recently reported an actual efficiency exceeding 33.9% for two-terminal perovskite / silicon heterojunction tandem solar cells, far surpassing the theoretical limit of crystalline silicon solar cells. Therefore, perovskite is an ideal and suitable solution for constructing two-terminal tandem solar cells based on crystalline silicon.

[0005] Currently, based on the different crystalline silicon base cells, perovskite / silicon tandem cells can be mainly divided into two types: perovskite / HJT and perovskite / TOPCon. Due to the advantages of HJT cells' natural TCO window layer and PIN structure, they can be integrated with perovskite wide-bandgap top cells to construct two-end tandem cells by simply adjusting the window layer thickness and material type. However, HJT cells do not have a cost advantage in the crystalline silicon cell industry. Therefore, although HJT-based tandem cell fabrication has advantages in efficiency and process, the manufacturing cost of HJT itself is a limiting factor for its future development.

[0006] Currently, many leading photovoltaic companies are focusing their attention on TOPCon base cell solutions, but research on perovskite / TOPCon tandem solutions is relatively lagging. This is because the mainstream TOPCon cells in the crystalline silicon industry are typical NIP structure cells, and integrating them with the most advanced PIN perovskite cells requires structural inversion. Furthermore, the passivation layer (such as SiN) in the tunnel oxide passivation structure, which is the core of TOPCon cells, requires further research. x The first layer (of silicon) must be removed from the stacked structure because it is inherently insulating. Furthermore, to achieve effective recombination of electrons at the bottom and holes at the top, an additional TCO composite layer is needed as an intermediate connecting layer between the top and bottom cells. The practical difficulties and problems of this approach also lie in the fact that hydrogen passivation of SiN in crystalline silicon cells is completed under high-temperature processes. x Afterwards, it needs to be removed with HF acid, but this step is relatively cumbersome and difficult to control. If the processing time is too short, the removal will be incomplete, which can easily affect the contact performance. If the processing time is too long, it will damage the passivation contact quality of the N-poly layer (doped polycrystalline silicon layer). Furthermore, when the TCO layer is sputtered subsequently as the composite junction of the tandem solar cell, sputtering damage is difficult to eliminate.

[0007] Therefore, finding new solutions that balance passivation, connectivity, and recombination effects is key to the further development of TOPCon tandem solar cells. Summary of the Invention

[0008] In view of the problems existing in the prior art, the purpose of this invention is to provide a TOPCon composite perovskite tandem solar cell and its preparation method. The tandem solar cell, by thinning the polycrystalline silicon layer, achieves hydrogen passivation of the polycrystalline silicon layer through the setting of a hydrogenated PN junction, which also effectively serves as an intermediate connecting layer, thereby realizing tunneling recombination of charge carriers in the tandem device and improving device performance.

[0009] To achieve this objective, the present invention adopts the following technical solution:

[0010] In a first aspect, the present invention provides a TOPCon composite perovskite tandem solar cell, the tandem solar cell comprising:

[0011] Perovskite top solar cell with a carrier transport layer;

[0012] TOPCon bottom cell has a thinned polycrystalline silicon layer with a thickness of 10-50nm;

[0013] A hydrogenated PN junction is disposed between the perovskite top cell and the TOPCon bottom cell, and is electrically connected to the perovskite top cell and the TOPCon bottom cell by contacting the carrier transport layer and the thinned polycrystalline silicon layer.

[0014] This invention proposes a novel TOPCon hydrogen passivation and non-sputtered stacked intermediate tunneling composite junction scheme. This is achieved by abandoning the traditional SiN... x The complex steps and process dependencies of manufacturing, hydrogen passivation, and fine removal eliminate the adverse effects of HF acid treatment. It also abandons the traditional method of forming the intermediate interconnect layer using ITO sputtering, avoiding sputtering damage to the device and ensuring the performance, repeatability, and scalability of the bottom cell and tandem cell manufacturing. To reduce near-infrared light loss, this invention innovatively thins the polycrystalline silicon layer. Based on this, by setting a hydrogenated PN junction, it can achieve both hydrogen passivation of the bottom cell containing the thinned polycrystalline silicon layer and effective tunneling recombination of carriers in the tandem device. This tandem scheme optimizes and reduces process steps and equipment investment while significantly improving device performance, providing a new direction for the industrialization of TOPCon and perovskite tandems.

[0015] Specifically, in existing technologies, TOPCon silicon solar cells are produced by fabricating SiN... x Achieving hydrogen passivation (supplementing hydrogen, SiN) X During the preparation process, both SiH4 and NH3, the raw materials, can provide hydrogen. However, when TOPCon is used as the bottom cell in a tandem solar cell, the insulating SiN... x Layer removal is required; therefore, in existing TOPCon stacking schemes, SiN is first prepared. x Then remove SiN x This step is cumbersome and difficult to control. However, this invention changes the approach from the outset, avoiding the preparation of conventional SiN. x The hydrogen passivation layer, by setting up a hydrogenated PN junction, introduces hydrogen elements during the preparation of the hydrogenated PN junction, thereby achieving hydrogen passivation of polycrystalline silicon. The formed PN junction can also play the role of carrier tunneling recombination.

[0016] It should also be noted that in existing single-cell silicon TOPCon solar cells, the thickness of the polycrystalline silicon layer forming the passivation contact structure is generally around 110 nm. This thickness is necessary not only to ensure passivation but also to prevent subsequent screen printing of silver paste from burning through the polycrystalline silicon and causing it to directly contact the silicon oxide layer (ultra-thin tunneling oxide layer). Polycrystalline silicon typically has good absorption of long-wavelength near-infrared light, but its impact on current is relatively small in single-cell photovoltaic cells. However, in the tandem battery of the present invention, the top cell absorbs short-wavelength visible light, while near-infrared light is mainly absorbed by the bottom silicon cell. At this time, the absorption of long-wavelength near-infrared light by the polycrystalline silicon layer will have a significant impact on the current and efficiency of the series device. In order to reduce the infrared absorption of polycrystalline silicon and improve the series current of the device, the polycrystalline silicon layer is thinned while ensuring the passivation effect. More importantly, the total thickness of the hydrogenated PN junction in the present invention is relatively thin. If the polycrystalline silicon layer is too thick, the hydrogen passivation effect produced by the ultra-thin hydrogenated PN junction will be worse. Therefore, this is another reason for thinning the polycrystalline silicon layer in the present invention. Furthermore, it is preferable to reduce the thickness of the polycrystalline silicon layer to about 30 nm.

[0017] The following are preferred technical solutions of the present invention, but are not intended to limit the technical solutions provided by the present invention. The technical objectives and beneficial effects of the present invention can be better achieved and realized through the following technical solutions.

[0018] As a preferred embodiment of the present invention, the hydrogenated PN junction comprises an N-type heavily doped silicon hydrogenate film and a P-type heavily doped silicon hydrogenate film in contact with each other.

[0019] In this invention, light doping cannot achieve the overlap of the valence band of the P-type silicon-based thin film and the conduction band of the N-type silicon-based thin film, thus preventing carrier tunneling in the hydrogenated PN junction. Therefore, preferably, the non-hydrogen impurity doping concentrations of both the heavily doped N-type and heavily doped P-type silicon-based thin films are ≥10%. 19 cm -3 Further optimization of ≥10 20 cm -3 .

[0020] As a preferred technical solution of the present invention, the hydrogenated silicon thin film includes any one of hydrogenated amorphous silicon, hydrogenated microcrystalline silicon, hydrogenated nanocrystalline silicon, and hydrogenated polycrystalline silicon.

[0021] As a preferred embodiment of the present invention, the thickness ratio of the N-type heavily doped silicon hydride film to the P-type heavily doped silicon hydride film is (0.2-5):1.

[0022] As a preferred embodiment of the present invention, the total thickness of the hydrogenated PN junction is 1 to 5 nm.

[0023] As a preferred technical solution of the present invention, the perovskite top solar cell includes, from top to bottom, a top metal electrode, a top transparent window layer, a first carrier transport layer, a perovskite active layer, and a second carrier transport layer; the second carrier transport layer is used to contact the hydrogenated PN junction.

[0024] As a preferred technical solution of the present invention, the TOPCon bottom cell includes, from bottom to top, a bottom metal electrode, a passivation layer, a diffusion layer, a silicon substrate, an ultrathin tunneling oxide layer, and the thinned polycrystalline silicon layer.

[0025] As a preferred embodiment of the present invention, in the TOPCon bottom cell, the silicon substrate includes an N-type silicon wafer, and the thinned polycrystalline silicon layer is N-type doped; in the perovskite top cell, the carrier transport layer in contact with the hydrogenated PN junction is a hole transport layer; in the hydrogenated PN junction, the N-type heavily doped hydrogenated silicon film is in contact with the thinned polycrystalline silicon layer, and the P-type heavily doped hydrogenated silicon film is in contact with the hole transport layer.

[0026] As a preferred embodiment of the present invention, the hole transport layer comprises at least one of a self-assembled monomolecular SAM layer, an organic hole layer, or an inorganic hole layer; the self-assembled monomolecular SAM layer comprises at least one of 2pacz, Meo-2pacz, or Me-4pacz; the organic hole layer comprises at least one of TATM, CuPc, PTAA, P3HT, Spiro-TTB, or Spiro-OMeTAD; and the inorganic hole layer comprises NiO. x and / or MoO x The thickness of the hole transport layer is 3–25 nm.

[0027] In a second aspect, the present invention provides a method for preparing the TOPCon composite perovskite tandem solar cell described in the first aspect, the method comprising:

[0028] A hydrogenated PN junction is fabricated on a thinned polycrystalline silicon layer of a TOPCon bottom cell, and then a perovskite top cell is fabricated on the hydrogenated PN junction to obtain a TOPCon composite perovskite tandem cell.

[0029] As a preferred technical solution of the present invention, the preparation method includes preparing an N-type heavily doped silicon hydride film on a thinned polycrystalline silicon layer of a TOPCon bottom cell, preparing a P-type heavily doped silicon hydride film on the N-type heavily doped silicon hydride film, and preparing a perovskite top cell on the P-type heavily doped silicon hydride film.

[0030] As a preferred technical solution of the present invention, the preparation method includes:

[0031] S1. The silicon substrate is cleaned and texturized on the front side to obtain a clean silicon substrate;

[0032] S2. Boron diffusion is performed on a clean silicon substrate to form a diffusion layer;

[0033] S3. Retain the front diffusion layer and remove the excess diffusion layer material on the back;

[0034] S4. Prepare an ultrathin tunneling oxide layer on the back side;

[0035] S5. An intrinsic crystalline silicon layer is prepared on the ultrathin tunneling oxide layer on the back side and phosphorus diffusion is performed to form a thinned polycrystalline silicon layer;

[0036] S6. Remove excess thinned polysilicon layer material on the front side and remove the front BSG and back PSG;

[0037] S7. An N-type heavily doped silicon hydride film is prepared on the back side, and then a P-type heavily doped silicon hydride film is prepared on the N-type heavily doped silicon hydride film to form a hydrogenated PN junction.

[0038] S8. A hole transport layer is prepared on a p-type heavily doped silicon hydride film as a second carrier transport layer;

[0039] S9. Prepare a perovskite active layer on the second carrier transport layer;

[0040] S10. An electron transport layer is prepared on the perovskite active layer as the first carrier transport layer;

[0041] S11. Prepare a top transparent window layer on the first carrier transport layer;

[0042] S12. Fabricate a top metal electrode on the top transparent window layer.

[0043] Compared with existing technical solutions, the present invention has at least the following beneficial effects:

[0044] The polycrystalline silicon layer of the bottom cell of the stacked battery described in this invention does not use conventional high-temperature SiN on the side near the top cell. x The hydrogen passivation process eliminates the need for the prior preparation of hydrogen passivated SiN. xThe post-HF acid removal process avoids the traditional method of using conventional sputtered TCO as an intermediate connecting layer, thus eliminating the impact of sputtering damage. Innovatively, the polycrystalline silicon layer is thinned and a hydrogenated PN junction is directly placed on it as an intermediate connecting layer. Hydrogen is provided by the hydrogenated silicon-based thin film in the hydrogenated PN junction to achieve effective hydrogen passivation of the bottom cell. Thinning the polycrystalline silicon layer to 10%–35% of its conventional thickness helps reduce near-infrared absorption and parasitic absorption, and supports better hydrogen passivation effects. Furthermore, since the refractive index of the silicon-based thin film in the hydrogenated PN junction is more compatible with the silicon cell, reflection loss is reduced, achieving better refractive index matching and increasing current density, thereby improving the overall performance of the device. Attached Figure Description

[0045] Figure 1 This is a schematic diagram of the structure of a TOPCon composite perovskite tandem solar cell provided in one embodiment of the present invention;

[0046] In the figure: 10-Perovskite top cell, 11-Top metal electrode, 12-Top transparent window layer, 13-Sputtering barrier layer, 14-First carrier transport layer, 15-Perovskite active layer, 16-Second carrier transport layer, 20-TOPCon bottom cell, 21-Bottom metal electrode, 22-Passivation layer, 23-Diffusion layer, 24-Silicon substrate, 25-Ultra-thin tunneling oxide layer, 26-Thinned polycrystalline silicon layer, 30-Hydrogenated PN junction, 31-N-type heavily doped hydrogenated silicon thin film, 32-P-type heavily doped hydrogenated silicon thin film. Detailed Implementation

[0047] The technical solution of the present invention will be further illustrated below through specific embodiments.

[0048] Those skilled in the art will understand that the embodiments described are merely illustrative of the invention and should not be construed as limiting the invention.

[0049] In some specific embodiments, the present invention provides a TOPCon composite perovskite tandem solar cell, such as... Figure 1 As shown, the stacked battery includes:

[0050] The perovskite top cell 10 has a carrier transport layer;

[0051] The TOPCon base cell 20 has a thinned polycrystalline silicon layer 26 with a thickness of 10-50 nm;

[0052] A hydrogenated PN junction 30 is disposed between the perovskite top cell 10 and the TOPCon bottom cell 20, and is electrically connected to the perovskite top cell 10 and the TOPCon bottom cell 20 by contacting the carrier transport layer and the thinned polycrystalline silicon layer 26.

[0053] In one embodiment, the thickness of the thinned polysilicon layer 26 is 10–50 nm, for example, it can be 10 nm, 12 nm, 14 nm, 16 nm, 20 nm, 20 nm, 23 nm, 25 nm, 28 nm, 30 nm, 33 nm, 35 nm, 38 nm, 40 nm, 42 nm, 44 nm, 46 nm, 48 nm or 50 nm, further 20–40 nm, and even further 28–32 nm, but is not limited to the listed values. Other unlisted values ​​within the above range are also applicable.

[0054] In one embodiment, the hydrogenated PN junction 30 includes an N-type heavily doped silicon hydrogenation film 31 and a P-type heavily doped silicon hydrogenation film 32 in contact with each other.

[0055] In one embodiment, the hydrogenated silicon thin film includes any one of hydrogenated amorphous silicon, hydrogenated microcrystalline silicon, hydrogenated nanocrystalline silicon, and hydrogenated polycrystalline silicon.

[0056] In one embodiment, the thickness ratio of the N-type heavily doped silicon hydride film 31 to the P-type heavily doped silicon hydride film 32 is (0.2 to 5):1, for example, 0.2:1, 0.5:1, 0.8:1, 1:1, 1.3:1, 1.5:1, 1.8:1, 2:1, 2.3:1, 2.5:1, 2.8:1, 3:1, 3.3:1, 35:1, 3.8:1, 4:1, 4.3:1, 4.5:1, 4.8:1, or 5:1, but is not limited to the listed values; other unlisted values ​​within the above range are also applicable.

[0057] In one embodiment, the total thickness of the hydrogenated PN junction 30 is 1 to 5 nm, such as 1 nm, 1.5 nm, 2 nm, 2.5 nm, 3 nm, 3.5 nm, 4 nm, 4.5 nm or 5 nm, but is not limited to the listed values. Other unlisted values ​​within the above range are also applicable.

[0058] In one embodiment, the thickness of the N-type heavily doped silicon hydride film 31 and the P-type heavily doped silicon hydride film 32 is 0.5 to 2.5 nm, for example, 0.5 nm, 0.8 nm, 1 nm, 1.2 nm, 1.4 nm, 1.6 nm, 1.8 nm, 2 nm, 2.3 nm or 2.5 nm, but is not limited to the listed values. Other unlisted values ​​within the above range are also applicable.

[0059] In one embodiment, the non-hydrogen impurity doping concentrations of both the N-type heavily doped silicon hydride film and the P-type heavily doped silicon hydride film are ≥10. 20 cm -3 .

[0060] It should be noted that, based on common knowledge in the art, in addition to the carrier transport layer, thinned polycrystalline silicon layer 26, and hydrogenated PN junction 30 described in this invention, the perovskite top cell 10 and the TOPCon bottom cell 20 also include other necessary layer structures and components to constitute a complete device. This invention does not limit the thickness and fabrication method of other layer structures in the perovskite-TOPCon tandem cell; these should be reasonably adjusted according to actual design and needs.

[0061] In one embodiment, the perovskite top solar cell 10 includes, from top to bottom, a top metal electrode 11, a top transparent window layer 12, a first carrier transport layer 14, a perovskite active layer 15, and a second carrier transport layer 16; the second carrier transport layer 16 is used to contact the hydrogenated PN junction 30.

[0062] In one embodiment, the TOPCon bottom cell 20 includes, from bottom to top, a bottom metal electrode 21, a passivation layer 22, a diffusion layer 23, a silicon substrate 24, an ultrathin tunneling oxide layer 25, and the thinned polycrystalline silicon layer 26.

[0063] In one embodiment, in the TOPCon bottom cell 20, the silicon substrate 24 includes an N-type silicon wafer, and the thinned polycrystalline silicon layer 26 is N-type doped; in the perovskite top cell 10, the carrier transport layer in contact with the hydrogenated PN junction 30 is a hole transport layer; in the hydrogenated PN junction 30, the N-type heavily doped hydrogenated silicon film 31 is in contact with the thinned polycrystalline silicon layer 26, and the P-type heavily doped hydrogenated silicon film 32 is in contact with the hole transport layer. That is, the diffusion layer 23 is P-type doped, the first carrier transport layer 14 is an electron transport layer, and the second carrier transport layer 16 is a hole transport layer. In this case, the top metal electrode 11 side of the TOPCon composite perovskite tandem cell is the light-incident surface.

[0064] In one embodiment, the hole transport layer includes at least one of a self-assembled monomolecular SAM layer, an organic hole layer, or an inorganic hole layer.

[0065] In one embodiment, the self-assembled monomolecular SAM layer includes at least one of 2pacz, Meo-2pacz, or Me-4pacz.

[0066] In one embodiment, the organic hole layer includes at least one of TATM, CuPc, PTAA, P3HT, Spiro-TTB, or Spiro-OMeTAD.

[0067] In one embodiment, the inorganic hole layer comprises NiO.x and / or MoO x .

[0068] In one embodiment, the thickness of the hole transport layer is 3 to 25 nm, such as 3 nm, 5 nm, 8 nm, 10 nm, 13 nm, 15 nm, 18 nm, 20 nm, 22 nm or 25 nm, but is not limited to the listed values. Other unlisted values ​​within the above range are also applicable.

[0069] In one embodiment, both the top metal electrode 11 and the bottom metal electrode 21 are made of silver, and their thickness is independently selected from 400 to 1000 nm, such as 400 nm, 450 nm, 500 nm, 550 nm, 600 nm, 650 nm, 700 nm, 750 nm, 800 nm, 830 nm, 850 nm, 880 nm, 900 nm, 930 nm, 950 nm, 980 nm or 1000 nm, but is not limited to the listed values. Other unlisted values ​​within the above range are also applicable.

[0070] In one embodiment, the material of the top transparent window layer 12 includes at least one of ITO, IZO, FTO, IWO, AZO, ICO, or IGO; the thickness is 100-140nm, such as 100nm, 105nm, 110nm, 115nm, 120nm, 125nm, 130nm, 135nm, or 140nm, but is not limited to the listed values. Other unlisted values ​​within the above range are also applicable.

[0071] In one embodiment, the first carrier transport layer 14 is an electron transport layer, and the material of the electron transport layer includes C. 60 And / or PCBM.

[0072] In one embodiment, the perovskite top solar cell 10 further includes a sputtering barrier layer 13 disposed between the first carrier transport layer 14 and the top transparent window layer 12.

[0073] In one embodiment, the sputtering barrier layer 13 is made of SnO2.

[0074] In one embodiment, the thickness of the electron transport sublayer and the sputtering barrier layer 13 is independently 5 to 20 nm, such as 5 nm, 8 nm, 10 nm, 12 nm, 14 nm, 16 nm, 18 nm or 20 nm, but is not limited to the listed values. Other unlisted values ​​within the above range are also applicable.

[0075] In one embodiment, the perovskite material in the perovskite active layer 15 has the general formula ABX3, wherein A includes CH3NH 3+ CH(NH2) 2+ Cs + or Rb + At least one of them; B includes Pb 2+ Sn 2+ Or Ge 2+ At least one of them; X includes Cl - ,Br - Or I - At least one of them.

[0076] In one embodiment, the band gap of the perovskite active layer 15 is ≥1.65 eV.

[0077] In one embodiment, the thickness of the perovskite active layer 15 is 450–800 nm, such as 450 nm, 460 nm, 470 nm, 480 nm, 490 nm, 500 nm, 510 nm, 520 nm, 530 nm, 540 nm, 580 nm, 600 nm, 630 nm, 650 nm, 680 nm, 700 nm, 730 nm, 750 nm, 780 nm, or 800 nm, but is not limited to the listed values. Other unlisted values ​​within the above range are also applicable.

[0078] In one embodiment, the passivation layer 22 is made of Al2O3 or SiN. x For example, in Si3N4, the thickness of the passivation layer 22 is 0.2 to 4 nm, such as 0.2 nm, 0.5 nm, 0.8 nm, 1 nm, 1.5 nm, 2 nm, 2.5 nm, 3 nm, 3.5 nm or 4 nm, but it is not limited to the listed values. Other unlisted values ​​within the above range are also applicable.

[0079] In one embodiment, the thickness of the diffusion layer 23 is 25 to 80 nm, such as 25 nm, 30 nm, 35 nm, 40 nm, 45 nm, 50 nm, 55 nm, 60 nm, 65 nm, 70 nm, 75 nm or 80 nm, but is not limited to the listed values. Other unlisted values ​​within the above range are also applicable.

[0080] In one embodiment, the ultrathin tunneling oxide layer 25 is made of SiO2. x .

[0081] In one embodiment, the thickness of the ultrathin tunneling oxide layer 25 is 0.1 to 2 nm, such as 0.1 nm, 0.3 nm, 0.5 nm, 0.8 nm, 1 nm, 1.3 nm, 1.5 nm, 1.8 nm or 2 nm, but is not limited to the listed values. Other unlisted values ​​within the above range are also applicable.

[0082] In some specific embodiments, the present invention provides a method for preparing the TOPCon composite perovskite tandem solar cell described in the above embodiments, the method comprising:

[0083] A hydrogenated PN junction 30 is fabricated on the thinned polycrystalline silicon layer 26 of the TOPCon bottom cell 20, and then a perovskite top cell 10 is fabricated on the hydrogenated PN junction 30 to obtain a TOPCon composite perovskite tandem cell.

[0084] As a preferred technical solution of the present invention, the preparation method includes preparing an N-type heavily doped silicon hydride film 31 on a thinned polycrystalline silicon layer 26 of the TOPCon bottom cell 20, preparing a P-type heavily doped silicon hydride film 32 on the N-type heavily doped silicon hydride film 31, and preparing a perovskite top cell 10 on the P-type heavily doped silicon hydride film 32.

[0085] In one embodiment, the preparation method includes:

[0086] S1. The silicon substrate 24 is cleaned and texturized on the front side to obtain a clean silicon substrate 24;

[0087] S2. Boron diffusion is performed on the clean silicon substrate 24 to form a diffusion layer 23;

[0088] S3. Retain the front diffusion layer 23 and remove the excess diffusion layer material on the back;

[0089] S4. Prepare an ultrathin tunneling oxide layer 25 on the back side;

[0090] S5. An intrinsic crystalline silicon layer is prepared on the ultrathin tunneling oxide layer 25 on the back side and phosphorus diffusion is performed to form a thinned polycrystalline silicon layer 26.

[0091] S6. Remove excess thinned polysilicon layer material on the front side and remove the front BSG and back PSG;

[0092] S7. An N-type heavily doped silicon hydride film 31 is prepared on the back side, and a P-type heavily doped silicon hydride film 32 is prepared on the N-type heavily doped silicon hydride film 31 to form a hydrogenated PN junction 30.

[0093] S8. A hole transport layer is prepared on a p-type heavily doped silicon hydrogenation thin film 32 as a second carrier transport layer 16;

[0094] S9. Prepare a perovskite active layer 15 on the second carrier transport layer 16;

[0095] S10. An electron transport layer is prepared on the perovskite active layer 15 as the first carrier transport layer 14;

[0096] S11. A top transparent window layer 12 is fabricated on the first carrier transport layer 14;

[0097] S12. Fabricate a top metal electrode 11 on the top transparent window layer 12.

[0098] In one embodiment, the preparation method includes:

[0099] S1. Provide a phosphorus-doped N-type single-crystal silicon wafer using the CZ method as the silicon substrate 24, with a thickness of 160–180 μm; texturing the front side of the silicon substrate 24 to achieve texture, specifically by immersing the silicon wafer in an alkaline solution (such as KOH and / or NaOH, concentration 0.2–0.3 mol·L) and an organic additive solution (sodium silicate and IPA, concentration 0.2%–0.6%) at 75–85 °C for 5–15 min to prepare a random pyramid morphology, and use a standard RCA cleaning procedure to remove organic compounds and metal contaminants from the silicon surface to obtain a clean silicon substrate 24;

[0100] S2. A clean silicon substrate 24 with a thickness of 0.5–2.5 μm is boron diffused in a boron diffusion furnace. The specific process is as follows: First, a large flow of N2 is introduced to expel the air from the quartz tube of the diffusion furnace, and the furnace is heated to 900–1200 °C and kept constant. Then, the wafer is placed in a quartz boat and preheated at the furnace opening for 10–30 minutes. Next, it is pushed into the constant temperature zone, where oxygen is introduced first, followed by boron trichloride for diffusion. The overall process time is 120–240 minutes. During the reaction, both the silicon source and O2 are in excess to ensure complete reaction of BCl3. After the reaction is complete, the equipment is purged with N2, and the wafer is automatically discharged.

[0101] S3. Retain the front diffusion layer 23 and remove the excess diffusion layer material on the back using acid washing (such as HF and / or HNO3);

[0102] S4. An ultrathin tunneling oxide layer 25 is prepared on the back side using a thermal oxidation method to prepare the SiO2 oxide layer. The entire oxidation process is carried out in an oxidation furnace, which is a closed atmospheric pressure device. O2 is electrically heated to react with the silicon wafer surface at high temperature to generate SiO2. The process parameters are: oxidation temperature 650–850℃, nitrogen flow rate 8–16 L / min, oxygen flow rate 3–8 L / min, and oxidation time 15–35 min. The ultrathin tunneling oxide layer 25 is obtained through oxidation deposition.

[0103] S5. On the ultrathin tunneling oxide layer 25 on the back side, an in-situ doped a-Si:H thin film is deposited by low-pressure chemical vapor deposition (LPCVD) using SiH4 and hydrogen H2 as reactant gases, wherein the SiH4 gas flow rate is 2000-5000 Sccm and the H2 gas flow rate is 8000-15000 Sccm. An intrinsic crystalline silicon layer is prepared at 500-600℃ and phosphorus diffusion is performed, wherein the PH3 gas flow rate is 50-250 Sccm. The thinned polycrystalline silicon layer 26 is formed by treating at 870-930℃ for 15-45 min.

[0104] S6. Use alkaline solution (such as KOH) for single-sided etching to remove excess thinned polysilicon layer material on the front side, then remove the front BSG and back PSG by acid washing (such as HF); then perform RCA cleaning and DI aqueous solution cleaning.

[0105] S7. Using PECVD or LPCVD, an N-type heavily doped silicon hydrogenation film 31 is prepared on the back side, and then a P-type heavily doped silicon hydrogenation film 32 is prepared on the N-type heavily doped silicon hydrogenation film 31 to form a hydrogenated PN junction 30. The specific reaction gases include silane (SiH4), borane (B2H6), phosphine (PH3), and hydrogen (H2). SiH4 is used to decompose and form the silicon-based film, and the gas flow ratio of H2 to SiH4 is between (3–7.5):1. Borane and phosphine are used to provide non-hydrogen impurities for doping to form P-type and N-type films, respectively. Hydrogen is used for hydrogenation doping of the film. The reaction time is controlled to adjust the film thickness; and the final doping concentration of P or B elements in the silicon-based hydrogenated film is ≥10%. 19 cm -3 Further optimization of ≥10 20 cm -3 To achieve overlap between the valence band top of the P-type silicon-based thin film and the conduction band top of the N-type silicon-based thin film, thus enabling effective tunneling of charge carriers. After the hydrogen-doped thin film is prepared, in order to effectively add hydrogen to the bottom thinned polycrystalline silicon layer 26, it is annealed at 450–600 °C for 20–40 min in an N2 atmosphere or N2 flow to initiate the hydrogen doping passivation process of the bottom thinned polycrystalline silicon layer 26.

[0106] S8. On a p-type heavily doped silicon hydrogenation film 32, a monomolecular self-assembled layer is prepared by solution method, with the concentration of the precursor solution controlled at 0.2-0.8 mg / mL, the spin coating speed at 2000-4000 rpm, the spin coating time at 20-40 s, the annealing temperature at 80-120℃, and the annealing time at 5-15 min, to form a hole transport layer as a second carrier transport layer 16;

[0107] S9. On the second carrier transport layer 16, a perovskite active layer 15 is prepared by solution method. The solvent in the precursor solution is controlled to be a mixed solvent of DMF and DMSO with a volume ratio of (3-5):1. The spin coating process is controlled to first spin coat at 500-1500 rpm for 5-15 s, then spin coat at 3500-5500 rpm for 25-45 s. The anti-solvent (such as EA) is added dropwise 13-23 s before the end of the last spin coating process. The annealing temperature is controlled to be 80-120℃ and the annealing time is 10-30 min.

[0108] S10. An electron transport layer is prepared on the perovskite active layer 15 by evaporation, with the evaporation rate controlled at [value missing]. As the first carrier transport layer 14; a sputtering barrier layer 13 is prepared on the first carrier transport layer 14 by thermal ALD, and the outgassing purging program is controlled as 0.1s (e.g., TDMASn source outgassing) / 10s (e.g., inert gas purging) / 0.08s (e.g., oxygen source outgassing) / 10s (e.g., inert gas purging) as one cycle, the number of cycles is 100 to 200, and the working temperature is 90 to 120℃;

[0109] S11. On the first carrier transport layer 14, a top transparent window layer 12 is prepared by magnetron sputtering, with the sputtering power controlled at 90-120W and the working pressure at 0.1-0.5Pa.

[0110] S12. A top metal electrode 11 is fabricated on the top transparent window layer 12 using a vapor deposition method, with the vapor deposition rate controlled at [value missing].

[0111] Example 1

[0112] This embodiment provides a TOPCon composite perovskite tandem solar cell, such as Figure 1 As shown, the stacked battery includes:

[0113] The perovskite top solar cell 10 includes, from top to bottom, a top metal electrode 11, a top transparent window layer 12, a sputtering barrier layer 13, an electron transport layer serving as a first carrier transport layer 14, a perovskite active layer 15, and a hole transport layer serving as a second carrier transport layer 16.

[0114] The TOPCon bottom cell 20 includes, from bottom to top, a bottom metal electrode 21, a passivation layer 22, a P-type doped diffusion layer 23, an N-type silicon substrate 24, an ultrathin tunneling oxide layer 25, and an N-type doped thinned polycrystalline silicon layer 26.

[0115] A hydrogenated PN junction 30 is disposed between the perovskite top cell 10 and the TOPCon bottom cell 20. It includes an N-type heavily doped silicon hydrogenation film 31 and a P-type heavily doped silicon hydrogenation film 32 that are in contact with each other. Both the N-type heavily doped silicon hydrogenation film 31 and the P-type heavily doped silicon hydrogenation film 32 are hydrogenated polycrystalline silicon. The N-type heavily doped silicon hydrogenation film 31 is in contact with the thinned polycrystalline silicon layer 26, and the P-type heavily doped silicon hydrogenation film 32 is in contact with the hole transport layer, so that the perovskite top cell 10 and the TOPCon bottom cell 20 are electrically connected.

[0116] The method for preparing the TOPCon composite perovskite tandem solar cell described in this embodiment includes:

[0117] S1. Provide a phosphorus-doped N-type single-crystal silicon wafer using the CZ method as a silicon substrate 24, the thickness of which is 170 μm; texturing is performed on the front side of the silicon substrate 24 to achieve texturing, specifically by immersing the silicon wafer in a KOH solution (0.27 mol·L) at 80 °C for 10 min to prepare a silicon substrate 24 with a random pyramidal morphology on the surface, and removing organic compounds and metal contaminants from the silicon surface using a standard RCA cleaning procedure to obtain a clean silicon substrate 24;

[0118] S2. Boron diffusion is performed on a clean silicon substrate 24 in a boron diffusion furnace to a thickness of 1 μm. The specific process is as follows: First, a large flow of N2 is introduced to expel the air from the quartz tube of the diffusion furnace, and the furnace is heated. After the furnace temperature reaches 1050℃ and remains constant, the wafer is placed in a quartz boat and sent to the furnace opening for preheating for 20 minutes. Then, it is pushed into the constant temperature zone, where oxygen is introduced first, followed by boron trichloride for diffusion. The overall process time is 180 minutes. During the reaction, both SiH4 and O2 are in excess, allowing BCl3 to react completely and form a diffusion layer 23 with a thickness of 1000 nm. After the reaction is completed, the equipment is purged with N2, and the wafer is automatically discharged.

[0119] S3. Retain the front diffusion layer 23 and use HF and HNO3 for acid etching to remove the excess diffusion layer material on the back.

[0120] S4. An ultrathin tunneling oxide layer 25 was prepared on the back side using a thermal oxidation method to prepare the SiO2 oxide layer. The entire oxidation process was carried out in an oxidation furnace, which was a closed atmospheric pressure device. O2 was reacted with the silicon wafer surface at high temperature to generate SiO2 by electric heating. The process parameters were: oxidation temperature 750℃, nitrogen flow rate 12L / min, oxygen flow rate 5L / min, and oxidation time 25min, resulting in an ultrathin tunneling oxide layer 25 with a thickness of 1.2nm.

[0121] S5. On the ultrathin tunneling oxide layer 25 on the back side, an in-situ doped a-Si:H thin film is deposited by low-pressure chemical vapor deposition (LPCVD) using SiH4 and hydrogen H2 as reactant gases, wherein the SiH4 gas flow rate is 3500 Sccm and the H2 gas flow rate is 11000 Sccm. An intrinsic crystalline silicon layer is prepared at 550 °C and phosphorus diffusion is performed, wherein the PH3 gas flow rate is 150 Sccm. A thinned polycrystalline silicon layer 26 with a thickness of 30 nm is formed by treating at 900 °C for 30 min.

[0122] S6. Single-sided etching is performed using alkaline KOH solution to remove excess thinned polysilicon layer material on the front side. Then, acid washing is performed using HF to remove the front side BSG and the back side PSG. Finally, RCA cleaning and DI aqueous solution cleaning are performed.

[0123] S7. Using PECVD, an N-type heavily doped silicon hydride film 31 is prepared on the back side, and then a P-type heavily doped silicon hydride film 32 is prepared on the N-type heavily doped silicon hydride film 31 to form a hydrogenated PN junction 30. The specific reaction gases include SiH4, borane (B2H6), phosphine (PH3), and hydrogen (H2). When preparing the N-type heavily doped silicon hydride film 31, the flow rate of H2 is controlled at 15000 Sccm, the flow rate of SiH4 at 3000 Sccm, and the flow rate of phosphine at 150 Sccm. When preparing the P-type heavily doped silicon hydride film 32, the flow rate of H2 is controlled at 15000 Sccm, the flow rate of SiH4 at 3000 Sccm, and the flow rate of borane at 75 Sccm. The reaction temperature is controlled at 500–600℃, the reaction time is 30 s, the film thickness is 1.5 nm, and the total thickness is 3 nm. The final doping concentration of P or B is ≥10%. 20 cm -3 Then, annealing at 510°C for 30 min in an N2 atmosphere initiates the hydrogen doping passivation process of the bottom thinned polycrystalline silicon layer 26.

[0124] S8. On a p-type heavily doped silicon hydrogen hydrate film 32, a monomolecular self-assembled layer was prepared by solution method. The concentration of the 2PACz precursor solution was controlled at 0.5 mg / mL, the spin coating speed was 3000 rpm, the spin coating time was 30 s, the annealing temperature was 100℃, and the annealing time was 10 min to form a hole transport layer as a second carrier transport layer 16.

[0125] S9. On the second carrier transport layer 16, a perovskite active layer 15 with a thickness of 500 nm is prepared by solution method. The selected perovskite material system is methylamine-free FA. 0.8 Cs 0.25 Pb(I 0.8 Br 0.23. The solvent in the precursor solution is a mixture of DMF and DMSO with a volume ratio of 4:1. The spin coating process is controlled as follows: spin coating at 1000 rpm for 10 s, then spin coating at 4500 rpm for 35 s. The antisolvent EA is added 17 s before the end of the second spin coating process. The annealing temperature is controlled at 100℃ and the annealing time is controlled at 20 min.

[0126] S10. An 8 nm thick C layer was prepared on the perovskite active layer 15 using an evaporation method. 60 The layer forms an electron transport layer, and the evaporation rate is controlled to be As the first carrier transport layer 14; a SnO2 layer with a thickness of 6 nm is prepared on the first carrier transport layer 14 by thermal ALD as a sputtering barrier layer 13, and the gas purging program is controlled as 0.1s (TDMASn source gas purging) / 10s (N2 purging) / 0.08s (oxygen source gas purging) / 10s (N2 purging) as one cycle, the number of cycles is 150, and the working temperature is 105℃;

[0127] S11. On the first carrier transport layer 14, an IZO layer with a thickness of 120 nm is prepared by magnetron sputtering as the top transparent window layer 12, and the sputtering power is controlled at 105 W and the working pressure is 0.3 Pa.

[0128] S12. A silver gate with a thickness of 600 nm is prepared on the top transparent window layer 12 using a vapor deposition method as the top metal electrode 11, and the vapor deposition rate is controlled to be...

[0129] Example 2

[0130] This embodiment provides a TOPCon composite perovskite tandem solar cell. In the tandem solar cell and its preparation method, the thickness of the thinned polycrystalline silicon layer 26 is adjusted from 30nm to 10nm. Apart from the above, the other conditions are exactly the same as in Embodiment 1.

[0131] Example 3

[0132] This embodiment provides a TOPCon composite perovskite tandem solar cell. In the tandem solar cell and its preparation method, the thickness of the thinned polycrystalline silicon layer 26 is adjusted from 30nm to 50nm. Apart from the above, the other conditions are exactly the same as in Embodiment 1.

[0133] Example 4

[0134] This embodiment provides a TOPCon composite perovskite tandem solar cell. In the tandem solar cell and its preparation method, the thickness ratio of the N-type heavily doped silicon hydride film 31 to the P-type heavily doped silicon hydride film 32 is kept unchanged, and the total thickness of the hydrogenated PN junction 30 is adjusted from 3nm to 1nm. Except for the above, the other conditions are exactly the same as in Example 1.

[0135] Example 5

[0136] This embodiment provides a TOPCon composite perovskite tandem solar cell. In the tandem solar cell and its preparation method, the thickness ratio of the N-type heavily doped silicon hydride film 31 to the P-type heavily doped silicon hydride film 32 is kept unchanged, and the total thickness of the hydrogenated PN junction 30 is adjusted from 3nm to 5nm. Except for the above, the other conditions are exactly the same as in Example 1.

[0137] Example 6

[0138] This embodiment provides a TOPCon composite perovskite tandem solar cell. In the tandem solar cell and its preparation method, the total thickness of the hydrogenated PN junction 30 is kept constant, and the thickness ratio of the N-type heavily doped silicon hydrogenate film 31 to the P-type heavily doped silicon hydrogenate film 32 is adjusted from 1:1 to 0.1:1. Except for the above, the other conditions are exactly the same as in Example 1.

[0139] Example 7

[0140] This embodiment provides a TOPCon composite perovskite tandem solar cell. In the tandem solar cell and its preparation method, the total thickness of the hydrogenated PN junction 30 is kept constant, and the thickness ratio of the N-type heavily doped silicon hydrogenate film 31 to the P-type heavily doped silicon hydrogenate film 32 is adjusted from 1:1 to 0.2:1. Except for the above, other conditions are exactly the same as in Example 1.

[0141] Example 8

[0142] This embodiment provides a TOPCon composite perovskite tandem solar cell. In the tandem solar cell and its preparation method, the total thickness of the hydrogenated PN junction 30 is kept constant, and the thickness ratio of the N-type heavily doped silicon hydrogenated film 31 to the P-type heavily doped silicon hydrogenated film 32 is adjusted from 1:1 to 5:1. Except for the above, other conditions are exactly the same as in Example 1.

[0143] Example 9

[0144] This embodiment provides a TOPCon composite perovskite tandem solar cell. In the tandem solar cell and its preparation method, the total thickness of the hydrogenated PN junction 30 is kept constant, and the thickness ratio of the N-type heavily doped silicon hydrogenated film 31 to the P-type heavily doped silicon hydrogenated film 32 is adjusted from 1:1 to 6:1. Except for the above, other conditions are exactly the same as in Example 1.

[0145] Comparative Example 1

[0146] This comparative example provides a TOPCon composite perovskite tandem solar cell. In the tandem solar cell and its preparation method, the thickness of the thinned polycrystalline silicon layer 26 is adjusted from 30nm to 7nm. Apart from the above, the other conditions are exactly the same as in Example 1.

[0147] Comparative Example 2

[0148] This comparative example provides a TOPCon composite perovskite tandem solar cell. In the tandem solar cell and its preparation method, the thickness of the thinned polycrystalline silicon layer 26 is adjusted from 30 nm to 53 nm. Apart from the above, the other conditions are exactly the same as in Example 1.

[0149] Comparative Example 3

[0150] This comparative example provides a TOPCon composite perovskite tandem solar cell, in which the N-type heavily doped silicon hydrogenation film 31 is replaced with a non-hydrogenated conventional N-type heavily doped polycrystalline silicon film, while the P-type heavily doped silicon hydrogenation film 32 remains unchanged. That is, in step S7 of the method for preparing the tandem solar cell, the N-type heavily doped polycrystalline silicon film is not hydrogenated. Except for the above, the other conditions are exactly the same as in Example 1.

[0151] Comparative Example 4

[0152] This comparative example provides a TOPCon composite perovskite tandem solar cell, in which the P-type heavily doped silicon hydrogenation film 32 is replaced with a non-hydrogenated conventional P-type heavily doped polycrystalline silicon film, while the N-type heavily doped silicon hydrogenation film 31 remains unchanged. That is, in step S7 of the method for preparing the tandem solar cell, the P-type heavily doped polycrystalline silicon film is not hydrogenated. Except for the above, the other conditions are exactly the same as in Example 1.

[0153] Comparative Example 5

[0154] This comparative example provides a TOPCon composite perovskite tandem solar cell, in which the hydrogenated PN junction 30 is adjusted to a non-hydrogenated conventional PN junction, that is, the N-type heavily doped silicon hydrogenated film 31 and the P-type heavily doped silicon hydrogenated film 32 are adjusted to non-hydrogenated conventional N-type heavily doped polycrystalline silicon films and non-hydrogenated conventional P-type heavily doped polycrystalline silicon films. That is, in step S7 of the preparation method of the tandem solar cell, neither the N-type heavily doped polycrystalline silicon film nor the P-type heavily doped polycrystalline silicon film is hydrogenated. Except for the above, the other conditions are exactly the same as in Example 1.

[0155] Comparative Example 6

[0156] This comparative example provides a TOPCon composite perovskite tandem solar cell, in which the hydrogenated PN junction 30 is replaced with a TCO composite junction. That is, step S7 of the preparation method of the tandem solar cell is: obtaining a 3nm thick ITO layer as the TCO composite layer by magnetron sputtering. Except for the above, the other conditions are exactly the same as those in Example 1.

[0157] Comparative Example 7

[0158] This comparative example provides a TOPCon composite perovskite tandem solar cell, wherein the tandem solar cell adopts the traditional TOPCcon bottom cell configuration with SiN on the back side. x The hydrogen passivation scheme, i.e., step S7 of the method for fabricating the tandem battery, is as follows: a 75nm thick SiN layer is fabricated on the back side (thinned polycrystalline silicon layer 26). x After preparation, the substrate is treated with 38% HF acid for 3–12 minutes (9 minutes in this example) to remove the SiN backing insulation. x Then, the TCO composite layer was prepared using the scheme of Comparative Example 6. Except for the above, the other conditions were exactly the same as those in Example 1.

[0159] Efficiency tests were conducted on the stacked cells obtained in the examples and comparative examples. Twenty cells were tested for each example. The champion efficiency and the percentage of devices with an efficiency of over 26% were statistically analyzed. The results are recorded in Table 1.

[0160] Table 1

[0161]

[0162]

[0163] As can be seen from Table 1:

[0164] In Embodiment 1 of the present invention, the N-side (back side) of the bottom battery is not made of SiN. x However, by using a hydrogenated PN junction 30 with a hydrogenated silicon-based thin film to passivate the thinned polycrystalline silicon layer 26 with hydrogen, without using a conventional sputtered TCO layer, and using a double-layer heavily doped N and P-type hydrogenated silicon-based thin film as a carrier tunneling layer, the highest champion efficiency of 29.8% was achieved, and 17 out of 20 cells exceeded 26%.

[0165] Comparative Example 5 uses a conventional silicon-based tunnel junction, but does not employ traditional SiN... x The hydrogen passivation scheme lacked effective hydrogen passivation, resulting in a maximum efficiency of only 22.85% for the 20-layer tandem cells. Similarly, Comparative Example 6 used a TCO composite junction as the intermediate connecting layer, but the bottom cell did not utilize traditional SiN passivation. xThe hydrogen passivation scheme, lacking effective hydrogen passivation, resulted in low device efficiencies, with the champion achieving only 21.3%, lower than Comparative Example 5. This lower efficiency stemmed from TCO sputtering damage. Comparative Example 7, although using a traditional SiN silicon-based solar cell... x Hydrogen passivation scheme, but SiN x The removal process is complex and difficult to control, and the TCO sputtering scheme inevitably results in sputtering damage. Therefore, although it achieves a champion efficiency of 26.56%, only 45% (9 cells) have an efficiency higher than 26%, while the remaining 11 sub-cells still have relatively low efficiency. High-temperature process for SiN fabrication... x The yield problem caused by the complex process of preparing and then removing the passivation layer 22 after hydrogen passivation cannot be ignored.

[0166] As can be seen from the above, this invention proposes a novel TOPCon hydrogen passivation and non-sputtered stacked intermediate tunneling composite junction scheme. This is achieved by abandoning the traditional SiN... x The hydrogen passivation scheme eliminates the dependence on and influence of the delicate post-processing of HF acid treatment, while also abandoning the traditional method of multilayer ITO sputtering composite junctions, effectively reducing the impact of sputtering damage on the device. To reduce near-infrared light loss, this invention innovatively thins the polycrystalline silicon layer to 10–50 nm, using heavily N-doped and heavily P-doped hydrogenated silicon-based thin films to form a hydrogenated PN junction. This achieves both hydrogen passivation of the ultrathin polycrystalline silicon and effective carrier tunneling recombination in the multilayer device. This scheme optimizes and reduces process steps and equipment investment, while significantly improving device performance, experimental repeatability, and device yield, providing a meaningful new direction for the industrialization of perovskite and TOPCon multilayers.

[0167] This invention illustrates the detailed process equipment and process flow through the above embodiments. However, this invention is not limited to the detailed process equipment and process flow described above, meaning that this invention does not necessarily depend on the detailed process equipment and process flow to be implemented. Those skilled in the art should understand that any improvements to this invention, equivalent substitutions of raw materials for the product of this invention, addition of auxiliary components, and selection of specific methods, all fall within the protection scope and disclosure scope of this invention.

[0168] The preferred embodiments of the present invention have been described in detail above. However, the present invention is not limited to the specific details in the above embodiments. Within the scope of the technical concept of the present invention, various simple modifications can be made to the technical solution of the present invention, and these simple modifications all fall within the protection scope of the present invention.

[0169] It should also be noted that the various specific technical features described in the above specific embodiments can be combined in any suitable manner without contradiction. In order to avoid unnecessary repetition, the present invention will not describe the various possible combinations separately.

[0170] Furthermore, various different embodiments of the present invention can be combined in any way, as long as they do not violate the spirit of the present invention, they should also be regarded as the content disclosed by the present invention.

Claims

1. A TOPCon composite perovskite stack cell, characterized in that, The stacked battery comprises: a perovskite top cell (10) having a carrier transport layer; a TOPCon bottom cell (20) having a thinned polysilicon layer (26) with a thickness of 10-50 nm; a hydrogenated PN junction (30) disposed between the perovskite top cell (10) and the TOPCon bottom cell (20) and electrically connecting the perovskite top cell (10) and the TOPCon bottom cell (20) by being in contact with the carrier transport layer and the thinned polysilicon layer (26).

2. The TOPCon composite perovskite tandem cell of claim 1, wherein, The hydrogenated PN junction (30) comprises an N-type heavily doped hydrogenated silicon thin film (31) and a P-type heavily doped hydrogenated silicon thin film (32) in contact with each other.

3. The TOPCon composite perovskite tandem cell of claim 2, wherein, The hydrogenated silicon thin film comprises any one of hydrogenated amorphous silicon, hydrogenated microcrystalline silicon, hydrogenated nanocrystalline silicon, and hydrogenated polysilicon.

4. The TOPCon composite perovskite tandem cell of claim 2, wherein, The thickness ratio of the N-type heavily doped hydrogenated silicon thin film (31) to the P-type heavily doped hydrogenated silicon thin film (32) is (0.2-5):

1.

5. The TOPCon composite perovskite tandem cell according to any one of claims 1-4, wherein The total thickness of the hydrogenated PN junction (30) is 1-5 nm.

6. The TOPCon composite perovskite stack cell according to any one of claims 1-4, wherein, The perovskite top cell (10) comprises, from top to bottom, a top metal electrode (11), a top transparent window layer (12), a first carrier transport layer (14), a perovskite active layer (15), and a second carrier transport layer (16); the second carrier transport layer (16) is used to be in contact with the hydrogenated PN junction (30).

7. The TOPCon composite perovskite stack cell according to any one of claims 1-4, wherein, The TOPCon bottom cell (20) comprises, from bottom to top, a bottom metal electrode (21), a passivation layer (22), a diffusion layer (23), a silicon substrate (24), an ultrathin tunneling oxide layer (25), and the thinned polysilicon layer (26).

8. The TOPCon composite perovskite stack cell according to any one of claims 2-4, wherein, In the TOPCon bottom cell (20), the silicon substrate (24) comprises an N-type silicon wafer, and the thinned polysilicon layer (26) is N-type doped; in the perovskite top cell (10), the carrier transport layer in contact with the hydrogenated PN junction (30) is a hole transport layer; in the hydrogenated PN junction (30), the N-type heavily doped hydrogenated silicon thin film (31) is in contact with the thinned polysilicon layer (26), and the P-type heavily doped hydrogenated silicon thin film (32) is in contact with the hole transport layer.

9. The TOPCon composite perovskite tandem cell of claim 8, wherein, The hole transport layer comprises at least one of a self-assembled monolayer (SAM) layer, an organic hole layer or an inorganic hole layer; the SAM layer comprises at least one of 2pacz, Meo-2pacz or Me-4pacz; the organic hole layer comprises at least one of TATM, CuPc, PTAA, P3HT, Spiro-TTB or Spiro-OMeTAD; the inorganic hole layer comprises NiO x and / or MoO x ; the thickness of the hole transport layer is 3-25 nm.

10. A method of manufacturing the TOPCon composite perovskite stacked cell according to any one of claims 1 to 9, characterized by, The preparation method comprises: preparing a hydrogenated PN junction (30) on the thinned polysilicon layer (26) of a TOPCon bottom cell (20), and then preparing a perovskite top cell (10) on the hydrogenated PN junction (30) to obtain a TOPCon composite perovskite stacked battery.

11. The method of claim 10, wherein the method further comprises: The preparation method comprises preparing an N-type heavily doped hydrogenated silicon thin film (31) on the thinned polysilicon layer (26) of a TOPCon bottom cell (20), then preparing a P-type heavily doped hydrogenated silicon thin film (32) on the N-type heavily doped hydrogenated silicon thin film (31), and then preparing a perovskite top cell (10) on the P-type heavily doped hydrogenated silicon thin film (32).

12. The method of producing a TOPCon composite perovskite stacked cell according to claim 10 or 11, characterized by, The preparation method comprises: S1. cleaning and texturing the front side of a silicon substrate (24) to obtain a clean silicon substrate (24); S2. boron diffusion of the clean silicon substrate (24) to form a diffusion layer (23); S3. Retain the front diffusion layer (23), remove the excess diffusion layer material on the back; S4. Prepare an ultra-thin tunneling oxide layer (25) on the back; S5. Prepare an intrinsic crystalline silicon layer on the ultra-thin tunneling oxide layer (25) on the back and perform phosphorus diffusion to form a thinned polysilicon layer (26); S6. Remove the excess thinned polysilicon layer (26) on the front and remove the front BSG and back PSG; S7. Prepare an N-type heavily doped hydrogenated silicon thin film (31) on the back, and then prepare a P-type heavily doped hydrogenated silicon thin film (32) on the N-type heavily doped hydrogenated silicon thin film (31) to form a hydrogenated PN junction (30); S8. Prepare a hole transport layer on the P-type heavily doped hydrogenated silicon thin film (32) as a second carrier transport layer (16); S9. Prepare a perovskite active layer (15) on the second carrier transport layer (16); S10. Prepare an electron transport layer on the perovskite active layer (15) as a first carrier transport layer (14); S11. Prepare a top transparent window layer (12) on the first carrier transport layer (14); S12. Prepare a top metal electrode (11) on the top transparent window layer (12).

Images