Perovskite crystalline silicon laminated structure and preparation method thereof

Abstract

The invention relates to a perovskite crystal silicon laminated structure and a preparation method thereof. The perovskite crystal silicon laminated structure comprises a crystal silicon bottom cell, a crystal silicon bottom cell and a crystal silicon bottom cell, a transparent conductive composite layer; the composite hole transport layer comprises a nickel oxide hole transport layer and a self-assembled monomolecular hole transport layer; a perovskite light absorption layer which contains a thiol additive; the thickness of the perovskite light absorption layer is 0.5-2 microns, and the perovskite light absorption layer is prepared in an air environment through slit coating and vacuum flash evaporation processes; a perovskite passivation layer; an electron transport layer; a transparent top electrode; metalizing the electrode; and an antireflection layer. The method is used for preparing the large-area perovskite thin film and the laminated cell in the humidity air environment, the stability of the perovskite thin film prepared in the humidity environment is improved by using the thiol as the additive, and the reductive sulfydryl can prevent iodide ions in perovskite from being oxidized and inhibit phase segregation.

Description

Technical Field

[0001] This invention relates to the field of perovskite solar cell technology, and in particular to a perovskite-silicon stacked structure and its preparation method. Background Technology

[0002] Solar energy, with its wide distribution and clean, pollution-free nature, holds a dominant position in the future development of new energy sources and has enormous potential. Perovskite solar cells, with their advantages of low cost, high efficiency, and adjustable bandgap, are considered one of the most promising photovoltaic technologies. Currently, the efficiency limit of single-junction perovskite solar cells is 33%, while the efficiency limit of perovskite tandem solar cells exceeds 40%, making it a promising photovoltaic technology for breaking through the efficiency limit of single-junction cells. The highest efficiency achieved so far for perovskite-silicon tandem solar cells is 34.8%, making tandem technology highly competitive in the market.

[0003] Typically, the absorption bandgap of perovskite thin films can be altered through composition engineering. For tandem solar cells, a wide-bandgap perovskite film acts as the top cell, absorbing higher-energy photons. The bottom cell can be a tandem solar cell constructed using crystalline silicon or copper indium gallium selenide (CIGS) cells in series. Mainstream tandem solar cells typically use heterocrystalline silicon cells as the bottom cell, connected in series with perovskite cells. Larger crystalline silicon bottom cells (generally exceeding 200 cm²) are used in these cases. 2 Fabricating high-quality perovskite thin films remains a significant challenge. Furthermore, large-area perovskite film preparation cannot be achieved using spin-coating with anti-solvent methods; it is typically carried out in an air environment via slot coating and vacuum flash evaporation. The unavoidable humidity conditions in air cause numerous defects in wide-bandgap perovskite films, making them more susceptible to phase separation after water erosion. Therefore, developing large-area perovskite tandem layers that can withstand the humidity conditions of air is one of the key technologies for the industrial production and application of tandem solar cells, possessing broad market potential and prospects.

[0004] In view of the above-mentioned shortcomings, the designer actively researched and innovated in order to create a perovskite-silicon stacked structure and preparation method, so as to make it more industrially valuable. Summary of the Invention

[0005] To address the aforementioned technical problems, the present invention aims to provide a perovskite-silicon stacked structure and its preparation method.

[0006] To achieve the above objectives, the present invention adopts the following technical solution: One of the objectives of this invention is: A perovskite-silicon stacked structure, comprising the following sequentially stacked components: Crystalline silicon bottom cells; Transparent conductive composite layer; A composite hole transport layer, comprising a nickel oxide hole transport layer and a self-assembling monomolecule hole transport layer; The perovskite light-absorbing layer contains thiol additives, wherein the thiol additives are selected from at least one of dodecyl mercaptan, 4-fluorophenylethyl mercaptan, pentafluorothiophenol, 4-tert-butylbenzyl mercaptan and 2-chloro-4-fluorophenyl mercaptan; The thickness of the perovskite light-absorbing layer is 0.5~2μm, and it is prepared in an air environment by slit coating and vacuum flash evaporation process; Perovskite passivation layer; Electron transport layer; Transparent top electrode; Metallized electrodes; Anti-reflective layer.

[0007] As a further improvement of the present invention, the thiol additive is 4-fluorophenylethylthiol, and its concentration in the perovskite precursor ink is 0.05~0.2wt%; the materials of the perovskite light-absorbing layer include formamidine iodide, cesium iodide, lead bromide, lead iodide, methylamine chloride and lead chloride, and the relative humidity of the perovskite light-absorbing layer prepared in the air environment is 30%~70%.

[0008] The second objective of this invention is: A method for preparing a perovskite-silicon stacked structure includes the following steps: Step 1: A transparent conductive composite layer is prepared on a crystalline silicon bottom cell by vacuum sputtering; Step 2: On the transparent conductive composite layer, a nickel oxide hole transport layer is prepared by magnetron sputtering. Then, Me-4PACZ ethanol solution is coated and annealed to form a self-monomer-packed hole transport layer, thus forming a composite hole transport layer. Step 3: Prepare perovskite precursor ink. The perovskite precursor ink contains formamidine iodide, cesium iodide, lead bromide, lead iodide, methylamine chloride, lead chloride, and 0.05~0.2wt% of 4-fluorophenylethyl mercaptan additive. The solvent is a mixture of DMF and DMSO. Step 4: On the composite hole transport layer, the perovskite precursor ink is coated into a perovskite wet film by slit coating. Step 5: The perovskite wet film is subjected to vacuum flash evaporation, followed by annealing and natural cooling to obtain the perovskite light-absorbing layer; Step 6: Coat the perovskite light-absorbing layer with a piperazine monoiodine solution in isopropanol, and then anneal it to form a perovskite passivation layer. Step 7: Prepare C on the perovskite passivation layer by vacuum evaporation. 60 Electron transport layer; Step 8: In C 60On the electron transport layer, a SnO2 hole blocking layer is prepared by atomic layer deposition; Step 9: On the SnO2 hole blocking layer, an ITO transparent top electrode and a metallized electrode are sequentially passed through magnetron sputtering.

[0009] As a further improvement of the present invention, in step 1, the crystalline silicon bottom cell is a heterocrystalline silicon cell or a TOPCon crystalline silicon tandem cell; the sputtering power is 0.8~1.2KW, and an argon-oxygen mixture is used, wherein the oxygen volume percentage is 8~12%.

[0010] As a further improvement of the present invention, in step 2, the sputtering power is 0.8~1.2KW, the temperature is 180~220℃, the height of the coating blade from the substrate is 180~220μm, the coating speed is 4~6mm / s, the annealing temperature is 80~120℃, and the annealing time is 8~12 minutes.

[0011] As a further improvement of the present invention, in step 4, the height of the slit coating blade is 80~120μm and the coating speed is 8~12mm / s.

[0012] As a further improvement of the present invention, in step 5, the conditions for vacuum flash treatment are as follows: the vacuum degree is evacuated to 8-12 Pa within 8-12 seconds and maintained at this vacuum degree for 8-12 seconds; the annealing temperature is 80-120°C and the annealing time is 28-32 minutes.

[0013] As a further improvement of the present invention, in step 6, the concentration of piperazine monoiodine solution is 0.1~0.3mg / mL, the coating speed is 14~16mm / s, the annealing temperature after coating is 80~120℃, and the annealing time is 4~6 minutes.

[0014] As a further improvement of the present invention, in step 7, the vacuum degree is 6 10 -4 Under Pa conditions, C10–30 nm of carbon is deposited at a rate of 0.1–0.2 Å / s through a linear evaporation source. 60 Thin film; In step 8, the chamber temperature is set to be stable at 60~100℃, the tin source is TDMASn, the oxygen source is pure water, the outlet temperature is 60~70℃, and the number of purging cycles is 70~90 times.

[0015] As a further improvement of the present invention, in step 9, the sputtering power is 0.8~1.2KW, an argon-oxygen mixture is used, wherein the oxygen volume ratio is 8~12%; the silver grid is prepared by screen printing, and the curing temperature of the silver paste is 80~120℃.

[0016] By means of the above-described solution, the present invention has at least the following advantages: This invention is used to prepare large-area perovskite thin films and tandem batteries in humid air environments. By using thiols as additives, the stability of perovskite thin films prepared in humid environments is improved. The reducing mercapto groups can prevent the oxidation of iodide ions in the perovskite and inhibit phase segregation.

[0017] This invention enhances the hydrophobicity of perovskite films by using long-chain alkanes, fluorine-containing materials, and benzene rings to prevent water erosion that could lead to film degradation.

[0018] The present invention uses a perovskite ink formulated with this additive to uniformly cover a pyramidal textured surface within 1 μm through a slit coating method, thereby obtaining a high-quality perovskite film.

[0019] Compared with the combination of vapor deposition and coating, the one-step solution coating method of the present invention can effectively control the material cost and preparation time. Under the requirements of industrial production cycle, the one-step solution method can obviously better meet the requirements, and the maintenance cost of the corresponding equipment will also be lower.

[0020] The above description is merely an overview of the technical solution of the present invention. In order to better understand the technical means of the present invention and to implement it in accordance with the contents of the specification, the following are preferred embodiments of the present invention described in detail with reference to the accompanying drawings. Attached Figure Description

[0021] To more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings used in the embodiments will be briefly introduced below. It should be understood that the following drawings only show some embodiments of the present invention and should not be regarded as a limitation on the scope. For those skilled in the art, other related drawings can be obtained based on these drawings without creative effort.

[0022] Figure 1 These are schematic diagrams of the perovskite / crystalline silicon tandem solar cells in the third and fourth embodiments of the present invention; Figure 2 These are XRD comparison images of the experimental and control groups of perovskite films in the second and / or third and / or fourth embodiments of the present invention; Figure 3 These are SEM images of the thin film surface of the control group in the second and / or third and / or fourth embodiments of the present invention; Figure 4 These are SEM images of the thin film surface of the experimental group in the second and / or third and / or fourth embodiments of the present invention; Figure 5 These are SEM images of the cross-sections of the thin films in the control group of the second and / or third and / or fourth embodiments of the present invention. Figure 6 These are SEM images of the cross-sections of the thin films in the experimental groups of the second, third, and / or fourth embodiments of the present invention. Detailed Implementation

[0023] The specific embodiments of the present invention will be described in further detail below with reference to the accompanying drawings and examples. The following examples are for illustrative purposes only and are not intended to limit the scope of the invention.

[0024] To enable those skilled in the art to better understand the present invention, the technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. The components of the embodiments of the present invention described and shown in the accompanying drawings can generally be arranged and designed in various different configurations. Therefore, the following detailed description of the embodiments of the present invention provided in the accompanying drawings is not intended to limit the scope of the claimed invention, but merely to illustrate selected embodiments of the invention. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without inventive effort are within the scope of protection of the present invention.

[0025] First embodiment of the present invention: This embodiment describes a commercially available perovskite-silicon stack structure, wherein the structure includes a crystalline silicon bottom cell, a transparent conductive composite layer, a hole transport layer, a perovskite layer, a passivation layer, an electron transport layer, a transparent top electrode, a metallized electrode, and an antireflection layer.

[0026] The bottom cell of the tandem battery can be any one of heterocrystalline silicon battery, TOPCON battery, copper indium gallium selenide battery, cadmium telluride battery, narrow bandgap perovskite solar cell, or organic solar cell.

[0027] The transparent conductive composite layer of the series bottom cell and top cell can be any one or more of ITO, IZO, AZO, and FTO; and its preparation method can be any one of magnetron sputtering, metal ion beam deposition, or pulsed laser deposition.

[0028] The perovskite layer is doped with thiol materials as additives to dope the perovskite solution. The reducing mercapto groups can prevent the oxidation of iodide ions in the perovskite and inhibit phase segregation. Long-chain alkanes, fluorine groups, and benzene rings all have certain hydrophobicity, which improves the moisture resistance of the perovskite film.

[0029] Furthermore, the thiol material is any one of dodecyl mercaptan, 4-fluorophenylethyl mercaptan, pentafluorothiophenol, 4-tert-butylbenzyl mercaptan, and 2-chloro-4-fluorophenyl mercaptan.

[0030] Furthermore, perovskite ink is uniformly coated onto a textured crystalline silicon substrate using a slit coating method, and most of the solvent in the perovskite wet film is removed using a vacuum flash evaporation device. Finally, the perovskite thin film is prepared by hot plate annealing.

[0031] Furthermore, the hole transport layer material is any one or more of poly[bis(4-phenyl)(2,4,6-trimethylphenyl)amine] (PTAA), nickel oxide (NiOx), Spiro-TTB, PEDOT-PSS, or self-contained monolayers (SAMs).

[0032] The hole transport layer can be prepared by any of the following methods: blade coating, slot coating, inkjet printing, magnetron sputtering, or vacuum evaporation.

[0033] The passivation layer material is any one or more of the following: phenylethyl ammonium iodide, piperazine monoiodide, piperazine iodide, oleylamine iodide, phenylethyl ammonium bromide, oleylamine chloride, ethylenediamine iodide, propylenediamine iodide, and lithium fluoride.

[0034] The passivation layer can be prepared by any of the following methods: blade coating, slot coating, inkjet printing, or vacuum evaporation.

[0035] The electron transport layer material is C. 60 Any one or more of the following materials: PCBM, zinc oxide, tin oxide, and titanium oxide.

[0036] The electron transport layer can be prepared by any of the following methods: blade coating, slot coating, inkjet printing, vacuum evaporation, or atomic layer deposition.

[0037] The antireflection layer material can be any one or more of lithium fluoride, magnesium fluoride, silicon dioxide, polytetrafluoroethylene, and aluminum oxide; and its preparation method can be any one of vacuum evaporation, magnetron sputtering, atomic layer deposition, and chemical vapor deposition.

[0038] The fabrication method of the large-area perovskite tandem solar cell in this embodiment includes the above-described structure for perovskite solar cells. The steps are as follows: A transparent conductive composite layer is prepared on the bottom battery by magnetron sputtering or deposition. The hole transport layer described above was prepared on a transparent composite layer by means of scraping, slot coating, inkjet printing, magnetron sputtering, and vacuum evaporation. A perovskite light-absorbing layer was prepared on the hole transport layer by vapor deposition of the above-mentioned inorganic salt, annealing the vapor-deposited inorganic salt, and finally coating with organic salt. The above-mentioned passivation layer was prepared on the perovskite light-absorbing layer by means of scraping, slit coating, inkjet printing, and vacuum evaporation. The above-mentioned electron transport layer was prepared on the passivation layer by means of scraping, slot coating, inkjet printing, vacuum evaporation, and atomic layer deposition. A transparent electrode layer is prepared on the electron transport layer by magnetron sputtering or deposition. Metal electrode layers are prepared on transparent electrode layers by vacuum evaporation or magnetron sputtering. An antireflection layer was prepared on the metal electrode layer by vacuum evaporation, magnetron sputtering, atomic layer deposition, and chemical vapor deposition. This yielded the large-area perovskite tandem solar cell.

[0039] The second embodiment of the present invention: This embodiment describes a fabrication process for a large-area inverted wide-bandgap perovskite solar cell. The process uses ITO as the conductive substrate, NiOx and self-assembled monolayer (SAM) as the hole transport layer, and a perovskite light-absorbing layer formed by vacuum flash annealing of a perovskite precursor ink. Piperazine monoiodine (PiPl) is used as the passivation layer, and C... 60 The electron transport layer is formed by SnO2, the hole blocking layer by SnO2, and the back electrode by ITO / Cu. The specific steps are as follows: Step 1: Place the laser-etched P1 ITO glass into a cleaning machine for cleaning. After cleaning, perform ultraviolet ozone surface treatment for 15 minutes and then remove it for later use.

[0040] Step 2: Apply a hole transport layer NiO to the ITO intermediate composite layer prepared in Step 1 using a vacuum sputtering deposition (PVD) system. x The preparation of NiO was carried out with a sputtering power of 1 kW. x The thickness was 13 nm, and the processing temperature was 200 °C, to obtain NiO. x Hole transport layer.

[0041] Step 3: Prepare NiO from Step 2 x The surface of the hole transport layer was coated with a self-assembled monolayer of Me-4PACz dissolved in ethanol as the hole transport layer. The doctor blade was 200 μm above the substrate, the coating speed was 5 mm / s, and 32 μL of Me-4PACz ethanol solution was taken. Then, it was annealed on a hot stage at 100 °C for 10 min to prepare the Me-4PACz hole transport layer.

[0042] Step 4: Weigh 12.5 mg of 4-fluorophenylethyl mercaptan, 6.38 g of formamidine iodide (FAI), 2.72 g of cesium iodide (CsI), 3.93 g of lead bromide (PbBr2), 17 g of lead iodide (PbI2), 0.15 g of methylamine chloride (MACl), and 0.66 g of lead chloride (PbCl2). Add 25 mL of DMF and DMSO solvent in a 4:1 volume ratio to prepare the experimental group perovskite precursor ink. Then weigh 6.38 g of formamidine iodide (FAI), 2.72 g of cesium iodide (CsI), 3.93 g of lead bromide (PbBr2), 17 g of lead iodide (PbI2), 0.15 g of methylamine chloride (MACl), and 0.66 g of lead chloride (PbCl2). Add 25 mL of DMF and DMSO solvent in a 4:1 volume ratio to prepare the control group perovskite precursor ink.

[0043] Step 5: The ink prepared in Step 4 is injected into the coating equipment through the ink injection system. The coating blade height is 100μm and the coating speed is 10mm / s. After coating, a perovskite wet film is obtained.

[0044] Step 6: Place the perovskite wet film obtained in Step 5 in a vacuum flash furnace. The vacuum flash evaporation is configured to be reduced to 10 Pa in 10 seconds, and the total flash evaporation time is set to 10 seconds. After the flash evaporation is completed, a dry perovskite film is obtained. Then, it is placed on a hot stage heated to 100°C for annealing for 30 minutes. After annealing, it is removed and allowed to cool naturally to obtain a wide-bandgap perovskite film.

[0045] Step 7: Weigh 5 mg of Pipl drug, add 25 mL of isopropanol solvent in a glove box to prepare a 0.2 mg / mL passivation layer solution, shake to fully dissolve it, and then coat the wide bandgap film prepared in step 6 with the Pipl passivation layer at a coating speed of 15 mm / s. After coating, place it on a hot plate heated to 100°C for annealing for 5 min to obtain the perovskite passivation layer.

[0046] Step 8: Apply an electron transport layer C to the passivation layer obtained in Step 7 using a vacuum evaporation method. 60 For preparation, the sample is placed on a matching mask and subjected to a vacuum of 6... 10 -4 Under the condition of Pa, approximately 20 nm of C is deposited through a linear evaporation source at a rate of 0.15 Å / s. 60 A thin film was used to prepare an electron transport layer.

[0047] Step 9: A hole-blocking layer (SnO2) is prepared on the electron transport layer surface obtained in Step 8 using atomic layer deposition (ALD). The sample is placed in a process vacuum chamber, with the chamber temperature set to a stable 80°C. The tin source is TDMASn, the oxygen source is pure water, the outlet temperature is 65°C, and the number of purging cycles is 80. The hole-blocking layer is thus prepared.

[0048] Step 10: A transparent conductive electrode, ITO, is fabricated on the hole-blocking layer obtained in Step 9 using a vacuum sputtering deposition (PVD) system. After fixing the sample on the substrate holder, it is fed into the deposition chamber via the equipment's transmission system. Once the set vacuum level is reached, the sputtering process is performed. The sputtering power is set to 1 kW, using an argon-oxygen mixture (oxygen content 10%), and the ITO thickness is 20 nm, thus obtaining a transparent ITO electrode. Subsequently, a Cu metal electrode is sputtered at a power of 7 kW, achieving a Cu thickness of 80 nm, thus fabricating a Cu metal electrode. Finally, a large-area inversion wide-bandgap perovskite solar cell is obtained.

[0049] The third embodiment of the present invention: This embodiment describes a fabrication process for a large-area perovskite / heterocrystalline silicon tandem solar cell, using a heterocrystalline silicon solar cell as the base cell. Figure 1 The layers consist of: an ITO intermediate composite layer (numbered 001), a NiOx layer (numbered 002), and a self-assembled monolayer (numbered 003) serving as a hole transport layer; a perovskite light-absorbing layer (numbered 004) formed by coating perovskite precursor ink and then annealing it under vacuum flash evaporation; a piperazine monoiodine (PiPl) passivation layer (numbered 005); and a C layer (numbered 006). 60 The electron transport layer, SnO2 (numbered 007) is a hole blocking layer, ITO transparent top electrode (numbered 008) and silver grid back electrode (numbered 009) are also present.

[0050] The specific steps are as follows: Step 1: An intermediate composite layer ITO is prepared on the n-side of a heterocrystalline silicon substrate using a vacuum sputtering deposition (PVD) system. After fixing the sample on the substrate holder, it is fed into the deposition chamber through the transmission system of the equipment. After reaching the set vacuum level, the sputtering process is performed. The sputtering power is set to 1KW, the gas mixture is argon-oxygen (oxygen content 10%), and the thickness of ITO is 20nm, thus obtaining the intermediate composite layer.

[0051] ITO was sputtered onto a crystalline silicon base cell with a textured surface using a specific power (1 kW) and atmosphere (argon-oxygen mixture). These parameters ensured continuous coverage of ITO on the rough textured surface with high conductivity, without damaging the PN junction of the base cell.

[0052] Step 2: Apply a hole transport layer NiO to the ITO intermediate composite layer prepared in Step 1 using a vacuum sputtering deposition (PVD) system. x The preparation of NiO was carried out with a sputtering power of 1 kW. x The thickness was 13 nm, and the processing temperature was 200 °C, to obtain NiO. x Hole transport layer.

[0053] NiOx was sputtered using PVD, with the thickness precisely controlled at 13nm. This thickness optimizes the balance between hole extraction capability and light transmittance; if it is too thin, extraction will be insufficient, while if it is too thick, the series resistance will increase and the light transmittance will decrease.

[0054] Step 3: Prepare NiO from Step 2 x The surface of the hole transport layer was coated with a self-assembled monolayer of Me-4PACz dissolved in ethanol as the hole transport layer. The doctor blade was 200 μm above the substrate, the coating speed was 5 mm / s, and 32 μL of Me-4PACz ethanol solution was taken. Then, it was annealed on a hot stage at 100 °C for 10 min to prepare the Me-4PACz hole transport layer.

[0055] Me-4PACz is coated on NiOx to form a NiOx / SAM composite hole transport structure. The SAM molecular energy level is tunable and can perfectly match the valence band top of perovskite, further improving hole extraction efficiency and reducing interfacial recombination.

[0056] Steps 1 through 3 constitute a three-step sequence that constructs a dual-gradient hole transport channel. ITO provides macroscopic conductivity, NiOx serves as the inorganic hole transport host, and SAM acts as a molecular-level interface modification layer. The combination of these three elements achieves perfect energy level matching, high extraction efficiency, and excellent interface stability, which is impossible with a single hole transport layer (such as Spiro-OMeTAD alone or PEDOT:PSS alone).

[0057] Step 4: Weigh 12.5 mg of 4-fluorophenylethyl mercaptan, 6.38 g of formamidine iodide (FAI), 2.72 g of cesium iodide (CsI), 3.93 g of lead bromide (PbBr2), 17 g of lead iodide (PbI2), 0.15 g of methylamine chloride (MACl), and 0.66 g of lead chloride (PbCl2). Add 25 mL of DMF and DMSO solvent in a 4:1 volume ratio to prepare the experimental group perovskite precursor ink. Then weigh 6.38 g of formamidine iodide (FAI), 2.72 g of cesium iodide (CsI), 3.93 g of lead bromide (PbBr2), 17 g of lead iodide (PbI2), 0.15 g of methylamine chloride (MACl), and 0.66 g of lead chloride (PbCl2). Add 25 mL of DMF and DMSO solvent in a 4:1 volume ratio to prepare the control group perovskite precursor ink.

[0058] In a novel approach, 4-fluorophenylethyl mercaptan is introduced as an additive into conventional perovskite components. Its innovation lies in its dual mechanism of action: the thiol group (-SH) acts as a reducing agent to inhibit iodide ions (I₂). - Oxidation, with its fluorophenyl groups providing hydrophobicity to resist moisture erosion. This is a solution directly addressing the core challenge of "preparation in air".

[0059] Step 5: The ink prepared in Step 4 is injected into the coating equipment through the ink injection system. The coating blade height is 100μm and the coating speed is 10mm / s. After coating, a perovskite wet film is obtained.

[0060] The use of slot coating instead of spin coating is for commercial applications with large areas (>200cm). 2 The necessary choice for production. The parameters (blade height 100μm, speed 10mm / s) are key to achieving uniform and complete coverage of high-viscosity, additive-containing inks on the textured surface.

[0061] Step 6: Place the perovskite wet film obtained in Step 5 in a vacuum flash furnace. The vacuum flash evaporation is configured to be reduced to 10 Pa in 10 seconds, and the total flash evaporation time is set to 10 seconds. After the flash evaporation is completed, a dry perovskite film is obtained. Then, it is placed on a hot stage heated to 100°C for annealing for 30 minutes. After annealing, it is removed and allowed to cool naturally to prepare a wide-bandgap perovskite film covered with a micro-textured surface.

[0062] Vacuum flash evaporation (evacuate to 10 Pa in 10 seconds, hold for 10 seconds) is a rapid solvent removal process that can instantly remove most of the solvent (especially DMSO) from the wet film, forming an intermediate phase film and greatly shortening the film's exposure time under harmful humidity. The subsequent hot plate annealing (100℃, 30 min) completes the grain growth and crystallization of perovskite under controlled conditions.

[0063] Steps 4 through 6 form a closed-loop system of "molecular protection - physical shaping - rapid fixation - precise crystallization". The thiol additive constructs a defense system at the molecular level, slot coating enables physical shaping on a large-area textured surface, vacuum flash evaporation, as a rapid fixation step, is a crucial bridge connecting coating and crystallization. It prevents moisture from attacking during the most vulnerable wet film stage by creating a brief solvent-free, low-humidity window. Hot plate annealing, on the safe basis of a fixed film, allows for controlled and precise crystallization. This combination successfully deconstructs and adapts the perovskite crystallization process, which can only be completed in an inert gas environment, to an air environment.

[0064] Step 7: Weigh 5 mg of Pipl drug, add 25 mL of isopropanol solvent in a glove box to prepare a 0.2 mg / mL passivation layer solution, shake to fully dissolve it, and then coat the wide bandgap film prepared in step 6 with the Pipl passivation layer at a coating speed of 15 mm / s. After coating, place it on a hot plate heated to 100°C for annealing for 5 min to obtain the perovskite passivation layer.

[0065] Immediately after the perovskite layer is completed, a piperazine monoiodine (PiPl) solution is applied. The cations and halide ions in PiPl effectively passivate uncoordinated Pb on the perovskite surface and grain boundaries. 2+ With iodine vacancies, this ultrathin passivation layer is key to achieving a high open-circuit voltage (Voc).

[0066] Step 8: Apply an electron transport layer C to the passivation layer obtained in Step 7 using a vacuum evaporation method. 60 For preparation, the sample is placed on a matching mask and subjected to a vacuum of 6... 10 -4 Under the condition of Pa, approximately 20 nm of C is deposited through a linear evaporation source at a rate of 0.15 Å / s. 60 A thin film was used to prepare an electron transport layer.

[0067] C prepared by vacuum evaporation 60 The electron transport layer ensures uniform and damage-free coverage on the PiPl passivation layer, forming an efficient electron extraction interface.

[0068] Step 9: A hole-blocking layer (SnO2) is prepared on the electron transport layer surface obtained in Step 8 using atomic layer deposition (ALD). The sample is placed in a process vacuum chamber, with the chamber temperature set to a stable 80°C. The tin source is TDMASn, the oxygen source is pure water, the outlet temperature is 65°C, and the number of purging cycles is 80. The hole-blocking layer is thus prepared.

[0069] Atomic layer deposition (ALD) in C 60 SnO2 was prepared on top. ALD technology can prepare dense, pinhole-free thin films, which serve as hole-blocking layers, effectively preventing holes from being transported back to the electron terminals, while protecting the underlying organic carbon layer. 60 And to protect the perovskite from damage during subsequent sputtering processes.

[0070] Steps 7 through 9 constitute a triple guarantee of "interface defect repair - efficient charge extraction - device structure protection". PiPl solves bulk and interface problems, C 60While responsible for electron transport, SnO2 simultaneously acts as a hole-blocking layer, a sputtering buffer layer, and a substrate for subsequent processes. This "organic-inorganic" composite electron transport / blocking structure balances high performance and high stability. Step 10: A transparent conductive electrode, ITO, is fabricated on the hole-blocking layer obtained in Step 9 using a vacuum sputtering deposition (PVD) system. After fixing the sample on the substrate holder, it is fed into the deposition chamber via the equipment's transmission system. Once the set vacuum level is reached, the sputtering process is performed. The sputtering power is set to 1 kW, using an argon-oxygen mixture (oxygen content 10%), and the ITO thickness is 40 nm, thus obtaining the ITO transparent electrode. Subsequently, a silver grid is fabricated by screen printing. The silver paste is cured at 100℃, finally yielding a large-area perovskite / heterocrystalline silicon tandem solar cell.

[0071] ITO is sputtered onto a SnO2 hole-blocking layer as a transparent top electrode. This order is crucial because SnO2 protection is a prerequisite for sputtering. Subsequently, metal gate lines (Cu or Ag) are fabricated to collect the current. The innovation of this step lies in using ALD-SnO2 as the sputtering substrate, making it possible to perform the sputtering process on the fragile perovskite structure, thereby achieving low resistance and high transmittance of the top electrode.

[0072] In this embodiment, the technical problem of preparing high-quality, stable wide-bandgap perovskite thin films and tandem cells on commercially available textured silicon substrates in an air environment is effectively solved. The unique effects of specific thiol additives in perovskite preparation in air (anti-oxidation + hydrophobicity) are discovered. The rapid solvent removal process of vacuum flash evaporation is integrated and placed between slot coating and thermal annealing. This specific timing arrangement is a key design for the challenges of the air environment, resulting in a synergistic effect of 1+1>2 (i.e., synergistic effect).

[0073] The photovoltaic performance parameters obtained by performing JV tests on the prepared tandem solar cells are summarized in Table 1 below.

[0074] Table 1 Photovoltaic performance parameters of perovskite / heterocrystalline silicon tandem solar cells Fourth embodiment of the present invention: This embodiment describes a fabrication process for a large-area perovskite / TOPCon crystalline silicon tandem solar cell, using a TopCon crystalline silicon cell as the base cell. Figure 1 The layers consist of: an ITO intermediate composite layer (numbered 001), a NiOx layer (numbered 002), and a self-assembled monolayer (numbered 003) serving as a hole transport layer; a perovskite light-absorbing layer (numbered 004) formed by coating perovskite precursor ink and then annealing it under vacuum flash evaporation; a piperazine monoiodine (PiPl) passivation layer (numbered 005); and a C layer (numbered 006).60 The electron transport layer, SnO2 (numbered 007) is a hole blocking layer, ITO transparent top electrode (numbered 008) and silver grid back electrode (numbered 009) are also present.

[0075] The specific steps are as follows: Step 1: An intermediate composite layer ITO is prepared on the n-side of a heterocrystalline silicon substrate using a vacuum sputtering deposition (PVD) system. After fixing the sample on the substrate holder, it is fed into the deposition chamber through the transmission system of the equipment. After reaching the set vacuum level, the sputtering process is performed. The sputtering power is set to 1KW, the gas mixture is argon-oxygen (oxygen content 10%), and the thickness of ITO is 20nm, thus obtaining the intermediate composite layer.

[0076] Step 2: Apply a hole transport layer NiO to the ITO intermediate composite layer prepared in Step 1 using a vacuum sputtering deposition (PVD) system. x The preparation of NiO was carried out with a sputtering power of 1 kW. x The thickness was 13 nm, and the processing temperature was 200℃, resulting in NiO. x Hole transport layer.

[0077] Step 3: Prepare NiO from Step 2 x The surface of the hole transport layer was coated with a self-assembled monolayer of Me-4PACz dissolved in ethanol as the hole transport layer. The doctor blade was 200 μm above the substrate, the coating speed was 5 mm / s, and 32 μL of Me-4PACz ethanol solution was taken. Then, it was annealed on a hot stage at 100 °C for 10 min to prepare the Me-4PACz hole transport layer.

[0078] Step 4: Weigh 12.5 mg of 4-fluorophenylethyl mercaptan, 6.38 g of formamidine iodide (FAI), 2.72 g of cesium iodide (CsI), 3.93 g of lead bromide (PbBr2), 17 g of lead iodide (PbI2), 0.15 g of methylamine chloride (MACl), and 0.66 g of lead chloride (PbCl2). Add 25 mL of DMF and DMSO solvent in a 4:1 volume ratio to prepare the experimental group perovskite precursor ink. Then weigh 6.38 g of formamidine iodide (FAI), 2.72 g of cesium iodide (CsI), 3.93 g of lead bromide (PbBr2), 17 g of lead iodide (PbI2), 0.15 g of methylamine chloride (MACl), and 0.66 g of lead chloride (PbCl2). Add 25 mL of DMF and DMSO solvent in a 4:1 volume ratio to prepare the control group perovskite precursor ink.

[0079] Step 5: The ink prepared in Step 4 is injected into the coating equipment through the ink injection system. The coating blade height is 100μm and the coating speed is 10mm / s. After coating, a perovskite wet film is obtained.

[0080] Step 6: Place the perovskite wet film obtained in Step 5 in a vacuum flash furnace. The vacuum flash evaporation is configured to be reduced to 10 Pa in 10 seconds, and the total flash evaporation time is set to 10 seconds. After the flash evaporation is completed, a dry perovskite film is obtained. Then, it is placed on a hot stage heated to 100°C for annealing for 30 minutes. After annealing, it is removed and allowed to cool naturally to prepare a wide-bandgap perovskite film covered with a micro-textured surface.

[0081] Step 7: Weigh 5 mg of Pipl drug, add 25 mL of isopropanol solvent in a glove box to prepare a 0.2 mg / mL passivation layer solution, shake to fully dissolve it, and then coat the wide bandgap film prepared in step 6 with the Pipl passivation layer at a coating speed of 15 mm / s. After coating, place it on a hot plate heated to 100°C for annealing for 5 min to obtain the perovskite passivation layer.

[0082] Step 8: Apply an electron transport layer C to the passivation layer obtained in Step 7 using a vacuum evaporation method. 60 For preparation, the sample is placed on a matching mask and subjected to a vacuum of 6... 10 -4 Under the condition of Pa, approximately 20 nm of C is deposited through a linear evaporation source at a rate of 0.15 Å / s. 60 A thin film was used to prepare an electron transport layer.

[0083] Step 9: A hole-blocking layer (SnO2) is prepared on the electron transport layer surface obtained in Step 8 using atomic layer deposition (ALD). The sample is placed in a process vacuum chamber, with the chamber temperature set to a stable 80°C. The tin source is TDMASn, the oxygen source is pure water, the outlet temperature is 65°C, and the number of purging cycles is 80. The hole-blocking layer is thus prepared.

[0084] Step 10: A transparent conductive electrode, ITO, is fabricated on the hole-blocking layer obtained in Step 9 using a vacuum sputtering deposition (PVD) system. After fixing the sample on the substrate holder, it is fed into the deposition chamber via the equipment's transmission system. Once the set vacuum level is reached, the sputtering process is performed. The sputtering power is set to 1 kW, using an argon-oxygen mixture (oxygen content 10%), and the ITO thickness is 40 nm, thus obtaining the ITO transparent electrode. Subsequently, a silver grid is fabricated by screen printing. The silver paste is cured at 100℃, finally yielding a large-area perovskite / heterocrystalline silicon tandem solar cell.

[0085] The effects of the preparation method of the present invention will be illustrated below using experimental data as an example.

[0086] Figure 1The diagram shows a structural model of a perovskite / heterocrystalline silicon solar cell. This invention provides a structure for a perovskite / crystalline silicon tandem solar cell. As shown in the figure, the structure includes a bottom crystalline silicon cell, an ITO intermediate composite layer (numbered 001), a NiOx layer (numbered 002), a hole transport layer (numbered 003), a perovskite light-absorbing layer (numbered 004) formed by coating perovskite precursor ink and vacuum flash annealing, a piperazine monoiodine (PiPl) passivation layer (numbered 005), and a C layer (numbered 006). 60 The perovskite film consists of an electron transport layer, a hole-blocking layer (SnO2, number 007), an ITO transparent top electrode (008), and a silver grid back electrode (009). The addition of 4-fluorophenylethanethiol during the fabrication of the perovskite light-absorbing layer effectively reduces the likelihood of perovskite ink oxidation, thus improving the hydrophobicity of the perovskite film. This tandem cell structure, combining perovskite and crystalline silicon solar cells, effectively absorbs light wavelengths from 300 to 1200 nm, exceeding the efficiency limit of single-junction cells.

[0087] Figure 2 The image shows the XRD patterns of perovskite films prepared on heterocrystalline silicon substrates using perovskite ink formulated with 4-fluorophenylethyl mercaptan as an additive. The results show that the experimental group with added 4-fluorophenylethyl mercaptan did not exhibit a significant PbI2 XRD characteristic peak (12.6 degrees), while the control group without the additive showed a significant PbI2 XRD characteristic peak and a weak δ-phase perovskite characteristic peak (13.4 degrees). This indicates that the influence of water and oxygen in the air caused a hydration reaction in the perovskite film during annealing, leading to film degradation. 4-fluorophenylethyl mercaptan, as an additive, can effectively inhibit this reaction process.

[0088] Figures 3-6 The images displayed are SEM morphology images of perovskite films with and without additives. From the images, we can obtain... Figure 2 The XRD results corroborated the findings. In the control group, lead iodide crystals and dendritic structures appeared on the film surface, and cross-sections revealed pores and voids between the film and the silicon substrate, leading to poor contact and affecting the cell's fill factor. In contrast, the experimental group's film surface lacked these substances, exhibited densely packed grains without pores, and cross-sections showed no pores or voids between the film and the silicon substrate. This indicates that 4-fluorophenylethyl mercaptan, as an additive, effectively mitigated the degradation of perovskite films caused by hydration reactions during air preparation.

[0089] This invention discloses a method for preparing commercially sized perovskite-silicon tandem layers in air. The disadvantage of wide-bandgap perovskite in air-based preparation—its poor resistance to water and oxygen corrosion—limits the development of large-area tandem solar cells. This method involves adding thiol-based materials as additives to dope the perovskite solution. The reducing mercapto groups can prevent the oxidation of iodide ions in the perovskite and inhibit phase segregation; the fluorine groups and benzene rings both have certain hydrophobicity, improving the crystallinity and moisture resistance of the perovskite film, thereby improving the stability of large-area tandem solar cell preparation.

[0090] In the description of this invention, it should be understood that the terms "center," "longitudinal," "lateral," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," and "outer," etc., indicating orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, are used only for the convenience of describing the invention and for simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of the invention. Furthermore, the terms "first," "second," etc., are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implying the number of indicated technical features. Thus, a feature defined with "first," "second," etc., may explicitly or implicitly include one or more of that feature. In the description of this invention, unless otherwise stated, "a plurality of" means two or more.

[0091] In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art will understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0092] The above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the technical principles of the present invention, and these improvements and modifications should also be considered within the scope of protection of the present invention.

Claims

1. A perovskite-silicon stacked structure, characterized in that, Including those set up in a stacked manner: Crystalline silicon bottom cells; Transparent conductive composite layer; A composite hole transport layer, comprising a nickel oxide hole transport layer and a self-assembling monomolecule hole transport layer; A perovskite light-absorbing layer comprising a thiol additive, wherein the thiol additive is selected from at least one of dodecyl mercaptan, 4-fluorophenylethyl mercaptan, pentafluorothiophenol, 4-tert-butylbenzyl mercaptan and 2-chloro-4-fluorophenyl mercaptan; The thickness of the perovskite light-absorbing layer is 0.5~2μm, and it is prepared in an air environment by slit coating and vacuum flash evaporation processes; Perovskite passivation layer; Electron transport layer; Transparent top electrode; Metallized electrodes; Anti-reflective layer.

2. The perovskite-silicon stacked structure as described in claim 1, characterized in that, The thiol additive is 4-fluorophenylethyl mercaptan, and its concentration in the perovskite precursor ink is 0.05~0.2wt%; the materials of the perovskite light-absorbing layer include formamidine iodide, cesium iodide, lead bromide, lead iodide, methylamine chloride and lead chloride, and the relative humidity of the perovskite light-absorbing layer prepared in an air environment is 30%~70%.

3. A method for preparing a perovskite-silicon stacked structure, characterized in that, The steps are as follows: Step 1: A transparent conductive composite layer is prepared on a crystalline silicon bottom cell by vacuum sputtering; Step 2: On the transparent conductive composite layer, a nickel oxide hole transport layer is prepared by magnetron sputtering, followed by coating with Me-4PACZ ethanol solution and annealing to form a self-contained monomolecular hole transport layer, thereby forming a composite hole transport layer. Step 3: Prepare perovskite precursor ink, wherein the perovskite precursor ink comprises formamidine iodide, cesium iodide, lead bromide, lead iodide, methylamine chloride, lead chloride, and 4-fluorophenylethyl mercaptan additive at a concentration of 0.05~0.2wt%, and the solvent is a mixture of DMF and DMSO. Step 4: On the composite hole transport layer, the perovskite precursor ink is coated into a perovskite wet film by slit coating. Step 5: The perovskite wet film is subjected to vacuum flash evaporation, followed by annealing and natural cooling to obtain the perovskite light-absorbing layer; Step 6: Coat the perovskite light-absorbing layer with a piperazine monoiodine solution in isopropanol, and then anneal it to form a perovskite passivation layer. Step 7: On the perovskite passivation layer, C is prepared by vacuum evaporation. 60 Electron transport layer; Step 8: In the C 60 On the electron transport layer, a SnO2 hole blocking layer is prepared by atomic layer deposition; Step 9: On the SnO2 hole blocking layer, an ITO transparent top electrode and a metallized electrode are sequentially passed through by magnetron sputtering.

4. The method for preparing a perovskite-silicon multilayer structure as described in claim 3, characterized in that, In step 1, the crystalline silicon base cell is a heterocrystalline silicon cell or a TOPCon crystalline silicon tandem cell; the sputtering power is 0.8~1.2KW, and an argon-oxygen mixture is used, wherein the oxygen volume percentage is 8~12%.

5. The method for preparing a perovskite-silicon multilayer structure as described in claim 3, characterized in that, In step 2, the sputtering power is 0.8~1.2KW, the temperature is 180~220℃, the height of the coating blade from the substrate is 180~220μm, the coating speed is 4~6mm / s, the annealing temperature is 80~120℃, and the annealing time is 8~12 minutes.

6. The method for preparing a perovskite-silicon stacked structure as described in claim 3, characterized in that, In step 4, the slit coating blade height is 80~120μm, and the coating speed is 8~12mm / s.

7. The method for preparing a perovskite-silicon multilayer structure as described in claim 3, characterized in that, In step 5, the conditions for the vacuum flash treatment are as follows: the vacuum degree is evacuated to 8-12 Pa within 8-12 seconds and maintained at this vacuum degree for 8-12 seconds; the annealing temperature is 80-120℃ and the annealing time is 28-32 minutes.

8. The method for preparing a perovskite-silicon stacked structure as described in claim 3, characterized in that, In step 6, the concentration of the piperazine monoiodine solution is 0.1~0.3 mg / mL, the coating speed is 14~16 mm / s, the annealing temperature after coating is 80~120℃, and the annealing time is 4~6 minutes.

9. The method for preparing a perovskite-silicon multilayer structure as described in claim 3, characterized in that, In step 7, at a vacuum level of 6 10 -4 Under Pa conditions, C10–30 nm of carbon is deposited at a rate of 0.1–0.2 Å / s through a linear evaporation source. 60 Thin film; in step 8, the chamber temperature is set to be stable at 60~100℃, the tin source is TDMASn, the oxygen source is pure water, the outlet temperature is 60~70℃, and the number of purging cycles is 70~90 times.

10. The method for preparing a perovskite-silicon multilayer structure as described in claim 3, characterized in that, In step 9, the sputtering power is 0.8~1.2KW, and an argon-oxygen mixture is used, in which the oxygen volume percentage is 8~12%; the silver grid is prepared by screen printing, and the curing temperature of the silver paste is 80~120℃.

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