Perovskite solar cells, tandem cells and photovoltaic modules

Abstract

The application relates to the technical field of solar cells, and provides a perovskite solar cell, a laminated cell and a photovoltaic module. The perovskite solar cell comprises a perovskite light-absorbing layer and a first charge transport layer arranged on one side of the perovskite light-absorbing layer. The first charge transport layer comprises a hole transport material, and the hole transport material comprises a compound shown in the following formula I. In the formula I, X is selected from O, S, a single bond and ; n is an integer of 2-4; and * represents a connecting site. The perovskite solar cell provided by the application has improved stability and photoelectric conversion efficiency.

Description

Technical Field

[0001] This application relates to the field of solar cell technology, and in particular to perovskite solar cells, tandem cells and photovoltaic modules. Background Technology

[0002] Perovskite solar cells (PSCs) are devices that utilize perovskite-type organometal halide semiconductors as light-absorbing materials to directly convert light energy into electrical energy through the photovoltaic effect. The hole transport layer (HTL) in their structure primarily functions to block electrons, enhance hole transport, and prevent quenching caused by direct contact between the perovskite active layer and the electrode. However, currently used hole transport materials, especially small organic molecule hole transport materials, often suffer from low tolerance to perovskite precursor solutions, leading to poor perovskite film formation and affecting the cell's stability and photoelectric conversion efficiency. Summary of the Invention

[0003] Based on this, this application provides a perovskite solar cell, a tandem cell, and a photovoltaic module, which can improve the film-forming properties of perovskite thin films, thereby enhancing the stability and photoelectric conversion efficiency of perovskite solar cells.

[0004] A first aspect of this application provides a perovskite solar cell, comprising a perovskite light-absorbing layer and a first charge transport layer disposed on one side of the perovskite light-absorbing layer, the first charge transport layer comprising a hole transport material, the hole transport material comprising a compound represented by Formula I:

[0005] Formula I,

[0006] In Formula I, X is selected from O, S, single bonds, and One of them, n is an integer from 2 to 4, and * represents the connection site.

[0007] In some embodiments of this application, the hole transport material comprises one or more compounds represented by Formula I-1, Formula I-2, Formula I-3 and Formula I-4:

[0008] Equation I-1,

[0009] Equation I-2,

[0010] Equation I-3,

[0011] Equation I-4.

[0012] In some embodiments of this application, the hole transport material comprises one or more compounds represented by formulas 1 to 12:

[0013] Formula 1, Equation 2, Formula 3,

[0014] Equation 4, Equation 5, Formula 6,

[0015] Equation 7, Formula 8, Formula 9,

[0016] Formula 10, Formula 11, Equation 12.

[0017] In some embodiments of this application, the perovskite light-absorbing layer comprises a perovskite material, which includes the compound ABY3, wherein A ions are monovalent cations, B ions are divalent cations, and Y ions are monovalent anions.

[0018] The A ion includes organic cations and Li. + Na + K + 、Rb + and Cs + One or more of the following; further, the organic cation includes at least one of methylamino, ethylamino, propylamino, butylamino, pentamino, hexamino, formamidinyl and imidazolyl;

[0019] The B ions include Pb. 2+ Sn 2+ Be 2+ Mg 2+ Ca 2+ 、Sr 2+ Ba 2+ Zn 2+ 、Ge 2+ Fe 2+ Co 2+ Cu 2+ and Ni 2+ One or more of the following;

[0020] The Y ions include F - Cl - ,Br - and I - One or more of them.

[0021] In some embodiments of this application, the perovskite light-absorbing layer contains perovskite grains, and the average grain size of the perovskite grains is 50nm~800nm, optionally 300nm~500nm.

[0022] In some embodiments of this application, the HOMO level of the hole transport material is 8.70 × 10⁻⁶. -5 eV ~1.65×10 -4 eV, selectable as 8.80×10 -5 eV ~1.65×10 -4 eV.

[0023] In some embodiments of this application, the surface roughness of the perovskite light-absorbing layer adjacent to the first charge transport layer is 12nm~25nm, and can be selected as 15nm~20nm.

[0024] In some embodiments of this application, the perovskite solar cell further includes a second charge transport layer disposed on the other side of the perovskite light-absorbing layer, the second charge transport layer comprising an electron transport material.

[0025] In some embodiments of this application, the perovskite solar cell further includes a first electrode and a second electrode; the first electrode is disposed on the side of the first charge transport layer opposite to the perovskite light-absorbing layer, and the second electrode is disposed on the side of the second charge transport layer opposite to the perovskite light-absorbing layer.

[0026] The first electrode is a transparent electrode.

[0027] The second aspect of this application provides a stacked solar cell, including a bottom cell and a top cell stacked together, wherein the top cell is the perovskite solar cell described in the first aspect of this application.

[0028] A third aspect of this application provides a photovoltaic module, including at least one of the perovskite solar cells described in the first aspect of this application and the tandem cells described in the second aspect of this application.

[0029] The hole transport material provided in this application has good tolerance to perovskite precursor solutions, which can reduce defects in the perovskite thin film formed on the hole transport material, reduce the interface trap density, optimize the interface contact, and improve the crystallinity and stability of the perovskite light-absorbing layer, thereby helping to improve the photoelectric conversion efficiency, stability and lifespan of perovskite solar cells. Attached Figure Description

[0030] Figure 1 This is a schematic diagram of a perovskite solar cell according to one embodiment of this application.

[0031] Figure 2This is a surface morphology diagram of the perovskite light-absorbing layer prepared in Example 1 of this application.

[0032] Figure 3 This is a cross-sectional morphology diagram of the perovskite light-absorbing layer prepared in Example 1 of this application.

[0033] Figure 4 The image shows the proton NMR spectrum of the hole transport material prepared in Example 1.

[0034] Figure 5 The image shows the proton NMR spectrum of the hole transport material prepared in Example 2.

[0035] Figure 6 The image shows the proton NMR spectrum of the hole transport material prepared in Example 3.

[0036] Figure 7 The image shows the proton NMR spectrum of the hole transport material prepared in Example 4.

[0037] Figure 8 The image shows the proton NMR spectrum of the hole transport material prepared in Example 5.

[0038] Figure 9 The image shows the proton NMR spectrum of the hole transport material prepared in Example 6.

[0039] Figure reference numerals: 11 Perovskite light-absorbing layer; 10 First charge transport layer; 13 Second charge transport layer; 12 First electrode; 16 Second electrode. Detailed Implementation

[0040] To facilitate understanding of this application, a more complete description will be provided below. However, this application can be implemented in many different forms and is not limited to the embodiments described herein. Rather, these embodiments are provided to provide a more thorough and complete understanding of the disclosure of this application.

[0041] For simplicity, this application only explicitly discloses some numerical ranges. However, any lower limit can be combined with any upper limit to form a range not explicitly stated; and any lower limit can be combined with other lower limits to form a range not explicitly stated, just as any upper limit can be combined with any other upper limit to form a range not explicitly stated. Furthermore, although not explicitly stated, every point or individual value between the endpoints of the range is included within that range. Therefore, each point or individual value can be used as its own lower or upper limit and combined with any other point or individual value or with other lower or upper limits to form a range not explicitly stated.

[0042] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs. The terminology used herein in the specification of this application is for the purpose of describing particular embodiments only and is not intended to be limiting of the application. It should be noted that, unless otherwise stated, the term "and / or" as used herein includes any and all combinations of one or more of the associated listed items, "above," "below," includes the stated number, and "one or more" with "multiple" means two or more.

[0043] In this document, when referring to numerical intervals (i.e., numerical ranges), unless otherwise specified, the distribution of selectable values ​​within a numerical interval is considered continuous, and includes the two endpoints (i.e., the minimum and maximum values) of the numerical interval, as well as every value between these two endpoints. Unless otherwise specified, when a numerical interval refers only to integers within that interval, it includes the two endpoint integers of the numerical range, as well as every integer between the two endpoints, which is equivalent to directly listing every integer. When multiple numerical ranges are provided to describe features or characteristics, these numerical ranges can be merged. In other words, unless otherwise specified, the numerical ranges disclosed herein should be understood to include any and all subranges included therein. The "numerical value" in this numerical interval can be any quantitative value, such as a number, percentage, ratio, etc. The term "numerical interval" can be broadly included to include percentage intervals, ratio intervals, proportion intervals, and other numerical interval types.

[0044] In this document, for methods involving multiple steps, unless otherwise explicitly stated herein, there is no strict order constraint on the execution of these steps; they may be executed in any order other than those described. Moreover, any step may include multiple sub-steps or multiple stages, which are not necessarily completed at the same time, but may be executed at different times, and their execution order is not necessarily sequential, but may be executed in turn, alternately, or simultaneously with other steps or parts of the sub-steps or stages of other steps.

[0045] The foregoing description of this application is not intended to describe every disclosed implementation or method. Instead, the following description provides more specific examples of exemplary embodiments. Throughout the application, guidance is provided through a series of embodiments that can be used in various combinations. The examples listed are representative only and should not be construed as exhaustive.

[0046] Currently, hole transport materials (HTMs) in perovskite solar cells are mainly classified into three categories: inorganic hole transport materials, organic small molecule hole transport materials, and organic polymer hole transport materials. Among them, organic small molecule hole transport materials have become the most common type in perovskite solar cells due to their advantages such as diverse synthesis methods, tunable properties, high purity, and ease of solution handling. However, because organic small molecule hole transport materials have a rigid structure, they have low tolerance to perovskite precursor solutions. Consequently, perovskite films formed adjacent to these small molecule hole transport materials are prone to pinhole morphological defects, resulting in poor film formation and instability under external stimuli. In addition, many small molecule hole transport materials require the addition of dopants during use. These factors all pose obstacles to the large-scale commercialization of perovskite solar cells. To solve these technical problems, the inventors have proposed the following technical solution in this application.

[0047] Firstly, this application provides a perovskite solar cell, see [link to previous application]. Figure 1 It includes a perovskite light-absorbing layer 11 and a first charge transport layer 10 disposed on one side of the perovskite light-absorbing layer 11. The first charge transport layer 10 contains a hole transport material, which includes a compound represented by Formula I:

[0048] Formula I,

[0049] In Formula I, X is selected from O, S, single bonds, and One of them, n is an integer from 2 to 4, and * represents the connection site.

[0050] In the hole transport material of Formula I provided in this application, a pyrene group is used as the end group to construct a conjugated framework, and a fused ring aromatic hydrocarbon structure is adopted to form a peri-fused polycyclic aromatic hydrocarbon system. Chemical inertness is achieved through a pure carbon framework, which enhances the intermolecular π-π stacking interaction. As a result, the three-dimensional conjugated system in the molecular structure provides stronger structural rigidity, which can effectively suppress the molecular reconstruction phenomenon during the use of the material, thereby helping to improve the photoelectric conversion efficiency, stability and lifespan of perovskite solar cells.

[0051] Meanwhile, in this material, phosphate groups can serve as anchoring units for hole transport materials, thereby improving the material's solubility, processability, and wettability. The material's good wettability also allows for better wettability to perovskite precursor solutions. Furthermore, groups with planar rigid structures (such as carbazole and phenothiazine groups) in this hole transport material are not easily dissolved by perovskite precursor solutions, thus exhibiting good tolerance to perovskite precursor solutions. This reduces defects in the perovskite thin film formed on the hole transport material, lowers the interface trap density, optimizes interface contact, and improves the crystallinity and stability of the perovskite light-absorbing layer. Ultimately, this contributes to improving the photoelectric conversion efficiency, stability, and lifespan of perovskite solar cells.

[0052] Furthermore, since this hole transport material can reduce interface defects and optimize interface contact, it does not require the addition of dopants needed for traditional small molecule hole transport materials, and it has good repeatability, which is conducive to the large-scale commercial application of perovskite solar cells.

[0053] In some embodiments, the hole transport material comprises one or more compounds represented by Formula I-1, Formula I-2, Formula I-3 and Formula I-4:

[0054] Equation I-1,

[0055] Equation I-2,

[0056] Equation I-3,

[0057] Equation I-4.

[0058] Hole transport materials comprising at least one compound of formulas I-1 to I-4 exhibit good tolerance and wettability to perovskite precursor solutions, which can reduce pinhole morphology defects in the perovskite light-absorbing layer formed adjacent to the hole transport material, lower the interface trap density, and improve the crystallinity and stability of the perovskite light-absorbing layer. Furthermore, at least one compound of formulas I-1 to I-4 can effectively suppress molecular reconstruction phenomena during material use. At the same time, the hole transport material has a high carrier mobility, which is beneficial for hole extraction and transport. Thus, it is beneficial to comprehensively improve the stability and photoelectric conversion efficiency of perovskite solar cells.

[0059] In some embodiments, the hole transport material comprises one or more compounds represented by formulas 1 to 12:

[0060] Formula 1, Equation 2, Formula 3,

[0061] Equation 4, Equation 5, Formula 6,

[0062] Equation 7, Formula 8, Formula 9,

[0063] Formula 10, Formula 11, Equation 12.

[0064] At least one compound from Formulas 1 to 12 can effectively suppress molecular reconstruction during the use of the material. Furthermore, the hole transport material exhibits good tolerance and wettability to the perovskite precursor solution, which is beneficial for promoting the crystallization and growth of perovskite grains and forming perovskite grains with a larger average grain size. This facilitates the close arrangement of perovskite grains, reduces boundary defects between grains, and consequently reduces pinhole morphology defects in the perovskite light-absorbing layer formed adjacent to the hole transport material. This lowers the interface trap density, improves the crystallinity and stability of the perovskite light-absorbing layer, and thus comprehensively improves the stability and photoelectric conversion efficiency of perovskite solar cells.

[0065] In some embodiments, the perovskite light-absorbing layer comprises a perovskite material, the perovskite material comprising the compound ABY3, wherein A ions are monovalent cations, B ions are divalent cations, and Y ions are monovalent anions;

[0066] The A ion includes organic cations and Li. + Na + K + 、Rb + and Cs + One or more of the following; further, the organic cation includes at least one of methylamino, ethylamino, propylamino, butylamino, pentamino, hexamino, formamidinyl and imidazolyl;

[0067] The B ions include Pb. 2+ Sn 2+ Be 2+ Mg 2+ Ca 2+ 、Sr 2+ Ba 2+ Zn 2+ 、Ge 2+ Fe 2+ Co 2+ Cu 2+ and Ni 2+ One or more of the following;

[0068] The Y ions include F - Cl - ,Br - and I - One or more of them.

[0069] In some embodiments, the perovskite light-absorbing layer comprises perovskite grains with an average grain size of 50 nm to 800 nm, optionally 300 nm to 500 nm. For example, the average grain size of the perovskite grains can be 50 nm, 91 nm, 152 nm, 263 nm, 374 nm, 485 nm, 596 nm, 617 nm, 728 nm, 800 nm, or any value within the range above. An average grain size within this range is beneficial for the close packing of perovskite grains, thus reducing boundary defects between grains, lowering interface trap density, and improving the crystallinity and stability of the perovskite light-absorbing layer, thereby improving the stability and photoelectric conversion efficiency of the perovskite solar cell.

[0070] In some embodiments, the HOMO level of the hole transport material is 8.70 × 10⁻⁶. -5 eV ~1.65×10 - 4 eV, selectable as 8.80×10 -5 eV ~1.65×10 -4 eV. For example, the HOMO level of hole transport materials can be 8.70 × 10⁻⁶ eV. - 5 eV, 9.80×10 -5 eV, 1.01×10 -4 eV, 1.12×10 -4 eV, 1.23×10 -4 eV, 1.34×10 -4 eV, 1.45×10 - 4 eV, 1.56×10 -4 eV, 1.65×10 -4 eV or within any of the above values. Thus, the hole transport material possesses a deep HOMO energy level, which facilitates better matching with the energy levels of the perovskite light-absorbing layer, thereby improving the photoelectric conversion efficiency of the perovskite solar cell.

[0071] In some embodiments, the surface roughness of the perovskite light-absorbing layer adjacent to the first charge transport layer is 12 nm to 25 nm, optionally 15 nm to 20 nm. For example, the roughness can be 12 nm, 15 nm, 17 nm, 21 nm, 23 nm, 25 nm, or within any range of the above values. The hole transport material of this application is beneficial for improving the film-forming properties of the perovskite light-absorbing layer, enabling the surface adjacent to the perovskite light-absorbing layer and the first charge transport layer to have a relatively small roughness, thereby reducing the defect density at the interface and improving the photoelectric conversion efficiency of the perovskite solar cell.

[0072] In some implementations, see Figure 1 The perovskite solar cell further includes a second charge transport layer 13 disposed on the other side of the perovskite light-absorbing layer 11, the second charge transport layer 13 containing an electron transport material.

[0073] The second charge transport layer contains electron transport materials, which facilitates the transport and extraction of electrons. This, in turn, facilitates the transport and recombination of electrons and holes between the first charge transport layer, the perovskite light-absorbing layer, and the second charge transport layer, thereby enabling the perovskite solar cell to have a high photoelectric conversion efficiency.

[0074] In some embodiments, the electron transport material includes fullerene C60, fullerene C70, and PC. 61 BM ([6,6]-phenyl-C61-butyrate methyl ester), [6,6]-phenyl-C71-butyrate methyl ester (PC) 71 One or more of BM).

[0075] In some implementations, see Figure 1 The perovskite solar cell further includes a first electrode 12 and a second electrode 16; the first electrode 12 is disposed on the side of the first charge transport layer 10 away from the perovskite light-absorbing layer 11, and the second electrode 16 is disposed on the side of the second charge transport layer 13 away from the perovskite light-absorbing layer 11.

[0076] In some embodiments, one of the first electrode and the second electrode is a transparent electrode for light incident. One of the first electrode and the second electrode is used to collect electron carriers, and the other is used to collect hole carriers.

[0077] In some embodiments, the first electrode is a transparent electrode; optionally, the first electrode comprises ITO glass, and the second electrode comprises a metal electrode. In this case, the perovskite solar cell has an inverted structure, and the perovskite light-absorbing layer is fabricated on a hole transport material. Because the hole transport material has good tolerance and wettability to the perovskite precursor solution, coating the perovskite precursor solution onto the hole transport material can reduce defects in the formed perovskite light-absorbing layer, lower the interface trap density, and improve the crystallinity and stability of the perovskite light-absorbing layer. Thus, in the inverted perovskite solar cell, the hole transport material has a better effect on improving the perovskite light-absorbing layer.

[0078] Secondly, this application provides a tandem solar cell, including a bottom cell and a top cell stacked together, wherein the top cell is the perovskite solar cell described in the first aspect of this application.

[0079] Thirdly, this application provides a photovoltaic module, including at least one of the perovskite solar cells described in the first aspect of this application and the tandem cells described in the second aspect of this application.

[0080] Fourthly, this application provides a method for preparing a hole transport material, which can be used to prepare the hole transport material described in the first aspect of this application, and may include the following steps:

[0081] The reactant II and compound III undergo a Suzuki coupling reaction to produce compound IV;

[0082] The compound of formula IV undergoes a hydrolysis reaction to generate the compound shown in formula I, thus forming a hole transport material;

[0083] Raw material II, Formula III,

[0084] Formula IV,

[0085] Formula I,

[0086] In Formula III, R1 is selected from halogen atoms, and can be Br atoms;

[0087] In Formula I, X is selected from O, S, single bonds, and One of them, n is an integer from 2 to 4, and * represents the connection site.

[0088] The above preparation methods are simple in synthesis steps, low in cost, and have good reproducibility, which is conducive to the large-scale preparation of hole transport materials and perovskite solar cells.

[0089] In some embodiments, the preparation method of the compound of formula III may include the following steps:

[0090] The compound of formula II undergoes a nucleophilic substitution reaction to generate the compound of formula III;

[0091] Formula II,

[0092] In Formula II, R2 is selected from halogen atoms, and can be Br atoms.

[0093] In some embodiments, the preparation method of the compound of formula II may include the following steps:

[0094] The raw material I undergoes a halogenation reaction to produce a compound of formula I'.

[0095] The compound of formula I' undergoes a substitution reaction to produce the compound of formula II;

[0096] Raw material I, Formula I'.

[0097] As a non-limiting example, the preparation method of the hole transport material is as follows:

[0098] Reaction step i: Under inert gas protection, raw material I and N-bromosuccinimide are added to the reaction vessel and reacted at 0~5°C for 12~16h to obtain compound I'. The amount of the compound involved in the reaction is calculated according to the standard of mass balance, and the ratio of raw material I to N-bromosuccinimide is 1:(1.1~1.8).

[0099] Reaction step ii: Add the compound of formula I', tetrabutylammonium halide, bromoalkane, and potassium hydroxide to a reaction vessel and react at 65°C~80°C for 8h~14h to obtain the compound of formula II. The amounts of the compounds involved in the reaction are calculated according to the standard of molar weight, and the ratio of compound of formula I': tetrabutylammonium halide: potassium hydroxide: bromoalkane is 1:(0.1~0.2):(5~10):(200~600). Among them, tetrabutylammonium halide includes tetrabutylammonium bromide and / or tetrabutylammonium iodide, and bromoalkane includes one or more of dibromobutane, dibromopropane, and dibromoethane.

[0100] Reaction step iii: Under inert gas protection, compound II and triethyl phosphite are added to the reaction vessel and reacted at 140°C~150°C for 8h~16h to obtain compound III. The amount of the compound participating in the reaction is calculated according to the standard of molar weight, and the ratio of compound II to triethyl phosphite is 1:(140~160).

[0101] Reaction step V: Under inert gas protection, compound III, raw material II, tetra(triphenylphosphine)palladium, potassium carbonate, toluene, ethanol and water are added to the reaction vessel and reacted at 85°C~90°C for 6h~12h to obtain compound IV. The amount of the compound participating in the reaction is calculated according to the standard of molar balance. Compound III: raw material II: potassium carbonate: tetra(triphenylphosphine)palladium = 1:(1.1~1.7):(2~5):(0.02~0.1).

[0102] Reaction step ⅵ: Under inert gas protection, compound IV, trimethylbromosilane, and 1,4-dioxane were added to a reaction vessel and reacted at 25°C for 8-14 hours to obtain a white solid. The solid was then dissolved in methanol solution and deionized water was added dropwise. The mixture was stirred at room temperature for 12 hours. The crude product was collected by filtration and washed with deionized water to obtain compound I. The amounts of the compounds involved in the reaction were calculated according to the molar balance standard. The ratio of compound IV to trimethylsilylbromine was 1:(10-30).

[0103] The following are specific embodiments, which describe the disclosure of this application in more detail. These embodiments are merely illustrative, as various modifications and variations within the scope of the disclosure of this application will be apparent to those skilled in the art. Unless otherwise stated, all parts, percentages, and ratios reported in the following embodiments are based on weight, and all reagents used in the embodiments are commercially available or synthesized by conventional methods and can be used directly without further processing, and the instruments used in the embodiments are commercially available.

[0104] Example 1

[0105] (1) Preparation of hole transport materials

[0106] Synthesis of Compound 2: Compound 1 (1.01 g, 5 mmol) and dichloromethane (20 mL) were added to a 100 mL round-bottom flask, followed by the addition of N-bromosuccinimide (1.24 g, 7 mmol). The mixture was stirred overnight at 5 °C. The reaction was quenched with water, extracted with dichloromethane, and the organic layers were bound together. The mixture was dried over anhydrous magnesium sulfate, and the organic solvent was removed using a rotary evaporator to obtain the crude product. Further purification was achieved by column chromatography with petroleum ether:dichloromethane as the eluent at a volume ratio of 10:1 to obtain Compound 2 (1.3 g, 91% yield).

[0107]

[0108] Synthesis of Compound 10: Compound 2 (0.87 g, 3 mmol) and tetrabutylammonium bromide (0.35 g, 0.3 mmol) were dissolved in dibromoethane (35 mL) in a 100 mL double-necked flask, followed by the dropwise addition of 5 mL of 50% potassium hydroxide aqueous solution. The mixture was heated to 65 °C and stirred overnight. The reaction mixture was quenched with water, extracted with dichloromethane, and the organic layer was dried in combination with anhydrous magnesium sulfate. The organic solvent was then removed by a rotary evaporator to obtain the crude product. Further purification was performed by silica gel column chromatography with petroleum ether:dichloromethane as the eluent in a volume ratio of 10:1 to obtain Compound 10 (0.96 g, 80% yield).

[0109]

[0110] Synthesis of Compound 11: Compound 10 (1.6 g, 4 mmol) and triethyl phosphite (30 mL) were added to a 100 mL double-necked flask. The mixture was then heated to 160 °C and stirred overnight under a nitrogen atmosphere. The organic solvent was then removed using a rotary evaporator to give crude compound 11 (1.6 g) in 88% yield.

[0111]

[0112] Synthesis of Compound 12: Compound 11 (1.82 g, 4 mmol), Compound 5 (1.23 g, 5 mmol), tetrakis(triphenylphosphine)palladium (0.092 g, 0.08 mmol), and potassium carbonate (1.38 g, 10 mmol) were weighed and added to a 100 mL two-necked reaction flask. The mixture was reacted at 85 °C for 8 hours under N2 atmosphere with DMF (40 mL) as solvent. After cooling to room temperature, the mixture was extracted with DCM, the organic phase was dried over anhydrous Mg2SO4, filtered, and distilled under reduced pressure. Finally, the mixture was purified by column chromatography (PE:DCM = 7:1) to obtain 1.36 g of compound 12 solid powder, with a yield of 59%.

[0113]

[0114] Synthesis of Py-2: Compound 12 (1.16 g, 2 mmol) was added to anhydrous 1,4-1,4-dioxane (10 mL) at room temperature in a 100 mL double-necked flask, followed by the dropwise addition of trimethylbromosilane (3.06 g, 20 mmol), and the mixture was stirred overnight. The 1,4-dioxane was removed using a rotary evaporator to obtain a solid powder. The solid powder was dissolved in methanol (10 mL) at room temperature, and then deionized water was added dropwise until the mixture became opaque, followed by stirring for 12 hours. The crude product was collected by filtration and washed with deionized water. The crude product was dissolved in THF (5 mL), reprecipitated in acetone (90 mL), and filtered to obtain the final product, the hole transport material, designated as Py-2 (0.7 g, 67% yield). The 1H NMR spectrum of product Py-2 is shown below. Figure 4 As shown.

[0115]

[0116] (2) Fabrication of stacked batteries

[0117] (2.1) Fabrication of crystalline silicon bottom solar cells

[0118] ① An n-type monocrystalline silicon wafer with a thickness of 160 μm was used as the substrate material for the bottom cell. The back side of the n-type silicon wafer was boron-doped in a high-temperature diffusion furnace to form a p+ emitter. The doping depth was controlled below 5 μm to achieve efficient carrier separation.

[0119] ② Using PECVD (Plasma Enhanced Chemical Vapor Deposition) technology, an aluminum oxide (Al2O3) layer with a thickness of 6nm is deposited on the silicon wafer surface as a tunneling oxide layer to reduce interfacial recombination.

[0120] ③Heavily doped hydrogenated microcrystalline silicon layer: n-type hydrogenated microcrystalline silicon (μc-Si:H), with a thickness of 20nm, serves as a charge extraction layer to enhance carrier transport efficiency.

[0121] ④ The passivation layer and charge extraction layer form a stacked structure: First, a 6nm silicon oxide layer (SiO2) is deposited. Then, a 20nm heavily doped hydrogenated microcrystalline silicon layer (n-μc-Si:H) is deposited to combine the effects of chemical passivation and field passivation.

[0122] ⑤ At 450℃, a 20nm layer of ITO was sputtered onto the surface using a mask as a composite layer. The contact area was 1.1 × 1.1 cm². 2 Slightly larger than the effective area of ​​the completed stacked battery, 1×1cm 2 The silicon wafer was cut into 2.5 × 2.5 cm pieces. 2 The base.

[0123] (2.2) Fabrication of perovskite rooftop solar cells

[0124] ① The crystalline silicon substrate was subjected to oxygen plasma treatment for 15 minutes. At room temperature, a 5 nm NiOx layer was deposited on the pre-cleaned substrate using radio frequency sputtering. The sputtering chamber pressure was 0.40 Pa, the radio frequency power was 90 W, the argon flow rate was 20 sccm, and the deposition time was 10 minutes. After deposition, the substrate was annealed in air for 30 minutes at a temperature of 350 °C. Subsequently, the NiOx substrate was directly transferred to a nitrogen glove box for the subsequent spin-coating process.

[0125] ② Preparation of the hole transport layer: Weigh 1 mg of the hole transport material Py-2 obtained in step (1) and completely dissolve it in 1 mL of a mixture of anhydrous ethanol and DMF. Take 100 μL of the solution and add it evenly to ITO. Let it stand for 5 seconds. Spin coat at 3000 rpm for 30 seconds, and then anneal at 100℃ for 10 minutes.

[0126] ③ Preparation of the perovskite light-absorbing layer: The crystalline silicon / ITO / NiOx / hole transport layer substrate obtained above was cooled to room temperature. 0.075 mmol of CsI, 1.098 mmol of FAI, 0.327 mmol of MABr, 0.354 mmol of PbBr2 and 1.146 mmol of PbI2 were dissolved in 1 mL of a mixed solvent of DMF:DMSO (volume ratio 4:1) to prepare a 1.5 mol / L perovskite precursor solution.

[0127] Spin-coating was performed at 3000 rpm for 30 seconds. Five seconds before the end of spin-coating, 150 μL of ethyl acetate (EA) was dropped onto the center of the film as an anti-solvent. The substrate was then immediately transferred to a heating stage and annealed at 100°C for 10 minutes to form a perovskite light-absorbing layer. The chemical formula of the perovskite material is Cs. 0.05 (FA 0.77 MA 0.23 ) 0.95 Pb(I 0.77 Br 0.23 )3, with a band gap of 1.68 eV.

[0128] ④ Perovskite interface passivation treatment: Dissolve P201 material in isopropanol with an ultrasonic concentration of 0.3 mg / ml, take 100 μL of solution and add it evenly to the substrate, spin coat at 5000 rpm for 30 s, and then anneal at 100℃ for 10 minutes.

[0129] ⑤ Fabrication of the electron transport layer: in a high vacuum (5×10⁻⁶) -4 C60 was thermally evaporated to 15 nm at a deposition rate of 0.1 Å / s under Pa conditions.

[0130] ⑥ Preparation of hole-blocking layer (BCP): In high vacuum (5×10⁻⁶), -4BCP was thermally evaporated to 10 nm at a deposition rate of 1 Å / s under Pa conditions.

[0131] ⑦ Fabrication of the transparent electrode: A 50 nm thick indium zinc oxide (IZO) transparent electrode (sheet resistance 60 Ω, area defined by a mask of 1.1 × 1.1 cm) was deposited at room temperature using radio frequency (RF) magnetron sputtering. 2 The radio frequency power is 80 W.

[0132] ⑧ Fabrication of Ag gate wires: in high vacuum (5×10⁻⁶) -4 Ag was thermally evaporated at a rate of 700 nm (deposition rate of 1 Å / s) under Pa conditions.

[0133] ⑨ Preparation of the antireflection layer: under high vacuum (5×10⁻⁶) -4 MgF2 was thermally evaporated at a depth of 100 nm under Pa (deposition rate of 0.5 Å / s).

[0134] ⑩ Preparation of the back electrode Ag: under high vacuum (5×10⁻⁶) -4 A tandem solar cell was obtained by thermally evaporating 400 nm of Ag on the back side of a crystalline silicon substrate at a deposition rate of 1 Å / s under Pa conditions.

[0135] The thicknesses of the C60, BCP, IZO, and MgF2 layers were calibrated using a spectroscopic ellipsometry, and the deposition rate and thickness of each experiment were monitored using a quartz crystal microbalance sensor.

[0136] Example 2

[0137] Similar to the preparation process in Example 1, the main difference is that in step (1), the preparation process of the hole transport material is as follows:

[0138] Synthesis of Compound 2: Compound 1 (1.01 g, 5 mmol) and dichloromethane (20 mL) were added to a 100 mL round-bottom flask, followed by the addition of N-bromosuccinimide (1.24 g, 7 mmol). The mixture was stirred overnight at 5 °C. The reaction was quenched with water, extracted with dichloromethane, and the organic layers were bound together. The mixture was dried over anhydrous magnesium sulfate, and the organic solvent was removed using a rotary evaporator to obtain the crude product. Further purification was performed by column chromatography with petroleum ether:dichloromethane as the eluent at a volume ratio of 10:1 to obtain Compound 2 (1.3 g, 91% yield).

[0139]

[0140] Synthesis of Compound 7: Compound 2 (0.88 g, 3 mmol) and tetrabutylammonium bromide (0.35 g, 0.3 mmol) were dissolved in dibromopropane (35 mL) in a 100 mL double-necked flask, followed by the dropwise addition of 50% potassium hydroxide aqueous solution (5 mL). The mixture was heated to 65 °C and stirred overnight. The reaction mixture was quenched with water, extracted with dichloromethane, and the organic layer was dried in combination with anhydrous magnesium sulfate. The organic solvent was then removed by a rotary evaporator to obtain the crude product. Further purification was performed by silica gel column chromatography with petroleum ether:dichloromethane as the eluent at a volume ratio of 10:1 to obtain Compound 7 (0.96 g, 78% yield).

[0141]

[0142] Synthesis of compound 8: Compound 7 (1.65 g, 4 mmol) and triethyl phosphite (30 mL) were added to a 100 mL double-necked flask, and the mixture was then heated to 160 °C and stirred overnight under a nitrogen atmosphere. The organic solvent was then removed by a rotary evaporator to give crude compound 8 (1.71 g), yield 91%.

[0143]

[0144] Synthesis of Compound 9: Compound 8 (1.88 g, 4 mmol), Compound 5 (1.23 g, 5 mmol), tetrakis(triphenylphosphine)palladium (0.092 g, 0.08 mmol), and potassium carbonate (1.38 g, 10 mmol) were weighed and added to a 100 mL two-necked reaction flask. The mixture was reacted at 85 °C for 8 hours under N2 atmosphere with DMF (40 mL) as solvent. After cooling to room temperature, the mixture was extracted with DCM, the organic phase was dried over anhydrous Mg2SO4, filtered, and distilled under reduced pressure. Finally, the mixture was purified by column chromatography (PE:DCM = 7:1) to obtain 1.3 g of Compound 9 solid powder, with a yield of 55%.

[0145]

[0146] Synthesis of Py-3: Compound 9 (1.18 g, 2 mmol) was added to anhydrous 1,4-1,4-dioxane (10 mL) at room temperature in a 100 mL double-necked flask, followed by the dropwise addition of trimethylbromosilane (3.06 g, 20 mmol), and the mixture was stirred overnight. The 1,4-dioxane was removed using a rotary evaporator to obtain a solid powder. The solid powder was dissolved in methanol (10 mL) at room temperature, and then deionized water was added dropwise until the mixture became opaque, followed by stirring for 12 hours. The crude product was collected by filtration and washed with deionized water. The crude product was dissolved in THF (5 mL), reprecipitated in acetone (90 mL), and filtered to obtain the final product, the hole transport material, designated as Py-3 (0.73 g, 62% yield). The 1H NMR spectrum of product Py-3 is shown below. Figure 5 As shown.

[0147]

[0148] Example 3

[0149] Similar to the preparation process in Example 1, the main difference is that in step (1), the preparation process of the hole transport material is as follows:

[0150] Synthesis of Compound 2: Compound 1 (1.01 g, 5 mmol) and dichloromethane (20 mL) were added to a 100 mL round-bottom flask, followed by the addition of N-bromosuccinimide (1.24 g, 7 mmol). The mixture was stirred overnight at 5 °C. The reaction was quenched with water, extracted with dichloromethane, and the organic layers were bound together. The mixture was dried over anhydrous magnesium sulfate, and the organic solvent was removed using a rotary evaporator to obtain the crude product. Further purification was performed by column chromatography with petroleum ether:dichloromethane as the eluent at a volume ratio of 10:1 to obtain Compound 2 (1.3 g, 91% yield).

[0151]

[0152] Synthesis of Compound 3: Compound 2 (0.87 g, 3 mmol) and tetrabutylammonium bromide (0.35 g, 0.3 mmol) dissolved in dibromobutane (35 mL) were added to a 100 mL double-necked flask, followed by the dropwise addition of 50% potassium hydroxide aqueous solution (5 mL). The mixture was heated to 65 °C and stirred overnight. The reaction mixture was quenched with water, extracted with dichloromethane, and the organic layer was dried in combination with anhydrous magnesium sulfate. The organic solvent was then removed by a rotary evaporator to obtain the crude product. Further purification was performed by silica gel column chromatography with petroleum ether:dichloromethane as the eluent in a volume ratio of 10:1 to obtain compound 3 (1.0 g, 79% yield).

[0153]

[0154] Synthesis of compound 4: Compound 3 (1.7 g, 4 mmol) and triethyl phosphite (30 mL) were added to a 100 mL double-necked flask, and the mixture was then heated to 160 °C and stirred overnight under a nitrogen atmosphere. The organic solvent was then removed by a rotary evaporator to give crude compound 4 (1.7 g) in 90% yield.

[0155]

[0156] Synthesis of Compound 6: Compound 4 (1.93 g, 4 mmol), Compound 5 (1.23 g, 5 mmol), tetrakis(triphenylphosphine)palladium (0.092 g, 0.08 mmol), and potassium carbonate (1.38 g, 10 mmol) were weighed and added to a 100 mL two-necked reaction flask. The mixture was reacted at 85 °C for 8 hours under N2 atmosphere with DMF (40 mL) as solvent. After cooling to room temperature, the mixture was extracted with DCM, the organic phase was dried over anhydrous Mg2SO4, filtered, and distilled under reduced pressure. Finally, the mixture was purified by column chromatography (PE:DCM = 7:1) to obtain 1.4 g of Compound 6 solid powder, with a yield of 58%.

[0157]

[0158] Synthesis of Py-4: Compound 6 (1.21 g, 2 mmol) was added to anhydrous 1,4-1,4-dioxane (10 mL) at room temperature in a 100 mL double-necked flask, followed by the dropwise addition of trimethylbromosilane (3.06 g, 20 mmol), and the mixture was stirred overnight. The 1,4-dioxane was removed using a rotary evaporator to obtain a solid powder. The solid powder was dissolved in methanol (10 mL) at room temperature, and then deionized water was added dropwise until the mixture became opaque, followed by stirring for 12 hours. The crude product was collected by filtration and washed with deionized water. The crude product was dissolved in THF (5 mL), reprecipitated in acetone (90 mL), and filtered to obtain the final product, the hole transport material, designated as Py-4 (0.7 g, 65% yield). The 1H NMR spectrum of product Py-4 is shown below. Figure 6 As shown.

[0159]

[0160] Example 4

[0161] Similar to the preparation method in Example 1, the main difference is that in step (1), the hole transport material prepared is The specific reaction formula and preparation process are as follows:

[0162]

[0163] Synthesis of Compound 2: Compound 1 (1.34 g, 6 mmol) and dichloromethane (20 mL) were added to a 100 mL round-bottom flask, followed by the addition of N-bromosuccinimide (1.33 g, 7.5 mmol). The mixture was stirred overnight at 5 °C. The reaction was quenched with water, extracted with dichloromethane, and the organic layers were bound together. The mixture was dried over anhydrous magnesium sulfate, and the organic solvent was removed using a rotary evaporator to obtain the crude product. Further purification was performed by column chromatography with petroleum ether:dichloromethane as the eluent at a volume ratio of 10:1 to obtain Compound 2 (1.7 g, 93% yield).

[0164] Synthesis of Compound 3: Compound 2 (0.93 g, 3 mmol) and tetrabutylammonium bromide (0.35 g, 0.3 mmol) dissolved in dibromobutane (35 mL) were added to a 100 mL double-necked flask, followed by the dropwise addition of 50% potassium hydroxide aqueous solution (5 mL). The mixture was heated to 65 °C and stirred overnight. The reaction mixture was quenched with water, extracted with dichloromethane, and the organic layer was dried in combination with anhydrous magnesium sulfate. The organic solvent was then removed by a rotary evaporator to obtain the crude product. Further purification was performed by silica gel column chromatography with petroleum ether:dichloromethane as the eluent at a volume ratio of 10:1 to obtain compound 3 (0.85 g, 71% yield).

[0165] Synthesis of compound 4: Compound 3 (2.01 g, 5 mmol) and triethyl phosphite (30 mL) were added to a 100 mL double-necked flask, and the mixture was then heated to 160 °C and stirred overnight under a nitrogen atmosphere. The organic solvent was then removed by a rotary evaporator to give crude compound 4 (1.9 g), yield 84%.

[0166] Synthesis of Compound 6: Compound 4 (1.9 g, 4 mmol), Compound 5 (1.23 g, 5 mmol), tetrakis(triphenylphosphine)palladium (0.092 g, 0.08 mmol), and potassium carbonate (1.38 g, 10 mmol) were weighed and added to a 100 mL two-necked reaction flask. The mixture was reacted at 85 °C for 8 hours under N2 atmosphere with DMF (40 mL) as solvent. After cooling to room temperature, the mixture was extracted with DCM, the organic phase was dried over anhydrous Mg2SO4, filtered, and distilled under reduced pressure. Finally, the mixture was purified by column chromatography (PE:DCM = 5:1) to obtain 1.2 g of Compound 6 solid powder, with a yield of 51%.

[0167] Synthesis of Compound Formula 4: Compound 6 (1.2 g, 2 mmol) was added to anhydrous 1,4-1,4-dioxane (10 mL) at room temperature in a 100 mL double-necked flask, followed by the dropwise addition of trimethylbromosilane (3.06 g, 20 mmol), and the mixture was stirred overnight. The 1,4-dioxane was removed using a rotary evaporator to obtain a solid powder. The solid powder was dissolved in methanol (10 mL) at room temperature, and then deionized water was added dropwise until the mixture became opaque, followed by stirring for 12 hours. The crude product was collected by filtration and washed with deionized water. The crude product was dissolved in THF (5 mL), reprecipitated in acetone (90 mL), and filtered to obtain the final product, which was the hole transport material, denoted as Compound Formula 4 (0.6 g, 60% yield). The 1H NMR spectrum of the product Compound Formula 4 is shown below. Figure 7 As shown.

[0168] Example 5

[0169] Similar to the preparation method in Example 1, the main difference is that in step (1), the hole transport material prepared is The specific reaction formula and preparation process are as follows:

[0170]

[0171] Synthesis of Compound 2: Compound 1 (1.44 g, 6 mmol) and dichloromethane (20 mL) were added to a 100 mL round-bottom flask, followed by the addition of N-bromosuccinimide (1.33 g, 7.5 mmol). The mixture was stirred overnight at 5 °C. The reaction was quenched with water, extracted with dichloromethane, and the organic layers were bound together. The mixture was dried over anhydrous magnesium sulfate, and the organic solvent was removed using a rotary evaporator to obtain the crude product. Further purification was performed by column chromatography with petroleum ether:dichloromethane as the eluent at a volume ratio of 6:1 to obtain Compound 2 (1.6 g, 89% yield).

[0172] Synthesis of Compound 3: Compound 2 (0.96 g, 3 mmol) and tetrabutylammonium bromide (0.35 g, 0.3 mmol) dissolved in dibromobutane (35 mL) were added to a 100 mL double-necked flask, followed by the dropwise addition of 50% potassium hydroxide aqueous solution (5 mL). The mixture was heated to 65 °C and stirred overnight. The reaction mixture was quenched with water, extracted with dichloromethane, and the organic layer was dried in combination with anhydrous magnesium sulfate. The organic solvent was then removed by a rotary evaporator to obtain the crude product. Further purification was performed by silica gel column chromatography with petroleum ether:dichloromethane as the eluent in a volume ratio of 7:1 to obtain compound 3 (0.75 g, yield 59%).

[0173] Synthesis of compound 4: Compound 3 (2.2 g, 5 mmol) and triethyl phosphite (30 mL) were added to a 100 mL double-necked flask. The mixture was then heated to 160 °C and stirred overnight under a nitrogen atmosphere. The organic solvent was then removed using a rotary evaporator to give crude compound 4 (1.8 g), in 78% yield.

[0174] Synthesis of Compound 6: Compound 4 (1.93 g, 4 mmol), Compound 5 (1.23 g, 5 mmol), tetrakis(triphenylphosphine)palladium (0.092 g, 0.08 mmol), and potassium carbonate (1.38 g, 10 mmol) were weighed and added to a 100 mL two-necked reaction flask. The mixture was reacted at 85 °C for 8 hours under N2 atmosphere with DMF (40 mL) as solvent. After cooling to room temperature, the mixture was extracted with DCM, the organic phase was dried over anhydrous Mg2SO4, filtered, and distilled under reduced pressure. Finally, the mixture was purified by column chromatography (PE:DCM = 6:1) to obtain 1.3 g of Compound 6 solid powder, with a yield of 54%.

[0175] Synthesis of Compound Formula 7: Compound 6 (1.1 g, 2 mmol) was added to anhydrous 1,4-1,4-dioxane (10 mL) at room temperature in a 100 mL double-necked flask, followed by the dropwise addition of trimethylbromosilane (3.06 g, 20 mmol), and the mixture was stirred overnight. The 1,4-dioxane was removed using a rotary evaporator to obtain a solid powder. The solid powder was dissolved in methanol (10 mL) at room temperature, and then deionized water was added dropwise until the mixture became opaque, followed by stirring for 12 hours. The crude product was collected by filtration and washed with deionized water. The crude product was dissolved in THF (5 mL), reprecipitated in acetone (90 mL), and filtered to obtain the final product, which was the hole transport material, denoted as Compound Formula 7 (0.57 g, yield 52%). The 1H NMR spectrum of the product Compound Formula 7 is shown below. Figure 8 As shown.

[0176] Example 6

[0177] Similar to the preparation method in Example 1, the main difference is that in step (1), the hole transport material prepared is The specific reaction formula and preparation process are as follows:

[0178]

[0179] Synthesis of Compound 2: Compound 1 (1.2 g, 6 mmol) and dichloromethane (20 mL) were added to a 100 mL round-bottom flask, followed by the addition of N-bromosuccinimide (1.33 g, 7.5 mmol). The mixture was stirred overnight at 5 °C. The reaction was quenched with water, and the mixture was extracted with dichloromethane. The organic layers were combined, dried over anhydrous magnesium sulfate, and the organic solvent was removed using a rotary evaporator to obtain the crude product. Further purification was performed by column chromatography with petroleum ether:dichloromethane as the eluent at a volume ratio of 6:1 to obtain Compound 2 (1.5 g, 94% yield).

[0180] Synthesis of Compound 3: Compound 2 (0.83 g, 3 mmol) and tetrabutylammonium bromide (0.35 g, 0.3 mmol) were dissolved in dibromobutane (35 mL) in a 100 mL double-necked flask, followed by the dropwise addition of 50% potassium hydroxide aqueous solution (5 mL). The mixture was heated to 65 °C and stirred overnight. The reaction mixture was quenched with water, extracted with dichloromethane, and the organic layer was dried in combination with anhydrous magnesium sulfate. The organic solvent was then removed by a rotary evaporator to obtain the crude product. Further purification was performed by silica gel column chromatography with petroleum ether:dichloromethane as the eluent in a volume ratio of 8:1 to obtain compound 3 (0.8 g, 69% yield).

[0181] Synthesis of compound 4: Compound 3 (1.9 g, 5 mmol) and triethyl phosphite (30 mL) were added to a 100 mL double-necked flask, and the mixture was then heated to 160 °C and stirred overnight under a nitrogen atmosphere. The organic solvent was then removed by a rotary evaporator to give crude compound 4 (1.78 g), yield 81%.

[0182] Synthesis of Compound 6: Compound 4 (1.76 g, 4 mmol), Compound 5 (1.23 g, 5 mmol), tetrakis(triphenylphosphine)palladium (0.092 g, 0.08 mmol), and potassium carbonate (1.38 g, 10 mmol) were weighed and added to a 100 mL two-necked reaction flask. The mixture was reacted at 85 °C for 8 hours under N2 atmosphere with DMF (40 mL) as solvent. After cooling to room temperature, the mixture was extracted with DCM, the organic phase was dried over anhydrous Mg2SO4, filtered, and distilled under reduced pressure. Finally, the mixture was purified by column chromatography (PE:DCM = 6:1) to obtain 1.4 g of Compound 6 solid powder, with a yield of 62%.

[0183] Synthesis of Compound 10: Compound 6 (1.12 g, 2 mmol) was added to anhydrous 1,4-1,4-dioxane (10 mL) at room temperature in a 100 mL double-necked flask, followed by the dropwise addition of trimethylbromosilane (3.06 g, 20 mmol), and the mixture was stirred overnight. The 1,4-dioxane was removed using a rotary evaporator to obtain a solid powder. The solid powder was dissolved in methanol (10 mL) at room temperature, and then deionized water was added dropwise until the mixture became opaque, followed by stirring for 12 hours. The crude product was collected by filtration and washed with deionized water. The crude product was dissolved in THF (5 mL), reprecipitated in acetone (90 mL), and filtered to obtain the final product, the hole transport material, denoted as Compound 10 (0.59 g, yield 58%). The 1H NMR spectrum of the product Compound 10 is shown below. Figure 9 As shown.

[0184] Comparative Example 1

[0185] The preparation method is similar to that of Example 3, the main difference being that step (1) is omitted, and in step (2) the hole transport material uses an equal mass. Replace Py-2.

[0186] Comparative Example 2

[0187] The preparation method is similar to that of Example 3, the main difference being that step (1) is omitted, and in step (2) the hole transport material uses an equal mass. Replace Py-2.

[0188] The perovskite solar cells prepared in Examples 1-6 and Comparative Examples 1-2 were subjected to relevant performance tests, and the test results are shown in Table 1 below. In Table 1, "roughness" refers to the roughness of the surface adjacent to the perovskite light-absorbing layer and the hole transport layer, and "average grain size" refers to the average grain size of the perovskite grains.

[0189] The test conditions or standards for each performance test item are as follows:

[0190] (1) HOMO level test of hole transport materials

[0191] Five mg of hole transport material was dissolved in a 0.1 mol / L solution of tetrabutylammonium hexafluorophosphate (Bu4NPF6) in dichloromethane, and calibrated using ferrocene as an external standard. Cyclic voltammetry curves were obtained on an electrochemical workstation at a purge rate of 0.01 V / s. The redox potentials of the curves were analyzed, and the HOMO level of the material was calculated using the formula.

[0192] (2) Roughness test of perovskite layer

[0193] The surface morphology of the perovskite thin film samples prepared on the hole transport layer was photographed using an atomic force microscope.

[0194] (3) Average grain size test of perovskite grains

[0195] Scanning electron microscopy (SEM) is used to test the perovskite thin film. A test sample with a length × width of 50 mm × 100 mm is randomly selected on the perovskite thin film. Multiple test areas (e.g., 5) are randomly selected in the test sample. At a certain magnification (e.g., 1000x during measurement), the grain size of each perovskite grain in each test area is read (i.e., the distance between the two farthest points on the perovskite grain is taken as the grain size of the perovskite grain). The number and grain size of perovskite grains in each test area are counted. The arithmetic mean of the grain size of perovskite grains in each test area is taken as the average grain size of perovskite grains in the test sample.

[0196] (4) Photovoltaic conversion efficiency test of tandem solar cells

[0197] Under normal temperature and pressure, and under standard simulated sunlight (AM 1.5G, 100 milliwatts per square centimeter (mW / cm²) 2 Under illumination, the battery performance was tested to obtain the IV curve (volt-ampere characteristic curve). Based on the IV curve and the data fed back by the testing equipment (four-channel digital source meter, Keithley 2440), the short-circuit current density Jsc (mA / cm2), open-circuit voltage Voc (volts (V)), maximum light output current Jmpp (mA (mA)), maximum light output voltage Vmpp (V) and series resistance (Ω) can be obtained.

[0198] The fill factor FF of the battery can be calculated using the formula FF = Jsc × Voc / (Jmpp × Vmpp), in percentage. The photoelectric conversion efficiency PCE of the battery can be calculated using the formula PCE = Jsc × Voc × FF / Pw, in percentage; Pw represents the input power, in milliwatts (mW).

[0199] "Normal temperature and pressure" refers to normal pressure: the pressure is one atmosphere at a temperature of 25℃; normal temperature refers to 20℃ to 30℃, and further, it can be 25℃.

[0200] (5) Stability test of stacked cells

[0201] After storing the tandem solar cell in an inert environment for 1200 hours, its photoelectric conversion efficiency was tested to characterize its stability.

[0202] Table 1

[0203]

[0204] Table 1 shows that the photoelectric conversion efficiency and stability of Examples 1-6 are significantly better than those of Comparative Example 2, indicating that the hole transport material of this application containing pyrene groups can effectively improve photoelectric conversion efficiency and stability compared with hole transport materials without pyrene groups. Furthermore, the comparison between Examples 1-6 and Comparative Example 1 shows that the photoelectric conversion efficiency and stability of Examples 1-6 are significantly better than those of Comparative Example 1, indicating that the hole transport material of this application using pyrene groups as end groups is beneficial for further improving photoelectric conversion efficiency and stability.

[0205] Depend on Figure 2 and Figure 3 It can be seen that the perovskite grains grown based on Py-2 are relatively uniform in size and large in size, and are densely packed with no obvious boundary defects. This indicates that the hole transport material provided in this application can promote the crystallization and growth of the perovskite film during the perovskite preparation process, and can effectively cover the hole transport layer completely, suppressing the severe charge recombination defects caused by direct contact between the electron transport layer and the hole transport layer, which is beneficial to improving the photoelectric conversion efficiency.

[0206] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0207] The embodiments described above are merely illustrative of several implementation methods of this application, and while the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the invention patent. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of this application, and these all fall within the protection scope of this application. Therefore, the protection scope of this patent application should be determined by the appended claims.

Claims

1. A perovskite solar cell, characterized in that, The device includes a perovskite light-absorbing layer and a first charge transport layer disposed on one side of the perovskite light-absorbing layer. The first charge transport layer contains a hole transport material, which includes a compound represented by Formula I. Formula I, In Formula I, X is selected from O, S, and One of them, n is an integer from 2 to 4, and * represents the connection site.

2. The perovskite solar cell according to claim 1, characterized in that, The hole transport material includes one or more compounds represented by Formula I-1, Formula I-2, and Formula I-3: Equation I-1, Equation I-2, Formula I-3.

3. The perovskite solar cell according to claim 1, characterized in that, The hole transport material includes one or more of the compounds shown in Formulas 1 to 9 below: Formula 1, Equation 2, Formula 3, Equation 4, Equation 5, Formula 6, Equation 7, Formula 8, Formula 9.

4. The perovskite solar cell according to any one of claims 1 to 3, characterized in that, The perovskite light-absorbing layer comprises a perovskite material, which includes the compound ABY3, wherein A ions are monovalent cations, B ions are divalent cations, and Y ions are monovalent anions. The A ion includes organic cations and Li. + Na + K + 、Rb + and Cs + One or more of the following; further, the organic cation includes at least one of methylamino, ethylamino, propylamino, butylamino, pentamino, hexamino, formamidinyl and imidazolyl; The B ions include Pb. 2+ Sn 2+ Be 2+ Mg 2+ Ca 2+ 、Sr 2+ Ba 2+ Zn 2+ 、Ge 2+ Fe 2+ Co 2+ Cu 2+ and Ni 2+ One or more of the following; The Y ions include F - Cl - ,Br - and I - One or more of them.

5. The perovskite solar cell according to any one of claims 1 to 3, characterized in that, The perovskite light-absorbing layer contains perovskite grains, and the average grain size of the perovskite grains is 50 nm to 800 nm.

6. The perovskite solar cell according to claim 5, characterized in that, The average grain size of the perovskite grains is 300 nm to 500 nm.

7. The perovskite solar cell according to any one of claims 1 to 3, characterized in that, The HOMO level of the hole transport material is 8.70 × 10⁻⁶. -5 eV ~1.65×10 -4 eV.

8. The perovskite solar cell according to claim 7, characterized in that, The HOMO level of the hole transport material is 8.80 × 10⁻⁶. -5 eV ~1.65×10 -4 eV.

9. The perovskite solar cell according to any one of claims 1 to 3, characterized in that, The surface roughness of the perovskite light-absorbing layer adjacent to the first charge transport layer is 12nm~25nm.

10. The perovskite solar cell according to claim 9, characterized in that, The surface roughness of the perovskite light-absorbing layer adjacent to the first charge transport layer is 15 nm to 20 nm.

11. The perovskite solar cell according to any one of claims 1 to 3, characterized in that, The perovskite solar cell further includes a second charge transport layer disposed on the other side of the perovskite light-absorbing layer, the second charge transport layer comprising an electron transport material.

12. The perovskite solar cell according to claim 11, characterized in that, The perovskite solar cell further includes a first electrode and a second electrode; the first electrode is disposed on the side of the first charge transport layer away from the perovskite light-absorbing layer, and the second electrode is disposed on the side of the second charge transport layer away from the perovskite light-absorbing layer. The first electrode is a transparent electrode.

13. A stacked battery, characterized in that, It includes a bottom cell and a top cell stacked together, wherein the top cell is a perovskite solar cell as described in any one of claims 1 to 12.

14. A photovoltaic module, characterized in that, It includes at least one of the perovskite solar cells according to any one of claims 1 to 12 and the tandem cell according to claim 13.

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