Perovskite cell and preparation method thereof, laminated cell and photovoltaic module

Abstract

The invention relates to the technical field of solar cells, in particular to a perovskite cell and a preparation method thereof, a laminated cell and a photovoltaic module, a hole transport material of the perovskite cell is a small molecular structure taking indolo [3, 2-B] carbazole as a core, the indolo [3, 2-B] carbazole is a multifunctional electron-rich fused heterocyclic unit, and the hole transport material is a hole transport material of the perovskite cell. The method has the characteristics of small recombination energy, high migration rate and capability of chemically modifying nitrogen and benzene ring sites; a phosphonic acid group is introduced, phosphorus-oxygen double bonds in the phosphonic acid group can interact with perovskite, and defects in the perovskite are passivated; dimethoxytriphenylamine / dimethylthio triphenylamine is introduced as an end group, and the HOMO energy level of molecules can be adjusted, so that the HOMO energy level is better matched with the perovskite energy level, better mobility is realized, and hole extraction and transmission are facilitated. The hole transport material of the perovskite cell has the advantages of low cost, high performance and high stability, and can realize low-cost, high-performance and stable large-area trans-perovskite cell application.

Description

Technical Field

[0001] This application relates to the technical field of solar cells, and particularly to perovskite cells and their preparation methods, tandem cells, and photovoltaic modules. Background Art

[0002] In the more than a decade since 2009, PSCs (perovskite solar cells) have shown excellent development momentum. As the most potential material in the photovoltaic market, PSCs still face huge challenges. In particular, perovskite materials are very sensitive to moisture and heat, and the perovskite absorption layer decomposes during the operation of the battery, and the device stability is damaged. To address the challenges faced by PSCs, researchers have reported various solutions. For inverted PSCs, the HTL (hole transport layer) is deposited on the surface of the conductive glass substrate prior to the perovskite absorption layer, which can regulate the perovskite crystal growth and interface properties, so it plays a crucial role in the preparation of high-efficiency devices.

[0003] As an important component of perovskite solar cells, the materials used for the hole transport layer are crucial. Therefore, selecting a suitable hole transport material is very helpful for the efficiency of the battery. The traditional Spiro-OMeTAD (2,2',7,7'-tetrakis(p-methoxyaniline)-9,9'-spirobifluorene) has a low hole mobility, complex and difficult preparation, and a high price, which limits its commercial application. Therefore, seeking a simpler and more suitable hole transport material is the key to the future development of perovskite solar cells. Currently, hole transport materials are generally divided into organic materials and inorganic materials. Relatively speaking, organic materials have the following advantages: (1) various chemical properties, and according to different molecular structures, various optimizations can be carried out, so that the materials have better optoelectronic properties and hole transport rates; (2) can be processed more conveniently, and the film-forming effect is remarkable; (3) can easily obtain cheap raw materials; (4) can be prepared into flexible thin films and are easily processed into various shapes to adapt to different environments; therefore, organic hole transport materials have been widely used in perovskite solar cells. However, these new hole transport materials still have many problems, such as the need for doping additives, poor stability, toxicity and pollution, and high raw material costs.

[0004] Therefore, how to develop a hole transport material with low cost, good stability, and high photoelectric conversion efficiency is still an urgent problem to be solved in current perovskite solar cells. Summary of the Invention

[0005] This application provides a perovskite cell and its preparation method, tandem cell, and photovoltaic module. The hole transport material of the perovskite cell has the advantages of low cost, high performance, and high stability, and can realize the application of large-area inverted perovskite cells with low cost, high performance, and stability.

[0006] In a first aspect, the present application provides a perovskite solar cell, which includes a hole transport layer, a perovskite absorption layer, and an electron transport layer sequentially arranged on one surface of a conductive substrate from near to far. The hole transport layer includes a hole transport material, and the structural formula of the hole transport material is shown in the following formula (1):

[0007] Wherein, R1 and R2 are independently selected from any one of the following structures (1-1) and (1-2):

[0008]

[0009] In a second aspect, an embodiment of the present application provides a method for preparing a perovskite solar cell, including preparing a hole transport material. The preparation steps of the hole transport material include:

[0010] Providing 2,8-dibromo-5,11-dihydroindolo[3,2-b]carbazole, mixing 2,8-dibromo-5,11-dihydroindolo[3,2-b]carbazole with dibromobutane for reaction to obtain Intermediate 1, and the structural formula of Intermediate 1 is:

[0011]

[0012] Mixing Intermediate 1 with triethyl phosphite for reaction to obtain Intermediate 2, and the structural formula of Intermediate 2 is:

[0013] Mixing Intermediate 2 with Intermediate 4 for reaction to obtain Intermediate 5, and the structural formula of the compound contained in Intermediate 4 is: The structural formula of Intermediate 5 is:

[0014] R1 and R2 are independently selected from any one of the following structures (1-1) and (1-2):

[0015]

[0016] Subjecting Intermediate 5 to a hydrolysis reaction to obtain the hole transport material, and the structural formula of the hole transport material is shown in the following formula (1):

[0017]

[0018] In a third aspect, an embodiment of the present application further provides a tandem solar cell, including:

[0019] A bottom cell, which includes at least one crystalline silicon solar cell and / or amorphous silicon solar cell;

[0020] The top cell is stacked on the bottom cell. The top cell includes one or more perovskite cells, wherein at least one perovskite cell is the perovskite cell as described in the first aspect, or at least one perovskite cell is prepared by the preparation method as described in the second aspect.

[0021] In a fourth aspect, an embodiment of the present application further provides a photovoltaic module, including the tandem cell as described in the third aspect.

[0022] Compared with the prior art, the technical solution of the present application has at least the following technical effects:

[0023] The hole transport material of the perovskite cell of the present application is a small molecule structure with indolo[3,2-b]carbazole as the core. Indolo[3,2-b]carbazole is a multifunctional electron-rich fused heterocyclic unit, which has the characteristics of small recombination energy, high mobility, and the ability of chemical modification at nitrogen and benzene ring sites. At the same time, a phosphonic acid group is introduced. The phosphorus-oxygen double bond in the phosphonic acid group can interact with the perovskite to passivate the defects in the perovskite. In addition, dimethoxytriphenylamine / dimethylthiotriphenylamine is introduced as the end group, which can adjust the HOMO energy level of the molecule, so as to better match the perovskite energy level, and then achieve better mobility, which is more conducive to the extraction and transport of holes. The hole transport material of the perovskite cell of the present application has a relatively high decomposition temperature and good thermal stability. It has good solubility in solvents such as dimethyl sulfoxide, N,N'-dimethylformamide, toluene, chlorobenzene, and dichloromethane, good film-forming properties, and good wettability with the perovskite precursor solvent, which is helpful for the crystallization and film formation of the perovskite. In addition, it also has the advantages of low raw material cost, simple preparation process, high repeatability, and can be used in inverted perovskite cells without doping any additives, which is suitable for industrial production and has good application prospects.

[0024] In summary, the hole transport material of the perovskite cell of the present application has the advantages of low cost, high performance, and high stability, and can realize the application of low-cost, high-performance, and stable perovskite cells. Description of the Drawings

[0025] The present invention will be further described below with reference to the drawings and embodiments.

[0026] Figure 1 1H NMR spectrum of ICZ-1 prepared in Example 1 of the present application;

[0027] Figure 2 1H NMR spectrum of ICZ-2 prepared in Example 2 of the present application;

[0028] Figure 3 J-V curve diagrams of ICZ-1 and ICZ-2 prepared in Example 1 and Example 2 of the present application respectively. Detailed Embodiments

[0029] In the present invention, unless otherwise specified, the raw materials and equipment used are common raw materials and equipment in the art; the methods used in the present invention, unless otherwise specified, are conventional methods in the art.

[0030] Unless otherwise specified, the meanings of the terms in this specification are the same as those generally understood by those skilled in the art. However, if there is a conflict, the definitions in this specification shall prevail.

[0031] As used herein, the terms "comprising", "including", "containing", "having" or other variants are intended to cover non-closed inclusion, and no distinction is made between these terms. The term "including" means that other steps and components can be added without affecting the final result. The term "including" also includes the terms "consisting of" and "consisting essentially of". The compositions and methods / processes of the present invention comprise, consist of, and consist essentially of the essential elements and limitations described herein, as well as any additional or optional ingredients, components, steps or limitations described herein.

[0032] All numerical values or expressions relating to component amounts, process conditions, etc. used in the specification and claims should be understood to be modified by "about" in all cases. All ranges relating to the same component or property include the endpoints, and these endpoints can be combined independently. Since these ranges are continuous, they include every numerical value between the minimum and maximum values. It should also be understood that any numerical range cited in this application is expected to include all sub-ranges within that range.

[0033] It should be understood that the term "and / or" used in the present invention is merely a correlative relationship describing the associated objects, indicating that there can be three relationships. For example, A and / or B can represent: A exists alone, A and B exist simultaneously, and B exists alone. In addition, the character " / " in this article generally represents an "or" relationship between the associated objects before and after.

[0034] In a first aspect, the present application provides a perovskite solar cell, which includes a hole transport layer, a perovskite absorption layer, and an electron transport layer sequentially arranged on one surface of a conductive substrate from near to far, and the hole transport layer includes a hole transport material.

[0035] In the embodiments of the present application, the structure of the hole transport material is shown in the following formula (1):

[0036] Wherein, R1 and R2 are independently selected from any one of the following structures (1-1) and (1-2):

[0037]

[0038] The hole transport material of the perovskite solar cell of the present application is a small molecule structure with indolo[3,2-b]carbazole as the core. Indolo[3,2-b]carbazole is a multifunctional electron-rich fused heterocyclic unit, which has the characteristics of small reorganization energy, high mobility, and the ability to chemically modify nitrogen and benzene ring sites. At the same time, a phosphonic acid group is introduced. The phosphorus-oxygen double bond in the phosphonic acid group can interact with the perovskite to passivate the defects in the perovskite. In addition, dimethoxytriphenylamine / dimethylthiotriphenylamine is introduced as the end group, which can adjust the HOMO energy level of the molecule, so as to better match the perovskite energy level, and then achieve better mobility, which is more conducive to the extraction and transport of holes. The hole transport material of the perovskite solar cell of the present application has a relatively high decomposition temperature and good thermal stability. It has good solubility in solvents such as dimethyl sulfoxide, N,N'-dimethylformamide, toluene, chlorobenzene, and dichloromethane, good film-forming properties, and good wettability with the perovskite precursor solvent, which helps the crystallization and film formation of the perovskite. In addition, it also has the advantages of low raw material cost, simple preparation process, high repeatability, and can be used in inverted quasi-two-dimensional perovskite solar cells without doping any additives, which is suitable for industrial production and has good application prospects.

[0039] In summary, the hole transport material of the perovskite solar cell of the present application has the advantages of low cost, high performance, and high stability, and can realize the application of low-cost, high-performance, and stable inverted perovskite solar cells.

[0040] In the embodiments of the present application, the conductive substrate can be an ITO glass substrate, a silicon substrate, or other common conductive substrates in the art. The embodiments of the present application do not make special limitations on this, and those skilled in the art can select according to specific application scenarios.

[0041] In the embodiments of the present application, the thicknesses of the hole transport layer, the perovskite absorption layer, and the electron transport layer can all be adjusted according to specific application scenarios.

[0042] In some embodiments, the thickness of the hole transport layer is 10-30 nm, specifically it can be 10 nm, 15 nm, 20 nm, 25 nm, 30 nm, or any value between them. Those skilled in the art can adjust according to actual application requirements.

[0043] In some embodiments, the thickness of the perovskite absorption layer is 500-700 mn, specifically it can be 500 nm, 550 nm, 600 nm, 650 nm, 700 mn, or any value between them. Those skilled in the art can adjust according to actual application requirements.

[0044] In some embodiments, the thickness of the electron transport layer is 80 to 120 nm, specifically, it can be 80 nm, 90 nm, 100 nm, 110 nm, 120 nm, or any value therebetween. Those skilled in the art can adjust it according to actual application requirements.

[0045] In the embodiments of the present application, the material of the perovskite light-absorbing layer can be a three-dimensional perovskite material or a quasi-two-dimensional perovskite material. The embodiments of the present application do not make special limitations in this regard, and those skilled in the art can select according to actual needs.

[0046] In the embodiments of the present application, the material of the electron transport layer can be selected from conventional materials in the art, such as C60, C70, PCBM, etc. The embodiments of the present application do not make special limitations in this regard, and those skilled in the art can select according to actual needs.

[0047] In some embodiments, an electrode is further provided on the side of the electron transport layer facing away from the perovskite absorption layer. The material of the electrode can be selected from conventional materials in the art, such as Au, Ag, Al, Cu, etc. The embodiments of the present application do not make special limitations in this regard, and those skilled in the art can select according to actual needs.

[0048] In a second aspect, the present application also provides a preparation method of a perovskite battery, and this preparation method can be used to prepare the perovskite battery described in the first aspect.

[0049] In the embodiments of the present application, the preparation method of the perovskite battery includes the steps of:

[0050] Providing a conductive substrate;

[0051] Successively disposing a hole transport layer, a perovskite absorption layer, an electron transport layer, and an electrode on one side of the conductive substrate.

[0052] In the embodiments of the present application, the hole transport layer includes the hole transport material as shown in the above structure (1).

[0053] In the embodiments of the present application, the preparation method of the hole transport material includes the following steps:

[0054] Providing 2,8-dibromo-5,11-dihydroindolo[3,2-b]carbazole, mixing 2,8-dibromo-5,11-dihydroindolo[3,2-b]carbazole with dibromobutane for reaction to obtain intermediate 1, and the structural formula of intermediate 1 is:

[0055]

[0056] Mixing intermediate 1 with triethyl phosphite for reaction to obtain intermediate 2, and the structural formula of intermediate 2 is:

[0057]

[0058] Mix intermediate 2 with intermediate 4 for reaction to obtain intermediate 5. The structural formula of the compound contained in intermediate 4 is: The structural formula of intermediate 5 is:

[0059]

[0060] Subject intermediate 5 to hydrolysis reaction to obtain a hole transporting material.

[0061] The preparation method of the hole transporting material will be described in more detail below:

[0062] In some embodiments, the preparation method of intermediate 4 includes the following steps:

[0063] Provide raw material 1, where raw material 1 is selected from at least one of 4-bromo-4',4'-dimethoxytriphenylamine and 4-bromo-4',4'-dimethythiotriphenylamine. Mix raw material 1 with 2-thiopheneboronic acid for reaction to obtain intermediate 3. The structural formula of the compound contained in intermediate 3 is:

[0064] Mix intermediate 3 with tert-butylpinacol borate for reaction to obtain intermediate 4.

[0065] In the above embodiments, the specific preparation steps of intermediate 3 include: according to the molar ratio of 1:(1.1 - 1.3):(0.02 - 0.1):(2 - 5), mix at least one of 4-bromo-4',4'-dimethoxytriphenylamine and 4-bromo-4',4'-dimethythiotriphenylamine with 2-thiopheneboronic acid, tetrakis(triphenylphosphine)palladium, and potassium carbonate, and react at 80°C - 90°C for 8h - 10h under the condition of N2 gas; after the reaction is completed, cool to room temperature, and purify the reaction mixture to obtain intermediate 3.

[0066] In the above embodiments, the specific preparation steps of intermediate 4 include: weigh intermediate 3, tert-butylpinacol borate, and n-butyllithium according to appropriate ratios. First, dissolve intermediate 3, then dropwise add n-butyllithium to the solution of intermediate 3, react at -70°C - 85°C for 1 - 1.5h, then add tert-butylpinacol borate, continue to react at -70°C - 85°C for 1 - 1.5h, then transfer to room temperature and continue to react for 10 - 15h, quench the reaction with deionized water, and purify the reaction mixture to obtain intermediate 4.

[0067] In some embodiments, the specific preparation steps of intermediate 1 include: dissolving 2,8-dibromo-5,11-dihydroindolo[3,2-b]carbazole, tetrabutylammonium bromide and KOH in 1,2-dibromobutane for reaction, wherein the molar ratio of 2,8-dibromo-5,11-dihydroindolo[3,2-b]carbazole, tetrabutylammonium bromide, KOH and 1,2-dibromobutane is 1:(0.1-0.2):(5-10):(50-150), the reaction temperature is 65°C - 70°C, and the reaction time is 12h - 24h; after the reaction is completed, it is cooled to room temperature, and the reaction mixture is purified to obtain intermediate 1.

[0068] In some embodiments, the specific preparation steps of intermediate 2 include: reacting intermediate I with triethyl phosphite, wherein the molar ratio of intermediate I to triethyl phosphite is 1:(25-50), the reaction temperature is 140°C - 150°C, and the reaction time is 12h - 16h; after the reaction is completed, it is cooled to room temperature, and the reaction mixture is purified to obtain intermediate 2.

[0069] In some embodiments, the specific preparation steps of intermediate 5 include: putting intermediate 2, intermediate 4, tetrakis(triphenylphosphine)palladium and potassium carbonate into a solvent for reaction, wherein the molar ratio of intermediate 2, intermediate 4, tetrakis(triphenylphosphine)palladium and potassium carbonate is 1:(2.2-2.5):(0.03-0.1):(5-7), the reaction temperature is 80°C - 90°C, and the reaction time is 6h - 12h; after the reaction is completed, it is cooled to room temperature, and the reaction mixture is purified to obtain intermediate 5.

[0070] In some embodiments, the specific steps of hydrolyzing intermediate 5 include:

[0071] Reacting intermediate 5 and trimethylbromosilane in a solvent, and removing the solvent after the reaction is completed to obtain a crude product, wherein the molar ratio of intermediate 5 to trimethylbromosilane is 1:(8-15);

[0072] Dissolve the crude product in methanol at room temperature, then dropwise add deionized water until the mixture becomes opaque, and then stir for 10h - 16h, and then filter and wash to obtain the hole transport material.

[0073] The preparation method provided by the embodiments of the present application has the advantages of simple synthesis route, low raw material cost and high reproducibility. By controlling the raw materials, their feeding amounts, reaction temperature, reaction time and other conditions in each reaction step, the yield of the product can be increased to a relatively high level.

[0074] In some embodiments, the specific preparation method of the perovskite solar cell includes the following steps:

[0075] (1) Cleaning: The ITO glass substrate (conductive substrate) is ultrasonically cleaned with deionized water, acetone, and ethanol in sequence for 15 - 20 minutes, then the residual solvent on the surface of the ITO glass substrate is blown dry using an N2 gas gun, followed by oxygen plasma treatment for 10 - 15 minutes, and subsequently the ITO glass substrate is transferred to a nitrogen glove box.

[0076] (2) Preparation of the hole - transporting layer: Weigh 3 - 15 mg of the hole - transporting material and dissolve it in 1 mL of chlorobenzene solution. Take an appropriate amount of the solution (e.g., 30 μL) and uniformly drop it onto the ITO glass substrate, spin - coat it at 4000 - 5000 rpm for 20 - 30 seconds, and then anneal it at 90 - 110 °C for 10 - 15 minutes to obtain a composite structure of ITO / hole - transporting layer.

[0077] (3) Preparation of the perovskite absorption layer: Cool the composite structure obtained in the above step (2) to room temperature, pre - heat it at 130 - 140 °C for 3 - 5 minutes, take an appropriate amount (e.g., 50 μL) of the perovskite solution and spread it over the surface of the hole - transporting layer, spin - coat it at 3000 - 5000 rpm for 20 - 30 seconds, and then anneal it at 90 - 100 °C for 10 - 15 minutes to obtain a composite structure of ITO / hole - transporting layer / perovskite absorption layer. Among them, the perovskite solution is prepared by mixing one or more of 3 - bromo - benzylammonium iodide, 3 - chlorobenzylammonium iodide, methylammonium chloride, and lead iodide in a certain molar ratio in solvents such as DMF and DMSO. For example, it is prepared by dissolving 3 - fluoro - benzylammonium iodide (3FBAI), methylammonium chloride (MACl), and lead iodide (PbI2) in a ratio of 2.2:3.5:4 in DMF.

[0078] (4) Preparation of the electron - transporting layer: Cool the composite structure obtained in the above step (3) to room temperature, prepare a solution of PC61 BM at 15 mg / mL, then take an appropriate amount (e.g., 30 μL) of the solution and spread it over the surface of the perovskite, spin - coat it at 1000 rpm for 30 - 50 seconds, and anneal it at 70 °C for 10 - 15 minutes to obtain a composite structure of ITO / hole - transporting layer / perovskite absorption layer / electron - transporting layer.

[0079] (5) Preparation of the electrode: Place the composite structure obtained in the above step (4) in a vacuum evaporation chamber, and evaporate Cr (with a thickness of 5 nm - 10 nm) and Au (with a thickness of 80 nm - 120 nm) onto the PC61 BM layer (electron - transporting layer) respectively to fabricate a tandem perovskite solar cell. Define the area on the ITO glass substrate that overlaps with the electrode as the effective area, and the effective area is 0.03 cm 2 .

[0080] In the third aspect, the present application proposes a tandem solar cell.

[0081] In the embodiments of the present application, the tandem cell includes a bottom cell and a top cell; wherein, the bottom cell includes at least one silicon cell, and the silicon cell is selected from any one of crystalline silicon cells and amorphous silicon cells. If the bottom cell includes multiple silicon cells, the multiple silicon cells are stacked; the top cell is stacked on the bottom cell, and the top cell includes one or more perovskite cells, wherein at least one perovskite cell is the perovskite cell described in the first aspect above, or is prepared by the preparation method described in the second aspect above. The top cell includes multiple perovskite cells, and the multiple perovskite cells are stacked.

[0082] In the embodiments of the present application, the crystalline silicon cell can be selected from any one of TOPCon (Tunnel Oxide Passivated Contact cell), HJT (Heterojunction cell), IBC (Interdigitated Back Contact cell), PERC (Passivated Emitter and Rear Cell), or other common crystalline silicon cells in the art. The embodiments of the present application do not make special limitations in this regard, and those skilled in the art can adjust according to the actual application scenario.

[0083] It should be noted that when the top cell includes multiple crystalline silicon cells, the types of the multiple crystalline silicon cells can be the same or different.

[0084] In the embodiments of the present application, the amorphous silicon cell can be selected from any one of single-junction amorphous silicon cells, amorphous silicon tandem cells (such as: double-junction / triple-junction tandem cells), or other common amorphous silicon cells in the art. The embodiments of the present application do not make special limitations in this regard, and those skilled in the art can adjust according to the actual application scenario.

[0085] Fourthly, the present application also provides a photovoltaic module, which includes a laminate and a frame, and the frame is installed at the edge of the laminate. Specifically, the laminate includes a photovoltaic glass, a first encapsulant film, a cell layer, a second encapsulant film, and a backsheet stacked in sequence, or the laminate includes a first photovoltaic glass, a first encapsulant film, a cell layer, a second encapsulant film, and a second photovoltaic glass stacked in sequence; wherein, the cell layer includes multiple cell strings connected in parallel, and each cell string includes multiple cells connected in series. The cell is a whole cell or a cut piece that is one-Nth of the whole cell, and at least some of the cells are the tandem cells described in the third aspect.

[0086] In some embodiments, adjacent cells in the present application are connected in series through a conductive connector (such as a wire or a solder strip) or a conductive adhesive, that is, one end of the conductive connector is welded to the back electrode of one cell, and the other end of the conductive connector is welded to the front electrode of another cell.

[0087] In some embodiments, adjacent cells can also form a photovoltaic module string by using high-density module technology, that is, the shingle technology, the stacked welding technology, or the diced cell technology, which greatly reduces or eliminates the gap between cells.

[0088] Overlap tile technology: The whole piece of battery is cut into several small battery strips by laser slicing technology, and the small battery strips are stacked and flexibly connected with conductive adhesive. This connection method optimizes the structure of the photovoltaic module string, realizes zero spacing between battery cells, makes full use of the limited area of the photovoltaic module, and more battery cells can be placed with the same form factor compared with other types of modules, effectively increasing the light-receiving area of the module.

[0089] Overlap welding technology: Adjacent half-cell battery slices are'micro-overlapped' and welded through special round wire solder tapes. This connection method greatly reduces the spacing between battery cells in the traditional welding process and realizes high energy density. Compared with ordinary flat solder tapes, the round wire solder tapes have a narrower cross-section, reducing the light-shielding effect of the solder tapes on the battery cells. In addition, the round side of the solder tape enhances the reflection of incident light and the secondary refractive index of light on the front plate glass. The introduction of the round solder tape effectively solves the inherent contradiction between main grid occlusion and increasing the current collection ability, improves the light absorption and utilization of the battery cells, and increases the power of the module.

[0090] Patchwork technology: Triangular solder tapes are used on the front side of the battery cells, and ultra-flexible flat solder tapes are used on the back side. Adjacent half-cell battery slices are welded with a micro-spacing through double solder tape technology, realizing high energy density. The triangular solder tapes used in the patchwork technology are welded three-dimensionally on the front side of the battery. The reflection ability of the nearly 45° side angle to incident light is further improved compared with round solder tapes, and the reflection can be more fully utilized to increase the light absorption ability of the battery and increase the power of the module.

[0091] In the embodiments of the present application, preferably, the frame is made of high-strength lightweight materials, such as: steel, aluminum, or composite materials made of resin and reinforcing materials, where the resin includes polyurethane, polyester, polycarbonate, etc., and the reinforcing materials include glass fiber, aluminum, steel, etc.

[0092] In the embodiments of the present application, the first adhesive film and the second adhesive film can independently be ethylene-vinyl acetate copolymer (EVA) adhesive film, polyethylene octene co-elastic body (POE) adhesive film, polyethylene terephthalate (PET) adhesive film, PVB adhesive film, EPE adhesive film (EVA and POE three-layer co-extruded adhesive film), EP adhesive film (EVA and POE two-layer co-extruded adhesive film), or other types of adhesive films. Those skilled in the art can make selections according to actual situations and are not limited herein.

[0093] The present invention will be further described below through more specific embodiments.

[0094] Embodiment 1

[0095] The synthesis route of ICZ-1 is as follows:

[0096]

[0097] The specific preparation steps of ICZ-1 are as follows:

[0098] Synthesis of Compound 2: Weigh Compound 1 (1.15 g, 3 mmol), 2-thiopheneboronic acid (0.46 g, 3.6 mmol), tetrakis(triphenylphosphine)palladium (0.092 g, 0.08 mmol), and potassium carbonate (1.2 g, 9 mmol) and add them to a 100 mL two-neck reaction flask. Using DMF (40 mL) as the solvent, react at 85 °C for 8 hours under N2 condition; after the reaction is completed, cool to room temperature, extract the reaction mixture with DCM, then successively dry the organic phase with anhydrous Mg2SO4, filter, and perform rotary evaporation under reduced pressure. Finally, purify the rotary evaporation product by column chromatography (PE:DCM = 12:1) to obtain 0.84 g of Compound 2 (Intermediate 3) as a green solid powder, with a yield of 71%.

[0099] Synthesis of Compound 3: Weigh Compound 2 (3.8 g, 10 mmol) and add it to a 500 mL three-neck flask, then add 30 mL of dry THF. Cool to -78 °C and stir for 10 min under N2 condition, then slowly dropwise add n-butyllithium (3.75 mL, 1.00 equiv, 1.6 M in n-hexane), react at -78 °C for 1 hour, then add tert-butylpinacol borate (2.75 mL, 15 mmol), continue to react at -78 °C for 1 hour, and finally transfer to room temperature and react for 12 hours; quench the reaction with 50 mL of deionized water, then extract the reaction mixture with saturated NaCl solution and DCM. Successively dry the organic phase with anhydrous Mg2SO4, filter, and finally purify the rotary evaporation product by column chromatography (PE:DCM = 15:1) to obtain 4.4 g of Compound 3 (Intermediate 4), with a yield of 80%.

[0100] Synthesis of Compound 5: Add Compound 4 (1.24 g, 3 mmol), tetrabutylammonium bromide (0.36 g, 0.3 mmol), and 1,4-dibromobutane (15 mL) to a 100 mL two-neck flask, then dropwise add 50% aqueous potassium hydroxide solution (5 mL), heat to 65 °C, and then stir overnight; quench the reaction with water, then extract the reaction mixture with dichloromethane. Successively dry the organic phase with anhydrous Mg2SO4, filter, and finally purify the rotary evaporation product by column chromatography (PE:DCM = 10:1) to obtain 1.43 g of Compound 5 (Intermediate 1), with a yield of 70%.

[0101] Synthesis of Compound 6: Add Compound 5 (2.05 g, 3.0 mmol) and triethyl phosphite (10 mL) into a 100 mL two-necked flask, heat to 160 °C, and stir overnight under a nitrogen atmosphere; after the reaction is completed, remove the organic solvent with a rotary evaporator to obtain 1.92 g of crude Compound 6 (Intermediate 2) with a yield of 81%.

[0102] Synthesis of Compound 7: Add Compound 6 (0.8 g, 1 mmol), Compound 3 (1.13 g, 2.2 mmol), tetrakis(triphenylphosphine)palladium (57 mg, 0.05 mmol) and potassium carbonate (0.83 g, 6 mmol) into a 100 mL two-necked flask. The solvent is toluene, ethanol and water (in a ratio of 2:1:1), and react at 85 °C for 6 hours; after the reaction is completed, cool to room temperature, extract the reaction mixture with DCM, dry the organic phase successively with anhydrous Mg2SO4, filter, and perform vacuum distillation. Finally, purify the vacuum distillation product by column chromatography (PE:DCM = 4:1) to obtain 0.77 g of Compound 7 (Intermediate 5) with a yield of 54%.

[0103] Synthesis of ICZ-1: Add Compound 7 (2.8 g, 2 mmol) and anhydrous 1,4-dioxane (10 mL) at room temperature into a 100 mL two-necked flask, dropwise add trimethylsilyl bromide (3.06 g, 20 mmol), and then stir overnight; after the reaction is completed, remove 1,4-dioxane in the reaction mixture by vacuum distillation to obtain a solid powder; dissolve the solid powder in methanol (10 mL) at room temperature, then dropwise add deionized water until the mixture becomes opaque, and stir for another 12 hours, then filter and collect successively, and wash with deionized water; dissolve the washed crude product in THF (5 mL), reprecipitate in acetone (20 mL), and filter to obtain 1.8 g of the final product ICZ-1 with a yield of 70%. For the 1H NMR spectrum of ICZ-1, please refer to Figure 2 。

[0104] Example 2

[0105] The synthesis route of ICZ-2 is as follows:

[0106]

[0107] The specific preparation steps of ICZ-2 are as follows:

[0108] Synthesis of Compound 9: Weigh 1.25 g (3 mmol) of Compound 8, 0.46 g (3.6 mmol) of 2-thiopheneboronic acid, 0.092 g (0.08 mmol) of tetrakis(triphenylphosphine)palladium, and 1.2 g (9 mmol) of potassium carbonate, and add them to a 100 mL two-neck reaction flask. Using DMF (40 mL) as the solvent, react at 85 °C for 8 hours under N2. After the reaction, cool to room temperature, extract the reaction mixture with DCM, then successively dry the organic phase over anhydrous Mg2SO4, filter, and perform rotary evaporation under reduced pressure. Finally, purify the product obtained by rotary evaporation under reduced pressure through column chromatography (PE:DCM = 12:1) to obtain 0.88 g of solid powder of Compound 9 (Intermediate 3) with a yield of 70%.

[0109] Synthesis of Compound 10: Weigh 4.2 g (10 mmol) of Compound 9 and add it to a 500 mL three-neck flask. Then add 30 mL of dry THF, cool to -78 °C under N2 and stir for 10 min. Then slowly add n-butyllithium (3.75 mL, 1.00 equiv, 1.6 M in n-hexane) dropwise, react at -78 °C for 1 hour, then add tert-butylpinacolborane (2.75 mL, 15 mmol), continue to react at -78 °C for 1 hour, and finally transfer to room temperature and react for 12 hours. Quench the reaction with 50 mL of deionized water, then extract the reaction mixture with saturated NaCl solution and DCM. Successively dry the organic phase over anhydrous Mg2SO4, filter, and finally purify the product obtained by rotary evaporation under reduced pressure through column chromatography (PE:DCM = 15:1) to obtain 4.3 g of Compound 10 (Intermediate 4) with a yield of 79%.

[0110] Synthesis of Compound 5: Add 1.24 g (3 mmol) of Compound 4, 0.36 g (0.3 mmol) of tetrabutylammonium bromide, and 15 mL of 1,4-dibromobutane to a 100 mL two-neck flask. Then add 5 mL of 50% aqueous potassium hydroxide solution dropwise, heat to 65 °C, and stir overnight. Quench the reaction with water, then extract the reaction mixture with dichloromethane. Successively dry the organic phase over anhydrous Mg2SO4, filter, and finally purify the product obtained by rotary evaporation under reduced pressure through column chromatography (PE:DCM = 10:1) to obtain 1.43 g of Compound 5 (Intermediate 1) with a yield of 70%.

[0111] Synthesis of Compound 6: Add 2.05 g (3.0 mmol) of Compound 5 and 10 mL of triethyl phosphite to a 100 mL two-neck flask, heat to 160 °C, and stir overnight under a nitrogen atmosphere. After the reaction, remove the organic solvent using a rotary evaporator to obtain 1.92 g of crude Compound 6 (Intermediate 2) with a yield of 81%.

[0112] Synthesis of Compound 11: In a 100 mL two-necked flask, add Compound 6 (0.8 g, 1 mmol), Compound 10 (1.22 g, 2.2 mmol), tetrakis(triphenylphosphine)palladium (57 mg, 0.05 mmol), and potassium carbonate (0.83 g, 6 mmol). The solvent is toluene, ethanol, and water (in a ratio of 2:1:1). React at 85 °C for 6 hours. After the reaction, cool to room temperature. Extract the reaction mixture with DCM. Dry the organic phase successively with anhydrous Mg2SO4, filter, and perform rotary evaporation under reduced pressure. Finally, purify the product obtained from rotary evaporation by column chromatography (PE:DCM = 4:1) to obtain 0.88 g of Compound 11 (Intermediate 5) with a yield of 59%.

[0113] Synthesis of ICZ-2: Add Compound 11 (2.95 g, 2 mmol) to 10 mL of anhydrous 1,4-dioxane at room temperature in a 100 mL two-necked flask. Dropwise add trimethylsilyl bromide (3.06 g, 20 mmol), and then stir overnight. After the reaction, remove 1,4-dioxane from the reaction mixture by rotary evaporation under reduced pressure to obtain a solid powder. Dissolve the solid powder in methanol (10 mL) at room temperature, and then dropwise add deionized water until the mixture becomes opaque. Stir for another 12 hours, and then filter and collect, and wash with deionized water. Dissolve the washed crude product in THF (5 mL), precipitate in acetone (20 mL), and filter to obtain 1.9 g of the final product ICZ-2 with a yield of 67%. For the 1H NMR spectrum of ICZ-2, please refer to Figure 2 。

[0114] Performance Testing

[0115] 1. HOMO Energy Level Testing:

[0116] To study the energy level matching between ICZ-1 and ICZ-2 materials as HTMs and the perovskite energy level, a three-electrode test system was used to measure the cyclic voltammograms (C-V) of these two polymer HTMs. A three-electrode test system was adopted. Using ferrocene as an external standard, the working electrode was a glassy carbon electrode, the counter electrode was a platinum wire electrode, and the reference electrode was an Ag / AgCl electrode. First, prepare ICZ-1 and ICZ-2 solutions with a concentration of 5 mg / mL in dichloromethane as the solvent, and then use the thin-film method to drop-coat them on the glassy carbon electrode and test in an acetonitrile solution of 0.1 M Bu4NPF6 with a scanning rate of 50 mV·s –1 , at room temperature, the C-V curve was obtained through multiple scans, and then the redox potential of the curve was analyzed, and the HOMO energy level of the material was calculated according to the formula.

[0117] 2. Hole Mobility:

[0118] The space-charge-limited current method was used for testing. A single-hole device of ITO / PEDOT:PSS / HTMs to be measured / MoO3 / Ag was fabricated. The thickness of each layer was determined by a step profiler. Under dark conditions, the J-V characteristic curve of the single-hole device was obtained using a Keithley 2450 Source-Measure instrument. Nonlinear fitting analysis was performed on the curve to obtain the hole mobility of the sample.

[0119] 3. Film-forming performance:

[0120] AFM was used to study the crystallization growth of quasi-two-dimensional perovskite films on different polymer HTMs (hole transport materials), and the RMS roughness on different polymer HTMs was measured.

[0121] 4. Photovoltaic performance and stability testing:

[0122] Using the same preparation method, inverted quasi-two-dimensional perovskite solar cell devices with ICZ-1 and ICZ-2 as hole transport materials were fabricated respectively. The specific preparation method refers to the preparation method of the perovskite solar cell above.

[0123] Under the illumination condition of AM 1.5G, the J-V curves of the devices were measured at a forward and reverse scan rate of 0.02 V·s -1 . As shown in Figure 3 , by analyzing the J-V curves, the photovoltaic parameters of the samples measured, such as Voc, short-circuit current density (Jsc), fill factor (FF), and power conversion efficiency (PCE), can be obtained.

[0124] After storing the devices in an inert environment for 1200 hours, the retention efficiency of the devices (relative to the initial power conversion efficiency) was measured.

[0125] Figure 1 . Performance test results of the hole transport materials prepared in Example 1 and Example 2

[0126]

[0127] The test results shown in Table 1 can prove that: the synthesized polyethylene-based hole transport material designed in this application has excellent film-forming properties (the prepared quasi-two-dimensional perovskite films all exhibit low RMS roughness). As an HTL substrate, it is beneficial to the diffusion and growth of perovskite, thus obtaining a dense, uniform, and smooth perovskite film. Moreover, it also has energy levels matching with perovskite and excellent hole mobility. These characteristics enable the inverted perovskite solar cell devices prepared based on the hole transport material provided in this application to have excellent power conversion efficiency. In addition, it can also be seen from Table 1 above that the structural stability of the inverted perovskite solar cell devices prepared based on the hole transport material provided in this application is also good.

[0128] The above are only the preferred embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principle of the present invention shall be included within the scope of protection of the present invention.

Claims

1. A perovskite cell, comprising a hole transport layer, a perovskite absorption layer and an electron transport layer arranged on a surface of one side of a conductive substrate from near to far, wherein the hole transport layer comprises a hole transport material, characterized in that: The structural formula of the hole transport material is shown in the following formula (1): Wherein, R1 and R2 are independently selected from any one of the following structures (1-1) and (1-2):

2. The perovskite battery according to claim 1, characterized in that The thickness of the hole transport layer is 10 to 30 nm; and / or, The thickness of the perovskite absorption layer is 500-700 nm; and / or, The thickness of the electron transport layer is 80-120 nm.

3. A method for preparing a perovskite battery, characterized in that: The method comprises preparing a hole transport material, wherein the preparation steps of the hole transport material include: 2,8-dibromo-5,11-dihydroindole[3,2-B]carbazole is provided, and 2,8-dibromo-5,11-dihydroindole[3,2-B]carbazole is mixed with dibromobutane to react to obtain an intermediate 1, wherein the intermediate 1 has the structural formula: The intermediate 1 is mixed with triethyl phosphite to react to obtain an intermediate 2, the structural formula of the intermediate 2 is: The intermediate 2 is mixed with the intermediate 4 to react to obtain the intermediate 5. The structural formula of the compound contained in the intermediate 4 is: The structural formula of the intermediate 5 is: R1 and R2 are independently selected from any one of the following structures (1-1) and (1-2): The intermediate 5 is subjected to a hydrolysis reaction to obtain a hole transport material, the structure of which is shown in the following formula (1):

4. The method for preparing a perovskite battery according to claim 3, characterized in that: The preparation steps of the intermediate 4 include: A raw material 1 is provided, wherein the raw material 1 is selected from at least one of 4-bromo-4',4'-dimethoxytriphenylamine and 4-bromo-4',4'-dimethylthiotriphenylamine, and the raw material 1 is mixed with 2-boric acid thiophene to react to obtain an intermediate 3, wherein the structural formula of the compound contained in the intermediate 3 is: The intermediate 3 is mixed with tert-butyl pinacol borate to react, thereby obtaining the intermediate 4.

5. The method for preparing a perovskite battery according to claim 3 or 4, characterized in that: The specific preparation steps of the intermediate 1 include: dissolving 2,8-dibromo-5,11-dihydroindole[3,2-B]carbazole, tetrabutylammonium bromide and KOH in dibromobutane for reaction, wherein the molar ratio of 2,8-dibromo-5,11-dihydroindole[3,2-B]carbazole, tetrabutylammonium bromide, KOH and dibromobutane is 1:(0.1-0.2):(5-10):(50-150), the reaction temperature is 65°C-70°C, and the reaction time is 12h-24h.

6. The method for preparing a perovskite battery according to claim 3 or 4, characterized in that: The specific preparation steps of the intermediate 2 include: reacting the intermediate I with triethyl phosphite, wherein the molar ratio of the intermediate I to triethyl phosphite is 1:(25-50), the reaction temperature is 140°C-150°C, and the reaction time is 12h-16h.

7. The method for preparing a perovskite battery according to claim 3 or 4, characterized in that: The specific preparation steps of the intermediate 5 include: placing the intermediate 2, intermediate 4, tetrakis(triphenylphosphine)palladium and potassium carbonate into a solvent for reaction, wherein the molar ratio of the intermediate 2, intermediate 4, tetrakis(triphenylphosphine)palladium and potassium carbonate is 1:(2.2-2.5):(0.03-0.1):(5-7), the reaction temperature is 80°C-90°C, and the reaction time is 6h-12h.

8. The method for preparing a perovskite battery according to claim 3 or 4, characterized in that: The specific steps of hydrolyzing the intermediate 5 include: The intermediate 5 and trimethylsilyl bromide are placed in a solvent for reaction, and after the reaction is completed, the solvent is removed to obtain a crude product, wherein the molar ratio of the intermediate 5 to trimethylsilyl bromide is 1:(8-15); The crude product was dissolved in methanol at room temperature, and then deionized water was added dropwise until the mixture became opaque, and then stirred for 10 h to 16 h, and then filtered and washed to obtain the hole transport material.

9. A laminated battery, characterized in that: include: A bottom cell, wherein the bottom cell comprises at least one crystalline silicon cell and / or an amorphous silicon cell; A top cell is stacked on the bottom cell, wherein the top cell comprises one or more perovskite cells, wherein at least one perovskite cell is the perovskite cell as described in claim 1 or 2, or at least one perovskite cell is prepared by the preparation method of the perovskite cell as described in any one of claims 3-8.

10. A photovoltaic module, characterized in that: Comprising the stacked battery as claimed in claim 9.

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