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

Abstract

The invention relates to the technical field of perovskite cells, provides a perovskite cell and a preparation method thereof, a laminated cell and a photovoltaic module, and at least can improve the efficiency of the perovskite cell. The perovskite cell comprises a transparent conductive substrate, a hole transport layer, a perovskite absorption layer, an electron transport layer and an electrode, the hole transport layer comprises a hole transport material, the chemical formula of the hole transport material is # imgabs0 #, and X is independently selected from O or S.

Description

Technical Field

[0001] This application relates to the technical field of perovskite solar cells, and particularly to a perovskite solar cell, a preparation method thereof, a tandem solar cell, and a photovoltaic module. Background Art

[0002] Perovskite solar cells (PSCs) are devices that use perovskite-type organometallic halide semiconductors as light-absorbing materials to directly convert light energy into electrical energy through the photovoltaic effect. The structure of perovskite solar cells mainly includes components such as a conductive substrate, an electron transport layer (ETL), a perovskite layer, a hole transport layer (HTL), and a metal electrode.

[0003] The hole transport layer plays a crucial role in hole extraction and transport, suppressing carrier recombination, and improving the crystallization and film formation of perovskite materials. Therefore, continuously developing hole transport materials (HTMs) with excellent film-forming properties, solvent resistance, thermal stability, hole mobility, and energy levels matching those of perovskite materials is a key factor in preparing efficient and stable perovskite solar cells.

[0004] Currently, how to develop high-efficiency and low-cost HTMs has become an important research topic. Summary of the Invention

[0005] Embodiments of this application provide a perovskite solar cell, a preparation method thereof, a tandem solar cell, and a photovoltaic module, which are at least beneficial to improving the efficiency of perovskite solar cells while reducing the cost of HTMs.

[0006] According to some embodiments of this application, on the one hand, embodiments of this application provide a perovskite solar cell, which includes a transparent conductive substrate, a hole transport layer, a perovskite absorption layer, an electron transport layer, and an electrode. Among them, the hole transport layer includes a hole transport material, and the chemical formula of the hole transport material is as follows:

[0007]

[0008] Wherein, each X independently selects from O or S.

[0009] According to some embodiments of the present application, on the other hand, an embodiment of the present application further provides a method for preparing a perovskite solar cell, including: sequentially forming a hole transport layer, a perovskite absorption layer, an electron transport layer, and an electrode on a transparent conductive substrate, wherein the preparation steps of the hole transport layer include: configuring the hole transport material in the above embodiments into a solution and then coating it on the transparent conductive substrate, and the preparation steps of the hole transport material are as follows: adding a first compound, a second compound, tetrakis(triphenylphosphine)palladium, and potassium carbonate into a solvent, the solvent being toluene, ethanol, and water with a volume ratio of 2:1:1, reacting at 80 °C to 85 °C for 6 h to 8 h to obtain a first product; the structural formula of the first compound is:

[0010]

[0011] The structural formula of the second compound is:

[0012] wherein, each X independently selected from O or S;

[0013] Dissolve the first product in anhydrous 1,4-dioxane at room temperature, add trimethylsilyl bromide and stir for reaction for 8 h to 14 h. After rotary evaporation to remove 1,4-dioxane, dissolve the obtained solid powder in methanol, add deionized water dropwise until the mixture becomes opaque, and then stir for 8 h to 14 h. The obtained crude product is collected by filtration and washed with deionized water. Dissolve the crude product in tetrahydrofuran and precipitate in acetone, and obtain the hole transport material after filtration.

[0014] In some embodiments, the molar ratio of the first compound, the second compound, potassium carbonate, and tetrakis(triphenylphosphine)palladium is 1:(2.2 - 3):(4 - 7):(0.02 - 0.1).

[0015] In some embodiments, the molar ratio of the first product to trimethylsilyl bromide is 1:(10 - 20).

[0016] In some embodiments, the preparation steps of the first compound include: adding raw material I and N-bromosuccinimide into tetrahydrofuran, reacting at 0 °C to 5 °C for 12 h to 16 h, quenching the reaction with water, extracting the organic phase with dichloromethane, drying the organic phase with anhydrous magnesium sulfate and then removing the solvent to obtain a first intermediate product; the chemical formula of raw material I is:

[0017]

[0018] Dissolve the first intermediate product and tetrabutylammonium bromide in 1,4-dibromobutane, dropwise add an aqueous potassium hydroxide solution with a mass fraction of 50%, react at 65 °C to 80 °C for 8 h to 14 h, quench the reaction with water, extract the organic phase with dichloromethane, dry the organic phase with anhydrous magnesium sulfate, and then remove the solvent to obtain the second intermediate product; mix the second intermediate product and triethyl phosphite, react at 140 °C to 160 °C for 8 h to 16 h, and remove the solvent by rotary evaporation to obtain the first compound.

[0019] In some embodiments, the molar ratio of raw material I to N-bromosuccinimide is 1:(2.2 - 3); the molar ratio of the first intermediate product, tetrabutylammonium bromide, potassium hydroxide, and 1,4-dibromobutane is 1:(0.1 - 0.2):(5 - 10):(200 - 600); the molar ratio of the second intermediate product to triethyl phosphite is 1:(140 - 160).

[0020] In some embodiments, the preparation steps of the second compound include: adding raw material II, 2-thiopheneboronic acid, tetrakis(triphenylphosphine)palladium, and potassium carbonate to N,N-dimethylformamide, reacting at 80 °C to 85 °C for 6 h to 8 h, cooling to room temperature, extracting the organic phase with dichloromethane, drying the organic phase with anhydrous magnesium sulfate, and then removing the solvent to obtain the third intermediate product; the chemical formula of raw material II is:

[0021] wherein, each X independently selected from O or S;

[0022] Add the third intermediate product to tetrahydrofuran, lower the temperature to -78 °C to -80 °C, stir for 10 min, then dropwise add n-butyllithium and stir at -78 °C to -80 °C for 1 h to 2 h, add pinacol borate ester and continue to stir at -78 °C to -80 °C for 1 h to 2 h, raise the temperature to room temperature and react for 12 h to 16 h, quench the reaction with water, extract the organic phase with saturated sodium chloride and dichloromethane, dry the organic phase with anhydrous magnesium sulfate, and then remove the solvent to obtain the second compound.

[0023] In some embodiments, the molar ratio of raw material II, 2-thiopheneboronic acid, tetrakis(triphenylphosphine)palladium, and potassium carbonate is 1:(1 - 1.4):(0.01 - 0.1):(4 - 8); the molar ratio of the third intermediate product, n-butyllithium, and pinacol borate ester is 1:(1 - 1.5):(1.1 - 2).

[0024] According to some embodiments of the present application, another aspect of the embodiments of the present application provides a stacked battery, including: a top cell, the top cell is the perovskite battery in the above embodiments; a crystalline silicon bottom cell, the crystalline silicon bottom cell is located on the side of the transparent conductive substrate of the perovskite battery away from the electrode.

[0025] According to some embodiments of the present application, on the other hand, an embodiment of the present application provides a photovoltaic module, including: a plurality of stacked cells as in the above embodiments; a connecting member for connecting adjacent stacked cells; a glue film covering the surface of the stacked cells; and a cover plate located on the surface of the glue film away from the stacked cells.

[0026] The technical solutions provided by the embodiments of the present application have at least the following advantages:

[0027] The perovskite cell provided by the embodiment of the present application includes a transparent conductive substrate, a hole transport layer, a perovskite absorption layer, an electron transport layer, and an electrode. Among them, the hole transport layer includes a hole transport material DCz-OME or DCz-SME. DCz-OME and DCz-SME have dibenzocarbazole as the core and thiophene-methoxytriphenylamine group or thiophene-methylthiotriphenylamine group as the end group. The group containing sulfur atoms in the molecule endows the HTMs with appropriate energy levels to increase intra- and / or intermolecular interactions, as well as enhanced buried interface interactions with quasi-two-dimensional layered perovskites, resulting in good mobility of the hole transport material, which is beneficial to the extraction and transport of holes. Moreover, the hole transport material has a HOMO energy level that matches the perovskite and is relatively deep, a higher decomposition temperature, and good thermal stability. DCz-OME or DCz-SME has good solubility in organic solvents, good film-forming properties, good wettability with the perovskite precursor solvent, and is helpful for the crystallization and film formation of perovskites. It can be used in inverted quasi-two-dimensional perovskite solar cells without doping any additives and has good application prospects. Description of the Drawings

[0028] One or more embodiments are exemplarily illustrated by the pictures in the corresponding drawings. These exemplary illustrations do not limit the embodiments unless otherwise stated. The figures in the drawings do not constitute a proportional limitation; in order to more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, the following will briefly introduce the drawings required to be used in the embodiments. Obviously, the following-described drawings are only some embodiments of the present application. For those of ordinary skill in the art, without creative efforts, other drawings can also be obtained based on these drawings.

[0029] Figure 1 It is a schematic structural diagram of a perovskite cell provided by an embodiment of the present application;

[0030] Figure 2 It is the 1H NMR spectrum corresponding to DCz-OME;

[0031] Figure 3 It is the 1H NMR spectrum corresponding to DCz-SME;

[0032] Figure 4They are the current density-voltage (J-V) characteristic curves corresponding to perovskite cell 1, perovskite cell 2, and perovskite cell 3. Detailed implementation manners

[0033] As can be seen from the background art, how to develop highly efficient and low-cost HTMs has become an important research topic.

[0034] Commonly used HTMs also include 2,2′,7,7′-tetrakis(N,N′-di-p-methoxyaniline)-9,9′-spirobifluorene (spiro-OMeTAD). However, its synthesis and purification processes are complex, usually involving low-temperature reactions (-78 °C) and the use of highly reactive reagent butyllithium. The harsh preparation conditions make it expensive. At the same time, spiro-OMeTAD itself has poor conductivity and needs to add dopants (such as tert-butylpyridine (t-BP) and lithium bis(trifluoromethanesulfonyl)imide (Li-TFSI)) to improve its conductivity and hole mobility. The use of dopants will also increase the preparation cost of perovskite cells and hinder their further commercialization.

[0035] Currently, promising inverted perovskite solar cells are prepared using self-assembled monolayers (SAMs) containing carbazolyl phosphoric acid (PA), such as [2-(9H-carbazol-9-yl)ethyl]phosphoric acid (2PACz), [2-(3,6-dimethoxy-9H-carbazol-9-yl)ethyl]phosphoric acid (MeO-2PACz), and [4-(3,6-dimethyl-9H-carbazol-9-yl)butyl]phosphoric acid (Me-4PACz). They have the ability to uniformly coat on rough surfaces, high hole extraction selectivity, and low interface electron trap density, so they can be used as excellent hole-selective contact layers. At the same time, HTMs containing triphenylamine (TPA) have good thermal stability and morphological stability, as well as good charge transport and ionization potential. The common method for constructing HTMs is still methoxy-substituted diphenylamine or triphenylamine.

[0036] The embodiments of this application provide a perovskite cell, a preparation method thereof, a tandem cell, and a photovoltaic module. The hole transport layer in the perovskite cell includes hole transport materials DCz-OMe and DCz-SMe. DCz-OMe and DCz-SMe have dibenzocarbazole as the core and thiophene-methoxytriphenylamine groups or thiophene-methylthiotriphenylamine groups as the end groups, and can be used as undoped HTMs in inverted PSCs devices, which is beneficial to improving the efficiency of perovskite cells while reducing the cost of HTMs.

[0037] In the description of the embodiments of this application, technical terms such as "first" and "second" are only used to distinguish different objects, and cannot be understood as indicating or implying relative importance or implicitly specifying the quantity, specific order, or primary-secondary relationship of the indicated technical features.

[0038] In the description of the embodiments of the present application, the meaning of "a plurality of" is more than two, unless otherwise specifically defined.

[0039] Referring to "embodiments" herein means that the specific features, structures or characteristics described in connection with the embodiments may be included in at least one embodiment of the present application. The phrase appears in various places in the specification does not necessarily refer to the same embodiment, nor is it an independent or alternative embodiment mutually exclusive with other embodiments. Those skilled in the art will explicitly and implicitly understand that the embodiments described herein may be combined with other embodiments.

[0040] In the description of the embodiments of the present application, when a certain component "comprises" another component, unless otherwise specified, other components are not excluded, and other components may further be included.

[0041] The terms used in the description of the various embodiments herein are only for the purpose of describing specific embodiments and are not intended to be limiting. As used in the descriptions of the various embodiments and the appended claims, "component" is also intended to include the plural form, unless the context clearly indicates otherwise.

[0042] The embodiments of the present application will be described in detail below in conjunction with the accompanying drawings. However, those of ordinary skill in the art can understand that in the embodiments of the present application, many technical details are provided to help readers better understand the present application. However, even without these technical details and various changes and modifications based on the following embodiments, the technical solutions claimed in the present application can still be implemented.

[0043] Figure 1 Schematic diagram of a perovskite battery structure provided for the embodiments of the present application.

[0044] According to some embodiments of the present application, on the one hand, the embodiments of the present application provide a perovskite battery. Referring to Figure 1 , the perovskite battery includes a transparent conductive substrate, a hole transport layer, a perovskite absorption layer, an electron transport layer, and an electrode. Among them, the hole transport layer includes a hole transport material, and the chemical formula of the hole transport material is as follows:

[0045]

[0046] Among them, X is independently selected from O or S.

[0047] For example, the hole transport material is DCz-OME, and the structural formula of DCz-OME is as follows:

[0048]

[0049] Alternatively, the hole transporting material is DCz-SME, and the structural formula of DCz-SME is as follows:

[0050]

[0051] Figure 2 is the 1H NMR spectrum corresponding to DCz-OME; Figure 3 is the 1H NMR spectrum corresponding to DCz-SME.

[0052] The perovskite solar cell provided by the embodiment of the present application includes a transparent conductive substrate, a hole transporting layer, a perovskite absorbing layer, an electron transporting layer, and an electrode. Among them, the hole transporting layer includes the hole transporting material DCz-OME or DCz-SME. DCz-OME and DCz-SME have dibenzocarbazole as the core and thiophene-methoxytriphenylamine group or thiophene-methylthiotriphenylamine group as the end group. The sulfur atom-containing group in the molecule endows the HTMs with appropriate energy levels to increase intra- and / or intermolecular interactions, as well as enhanced buried interface interactions with quasi-two-dimensional layered perovskites, resulting in good mobility of the hole transporting material, which is beneficial to the extraction and transport of holes. Moreover, the hole transporting material has a HOMO energy level that matches the perovskite and is relatively deep, a high decomposition temperature, and good thermal stability. DCz-OME or DCz-SME has good solubility in organic solvents, good film-forming properties, good wettability with the perovskite precursor solvent, and is helpful for the crystallization and film formation of perovskite. It can be used in inverted quasi-two-dimensional perovskite solar cells without doping any additives and has good application prospects.

[0053] The material of the transparent conductive substrate includes ITO glass, which is processed by plating a layer of indium tin oxide (commonly known as ITO) film on the basis of soda-lime or borosilicate substrate glass by means of magnetron sputtering.

[0054] The material of the perovskite absorbing layer can be a compound composed of A, B, and X3. Among them, A can be one or more of FA (HC(NH2)2), MA (CH3NH3), Cs, and Rb, B can be one or more of Pb, Sn, and Sr, and X can be one or more of Br, I, and Cl.

[0055] The materials of the electron transporting layer include materials such as tin oxide, titanium dioxide, C60, fullerenes, and their derivatives.

[0056] The materials of the electrode include at least one of chromium (Cr) and gold (Au).

[0057] Correspondingly, another embodiment of the present application further provides a method for preparing a perovskite solar cell, which can be used to manufacture the perovskite solar cell provided in the above embodiment. The following will describe in detail the method for preparing the perovskite solar cell provided in another embodiment of the present application. For the same or corresponding parts as those in the previous embodiment, reference can be made to the corresponding description in the previous embodiment, and the following will not be elaborated in detail.

[0058] The method for preparing a perovskite solar cell includes: sequentially forming a hole transport layer, a perovskite absorption layer, an electron transport layer, and an electrode on a transparent conductive substrate. The specific steps are as follows:

[0059] S11. Cleaning step: Ultrasonically clean the transparent conductive substrate with deionized water, acetone, and ethanol in sequence for 15 - 20 minutes. After drying the transparent conductive substrate, perform oxygen plasma treatment for 10 - 15 minutes, and then transfer the transparent conductive substrate into a nitrogen glove box;

[0060] S12. Preparing the hole transport layer: Weigh 3 - 15 mg of hole transport material DCz - OME or DCz - SME, dissolve it in 1 mL of chlorobenzene solution, take an appropriate amount of the mixed solution and drop it onto the transparent conductive substrate, spin - coat it at a speed of 4000 - 5000 rpm for 20 - 30 s, and then anneal it at 90 - 100 °C for 10 min;

[0061] S13. Preparing the perovskite absorption layer: Cool the transparent conductive substrate with the hole transport layer to room temperature, preheat it at 130 - 140 °C for 3 - 5 min, take 50 μL of perovskite solution and spread it over the surface of the hole transport layer, spin - coat it at a speed of 3000 - 5000 rpm for 20 - 30 s, and then anneal it at 90 - 100 °C for 10 min. Among them, the solute of the perovskite solution is 3 - bromo - benzylammonium iodide or 3 - chloro - benzylammonium iodide, methylammonium chloride, and lead iodide, and the solvent is N,N - dimethylformamide and dimethyl sulfoxide;

[0062] S14. Preparing the electron transport layer: Cool the transparent conductive substrate with the perovskite absorption layer to room temperature, take 40 μL of (6,6) - phenyl - C61 - butyric acid methyl ester solution with a concentration of 15 mg / mL, spread the (6,6) - phenyl - C61 - butyric acid methyl ester solution over the perovskite absorption layer, spin - coat it at a speed of 1000 - 2000 rpm for 30 - 50 s, and then anneal it at 70 - 80 °C for 10 min;

[0063] S15. Preparing the electrode: Place the transparent conductive substrate with the electron transport layer in a vacuum evaporation chamber, and evaporate at least one of metal chromium or gold onto the electron transport layer.

[0064] The preparation method of the perovskite battery provided by the embodiment of the present application uses the hole transport materials DCz-OME or DCz-SME to fabricate the hole transport layer. The hole transport materials DCz-OME and DCz-SME have good solubility in organic solvents, good film-forming properties, good wettability with the perovskite precursor solvent, and are helpful for the crystallization and film formation of perovskite.

[0065] The preparation steps of the hole transport material DCz-OME or DCz-SME include:

[0066] S21: Add the first compound, the second compound, tetrakis(triphenylphosphine)palladium, and potassium carbonate to a solvent. The solvent is toluene, ethanol, and water with a volume ratio of 2:1:1, and react at 80 °C to 85 °C for 6 h to 8 h to obtain a first product.

[0067] The structural formula of the first compound is:

[0068]

[0069] The structural formula of the second compound is:

[0070] Wherein, each X is independently selected from O or S.

[0071] The reaction formula for preparing the first product is as follows:

[0072]

[0073] In some embodiments, the molar ratio of the first compound, the second compound, potassium carbonate, and tetrakis(triphenylphosphine)palladium is 1:(2.2 - 3):(4 - 7):(0.02 - 0.1).

[0074] In some embodiments, after obtaining the first product, it further includes purifying the first product by column chromatography. The eluent for column chromatography is petroleum ether and dichloromethane with a volume ratio of 4:1.

[0075] S22: Dissolve the first product in anhydrous 1,4-dioxane at room temperature, add trimethyl bromosilane and stir for 8 h to 14 h. After rotary evaporation to remove 1,4-dioxane, dissolve the obtained solid powder in methanol, add deionized water dropwise until the mixture becomes opaque, and then stir for 8 h to 14 h. The obtained crude product is collected by filtration and washed with deionized water. Dissolve the crude product in tetrahydrofuran and precipitate in acetone, and filter to obtain the hole transport material DCz-OME or DCz-SME.

[0076] The reaction formula for preparing DCz-OME or DCz-SME is as follows:

[0077]

[0078] In some embodiments, the molar ratio of the first product to trimethyl bromosilane is 1:(10 - 20).

[0079] The preparation steps of the first compound include:

[0080] S31. Add raw material I and N-bromosuccinimide to tetrahydrofuran, react at 0°C - 5°C for 12 h - 16 h, quench the reaction with water, extract the organic phase with dichloromethane, dry the organic phase with anhydrous magnesium sulfate, and then remove the solvent to obtain the first intermediate.

[0081] The chemical formula of raw material I is:

[0082]

[0083] The reaction formula for preparing the first intermediate is:

[0084]

[0085] In some embodiments, the molar ratio of raw material I to N-bromosuccinimide is 1:(2.2 - 3).

[0086] In some embodiments, after obtaining the first intermediate, it further includes purifying the first intermediate by flash column chromatography, and the eluent is petroleum ether and dichloromethane with a volume ratio of 10:1.

[0087] S32. Dissolve the first intermediate and tetrabutylammonium bromide in 1,4-dibromobutane, dropwise add a 50% aqueous potassium hydroxide solution, react at 65°C - 80°C for 8 h - 14 h, quench the reaction with water, extract the organic phase with dichloromethane, dry the organic phase with anhydrous magnesium sulfate, and then remove the solvent to obtain the second intermediate.

[0088] The reaction formula for preparing the second intermediate is:

[0089]

[0090] In some embodiments, the molar ratio of the first intermediate, tetrabutylammonium bromide, potassium hydroxide, and 1,4-dibromobutane is 1:(0.1 - 0.2):(5 - 10):(200 - 600).

[0091] In some embodiments, after obtaining the second intermediate, it further includes purifying the second intermediate by column chromatography, and the eluent for column chromatography is petroleum ether and dichloromethane with a volume ratio of 10:1.

[0092] S33. Mix the second intermediate product with triethyl phosphite, react at 140°C to 160°C for 8 h to 16 h, and obtain the first compound after removing the solvent by rotary evaporation.

[0093] The reaction formula for preparing the first compound is:

[0094]

[0095] In some embodiments, the molar ratio of the second intermediate product to triethyl phosphite is 1:(140 - 160).

[0096] The preparation steps of the second compound include:

[0097] S41. Add raw material II, 2-thiopheneboronic acid, tetrakis(triphenylphosphine)palladium, and potassium carbonate to N,N-dimethylformamide, react at 80°C to 85°C for 6 h to 8 h, cool to room temperature, extract the organic phase with dichloromethane, dry the organic phase with anhydrous magnesium sulfate, and then remove the solvent to obtain the third intermediate product.

[0098] The chemical formula of raw material II is:

[0099] Wherein, each X independently selects from O or S.

[0100] The reaction formula for preparing the third intermediate product is:

[0101]

[0102] In some embodiments, the molar ratio of raw material II, 2-thiopheneboronic acid, tetrakis(triphenylphosphine)palladium, and potassium carbonate is 1:(1 - 1.4):(0.01 - 0.1):(4 - 8).

[0103] In some embodiments, after obtaining the third intermediate product, it further includes subjecting the third intermediate product to column chromatography purification, and the eluent for column chromatography is petroleum ether and dichloromethane with a volume ratio of 12:1.

[0104] S42. Add the third intermediate product to tetrahydrofuran, lower the temperature to -78°C to -80°C, stir for 10 min, then dropwise add n-butyllithium and stir at -78°C to -80°C for 1 h to 2 h, add pinacol borate ester and continue to stir at -78°C to -80°C for 1 h to 2 h, raise the temperature to room temperature and react for 12 h to 16 h, quench the reaction with water, extract the organic phase with saturated sodium chloride and dichloromethane, dry the organic phase with anhydrous magnesium sulfate, and then remove the solvent to obtain the second compound.

[0105] The reaction formula for preparing the second compound is:

[0106]

[0107] In some embodiments, the molar ratio of the third intermediate product, n-butyllithium, and pinacol borate is 1:(1-1.5):(1.1-2).

[0108] In some embodiments, after obtaining the second compound, column chromatography purification is further included for the second compound, and the eluent for column chromatography is petroleum ether and dichloromethane with a volume ratio of 15:1.

[0109] The preparation method of the hole transport materials DCz-OME or DCz-SME provided by the embodiments of the present application has low raw material costs, a simple preparation process, and is suitable for industrial production.

[0110] Correspondingly, on the other hand, an embodiment of the present application provides a tandem cell, including: a top cell, which is the perovskite cell in the above embodiments; a crystalline silicon bottom cell, which is located on the side of the transparent conductive substrate of the perovskite cell away from the electrode.

[0111] The crystalline silicon bottom cell includes any one of a PERC cell (Passivated Emitter and Rear Cell), a PERT cell (Passivated Emitter and Rear Totally-diffused cell), a TOPCon cell (Tunnel Oxide Passivated Contact), a HIT / HJT cell (Heterojunction Technology), or a BC cell (BackContact).

[0112] The crystalline silicon bottom cell further includes a monocrystalline silicon solar cell, a polycrystalline silicon solar cell, an amorphous silicon solar cell, or a multi-component compound solar cell. The multi-component compound solar cell may specifically be a cadmium sulfide solar cell, a gallium arsenide solar cell, a copper indium selenide solar cell, or a perovskite solar cell.

[0113] Correspondingly, on yet another aspect, an embodiment of the present application provides a photovoltaic module, including: a plurality of tandem cells as in the above embodiments; a connecting component, which is used to connect adjacent tandem cells; a glue film, which covers the surface of the tandem cells; and a cover plate, which is located on the surface of the glue film away from the tandem cells.

[0114] The connecting component includes an interconnecting solder tape and a bus bar. The interconnecting solder tape is a tinned solder tape used to connect the tandem cells, collect, and transmit the current of the tandem cells; the bus bar is a tinned solder tape used to connect the tandem cell string and the junction box and transmit the current of the tandem cell string.

[0115] The encapsulant film can be an organic encapsulant film such as ethylene-vinyl acetate copolymer (EVA) film, polyolefin elastomer (POE) film, or polyvinyl butyral (PVB) film.

[0116] The cover plate can be a cover plate with a light-transmitting function such as a glass cover plate or a plastic cover plate. In some embodiments, the surface of the cover plate facing the encapsulation layer can be an uneven surface, thereby increasing the utilization rate of incident light.

[0117] The following are specific embodiments of the present application:

[0118] Example 1

[0119] Preparation of DCz-OMe:

[0120] Add 1.07 g of raw material I and 20 mL of tetrahydrofuran to a 100 mL round-bottom flask, then add 1.51 g of N-bromosuccinimide. React the mixture at 0 °C to 5 °C for 12 h. After quenching the reaction with water, extract the organic phase with dichloromethane. After drying the organic phase with anhydrous magnesium sulfate, remove the solvent with a rotary evaporator to obtain the crude product of the first intermediate. Purify by flash column chromatography with a petroleum ether:dichloromethane eluent of 10:1 to obtain the purified first intermediate (yield 90%).

[0121] Add 1.27 g of the first intermediate and 0.35 g of tetrabutylammonium bromide to a 100 mL two-necked flask and dissolve in 15 mL of 1,4-dibromobutane. Then add dropwise 5 mL of a 50% potassium hydroxide aqueous solution by mass. Heat the mixture to 65 °C and react for 12 h. After quenching the reaction with water, extract the organic phase with dichloromethane. After drying the organic phase with anhydrous magnesium sulfate, remove the solvent to obtain the crude product of the second intermediate. Purify the second intermediate by silica gel column chromatography with a petroleum ether:dichloromethane eluent of 10:1 by volume to obtain the purified second intermediate (yield 81%).

[0122] Add 1.4 g of the second intermediate and 10 mL of triethyl phosphite to a 100 mL two-necked flask. Heat the mixture to 160 °C and stir for 12 h. Remove the solvent with a rotary evaporator to obtain the crude product of the first compound (yield 72%).

[0123] 1.15 g of raw material II, 0.46 g of 2-thiopheneboronic acid, 0.092 g of tetrakis(triphenylphosphine)palladium, 1.2 g of potassium carbonate and 40 mL of N,N-dimethylformamide were added to a 100 mL two-necked flask, and the reaction was carried out at 85 °C for 8 h. After cooling to room temperature, the organic phase was extracted with dichloromethane, dried with anhydrous magnesium sulfate and then the solvent was removed to obtain the crude product of the third intermediate. The third intermediate was purified by silica gel column chromatography using a petroleum ether and dichloromethane eluent with a volume ratio of 12:1 to obtain the purified third intermediate (yield 71%).

[0124] Among them, the chemical formula of raw material II is:

[0125]

[0126] 3.88 g of the third intermediate was added to a 500 mL three-necked flask, and then 30 mL of tetrahydrofuran was added. After cooling to -78 °C and stirring for 10 min, 3.75 mL of n-butyllithium (the molar concentration of n-butyllithium in hexane is 1.6 M) was added dropwise. After stirring at -78 °C for 1 h, 2.75 mL of pinacol borate was added, and after continuing to stir at -78 °C for 1 h, the reaction was transferred to room temperature for 12 h. The reaction was quenched with 50 mL of deionized water, and the organic phase was extracted with saturated sodium chloride and dichloromethane, dried with anhydrous magnesium sulfate and then the solvent was removed to obtain the crude product of the second compound. The second compound was purified by silica gel column chromatography using a petroleum ether and dichloromethane eluent with a volume ratio of 15:1 to obtain the purified second compound (yield 78%).

[0127] 0.62 g of the first compound, 1.13 g of the second compound, 57 mg of tetrakis(triphenylphosphine)palladium, 0.83 g of potassium carbonate and a solvent were added to a 100 mL two-necked flask. The solvent was toluene, ethanol and water with a volume ratio of 2:1:1. The reaction was carried out at 85 °C for 6 h. After cooling to room temperature, the organic phase was extracted with dichloromethane, dried with anhydrous magnesium sulfate and then the solvent was removed to obtain the crude product of the first product. The first product was purified by silica gel column chromatography using a petroleum ether and dichloromethane eluent with a volume ratio of 4:1 to obtain the purified first product (yield 56%).

[0128] Add 2.5 g of the first product and 10 mL of anhydrous 1,4-dioxane to a 100 mL two-necked flask. Dropwise add 3.0 g of trimethylsilyl bromide at room temperature and stir for 12 h. After removing 1,4-dioxane by rotary evaporation, dissolve the obtained solid powder in 10 mL of methanol. Dropwise add deionized water until the mixture becomes opaque, and then stir for 12 h. The obtained crude product is collected by filtration and washed with deionized water. Dissolve the crude product in 5 mL of tetrahydrofuran and precipitate it in 20 mL of acetone. After filtration, DCz-OME is obtained (yield 72%).

[0129] Use DCz-OME as the hole transport material to prepare the corresponding perovskite solar cell 1.

[0130] Example 2

[0131] Prepare DCz-SMe:

[0132] Add 1.0 g of raw material I and 20 mL of tetrahydrofuran to a 100 mL round-bottomed flask, and then add 1.51 g of N-bromosuccinimide. React the mixture at 0 °C - 5 °C for 12 h. Quench the reaction with water, extract the organic phase with dichloromethane, dry the organic phase with anhydrous magnesium sulfate, and then remove the solvent with a rotary evaporator to obtain the crude product of the first intermediate. Purify it by flash column chromatography using a eluent of petroleum ether and dichloromethane with a ratio of 10:1 to obtain the purified first intermediate (yield 90%).

[0133] Add 1.27 g of the first intermediate and 0.35 g of tetrabutylammonium bromide dissolved in 15 mL of 1,4-dibromobutane to a 100 mL two-necked flask. Then dropwise add 5 mL of a 50% potassium hydroxide aqueous solution by mass. Heat the mixture to 65 °C and react for 12 h. Quench the reaction with water, extract the organic phase with dichloromethane, dry the organic phase with anhydrous magnesium sulfate, and then remove the solvent to obtain the crude product of the second intermediate. Purify the second intermediate by silica gel column chromatography using a eluent of petroleum ether and dichloromethane with a volume ratio of 10:1 to obtain the purified second intermediate (yield 81%).

[0134] Add 1.4 g of the second intermediate and 10 mL of triethyl phosphite to a 100 mL two-necked flask. Heat the mixture to 160 °C and stir for 12 h. Remove the solvent with a rotary evaporator to obtain the crude product of the first compound (yield 72%).

[0135] 1.25 g of starting material II, 0.46 g of 2-thiopheneboronic acid, 0.092 g of tetrakis(triphenylphosphine)palladium, 1.2 g of potassium carbonate and 40 mL of N,N-dimethylformamide were added to a 100 mL two-necked flask, and the reaction was carried out at 85 °C for 8 h. After cooling to room temperature, the organic phase was extracted with dichloromethane, dried over anhydrous magnesium sulfate and then the solvent was removed to obtain the crude product of the third intermediate. The third intermediate was purified by silica gel column chromatography using a petroleum ether and dichloromethane eluent with a volume ratio of 12:1 to obtain the purified third intermediate (yield 69%).

[0136] Among them, the chemical formula of starting material II is:

[0137]

[0138] 4.2 g of the third intermediate was added to a 500 mL three-necked flask, and then 30 mL of tetrahydrofuran was added. After cooling to -78 °C and stirring for 10 min, 3.75 mL of n-butyllithium (the molar concentration of n-butyllithium in hexane is 1.6 M) was added dropwise. After stirring at -78 °C for 1 h, 2.75 mL of pinacol borate was added, and after stirring at -78 °C for another 1 h, the reaction was transferred to room temperature and reacted for 12 h. The reaction was quenched with 50 mL of deionized water, and the organic phase was extracted with saturated sodium chloride and dichloromethane, dried over anhydrous magnesium sulfate and then the solvent was removed to obtain the crude product of the second compound. The second compound was purified by silica gel column chromatography using a petroleum ether and dichloromethane eluent with a volume ratio of 15:1 to obtain the purified second compound (yield 71%).

[0139] 0.62 g of the first compound, 1.2 g of the second compound, 57 mg of tetrakis(triphenylphosphine)palladium, 0.83 g of potassium carbonate and a solvent were added to a 100 mL two-necked flask. The solvent was toluene, ethanol and water with a volume ratio of 2:1:1. The reaction was carried out at 85 °C for 6 h. After cooling to room temperature, the organic phase was extracted with dichloromethane, dried over anhydrous magnesium sulfate and then the solvent was removed to obtain the crude product of the first product. The first product was purified by silica gel column chromatography using a petroleum ether and dichloromethane eluent with a volume ratio of 4:1 to obtain the purified first product (yield 51%).

[0140] Add 2.59 g of the first product and 10 mL of anhydrous 1,4-dioxane to a 100 mL two-necked flask. Dropwise add 3.06 g of trimethylsilyl bromide at room temperature and stir for 12 h. After removing 1,4-dioxane by rotary evaporation, dissolve the resulting solid powder in 10 mL of methanol. Dropwise add deionized water until the mixture becomes opaque, and then stir for 12 h. The obtained crude product is collected by filtration and washed with deionized water. Dissolve the crude product in 5 mL of tetrahydrofuran and precipitate it in 20 mL of acetone. After filtration, DCz-OME is obtained (yield 69%).

[0141] Use DCz-OME as the hole transport material to prepare the corresponding perovskite solar cell 2.

[0142] Comparative Example 1

[0143] Use poly[bis(4-phenyl)(2,4,6-trimethylphenyl)amine] (PTAA) as the hole transport material to prepare the corresponding perovskite solar cell 3.

[0144] Use atomic force microscopy (AFM) to measure the surface roughness (RMS) of the perovskite absorption layers of perovskite solar cell 1 and perovskite solar cell 2. The roughnesses of perovskite solar cell 1 and perovskite solar cell 2 are 15.4 nm and 16.8 nm, respectively. It shows that using DCz-OMe and DCz-SMe as HTMs is beneficial to the diffusion and growth of the inverted quasi-two-dimensional perovskite, thereby obtaining a dense, uniform, and smooth perovskite absorption layer.

[0145] Perform photoelectric conversion efficiency tests on perovskite solar cell 1, perovskite solar cell 2, and perovskite solar cell 3. Under the illumination condition of AM 1.5G, measure the current density-voltage (J-V) characteristic curves with a scanning speed of 0.02 V s -1 in both forward and reverse scans. The detailed photovoltaic parameters open circuit voltage (Voc), short circuit current density (Jsc), fill factor (FF), and photoelectric conversion efficiency (PCE) are shown in Table 1. Figure 4 Figure 1 shows the current density-voltage (J-V) characteristic curves corresponding to perovskite solar cell 1, perovskite solar cell 2, and perovskite solar cell 3.

[0146] Table 1 Photovoltaic parameters corresponding to perovskite solar cell 1, perovskite solar cell 2, and perovskite solar cell 3

[0147] Experimental Example PCE / % Voc / V <![CDATA[Jsc / mA·cm -2 > FF / % Example 1 19.37 1.20 21.05 76.79 Example 2 20.06 1.20 20.79 80.48 Comparative Example 1 18.98 1.20 20.85 76.00

[0148] Combined with Table 1 and Figure 4It is found that the perovskite solar cells 1 and 2 provided by the embodiments of the present application have higher fill factors and short-circuit current densities, and the open-circuit voltage is comparable to that of the perovskite solar cells with conventional PTAA as the hole transport material. Generally speaking, the perovskite solar cells 1 and 2 provided by the embodiments of the present application have relatively high photoelectric conversion efficiencies.

[0149] Those of ordinary skill in the art can understand that the above-described embodiments are specific embodiments for implementing the present application. In actual applications, various changes can be made in form and details without departing from the spirit and scope of the present application. Any person skilled in the art can make various modifications and alterations without departing from the spirit and scope of the present application. Therefore, the protection scope of the present application should be determined by the scope defined by the claims.

Claims

1. A perovskite battery, characterized in that: The perovskite cell comprises a transparent conductive substrate, a hole transport layer, a perovskite absorption layer, an electron transport layer and an electrode, wherein the hole transport layer comprises a hole transport material, and the chemical formula of the hole transport material is as follows: Wherein, X is independently selected from O or S.

2. A method for preparing a perovskite battery, characterized in that: include: A hole transport layer, a perovskite absorption layer, an electron transport layer and an electrode are sequentially formed on a transparent conductive substrate, wherein the step of preparing the hole transport layer comprises: preparing the hole transport material according to claim 1 into a solution and then coating it on the transparent conductive substrate, and the step of preparing the hole transport material is as follows: The first compound, the second compound, tetrakis(triphenylphosphine)palladium and potassium carbonate are added to a solvent, wherein the solvent is toluene, ethanol and water in a volume ratio of 2:1:1, and react at 80° C. to 85° C. for 6 h to 8 h to obtain a first product; The structural formula of the first compound is: The structural formula of the second compound is: Wherein, X is independently selected from O or S; The first product is dissolved in anhydrous 1,4-dioxane at room temperature, trimethylsilyl bromide is added dropwise, and the reaction is stirred for 8h to 14h. After rotary evaporation to remove 1,4-dioxane, the obtained solid powder is dissolved in methanol, deionized water is added dropwise until the mixture becomes opaque, and then stirred for 8h to 14h. The obtained crude product is collected by filtration and washed with deionized water. The crude product is dissolved in tetrahydrofuran, precipitated in acetone, and filtered to obtain the hole transport material.

3. The method for preparing a perovskite battery according to claim 2, characterized in that: The molar ratio of the first compound, the second compound, potassium carbonate and tetrakis(triphenylphosphine)palladium is 1:(2.2-3):(4-7):(0.02-0.1).

4. The method for preparing a perovskite battery according to claim 2, characterized in that: The molar ratio of the first product to trimethylsilyl bromide is 1:(10-20).

5. The method for preparing a perovskite battery according to claim 2, characterized in that: The preparation steps of the first compound include: Adding raw material I and N-bromosuccinimide to tetrahydrofuran, reacting at 0°C to 5°C for 12h to 16h, quenching the reaction with water, extracting the organic phase with dichloromethane, drying the organic phase with anhydrous magnesium sulfate, and removing the solvent to obtain a first intermediate product; The chemical formula of the raw material I is: The first intermediate product and tetrabutylammonium bromide are dissolved in 1,4-dibromobutane, a 50% by mass aqueous solution of potassium hydroxide is added dropwise, and the mixture is reacted at 65° C. to 80° C. for 8 h to 14 h. After the reaction is quenched with water, the organic phase is extracted with dichloromethane, and the organic phase is dried with anhydrous magnesium sulfate and the solvent is removed to obtain a second intermediate product; The second intermediate product and triethyl phosphite are mixed, reacted at 140° C. to 160° C. for 8 h to 16 h, and the first compound is obtained by removing the solvent through rotary evaporation.

6. The method for preparing a perovskite battery according to claim 5, characterized in that: The molar ratio of the raw material I to N-bromosuccinimide is 1:(2.2-3); the molar ratio of the first intermediate product, tetrabutylammonium bromide, potassium hydroxide and 1,4-dibromobutane is 1:(0.1-0.2):(5-10):(200-600); the molar ratio of the second intermediate product to triethyl phosphite is 1:(140-160).

7. The method for preparing a perovskite battery according to claim 2, characterized in that: The preparation steps of the second compound include: Adding raw material II, 2-thiophene borate, tetrakis(triphenylphosphine)palladium and potassium carbonate to N,N-dimethylformamide, reacting at 80°C to 85°C for 6h to 8h, cooling to room temperature, extracting the organic phase with dichloromethane, drying the organic phase with anhydrous magnesium sulfate and removing the solvent to obtain a third intermediate product; The chemical formula of the raw material II is: Wherein, X is independently selected from O or S; The third intermediate product is added to tetrahydrofuran, the temperature is lowered to -78°C to -80°C and stirred for 10 minutes, n-butyl lithium is added dropwise and stirred at -78°C to -80°C for 1 hour to 2 hours, pinacol borate is added and the mixture is continued to be stirred at -78°C to -80°C for 1 hour to 2 hours, the temperature is raised to room temperature and the reaction is carried out for 12 hours to 16 hours, the reaction is quenched with water, and the organic phase is extracted with saturated sodium chloride and dichloromethane, the organic phase is dried with anhydrous magnesium sulfate, and the solvent is removed to obtain the second compound.

8. The method for preparing a perovskite battery according to claim 7, characterized in that: The molar ratio of the raw material II, 2-boric acid thiophene, tetrakis(triphenylphosphine)palladium and potassium carbonate is 1:(1-1.4):(0.01-0.1):(4-8); the molar ratio of the third intermediate product, n-butyl lithium and pinacol borate is 1:(1-1.5):(1.1-2).

9. A laminated battery, characterized in that: include: A top cell, wherein the top cell is the perovskite cell according to claim 1; A crystalline silicon bottom cell, wherein the crystalline silicon bottom cell is located on a side of the transparent conductive substrate of the perovskite cell away from the electrode.

10. A photovoltaic module, characterized in that: include: A plurality of stacked batteries as claimed in claim 9; A connecting component, the connecting component is used to connect adjacent stacked batteries; An adhesive film, the adhesive film covers the surface of the laminated battery; A cover plate is located on a surface of the adhesive film away from the laminated battery.

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