Perovskite solar cell and manufacturing method therefor, and photovoltaic module
By using R-2Ph-xPACz material as a hole extraction layer in perovskite solar cells, the problem of insufficient hole transport layer extraction capability was solved, thereby improving the energy conversion efficiency and stability of the solar cells.
Patent Information
- Authority / Receiving Office
- WO · WO
- Patent Type
- Applications
- Current Assignee / Owner
- TONGWEI SOLAR ENERGY (CHENGDU) CO LID
- Filing Date
- 2025-07-23
- Publication Date
- 2026-05-15
AI Technical Summary
The hole extraction capability of the hole transport layer in existing perovskite solar cells is poor, which limits the improvement of the energy conversion efficiency of solar cells.
R-2Ph-xPACz material was used as the hole extraction layer. Through the synergistic effect of R and Ph groups, the electron density was increased and the intermolecular forces were reduced, thereby improving the hole extraction and transport effect. Furthermore, the series resistance was reduced by optimizing the film thickness and material arrangement.
This improved the energy conversion efficiency of perovskite solar cells, reduced the series resistance, and enhanced the material's spreading uniformity and stability.
Smart Images
Figure CN2025110167_15052026_PF_FP_ABST
Abstract
Description
Perovskite solar cells and their fabrication methods, photovoltaic modules
[0001] Related cross-references
[0002] This application claims priority to Chinese Patent Application No. 2024115806847, filed on November 7, 2024, entitled "Perovskite Solar Cell and Preparation Method Thereof, Photovoltaic Module", the entire contents of which are incorporated herein by reference. Technical Field
[0003] This application relates to the field of solar cells, and more particularly to a perovskite solar cell and its preparation method, as well as a photovoltaic module. Background Technology
[0004] In perovskite solar cells, the main function of the hole transport layer is to extract holes generated in the perovskite layer and transport them to the metal electrode. Therefore, the hole transport layer's ability to extract holes has a significant impact on the photoelectric conversion efficiency and performance stability of perovskite solar cells.
[0005] Currently, the hole transport layer has a poor ability to extract holes, which limits the further improvement of the energy conversion efficiency of solar cells. Summary of the Invention
[0006] To improve the hole transport layer's ability to extract holes, this application discloses a perovskite solar cell, its preparation method, and a photovoltaic module.
[0007] In a first aspect, embodiments of this application provide a perovskite solar cell.
[0008] A perovskite solar cell includes a substrate, a hole extraction layer, a perovskite layer, an electron transport layer, and a first electrode stacked sequentially. The hole extraction layer is made of R-2Ph-xPACz, and the structure of R-2Ph-xPACz is shown in Equation 1.
[0009] Wherein, R is any one of CH3CH2O, CH3O, (CH3)3C or a heterocycle containing a lone pair of electrons, and x is 2 to 10.
[0010] Secondly, embodiments of this application provide a method for preparing a perovskite solar cell.
[0011] A method for fabricating a perovskite solar cell as described in the first aspect includes the following steps:
[0012] Deposit the hole extraction layer containing R-2Ph-xPACz on the substrate surface;
[0013] The perovskite layer, the electron transport layer, and the first electrode are sequentially prepared on the side of the hole extraction layer opposite to the substrate.
[0014] Thirdly, embodiments of this application provide a photovoltaic module.
[0015] A photovoltaic module includes a perovskite solar cell as described in the first aspect or a perovskite solar cell prepared by the preparation method described in the second aspect.
[0016] Compared with the prior art, the beneficial effects of this application are as follows:
[0017] The perovskite solar cell provided in this application embodiment features a hole extraction layer in which the R and Ph groups in R-2Ph-xPACz work together to synergistically increase electron density, which is beneficial for hole extraction in the perovskite layer, thereby improving hole extraction and transport efficiency. Moreover, through the coordination of the R and Ph groups, the overall spatial distortion range of the material is larger, which significantly reduces the intermolecular forces of R-2Ph-xPACz and enhances the orderly arrangement and uniform spreading of R-2Ph-xPACz, which helps to reduce series resistance and improve the energy conversion efficiency of the solar cell. Attached Figure Description
[0018] To more clearly illustrate the technical solutions in the embodiments of this application, the accompanying drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.
[0019] Figure 1 is a schematic diagram of the structure of the perovskite solar cell disclosed in the embodiments of this application.
[0020] Icons: 1. Substrate; 11. Texturized base cell; 111. Second electrode; 12. Composite layer; 21. Hole transport layer; 22. Hole extraction layer; 3. Perovskite layer; 4. Passivation layer; 5. Electron transport layer; 6. Buffer layer; 7. Transparent conductive layer; 8. Antireflection layer; 9. First electrode. Detailed Implementation
[0021] In this application, the terms "upper," "lower," "left," "right," "front," "rear," "top," "bottom," "inner," "outer," "middle," "vertical," "horizontal," "lateral," and "longitudinal" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. These terms are primarily for the purpose of better describing this application and its embodiments, and are not intended to limit the indicated device, element, or component to having a specific orientation, or to be constructed and operated in a specific orientation.
[0022] Furthermore, in addition to indicating location or positional relationship, some of the aforementioned terms may also have other meanings. For example, the term "above" may also be used in some cases to indicate a certain dependency or connection relationship. Those skilled in the art can understand the specific meaning of these terms in this application based on the specific circumstances.
[0023] Furthermore, the terms "installation," "setup," "equipped with," "connection," and "linked" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral structure; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium, or an internal connection between two devices, components, or parts. Those skilled in the art can understand the specific meaning of these terms in this application based on the specific circumstances.
[0024] Furthermore, the terms "first," "second," etc., are primarily used to distinguish different devices, elements, or components (which may be the same or different in specific type and construction), and are not intended to indicate or imply the relative importance or quantity of the indicated devices, elements, or components. Unless otherwise stated, "a plurality of" means two or more.
[0025] The technical solution of this application will be further described below with reference to the embodiments and accompanying drawings.
[0026] Firstly, referring to FIG1, an embodiment of this application provides a perovskite solar cell.
[0027] A perovskite solar cell includes a substrate 1, a hole extraction layer 22, a perovskite layer 3, an electron transport layer 5, and a first electrode 9, which are stacked sequentially. The hole extraction layer 22 is made of R-2Ph-xPACz, and the structure of R-2Ph-xPACz is shown in Equation 1.
[0028] Wherein, R is any one of CH3CH2O, CH3O, (CH3)3C or a heterocycle containing a lone pair of electrons, and x is 2 to 10.
[0029] The inventors' experiments revealed that, compared to commonly used self-assembled materials such as 2PACz or MeO-2PACz, the combination of R and Ph groups in the aforementioned R-2Ph-xPACz can synergistically increase electron density, which is beneficial for the extraction of holes in the perovskite layer 3, thereby improving the hole extraction and transport effect. Moreover, through the combination of the aforementioned R and Ph groups, the overall spatial distortion range of the material is larger, which significantly reduces the intermolecular forces of R-2Ph-xPACz. The arrangement order and spreading uniformity of R-2Ph-xPACz are enhanced, which is beneficial for reducing series resistance and improving the energy conversion efficiency of solar cells.
[0030] It should be noted that x represents the number of methylene groups between the carbazole group and the phosphate group in R-2Ph-xPACz, and x can be any value among 2, 4, 5, 6, 7 or 8.
[0031] For example, R-2Ph-xPACz can be:
[0032] wait.
[0033] Furthermore, the hole extraction layer 22 can be a membrane containing only R-2Ph-xPACz, or a membrane formed by mixing R-2Ph-xPACz with other hole extraction materials. Preferably, the hole extraction layer can be formed by mixing self-assembling materials such as 2PACz, 4PACz, or CH3O-2PACz with R-2Ph-xPACz.
[0034] In some embodiments, R is CH3O and x is 4.
[0035] When R is CH3O and x is 4, CH3O can provide a more compact electron cloud, with concentrated electron effects, which is more conducive to coordination with phenyl groups, increasing electron density and facilitating better hole extraction. Furthermore, the introduction of the CH3O group enhances the structural stability of CH3O-2Ph-4PACz, making it less prone to oxidation or decomposition in humid environments. With x = 4, the methylene length is moderate, resulting in lower intermolecular forces and less aggregation of CH3O-2Ph-4PACz, exhibiting good solubility in good solvents such as ethanol and isopropanol. This leads to excellent coating and dispersion properties of CH3O-2Ph-4PACz, allowing for good coverage of planar or textured substrate 1 even with a relatively small amount of CH3O-2Ph-4PACz. Therefore, the thickness of the hole extraction layer 22 can be reduced by decreasing the amount of CH3O-2Ph-4PACz, thereby better reducing the series resistance of the solar cell. In addition, the carbazole and phosphate groups are in relatively flexible positions in the molecule, which is conducive to forming good contact with the interface of the perovskite layer 3, and can further promote hole extraction.
[0036] It should be noted that a planar structure refers to a structure in which the various layers of materials in a solar cell are stacked parallel to each other in a specific order on a planar substrate 1. The process for fabricating solar cells on this type of substrate 1 is relatively simple and the manufacturing process is quite mature. The surface of the planar substrate 1 is relatively flat, such as the surface of a polished glass or silicon wafer.
[0037] A textured surface refers to a pyramid-shaped textured surface formed on the surface of substrate 1 after a texturing process. This structure enhances light trapping and absorption. The textured surface structure is beneficial for improving the energy conversion efficiency of solar cells. In perovskite-silicon tandem solar cells, a textured substrate cell 11 (such as a heterojunction substrate cell) with a textured surface structure can be used as substrate 1.
[0038] In some embodiments, the heterocycle containing lone pairs of electrons is either thiophene or pyrrole.
[0039] Thiophene is a strong π-electron donor, and the nitrogen atom with lone pairs of electrons in pyrrole participates in conjugation, making the electron cloud density on the pyrrole heterocycle relatively large. Therefore, both thiophene and pyrrole can donate electrons to the benzene ring through the conjugation effect, increasing the electron density to facilitate hole extraction.
[0040] In some embodiments, the thickness of the hole extraction layer 22 is 3 nm to 15 nm.
[0041] Within the aforementioned thickness range, the hole extraction layer 22 exhibits excellent coverage of the substrate 1. Furthermore, R-2Ph-xPACz demonstrates superior coverage. This allows the hole extraction layer 22, with a thickness ranging from 3nm to 15nm, to achieve both effective coverage of the substrate 1 and reduced series resistance of the solar cell, thereby improving the fill factor and open-circuit voltage of the solar cell.
[0042] In some embodiments, the substrate 1 includes a textured bottom cell 11 and a composite layer 12 stacked on the textured bottom cell 11. The solar cell also includes a transparent conductive layer 7 located on the side of the first electrode 9 near the substrate 1.
[0043] The surface of the textured bottom cell 11 has a textured structure. The film layers disposed on the textured bottom cell 11 are all grown along the textured surface of the textured bottom cell 11 in a conformal manner. This can maintain the light trapping advantage of the textured structure, while promoting the tight bonding of the film layer structure, improving the mechanical stability of the solar cell, and thus improving the overall performance of the solar cell.
[0044] In this application, the various film layers above the substrate 1 together form the top cell, and the composite layer 12 serves as the physical connection layer between the textured bottom cell 11 and the top cell. The textured bottom cell 11 and the top cell are connected in series through the composite layer 12 to achieve effective current transmission.
[0045] The textured bottom solar cell 11 has a second electrode 111 corresponding to the first electrode 9. Both the first electrode 9 and the second electrode 111 are made of a metallic material with good conductivity, such as silver, copper, or zinc. The first electrode 9 and the second electrode 111 are also used to collect photogenerated charge carriers, ensuring that the charge can be smoothly discharged from the inside of the solar cell, thus promoting the efficient operation of the solar cell.
[0046] The second electrode 111 can be obtained by vapor deposition. The thickness of the second electrode 111 is 300 nm to 500 nm. For example, the thickness of the second electrode 111 can be 300 nm, 320 nm, 350 nm, 360 nm, 390 nm, 420 nm, 480 nm or 500 nm, etc.
[0047] In addition, in some embodiments, the substrate 1 can also be any substrate with a pyramidal textured surface, such as an ITO glass substrate.
[0048] In some embodiments, the composite layer 12 is made of a transparent conductive material; and / or, the thickness of the composite layer 12 is 15 nm to 30 nm; and / or, the transparent conductive layer 7 is made of a transparent conductive material; and / or, the thickness of the transparent conductive layer 7 is 70 nm to 110 nm.
[0049] The transparent conductive material can be indium tin oxide, indium zinc oxide, etc. For example, the composite layer 12 is made of indium tin oxide, and the transparent conductive layer 7 is made of indium zinc oxide.
[0050] For example, the thickness of the composite layer 12 can be 15nm, 18nm, 20nm, 23nm, 25nm, 28nm or 30nm, etc.
[0051] For example, the thickness of the transparent conductive layer 7 can be 70nm, 75nm, 80nm, 85nm, 90nm, 95nm, 100nm or 110nm, etc.
[0052] In some embodiments, the perovskite solar cell further includes a hole transport layer 21, which is stacked on the side of the hole extraction layer 22 away from the perovskite layer 3. The material of the hole transport layer 21 includes Cu2O, CuO, and MoO. x NiMgLiO or NiO x One or more combinations thereof.
[0053] Substrate 1 is a textured bottom battery 11 and a composite layer 12, consisting of Cu2O, CuO, and MoO. x NiMgLiO or NiO x Metal oxides exhibit superior dispersion on the surface of composite layer 12, enabling uniform deposition to form a hole transport layer 21 with excellent texture and shape retention. This is due to the presence of Cu₂O, CuO, and MoO. x NiMgLiO or NiO xThe hydroxyl groups on the surface of the hole transport layer 21 formed by metal oxides can easily bond with the phosphate groups in R-2Ph-xPACz through anchoring. Furthermore, the excellent spreading uniformity of R-2Ph-xPACz allows it to uniformly self-assemble onto the surface of the hole transport layer 21, forming a dense and uniform self-assembled molecular layer. This results in excellent textured surface preservation for the composite layer 12, hole transport layer 21, and hole extraction layer 22 stack, which is beneficial for improving carrier transport performance.
[0054] Preferably, the hole transport layer 21 is made of NiO. x The composite layer 12, hole transport layer 21, and hole extraction layer 22 stacked together have a better textured surface and better carrier transport performance, which is conducive to improving the energy conversion efficiency of solar cells.
[0055] In some embodiments, the thickness of the hole transport layer 21 is 10 nm to 20 nm.
[0056] For example, the thickness of the hole transport layer 21 can be 10nm, 12nm, 14nm, 16nm, 18nm, and 20nm, etc.
[0057] In some embodiments, the thickness of the perovskite layer 3 is 600 nm to 900 nm; and / or, the thickness of the electron transport layer 5 is 10 nm to 30 nm; and / or, the thickness of the first electrode 9 is 250 nm to 400 nm.
[0058] The hole extraction layer 22 exhibits excellent texture retention, providing a good growth substrate 1 for the subsequent growth of the perovskite layer 3, which is beneficial to improving the texture retention and film quality of the perovskite layer 3.
[0059] For example, the thickness of the perovskite layer 3 can be 600nm, 630nm, 660nm, 700nm, 750nm, 800nm, 850nm and 900nm, etc., and the thickness of the lead halide framework layer can be 300nm, 330nm, 360nm, 400nm, 450nm, 500nm, 550nm and 600nm, etc.
[0060] For example, the thickness of the electron transport layer 5 can be 10nm, 15nm, 20nm, 25nm, 27nm, and 30nm, etc.
[0061] For example, the thickness of the first electrode 9 can be 250nm, 265nm, 280nm, 300nm, 340nm, 360nm, 380nm and 400nm, etc.
[0062] In some embodiments, the solar cell further includes a passivation layer 4, which is stacked between the perovskite layer 3 and the electron transport layer 5; and / or,
[0063] The solar cell also includes a buffer layer 6, which is stacked between the electron transport layer 5 and the transparent conductive layer 7; and / or,
[0064] The solar cell also includes an antireflection layer 8, which is stacked on the side of the transparent conductive layer 7 facing away from the substrate 1.
[0065] The passivation layer 4 is made of LiF and has a thickness of 1 nm to 2 nm. For example, the thickness of the passivation layer 4 is 1 nm, 1.5 nm, and 2 nm.
[0066] The material of the buffer layer 6 is SnO2, and the thickness is 10nm to 30nm. For example, the thickness of the buffer layer 6 is 10nm, 15nm, 20nm, 25nm, 27nm and 30nm.
[0067] The antireflection layer 8 is made of LiF and has a thickness of 80 nm to 120 nm. For example, the thickness of the antireflection layer 8 is 80 nm, 90 nm, 95 nm, 100 nm, 103 nm, 109 nm, 116 nm and 120 nm.
[0068] Secondly, embodiments of this application provide a method for preparing a perovskite solar cell.
[0069] A method for fabricating a perovskite solar cell as mentioned in the first aspect includes the following steps:
[0070] A hole extraction layer 22 containing R-2Ph-xPACz is deposited on the surface of substrate 1;
[0071] A perovskite layer 3, an electron transport layer 5, and a first electrode 9 are sequentially prepared on the side of the hole extraction layer 22 facing away from the substrate 1.
[0072] The R-2Ph-xPACz solution exhibits excellent spreading uniformity, and can adhere evenly to the surface of substrate 1 when the substrate 1 has a textured surface, without easily accumulating to the bottom of the textured surface. Therefore, the cavity extraction layer 22 prepared by the R-2Ph-xPACz solution demonstrates excellent shape retention.
[0073] The hole extraction layer 22 exhibits excellent shape retention, providing a good growth substrate 1 for the subsequent growth of the perovskite layer 3 and electron transport layer 5, thereby improving the performance of the solar cell.
[0074] Furthermore, the preparation method of R-2Ph-xPACz includes the following steps:
[0075] The first compound shown in Formula 2-1 is reacted with a dibromoalkyl group to produce the second compound shown in Formula 2-2;
[0076] The second compound shown in Formula 2-2 was reacted with triethyl phosphite, followed by the sequential addition of bromotrimethylsilane, methanol and water to generate R-2Ph-xPACz.
[0077] The structure of the first compound shown in Formula 2-1 is as follows: The structure of the second compound shown in Formula 2-2 is as follows:
[0078] The reaction formula for synthesizing the second compound shown in formula 2-2 from the first compound shown in formula 2-1 is as follows:
[0079] The reaction formula for synthesizing R-2Ph-xPACz from the second compound is as follows:
[0080] Specifically, in the step of synthesizing the second compound from the first compound, the first compound and dibromoalkyl are first mixed, then tetrabutylammonium bromide and an inorganic alkaline aqueous solution are added, heated to 70℃~80℃ and stirred for 10h~14h to obtain the second compound.
[0081] After the reaction to synthesize the second compound is completed, a crude product containing the second compound is obtained. The purification method for this crude product includes the following steps: extraction of the crude product with dichloromethane, followed by drying to remove water, removing the solvent under reduced pressure, and purification by column chromatography to obtain the second compound. In the drying step, anhydrous sodium sulfate is used as the drying reagent. In the column chromatography purification step, petroleum ether and dichloromethane in a volume ratio of 1:1 are used as the eluent.
[0082] Preferably, for every 1 mmol of the first compound added, 5 mL to 6 mL of dibromoalkyl is added; further, the mass concentration of the inorganic alkaline aqueous solution is 50%, and for every 1 mmol of the first compound added, the volume of the inorganic alkaline aqueous solution added is 1.1 mL.
[0083] In the steps of synthesizing R-2Ph-xPACz from the second compound, the second compound is first mixed with triethyl phosphite, and then heated overnight at 135℃~150℃ to obtain the product precursor. The product precursor is purified, and then the purified product precursor is mixed with trimethylbromosilane and reacted at 24℃~28℃ for 22h~26h. Methanol is added, and the reaction is carried out at 24℃~28℃ for 2.5h~3.5h. Water is added, and the reaction is carried out at 24℃~28℃ for 100min~140min to obtain R-2Ph-xPACz.
[0084] Furthermore, the purification process of the product precursor includes the following steps:
[0085] First, reduce the pressure and distill to remove the solvent from the product precursor;
[0086] The solution is then purified by column chromatography, wherein the eluent used in the column chromatography purification is composed of dichloromethane and ethyl acetate in a volume ratio of (1.95–2.1):1.
[0087] Preferably, the purified product precursor is a pale yellow resin.
[0088] In the reaction process for synthesizing R-2Ph-xPACz, distilled water is preferred and is added dropwise. During the addition of water, the reaction mixture gradually becomes opaque.
[0089] After the reaction for synthesizing R-2Ph-xPACz is completed, a crude product containing R-2Ph-xPACz is obtained. The purification method for this crude product includes the following steps:
[0090] The solid product was filtered out, washed with water, and recrystallized in a mixed solvent of tetrahydrofuran and dichloromethane to obtain R-2Ph-xPACz.
[0091] During recrystallization, the precipitated green powder is R-2Ph-xPACz. In the mixed solvent of tetrahydrofuran and dichloromethane, any ratio of tetrahydrofuran and dichloromethane can be used, with a preferred tetrahydrofuran:dichloromethane ratio of 1:2 to 2:1.
[0092] Furthermore, for every 1.5 mmol of the second compound added, at least 52.49 mmol of triethyl phosphite, 11 mmol to 12 mmol of trimethylsilane, 2 mL to 2.5 mL of methanol, and 15 mL to 16.5 mL of water are added.
[0093] More preferably, the amount of triethyl phosphite added is 52.49 mmol to 54 mmol.
[0094] In some embodiments, R-2Ph-xPACz is deposited using slot coating, spin coating, spray coating, blade coating, inkjet printing, or vapor deposition.
[0095] For example, when performing coating deposition of R-2Ph-xPACz, R-2Ph-xPACz is first placed in a solution environment. Then, the solution containing R-2Ph-xPACz is deposited on the substrate surface by means of slit coating, blade coating, spin coating or spray coating to form a wet film layer of R-2Ph-xPACz. Then, annealing is performed to evaporate the solvent in the wet film layer of R-2Ph-xPACz, and the corresponding hole extraction layer 22 is obtained.
[0096] In some embodiments, in the step of preparing the hole extraction layer 22, an R-2Ph-xPACz solution with a concentration of 1 mg / mL to 1.5 mg / mL is first prepared, and then the R-2Ph-xPACz solution is coated by spin coating at a speed of 3000 rpm to 5000 rpm for 30 s to 50 s.
[0097] By controlling the concentration of R-2Ph-xPACz and the spin-coating parameters, a hole extraction layer 22 with better thickness and film uniformity can be prepared, thereby further optimizing the performance of solar cells.
[0098] In some embodiments, the solvent for the R-2Ph-xPACz solution is one or a mixture of anhydrous ethanol, isopropanol, or cyclohexane.
[0099] Anhydrous ethanol, isopropanol, or cyclohexane exhibit good solubility for R-2Ph-xPACz, which facilitates its uniform dispersion, thereby promoting the formation of a high-quality, uniform thin film and improving the performance of the solar cell. Furthermore, the good volatility of anhydrous ethanol, isopropanol, or cyclohexane allows for rapid removal during film formation, reducing solvent residue and contributing to improved quality of the hole extraction layer 22 and the stability of the solar cell.
[0100] In some embodiments, the method for preparing the perovskite layer 3 includes the following steps:
[0101] A lead halide framework layer was prepared on the cavity extraction layer 22;
[0102] A cationic solution was coated onto the lead halide framework layer, and then annealed to obtain the perovskite layer 3.
[0103] The perovskite layer 3 prepared by the above method exhibits excellent conformation retention and is suitable for use on film surfaces with textured surfaces. Furthermore, there is a strong interaction between R-2Ph-xPACz and lead halide, which can guide the lead halide framework layer to grow with high conformation retention on the surface of the hole extraction layer 22, further enhancing the conformation retention effect of the perovskite layer 3 after the reaction of the cation solution with the lead halide framework layer.
[0104] Furthermore, the lead halide framework layer is composed of lead iodide and cesium halide, wherein the mass ratio of lead iodide to cesium halide is 5 to 10:1, and the cesium halide is any one of cesium bromide, cesium chloride, or cesium iodide. Preferably, the cesium halide is cesium bromide.
[0105] Furthermore, the cationic solution can be applied to the lead halide framework layer by spin coating, spraying, blade coating, or slot coating. The cationic solution consists of one or more of FAI, FABr, MACl, and MABr. Preferably, the cationic solution consists of FAI, FABr, MACl, and MABr in a mass ratio of 50:14:10:8.
[0106] In some embodiments, the method for fabricating a perovskite solar cell further includes: fabricating a hole transport layer 21 between the substrate 1 and the hole extraction layer 22.
[0107] Thirdly, embodiments of this application provide a photovoltaic module.
[0108] A photovoltaic module includes a perovskite solar cell as mentioned in the first aspect or a perovskite solar cell prepared by the preparation method mentioned in the second aspect.
[0109] The technical solution of this application will be further described below with reference to the embodiments and accompanying drawings.
[0110] Example 1
[0111] This application provides a solar cell, including:
[0112] Heterojunction bottom cells;
[0113] A composite layer is stacked on the surface of the heterojunction bottom cell. The composite layer is made of indium tin oxide and has a thickness of 30 nm.
[0114] The hole transport layer is stacked on the side of the composite layer away from the heterojunction bottom cell, and the material of the hole transport layer is NiO. x The thickness is 15nm;
[0115] A hole extraction layer is stacked on the side of the hole transport layer away from the heterojunction bottom cell. The material of the first transport layer is CH3O-2Ph-4PACz. The structure of CH3O-2Ph-4PACz is shown in Equation 1-1, and the thickness is 6nm.
[0116] The perovskite layer is stacked on the side of the hole extraction layer away from the heterojunction bottom cell. The perovskite layer is formed by reacting the lead iodide framework layer with a cation solution. The lead iodide framework layer has a thickness of 450 nm, and the perovskite layer has a thickness of 700 nm.
[0117] A passivation layer is stacked on the side of the perovskite layer away from the heterojunction bottom cell. The passivation layer is made of LiF and has a thickness of 1.5 nm.
[0118] An electron transport layer is stacked on the side of the passivation layer away from the heterojunction bottom cell. The material of the electron transport layer is C. 60 The thickness is 20nm;
[0119] A buffer layer is stacked on the side of the electron transport layer away from the heterojunction bottom cell. The buffer layer is made of SnO2 and has a thickness of 15nm.
[0120] A transparent conductive layer is stacked on the side of the buffer layer away from the heterojunction bottom cell. The transparent conductive layer is indium zinc oxide and has a thickness of 100 nm.
[0121] An antireflection layer is stacked on the side of the transparent conductive layer away from the heterojunction bottom cell. The antireflection layer is made of LiF and has a thickness of 100 nm.
[0122] The first electrode, made of Ag, forms an ohmic contact with the transparent conductive layer through the antireflection layer and has a height of 300 nm.
[0123] The above-mentioned method for preparing solar cells includes the following steps:
[0124] Preparation of CH3O-2Ph-4PACz:
[0125] Compound 1 (2 mmol) was dissolved in 1,4-dibromobutane (10 mL), and tetrabutylammonium bromide (0.16 g, 0.5 mmol) and 50% KOH aqueous solution (1.1 mL, 20 mmol) were added. The mixture was then heated to 70 °C and stirred overnight. After the reaction was complete, the mixture was extracted with dichloromethane. The organic layer was dried over anhydrous Na2SO4 and the solvent was removed under reduced pressure. The crude product was purified by column chromatography using petroleum ether and dichloromethane in a volume ratio of 1:1 as eluents to obtain a white crystalline solid, which was compound 2.
[0126] Compound 2 (1.5 mmol) was dissolved in triethyl phosphite (10 mL, 52.49 mmol) and heated overnight at 140 °C. The solvent was removed under reduced pressure, and the crude product was purified by column chromatography using dichloromethane and ethyl acetate in a volume ratio of 1:2 to obtain a pale yellow resin. The pale yellow resin was dissolved in anhydrous 1,4-dioxane (15 mL) under an argon atmosphere, and bromotrimethylsilane (1.5 mL, 11 mmol) was added dropwise. The mixture was stirred for 22 h at 25 °C under an argon atmosphere, followed by the addition of methanol (2 mL) and stirring for another 3 h. Finally, distilled water (15 mL) was added dropwise until the solution became opaque. After stirring for another 2 h, the product was filtered off, washed with water, and recrystallized in a mixed solvent of tetrahydrofuran and dichloromethane to obtain a green powder, namely MeO-2Ph-4PACz.
[0127] Fabrication of solar cells:
[0128] Provide heterojunction base cells;
[0129] A composite layer was prepared on a heterojunction bottom cell using magnetron sputtering.
[0130] A hole transport layer was prepared on the composite layer using physical vapor deposition.
[0131] A hole extraction layer was prepared on the hole transport layer using a solution spin-coating method, as detailed below:
[0132] Take 0.2 mL of CH3O-2Ph-4PACz isopropanol solution with a concentration of 1.3 mg / mL, spin-coat at 4000 rpm for 30 s to spin-coat the CH3O-2Ph-4PACz solution onto the surface of the hole transport layer, and then anneal at 100℃ for 10 min to obtain the hole extraction layer.
[0133] A perovskite layer was prepared on the hole extraction layer using a two-step method, as detailed below:
[0134] Lead iodide and cesium bromide were co-deposited on the surface of the hole extraction layer, with the deposition rate ratio of lead iodide to cesium bromide being 5:1, to obtain a lead iodide framework layer.
[0135] A cationic solution was spin-coated onto the lead iodide framework layer. The cationic solution was prepared by dissolving FAI, FABr, MACl and MABr in 1 mL of isopropanol at a mass ratio of 50:14:10:8. The solution was then annealed at 150 °C for 20 min to obtain a perovskite layer.
[0136] A passivation layer was prepared on the perovskite layer by vapor deposition.
[0137] An electron transport layer was prepared on the passivation layer by vapor deposition.
[0138] A buffer layer was prepared on the electron transport layer using atomic layer deposition.
[0139] A transparent conductive layer was prepared on the buffer layer using magnetron sputtering.
[0140] An antireflection layer was prepared on a transparent conductive layer using a vapor deposition method.
[0141] The first electrode was prepared by vapor deposition.
[0142] Comparative Example 1
[0143] This application provides a comparative example of a solar cell, which differs from Example 1 in that CH3O-4PACz is used instead of CH3O-2Ph-4PACz. The CAS number of CH3O-4PACz is 2922526-56-3, and its structure is shown in Equations 1-5.
[0144] Everything else remains the same as in Example 1.
[0145] Comparative Example 2
[0146] This application provides a comparative example of a solar cell, which differs from Example 1 in that CH3O-2PACz is used instead of CH3O-2Ph-4PACz. The CAS number of CH3O-2PACz is 2377770-18-6, and its structure is shown in Equations 1-6.
[0147] Everything else remains the same as in Example 1.
[0148] Comparative Example 3
[0149] This application provides a comparative example of a solar cell, which differs from Example 1 in that it uses 2Ph-4PACz instead of CH3O-2Ph-4PACz. The CAS number of 2Ph-4PACz is 2814500-04-2, and its structure is shown in Equations 1-7.
[0150] Everything else remains the same as in Example 1.
[0151] Performance Testing
[0152] The performance of perovskite tandem solar cells was tested using the Wavelabs solar simulator under the following conditions: AM1.5, 1000 W / m². 2 The test environment temperature was 25℃. Before testing, the light source was calibrated to simulate sunlight intensity using a standard silicon cell. Performance tests included energy conversion efficiency (%), open-circuit voltage (V), and short-circuit current (mA / cm²). 2 , fill factor, in percentage.
[0153] The test results of the above embodiments and comparative examples are shown in Table 1.
[0154] Table 1
[0155] By comparing the data of Example 1 with those of Comparative Examples 1, 2, and 3 in Table 1, it can be seen that by introducing phenyl groups and specific groups onto the carbazole group, the electron density can be increased more synergistically, the hole extraction capability can be improved, the intermolecular forces can be reduced, the uniformity of the hole extraction layer can be improved, and thus the energy conversion efficiency of the solar cell can be improved.
[0156] The technical solutions disclosed in the embodiments of this application have been described in detail above. Specific examples have been used in this document to illustrate the principles and implementation methods of this application. The description of the above embodiments is only for the purpose of helping to understand the technical solutions and core ideas of this application. At the same time, for those skilled in the art, there will be changes in the specific implementation methods and application scope based on the ideas of this application. Therefore, the content of this specification should not be construed as a limitation of this application.
Claims
1. A perovskite solar cell, characterized by, The structure comprises a substrate, a hole extraction layer, a perovskite layer, an electron transport layer, and a first electrode, which are stacked sequentially. The hole extraction layer is made of R-2Ph-xPACz, and the structure of R-2Ph-xPACz is shown in Equation 1. Wherein, R is any one of CH3CH2O, CH3O, (CH3)3C or a heterocycle containing a lone pair of electrons, and x is 2 to 10.
2. The perovskite solar cell according to claim 1, characterized in that, R is CH3O, and x is 4. 3.The perovskite solar cell of claim 1, wherein, The heterocycle containing lone pairs of electrons is either thiophene or pyrrole. 4.The perovskite solar cell of claim 1, wherein, The thickness of the hole extraction layer is 3nm to 15nm.
5. The perovskite solar cell according to any one of claims 1-4, characterized in that, The substrate is a textured base cell and a composite layer stacked on the textured base cell. The solar cell also includes a transparent conductive layer located on the side of the first electrode near the substrate. or, The substrate is a glass substrate.
6. The perovskite solar cell according to claim 5, characterized in that, The composite layer is made of a transparent conductive material; and / or, the thickness of the composite layer is 15 nm to 30 nm; and / or, the transparent conductive layer is made of a transparent conductive material; and / or, the thickness of the transparent conductive layer is 70 nm to 110 nm.
7. The perovskite solar cell according to any one of claims 1-4, characterized in that, The perovskite solar cell further comprises a hole transport layer, which is laminated on the side of the hole extraction layer away from the perovskite layer, and the material of the hole transport layer comprises one or more combinations of Cu2O, CuO, MoO x , NiMgLiO or NiO x .
8. The perovskite solar cell according to claim 7, characterized in that, The thickness of the hole transport layer is 10nm to 20nm.
9. The perovskite solar cell according to any one of claims 1-4, characterized in that, The thickness of the perovskite layer is 600 nm to 900 nm; and / or the thickness of the electron transport layer is 10 nm to 30 nm; and / or the thickness of the first electrode is 250 nm to 400 nm.
10. A method of producing a perovskite solar cell, characterized by, The method for preparing a perovskite solar cell according to any one of claims 1-9 includes the following steps: Deposit the hole extraction layer containing R-2Ph-xPACz on the substrate surface; The perovskite layer, the electron transport layer, and the first electrode are sequentially prepared on the side of the hole extraction layer opposite to the substrate. 11.The method of claim 10, wherein the perovskite solar cell is prepared by the steps of: The preparation method of R-2Ph-xPACz includes the following steps: The first compound shown in Formula 2-1 is reacted with a dibromoalkyl group to produce the second compound shown in Formula 2-2; The second compound shown in Formula 2-2 was reacted with triethyl phosphite, followed by the sequential addition of bromotrimethylsilane, methanol and water to generate R-2Ph-xPACz. wherein the first compound of formula 2-1 has the structure: The structure of the second compound shown in Formula 2-2 is: 12.The method of claim 11, wherein the perovskite solar cell is prepared by the steps of: In the step of synthesizing the second compound from the first compound, the first compound and the dibromoalkyl group are first mixed, then tetrabutylammonium bromide and an inorganic base aqueous solution are added, the mixture is heated to 70°C–80°C and stirred for 10–14 hours to obtain the second compound; and / or In the step of synthesizing R-2Ph-xPACz from the second compound, the second compound is first mixed with triethyl phosphite, and then heated overnight at 135℃~150℃ to obtain a product precursor. The product precursor is purified, and then the purified product precursor is mixed with the trimethylbromosilane and reacted at 24℃~28℃ for 22h~26h. Methanol is added, and the reaction is carried out at 24℃~28℃ for 2.5h~3.5h. Water is added, and the reaction is carried out at 24℃~28℃ for 100min~140min to obtain R-2Ph-xPACz.
13. The method of claim 12, wherein the perovskite solar cell is prepared by the steps of: In the step of synthesizing R-2Ph-xPACz from the second compound, the purification treatment of the product precursor includes the following steps: First, remove the solvent from the product precursor by vacuum distillation; The solution is then purified by column chromatography, wherein the eluent used in the column chromatography purification is composed of dichloromethane and ethyl acetate in a volume ratio of (1.95–2.1):
1. 14.The method of claim 11, wherein the perovskite solar cell is prepared by the steps of: For every 1 mmol of the first compound added, the dibromoalkyl group is added in 5 mL to 6 mL; and / or, For every 1.5 mmol of the second compound added, at least 52.49 mmol of triethyl phosphite, 11 mmol to 12 mmol of trimethylbromosilane, 2 mL to 2.5 mL of methanol, and 15 mL to 16.5 mL of water are added. 15.The method of claim 10, wherein the perovskite solar cell is prepared by the steps of: The R-2Ph-xPACz is deposited using methods such as slot coating, spin coating, spraying, blade coating, inkjet printing, or vapor deposition; and / or, In the step of preparing the cavity extraction layer, an R-2Ph-xPACz solution with a concentration of 1 mg / mL to 1.5 mg / mL is first prepared, and then the R-2Ph-xPACz solution is coated by spin coating at a speed of 3000 rpm to 5000 rpm for 30 s to 50 s.
16. The method of claim 15, wherein the perovskite solar cell is prepared by the steps of: The solvent for the R-2Ph-xPACz solution is one or a mixture of anhydrous ethanol, isopropanol, or cyclohexane.
17. The method for preparing a perovskite solar cell according to claim 10 or 11, characterized in that, The method for preparing the perovskite layer includes the following steps: A lead halide framework layer was prepared on the hole extraction layer; A cationic solution is coated onto the lead halide framework layer, followed by annealing to obtain the perovskite layer.
18. The method of claim 10 or 11, wherein the perovskite solar cell is prepared by the steps of: The method for preparing the perovskite solar cell further includes: preparing a hole transport layer between the substrate and the hole extraction layer.
19. A photovoltaic module, characterized in that, This includes perovskite solar cells as described in any one of claims 1-9 or perovskite solar cells prepared by any one of claims 10-18.