Hole transport material solution, perovskite solar cell and preparation method

Abstract

The invention relates to the technical field of solar cells, and mainly provides a hole transport material solution, a perovskite solar cell and a preparation method. The hole transport material solution comprises a self-assembly molecular material, polyethylene glycol and an organic solvent. According to the technical scheme, the hole transport material solution can form a hole transport layer with good wettability, and a large-area and uniform-texture perovskite light absorption layer can be formed on the hole transport layer.

Description

Technical Field

[0001] The present application belongs to the technical field of solar cells, and in particular relates to a hole transport material solution, a perovskite solar cell and a preparation method thereof. Background Art

[0002] At present, the development of efficient, stable and low-cost charge transport materials, especially hole transport materials (HTMs), will help promote the commercialization of perovskite solar cells (PSCs). Anchor-based self-assembled molecular materials have been shown to be able to construct efficient hole transport layers for high-performance pin-structured PSCs. Self-assembled molecular materials have anchoring groups that can spontaneously adsorb onto the surface of oxide substrates to form self-assembled monolayers, which have the advantages of minimal material consumption and low parasitic absorption. In addition, the chemical bath deposition method is a low-cost and scalable process route that has been successfully applied to small modules as well as large-area perovskite silicon tandem solar cells.

[0003] However, the current hole transport material solutions still have problems with insufficient stability and poor wettability; in addition, during the large-area preparation process, there is also the problem of poor uniformity, which easily leads to leakage.

[0004] It should be noted that the above content is not necessarily prior art, nor is it intended to limit the scope of patent protection of this application. Summary of the invention

[0005] The embodiments of the present application provide a hole transport material solution, a perovskite solar cell and a preparation method to solve or alleviate the technical problems mentioned above. The hole transport material solution in the technical solution of the present application can form a hole transport layer with good wettability, which helps to form a large-area and uniform perovskite light absorption layer on the hole transport layer.

[0006] In a first aspect, an embodiment of the present application provides a hole transport material solution, comprising: a self-assembled molecular material, polyethylene glycol, and an organic solvent.

[0007] Optionally, the self-assembling molecular material includes one or more of [2-(9H-carbazole-9-yl)ethyl]phosphonic acid, [4-(9H-carbazole-9-yl)butyl]phosphonic acid, [2-(3,6-dimethoxy-9H-carbazole-9-yl)ethyl]phosphonic acid, [4-(3,6-dimethoxy-9H-carbazole-9-yl)butyl]phosphonic acid, [4-(3,6-dimethyl-9H-carbazole-9-yl)butyl]phosphonic acid, [4-(7H-dibenzocarbazole-7-yl)butyl]phosphonic acid, [4-(3,6-diphenyl-9H-carbazole-9-yl)butyl]phosphonic acid, and 4-(2,7-dibromo-9,9-dimethylacridine-10(9H)-yl)butyl]phosphonic acid.

[0008] Optionally, the polyethylene glycol includes one or more of PEG-1500, PEG-2000, PEG-3000, PEG-4000, PEG-6000, PEG-8000, PEG-10000, and PEG-20000.

[0009] Optionally, the organic solvent includes one or both of ethanol and isopropanol.

[0010] Optionally, the self-assembling molecular material includes one or more of [2-(3,6-dimethoxy-9H-carbazole-9-yl)ethyl]phosphonic acid, [4-(3,6-dimethyl-9H-carbazole-9-yl)butyl]phosphonic acid, and 4-(2,7-dibromo-9,9-dimethylacridin-10(9H)-yl)butyl]phosphonic acid; The polyethylene glycol includes one or more of PEG-2000, PEG-3000, and PEG-4000; The organic solvent includes one or both of ethanol and propanol.

[0011] Optionally, the hole transport material solution comprises: 5-30 parts by mass of self-assembly molecular material, 0.5-2 parts by mass of polyethylene glycol and 7500-8500 parts by mass of organic solvent.

[0012] Optionally, the mass ratio of the self-assembling molecular material to the polyethylene glycol is 5-30.

[0013] Optionally, the concentration of the self-assembling molecular material is 0.1-2.5 mg / mL.

[0014] In a second aspect, an embodiment of the present application provides a perovskite solar cell, comprising: a substrate, a transparent conductive oxide layer, a hole transport layer, a perovskite light absorption layer, an electron transport layer, and an electrode stacked in sequence; Wherein, the hole transport layer is formed by a hole transport material solution, and the hole transport material solution includes a self-assembly molecular material, polyethylene glycol and an organic solvent.

[0015] Optionally, the hole transport layer has a thickness of 1-10 nm.

[0016] In a third aspect, an embodiment of the present application provides a method for preparing a perovskite solar cell, comprising: providing a substrate; forming a transparent conductive oxide layer on the substrate; placing a hole transport material solution on the transparent conductive oxide layer to form a hole transport layer; forming a perovskite light absorbing layer on the hole transport layer; forming an electron transport layer on the perovskite light absorbing layer; forming an electrode on the electron transport layer; Wherein, the hole transport material solution comprises self-assembly molecular material, polyethylene glycol and organic solvent.

[0017] The above technical solution adopted in the embodiment of the present application may have the following advantages: The hole transport material solution includes self-assembled molecular materials (SAM), polyethylene glycol (PEG) and organic solvents. PEG is an alcohol-soluble high molecular polymer that not only has good film-forming properties, but also can provide a network scaffold structure for small molecule SAM to form a PEG-SAM blend, so that SAM is evenly dispersed in the hole transport material solution, which helps SAM to spread evenly on the substrate to form a hole transport layer with uniform texture. Moreover, PEG has good surface activity, which makes the formed hole transport layer have good wettability, which helps to form a large area and uniform perovskite light absorption layer on the hole transport layer, which is beneficial to the preparation of large-area batteries. In addition, PEG has carbon-oxygen polar covalent bonds, and the oxygen atoms in PEG can interact with the lead atoms in the perovskite material to passivate the perovskite interface defects, thereby improving the performance and stability of the device. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] In the accompanying drawings, unless otherwise specified, the same reference numerals throughout the multiple drawings represent the same or similar parts or elements. These drawings are not necessarily drawn to scale. It should be understood that these drawings only depict some embodiments disclosed in the present application and should not be regarded as limiting the scope of the present application.

[0019] Figure 1 is a schematic structural diagram of a perovskite solar cell provided by an embodiment of the present application; Figure 2 It is a schematic diagram of the structure of a perovskite solar cell provided in another embodiment of the present application.

[0020] Description of reference numerals: 10. substrate; 20. transparent conductive oxide layer; 30. hole transport layer; 40. perovskite light absorption layer; 50. electron transport layer; 60. hole blocking layer; 70. electrode. DETAILED DESCRIPTION

[0021] Embodiments of the present application are described in detail below, and examples of the embodiments are shown in the accompanying drawings. In the accompanying drawings, for clarity, the sizes of layers, regions, elements and their relative sizes may be exaggerated. The same or similar reference numerals throughout represent the same or similar elements or elements with the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present application, and cannot be understood as limitations on the present application. It should be noted that the embodiments in the present application and the features in the embodiments can be combined with each other without conflict.

[0022] The embodiment of the present application provides a hole transport material solution, including: a self-assembly molecular material, polyethylene glycol and an organic solvent.

[0023] The hole transport material solution of the embodiment of the present application includes a self-assembled molecular material (SAM), polyethylene glycol (PEG) and an organic solvent. PEG is an alcohol-soluble high molecular polymer that not only has good film-forming properties, but also can provide a network scaffold structure for small molecule SAM to form a PEG-SAM blend, so that SAM is evenly dispersed in the hole transport material solution, which helps SAM to spread evenly on the substrate to form a hole transport layer with uniform texture. Moreover, PEG has good surface activity, so that the formed hole transport layer has good wettability, which helps to form a large-area and uniform perovskite light-absorbing layer on the hole transport layer, which is beneficial to the preparation of large-area batteries. In addition, PEG has carbon-oxygen polar covalent bonds, and the oxygen atoms in PEG can interact with the lead atoms in the perovskite material to passivate the perovskite interface defects, thereby improving the performance and stability of the device.

[0024] In some embodiments, the self-assembling molecular material includes [2-(9H-carbazole-9-yl)ethyl]phosphonic acid (2PACz), [4-(9H-carbazole-9-yl)butyl]phosphonic acid (4PACz), [2-(3,6-dimethoxy-9H-carbazole-9-yl)ethyl]phosphonic acid (MeO-2PACz), [4-(3,6-dimethoxy-9H-carbazole-9-yl)butyl]phosphonic acid (MeO-4PACz), [4 [4-(7H-dibenzocarbazole-7-yl)butyl]phosphonic acid (4PADCB), [4-(3,6-diphenyl-9H-carbazole-9-yl)butyl]phosphonic acid (Ph-4PACz), or one or more of 4-(2,7-dibromo-9,9-dimethylacridin-10(9H)-yl)butyl]phosphonic acid (DMAcPA).

[0025] These self-assembled molecular materials are phosphate anchor molecules with carbazole or acridinium as the core. The phosphate group can enhance the anchoring ability of the material on the substrate, and the carbazole or acridinium group enables the hole transport material to have better hole transport ability, thereby improving the interface hole transport efficiency.

[0026] In some embodiments, the polyethylene glycol includes one or more of PEG-1500, PEG-2000, PEG-3000, PEG-4000, PEG-6000, PEG-8000, PEG-10000, and PEG-20000.

[0027] These polyethylene glycols have appropriate molecular weights and good compatibility with self-assembled molecular materials, and can improve the stability of hole transport material solutions to form a uniform and dense hole transport layer.

[0028] In some embodiments, the organic solvent includes one or both of ethanol and isopropanol. Ethanol and isopropanol have good solubility for self-assembled molecular materials (SAM) and polyethylene glycol (PEG), which not only help to form a uniform and stable hole transport material solution, but also can effectively adjust the viscosity of the hole transport material solution, thereby improving the formation and performance of the hole transport layer.

[0029] In some embodiments, the self-assembling molecular material includes one or more of [2-(3,6-dimethoxy-9H-carbazole-9-yl)ethyl]phosphonic acid, [4-(3,6-dimethyl-9H-carbazole-9-yl)butyl]phosphonic acid, 4-(2,7-dibromo-9,9-dimethylacridin-10(9H)-yl)butyl]phosphonic acid; Polyethylene glycol includes one or more of PEG-2000, PEG-3000, and PEG-4000; The organic solvent includes one or both of ethanol and propanol.

[0030] In order to further improve the performance of the hole transport layer, it is necessary to reasonably control the amount of various components in the hole transport material solution. In some embodiments, the hole transport material solution includes: 5-30 parts by mass of self-assembled molecular materials, 0.5-2 parts by mass of polyethylene glycol and 7500-8500 parts by mass of organic solvent. Within this dosage range, it can be ensured that the self-assembled molecular materials and polyethylene glycol are completely dissolved in the organic solvent, and the compatibility of various components is good, thereby improving the anchoring adsorption effect of the self-assembled molecular materials and the wettability of the hole transport layer. Specifically, the amount of self-assembled molecular materials can be 5 parts by mass, 10 parts by mass, 15 parts by mass, 20 parts by mass, 25 parts by mass or 30 parts by mass, the amount of polyethylene glycol can be 0.5 parts by mass, 1 part by mass, 1.5 parts by mass or 2 parts by mass, and the amount of organic solvent can be 7500 parts by mass, 7700 parts by mass, 7900 parts by mass, 8000 parts by mass, 8200 parts by mass or 8500 parts by mass.

[0031] In some embodiments, the mass ratio C1 of the self-assembling molecular material to the polyethylene glycol is 5-30.

[0032] By rationally controlling the mass ratio of the self-assembling molecular material to the polyethylene glycol, the viscosity of the hole transport layer solution can be regulated, thereby improving the spreadability, wettability, uniform density and other properties of the hole transport layer. Specifically, the mass ratio C1 of the self-assembling molecular material to the polyethylene glycol can be 5, 10, 15, 20, 25 or 30.

[0033] In some embodiments, in the hole transport material solution, the concentration C2 of the self-assembling molecular material is 0.1-2.5 mg / mL.

[0034] The concentration of the self-assembled molecular material in the hole transport material solution affects the viscosity of the solution and the film-forming quality of the hole transport layer. When the concentration of the self-assembled molecular material is 0.1-2.5 mg / mL, it effectively prevents the clustering of the self-assembled molecular material, makes the distribution of the self-assembled molecular material more uniform, and the solution viscosity is moderate, the self-assembly behavior can be accurately controlled, so that a hole transport layer with good wettability and uniform density can be obtained, and the electrical performance and stability of the battery can be improved. Specifically, in the hole transport material solution, the concentration C2 of the self-assembled molecular material is 0.1 mg / mL, 0.5 mg / mL, 1 mg / mL, 1.5 mg / mL, 2 mg / mL or 2.5 mg / mL.

[0035] In an optional embodiment, the self-assembling molecular material and polyethylene glycol are dispersed in an organic solvent according to a desired formula, and ultrasonicated to obtain a hole transport material solution, wherein the ultrasonication time may be 10-30 min (eg, 10 min, 20 min or 30 min).

[0036] like Figure 1 and Figure 2 As shown, the embodiment of the present application provides a perovskite solar cell, comprising: a substrate 10, a transparent conductive oxide layer 20, a hole transport layer 30, a perovskite light absorbing layer 40, an electron transport layer 50, and an electrode 70 which are stacked in sequence; The hole transport layer 30 is formed of a hole transport material solution, and the hole transport material solution includes a self-assembly molecular material, polyethylene glycol and an organic solvent.

[0037] The perovskite solar cell in the embodiment of the present application may be a single-junction perovskite solar cell or a tandem perovskite solar cell; wherein the tandem perovskite solar cell may be one of a two-terminal tandem cell, a three-terminal tandem cell and a four-terminal tandem cell.

[0038] The structure of each layer of the perovskite solar cell and its coordination with other layers will be further introduced as an example below.

[0039] In some embodiments, the substrate may be a transparent glass or plastic substrate. The thickness of the substrate may be 2.5-3.5 mm. The substrate may be cleaned, laser etched, and ultraviolet treated to remove organic impurities on its surface and optimize its surface wettability. The step of cleaning the substrate may include: placing the substrate in an ultrasonic cleaning instrument, and ultrasonically cleaning it with deionized water, acetone, and isopropanol in sequence, with the cleaning time of each step being 20-40 minutes. The step of ultraviolet treating the substrate may include: treating the substrate with a UV-zone, wherein the treatment time is 20-40 minutes.

[0040] In an optional embodiment, the transparent conductive oxide material includes, but is not limited to, one or more of indium tin oxide (ITO), indium zinc oxide (IZO), tungsten-doped indium oxide (IWO), fluorine-doped tin oxide (FTO), cerium-doped indium oxide (ICO), aluminum-doped zinc oxide (AZO), and boron-doped zinc oxide (BZO). In an optional embodiment, the transparent conductive oxide layer can be prepared by vacuum evaporation, magnetron sputtering, atomic layer deposition, chemical vapor deposition, ion beam deposition, pulsed laser deposition, spin coating, scraping, 3D printing, printing, spraying, etc.; the thickness of the transparent conductive oxide layer can be 80-150nm.

[0041] In some embodiments, the thickness of the hole transport layer is 1-10 nm. When the thickness of the hole transport layer is 1-10 nm, it can ensure the effective transmission of holes, while reducing the series resistance of the device and improving the transmission efficiency of holes. Specifically, the thickness of the hole transport layer can be 1 nm, 3 nm, 5 nm, 8 nm or 10 nm.

[0042] In an optional embodiment, the hole transport material includes but is not limited to [2-(9H-carbazole-9-yl)ethyl]phosphonic acid (2PACz), [4-(9H-carbazole-9-yl)butyl]phosphonic acid (4PACz), [2-(3,6-dimethoxy-9H-carbazole-9-yl)ethyl]phosphonic acid (MeO-2PACz), [4-(3,6-dimethoxy-9H-carbazole-9-yl)butyl]phosphonic acid (MeO-4PACz), [4-(3,6-dimethyl-9H-carbazole-9-yl)butyl]phosphonic acid (Me-4PACz), [4-(7H-dibenzocarbazole-7-yl)butyl]phosphonic acid (4PADCB), [4-(3,6-diphenyl-9H-carbazole-9-yl)butyl]phosphonic acid (Ph-4PACz), 4-(2,7-dibromo-9,9-dimethylacridin-10(9H)-yl)butyl]phosphonic acid (DMAcPA) or more. In an optional embodiment, the hole transport layer can be prepared by spin coating, slit coating, vacuum evaporation, magnetron sputtering, atomic layer deposition, and the like.

[0043] The perovskite light-absorbing layer is formed by a perovskite material. The perovskite material has a three-dimensional structure, and its general structural formula can be ABX3; wherein A is a monovalent cation, including but not limited to a cesium ion (Cs + ), rubidium ions (Rb + ), methylamine cation (CH3NH3 + ), carboxamidino cation (CH2(NH2)2 + ) is a mixture of one or more of: B is a divalent cation, including but not limited to lead ions (Pb 2+ ), copper ions (Cu 2+ )、Zn ion(Zn 2+ ), gallium ions (Ga 2+ ), tin ions (Sn 2+ ), calcium ions (Ca 2+ ) or a mixture of one or more thereof; X is a monovalent anion, including but not limited to iodide ion (I - ), bromide ion (Br - ), chloride ion (Cl - ), fluoride ion (F - ), thiocyanate ion (SCN - ) or a mixture of one or more of the above. In an optional embodiment, the perovskite light absorbing layer may be prepared by spin coating, blade coating, evaporation, printing, spray coating, spray pyrolysis, slit coating, or the like. The thickness of the perovskite light absorbing layer may be 10 nm-100 μm, or 300-1000 nm.

[0044] In an optional embodiment, the material of the electron transport layer includes but is not limited to TiO2, SnO2, ZnO, ZrO2, gallium zinc oxide (GZO), indium zinc oxide (IZO), fluorine-doped tin oxide (FTO), indium tin oxide (ITO), BaSnO3, TiSnO x SnZnO x , fullerene, fullerene derivatives, 2,9-dimethyl-4,7-diphenyl-1,10-phenanthroline (BCP) or more. Exemplarily, fullerene can be selected from C 60 , C 70 One or two of the above, the fullerene derivative can be PCBM (such as [6,6]-phenyl-C61-butyric acid methyl ester, [6,6]-phenyl-C71-butyric acid methyl ester). The electron transport layer can be prepared by spin coating, vacuum evaporation, sputtering, chemical deposition, atomic deposition and other methods. The thickness of the electron transport layer can be 20-50nm.

[0045] In an optional embodiment, the electrode includes a metal electrode, a transparent conductive electrode or a carbon electrode; the material of the metal electrode includes but is not limited to one of Au, Ag, Al, and Cu, and the transparent conductive electrode includes one of indium tin oxide, indium zinc oxide, tungsten-doped indium oxide, and aluminum-doped zinc oxide. The electrode can be prepared by thermal evaporation, vacuum evaporation, sputtering, atomic layer deposition, 3D printing, screen printing, inkjet printing, etc. The thickness of the electrode can be 50-150nm.

[0046] like Figure 2 As shown, in an optional implementation, the perovskite solar cell further includes a hole blocking layer 60 located between the electron transport layer 50 and the electrode 70 .

[0047] In an optional implementation, the material of the hole blocking layer includes, but is not limited to, one or more of 2,9-dimethyl-4,7-biphenyl-1,10-phenanthroline (BCP), 1,3,5-tri(1-phenyl-1H-benzimidazol-2-yl)benzene (TPBi), and zirconium acetylacetonate. The hole blocking layer can be prepared by slit coating, spin coating, vacuum evaporation, sputtering, atomic layer deposition, and the like. The thickness of the hole blocking layer can be 5-20 nm.

[0048] The present application provides a method for preparing a perovskite solar cell, comprising: S100: providing a substrate; S200: forming a transparent conductive oxide layer on the substrate; S300: placing a hole transport material solution on the transparent conductive oxide layer to form a hole transport layer; S400: forming a perovskite light absorbing layer on the hole transport layer; S500: forming an electron transport layer on the perovskite light absorbing layer; S600: forming an electrode on the electron transport layer; The hole transport material solution includes self-assembled molecular materials, polyethylene glycol and an organic solvent.

[0049] In an optional embodiment, in step S300, the preparation method of the hole transport material solution includes: dispersing the self-assembling molecular material and polyethylene glycol in an organic solvent according to a formula, and performing ultrasound to obtain the hole transport material solution. The ultrasound time can be 10-30 minutes (for example, 10 minutes, 20 minutes or 30 minutes).

[0050] In an optional embodiment, the specific steps of step S400 are: mixing the perovskite material and the organic solution evenly to form a perovskite precursor solution; using a slit coating method to coat the perovskite precursor solution on the hole transport layer, and annealing to form a perovskite light absorbing layer.

[0051] Before forming the electrode in step S600, the method for preparing a perovskite solar cell further includes: S700: forming a hole blocking layer on the electron transport layer.

[0052] When a hole blocking layer is included in the perovskite solar cell, the electrode is formed on the hole blocking layer.

[0053] The following specific examples further illustrate the present application, but should not be construed as limiting the present application. Without departing from the spirit and substance of the present application, modifications or replacements made to the methods, steps or conditions of the present application are within the scope of the present application.

[0054] Example 1 like Figure 2 As shown, the specific structure of the perovskite solar cell of Example 1 is: A substrate 10, a transparent conductive oxide layer 20, a hole transport layer 30, a perovskite light absorbing layer 40, an electron transport layer 50, a hole blocking layer 60, and an electrode 70 are sequentially stacked.

[0055] The specific preparation process of the perovskite solar cell of Example 1 is as follows: Step S100a: providing a substrate, the substrate is transparent glass, and the thickness of the substrate is 3 mm; Step S200a: using magnetron sputtering to deposit ITO on the substrate to form a transparent conductive oxide layer with a thickness of 100 nm; Step S300a: using a spin coating method, placing a hole transport material solution on the transparent conductive oxide layer to form a hole transport layer with a thickness of 5 nm; wherein the formula of the hole transport material solution is shown in Table 1; Step S400a: using a spin coating method, placing a perovskite precursor solution on the hole transport layer to form a perovskite light absorption layer with a thickness of 500 nm; Step S500a: using a spin coating method, placing a PCBM (such as [6,6]-phenyl-C61-butyric acid methyl ester) solution on the perovskite light absorption layer to form an electron transport layer with a thickness of 30 nm; Step S700a: using a spin coating method, placing a 2,9-dimethyl-4,7-biphenyl-1,10-phenanthroline (BCP) solution on the electron transport layer to form a hole blocking layer with a thickness of 6 nm; Step S600a: using a vacuum evaporation method, depositing metallic silver on the hole blocking layer to form an electrode with a thickness of 100 nm.

[0056] Example 2-Example 8 The perovskite solar cells of Examples 2 to 8 were prepared by referring to the preparation method of Example 1, except that the formula of the hole transport material solution in step S300a was different. The formula of the hole transport material solution of Examples 2 to 8 is shown in Table 1.

[0057] In order to more clearly illustrate the technical effects of the embodiments of the present application, the present application also points out the structure and preparation method of the perovskite solar cell of Comparative Example 1.

[0058] Comparative Example 1 The perovskite solar cell of Comparative Example 1 was prepared by referring to the preparation method of Example 1, except that the formula of the hole transport material solution in step S300a of Comparative Example 1 was different. The formula of the hole transport material solution of Comparative Example 1 is shown in Table 1.

[0059] Table 1

[0060] Table 1 (continued)

[0061] The device performance of the perovskite solar cells of Examples 1-8 and Comparative Example 1 of the present application was tested below to obtain the short-circuit current density J of the corresponding battery devices. sc , open circuit voltage V oc , fill factor FF, photoelectric conversion efficiency PCE, and the test results are shown in Table 2.

[0062] Table 2 Performance test results of perovskite solar cells of Examples 1-8 and Comparative Example 1

[0063] It can be seen from the data in Table 2 that, compared with Comparative Example 1, the short-circuit current density of the perovskite solar cells of Examples 1-8 of the present application is slightly improved, and the filling factor and photoelectric conversion efficiency are significantly improved. This shows that the hole transport material solution in Examples 1-8 of the present application can form a hole transport layer with stable quality, dense and uniform, and good wettability, which helps to form a large area and uniform perovskite light absorption layer on the hole transport layer; and can achieve passivation of perovskite interface defects, improving the performance and stability of the device.

[0064] In summary, the hole transport material solution of the embodiment of the present application includes a self-assembled molecular material (SAM), polyethylene glycol (PEG) and an organic solvent. PEG is an alcohol-soluble high molecular polymer that not only has good film-forming properties, but also can provide a network scaffold structure for small molecule SAM to form a PEG-SAM blend, so that SAM is evenly dispersed in the hole transport material solution, which helps SAM to spread evenly on the substrate to form a hole transport layer with uniform texture. Moreover, PEG has good surface activity, so that the formed hole transport layer has good wettability, which helps to form a large area and uniform perovskite light absorption layer on the hole transport layer, which is beneficial to the preparation of large-area batteries. In addition, PEG has carbon-oxygen polar covalent bonds, and the oxygen atoms in PEG can interact with the lead atoms in the perovskite material to passivate the perovskite interface defects, thereby improving the performance and stability of the device.

[0065] The embodiment of the present application provides a photovoltaic module (not shown), including the perovskite solar cell provided by any of the above embodiments. The photovoltaic module also has the advantages of the above perovskite solar cell, which will not be repeated here.

[0066] The embodiment of the present application can provide a photovoltaic system, including the photovoltaic components in any of the above embodiments. The advantages of the above photovoltaic components are also possessed by the photovoltaic system, which will not be repeated here. The above photovoltaic system has a wide range of applications, not only limited to photovoltaic power stations, such as ground power stations, rooftop power stations and water power stations, but also includes various equipment and devices that use solar energy to generate electricity, such as user solar power supplies, solar street lights, solar cars and solar buildings. Of course, it can be understood that the application scenarios of the photovoltaic system are not limited to this, that is to say, the photovoltaic system can be used in all fields where solar energy is required for power generation. Taking the photovoltaic power generation system network as an example, the photovoltaic system may include a photovoltaic array, a junction box and an inverter. The photovoltaic array may be an array combination of multiple photovoltaic components. For example, multiple photovoltaic components may form multiple photovoltaic arrays. The photovoltaic array is connected to a junction box. The junction box can converge the current generated by the photovoltaic array. The converged current flows through the inverter and is converted into the alternating current required by the mains power grid, and then connected to the mains network to realize solar power supply.

[0067] It should be noted that the terms "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", etc. are only for the convenience of describing the present application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present application. The orientation words "inside" and "outside" refer to the inside and outside relative to the outline of each component itself. For example, if the device in the accompanying drawings is inverted, the device described as "above other devices or structures" or "above other devices or structures" will be positioned as "below other devices or structures" or "below other devices or structures". Therefore, the exemplary term "above..." can include both "above..." and "below..." orientations. The device can also be positioned in other different ways (rotated 90 degrees or in other orientations), and the spatial relative descriptions used here are interpreted accordingly.

[0068] It should be noted that the terms "first", "second", etc. in the specification and claims of the present application and the above-mentioned drawings are used to distinguish similar objects, and are not necessarily used to describe a specific order or sequence. It should be understood that the terms used in this way can be interchangeable where appropriate, so that the embodiments of the present application described herein can be implemented in an order other than those illustrated or described herein, for example. In addition, the terms "including" and "having" and any of their variations are intended to cover non-exclusive inclusions, for example, a process, method, system, product or device that includes a series of steps or units is not necessarily limited to those steps or units that are clearly listed, but may include other steps or units that are not clearly listed or inherent to these processes, methods, products or devices.

[0069] It should also be noted that "one embodiment", "another embodiment", "embodiment", etc. mentioned in this application refer to the specific features, structures or characteristics described in conjunction with the embodiment included in at least one embodiment generally described in this application. The same expression appearing in multiple places in the specification does not necessarily refer to the same embodiment. Further, when describing a specific feature, structure or characteristic in conjunction with any embodiment, it is claimed that the realization of such feature, structure or characteristic in conjunction with other embodiments also falls within the scope of this application.

[0070] In the above embodiments, the description of each embodiment has its own emphasis. For parts that are not described in detail in a certain embodiment, reference can be made to the relevant descriptions of other embodiments.

[0071] It should also be noted that the above are only preferred embodiments of the present application, and the patent protection scope of the present application is not limited thereto. Any equivalent structure or equivalent process transformation made using the contents of the present application specification and drawings, or directly or indirectly used in other related technical fields, are also included in the patent protection scope of the present application.

Claims

1. A hole transport material solution, characterized in that: include: Self-assembled molecular materials, polyethylene glycol and organic solvents.

2. The hole transport material solution according to claim 1, characterized in that: The self-assembling molecular material includes one or more of [2-(9H-carbazole-9-yl)ethyl]phosphonic acid, [4-(9H-carbazole-9-yl)butyl]phosphonic acid, [2-(3,6-dimethoxy-9H-carbazole-9-yl)ethyl]phosphonic acid, [4-(3,6-dimethoxy-9H-carbazole-9-yl)butyl]phosphonic acid, [4-(3,6-dimethyl-9H-carbazole-9-yl)butyl]phosphonic acid, [4-(7H-dibenzocarbazole-7-yl)butyl]phosphonic acid, [4-(3,6-diphenyl-9H-carbazole-9-yl)butyl]phosphonic acid, and 4-(2,7-dibromo-9,9-dimethylacridine-10(9H)-yl)butyl]phosphonic acid.

3. The hole transport material solution according to claim 1, characterized in that: The polyethylene glycol includes one or more of PEG-1500, PEG-2000, PEG-3000, PEG-4000, PEG-6000, PEG-8000, PEG-10000, and PEG-20000.

4. The hole transport material solution according to claim 1, characterized in that: The organic solvent includes one or both of ethanol and isopropanol.

5. The hole transport material solution according to claim 1, characterized in that: The self-assembling molecular material includes one or more of [2-(3,6-dimethoxy-9H-carbazole-9-yl)ethyl]phosphonic acid, [4-(3,6-dimethyl-9H-carbazole-9-yl)butyl]phosphonic acid, and 4-(2,7-dibromo-9,9-dimethylacridin-10(9H)-yl)butyl]phosphonic acid; The polyethylene glycol includes one or more of PEG-2000, PEG-3000, and PEG-4000; The organic solvent includes one or both of ethanol and propanol.

6. The hole transport material solution according to claim 1, characterized in that: include: 5-30 parts by mass of self-assembling molecular materials, 0.5-2 parts by mass of polyethylene glycol and 7500-8500 parts by mass of organic solvents.

7. The hole transport material solution according to claim 1, characterized in that: The mass ratio of the self-assembling molecular material to the polyethylene glycol is 5-30.

8. The hole transport material solution according to claim 1, characterized in that: The concentration of the self-assembling molecular material is 0.1-2.5 mg / mL.

9. A perovskite solar cell, characterized in that: include: A substrate, a transparent conductive oxide layer, a hole transport layer, a perovskite light absorbing layer, an electron transport layer, and an electrode are sequentially stacked; Wherein, the hole transport layer is formed by a hole transport material solution, and the hole transport material solution includes a self-assembly molecular material, polyethylene glycol and an organic solvent.

10. The perovskite solar cell according to claim 9, characterized in that: The thickness of the hole transport layer is 1-10 nm.

11. A method for preparing a perovskite solar cell, characterized in that: include: providing a substrate; forming a transparent conductive oxide layer on the substrate; placing a hole transport material solution on the transparent conductive oxide layer to form a hole transport layer; forming a perovskite light absorbing layer on the hole transport layer; forming an electron transport layer on the perovskite light absorbing layer; forming an electrode on the electron transport layer; Wherein, the hole transport material solution comprises self-assembly molecular material, polyethylene glycol and organic solvent.

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