Perovskite solar cell and preparation method therefor, and photovoltaic module

Abstract

The application discloses a perovskite solar cell and a preparation method thereof and a photovoltaic module. The perovskite solar cell comprises a substrate, a dipole layer arranged on one side of the substrate, the dipole layer comprising valeric acid derivatives and hexafluoropropane derivatives, a perovskite layer arranged on a side of the dipole layer away from the substrate, and an electrode layer arranged on a side of the perovskite layer away from the dipole layer. Therefore, the charge collection rate of the insulating dipole layer can be improved, the efficiency of photo-generated charges transmitted from the perovskite layer to the electrode layer can be improved, and the photoelectric conversion efficiency of the perovskite solar cell can be improved.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of solar cells, in particular, the present application relates to a perovskite solar cell and a preparation method thereof, and a photovoltaic module. BACKGROUND

[0002] The rapid development of perovskite solar cells (PSC) marks a revolution in the third generation of photovoltaic research. High-efficiency organic-inorganic hybrid perovskite solar cells have become one of the most promising light-absorbing materials due to their excellent optoelectronic properties such as long carrier diffusion length and high absorption coefficient. With continuous technological innovation and device optimization, the certified power conversion efficiency (PCE) of perovskite has increased from 3.8% to 26.1%, so perovskite solar cells have become the most promising alternative to crystalline silicon solar cells.

[0003] In practical large-area applications, in order to output larger voltage, individual perovskite solar cells need to be connected in series. Like traditional solar cells, when PSCs are used in series in large-area modules and panels, special attention needs to be paid to the problem of reverse bias of sub-cells. This is mainly because in the actual environment, external factors such as trees, fallen leaves, and snow will block part of the module units, producing a shading effect. For PSCs in the module, the shaded sub-cells may be subjected to reverse bias provided by other well-illuminated sub-cells. This is because the photoelectric current generated by the well-illuminated sub-cells will flow into the shaded sub-cells as a reverse current, causing power consumption and thermal degradation of the shaded sub-cells. This not only deteriorates the power output of the entire panel, but also can cause local thermal breakdown, causing irreversible damage.

[0004] Therefore, the current perovskite solar cells still need to be further improved. SUMMARY

[0005] The present application aims to at least partially solve at least one of the technical problems existing in the prior art.

[0006] In a first aspect of the present application, a perovskite solar cell is provided. According to embodiments of the present application, the perovskite solar cell comprises: a substrate; a dipole layer disposed on one side of the substrate, the dipole layer comprising a valeric acid derivative and a hexafluoropropane derivative; a perovskite layer disposed on a side of the dipole layer away from the substrate; and an electrode layer disposed on a side of the perovskite layer away from the dipole layer. Therefore, the charge collection rate of the insulating dipole layer can be improved, the efficiency of the photo-generated charge transferred from the perovskite layer to the electrode layer can be improved, and the photoelectric conversion efficiency of the perovskite solar cell can be improved.

[0007] According to an embodiment of the present application, the perovskite solar cell can further include at least one of the following additional technical features:

[0008] According to an embodiment of the present application, the mass ratio of the valeric acid derivative to the hexafluoropropane derivative in the dipole layer is (5-10):(2-5). Thereby, by making the mass ratio of the valeric acid derivative to the hexafluoropropane derivative within the above range, the charge collection and transport efficiency of the dipole layer can be improved, and the photoelectric conversion efficiency of the cell can be improved.

[0009] According to an embodiment of the present application, based on the total mass of the dipole layer, the mass percentage of the valeric acid derivative is 0.5%-1.5%, and the mass percentage of the hexafluoropropane derivative is 0.1%-1%. Thereby, by making the mass percentage of the valeric acid derivative and the mass percentage of the hexafluoropropane derivative within the above range, the charge collection and transport efficiency of the dipole layer can be improved, and the photoelectric conversion efficiency of the cell can be improved.

[0010] According to an embodiment of the present application, the thickness of the dipole layer is 4nm-6nm. Thereby, the content of the valeric acid derivative and the hexafluoropropane derivative can be improved, the charge collection rate of the dipole layer can be further improved, and the photoelectric conversion efficiency of the perovskite solar cell can be improved.

[0011] According to an embodiment of the present application, the valeric acid derivative includes at least one of 3-aminovaleric acid, 5-aminovaleric acid, 5-(dimethylamino)valeric acid, 5-amino-5-oxovaleric acid, 5-aminovaleric acid hydrochloride, 5-(dimethylamino)valeric acid hydrochloride, 5-aminovaleric acid hydrogen iodide, 5-aminovaleric acid ethyl ester hydrochloride, 5-amino-5-oxovaleric acid, 5-benzoylvaleric acid, 5-(benzoylamino) n-valeric acid, or 4-cyano-4-(phenylthiocarbamothioyl) valeric acid. Thereby, the above-mentioned kinds of valeric acid derivatives can promote the formation of the dipole layer, ensure the quasi-ohmic contact at the interface between the dipole layer and the perovskite layer, promote the perovskite solar cell to change from the Schottky / PN cascade heterojunction type to a single PN heterojunction device, reduce the loss of electrons in the transport process, and improve the transport efficiency of the electrons.

[0012] According to embodiments of the present application, the hexafluoropropane derivative includes at least one of 2,2-bis(4-aminophenyl)hexafluoropropane, 2,2-bis(4-carboxyphenyl)hexafluoropropane, 2,2-bis(3,4-dimethylphenyl)hexafluoropropane, 2,2-bis(3-nitrophenyl)hexafluoropropane, 2,2-bis(4-methylphenyl)hexafluoropropane, 2,2-bis(4-isocyanatophenyl)hexafluoropropane, 2,2-bis(3-amino-4-hydroxyphenyl)hexafluoropropane, or 2,2-bis[4-(4-aminophenoxyphenyl)]hexafluoropropane. Thus, the hexafluoropropane derivative of the above kind has high symmetry, which can promote the formation of the perovskite layer and the close connection between the perovskite layer and the dipole layer, avoid the hydrolysis of the perovskite, improve the stability of the perovskite layer, and promote the charge collection efficiency of the dipole layer.

[0013] According to embodiments of the present application, the perovskite solar cell further includes a hole transport layer disposed on a side of the perovskite layer away from the dipole layer, the valeric acid derivative includes at least one of 3-aminopentanoic acid, 5-aminopentanoic acid, 5-(dimethylamino)pentanoic acid, 5-amino-5-oxopentanoic acid, 5-aminopentanoic acid hydrochloride, 5-(dimethylamino)pentanoic acid hydrochloride, 5-aminopentanoic acid hydrogen iodide, or 5-aminopentanoic acid ethyl ester hydrochloride, and the hexafluoropropane derivative includes at least one of 2,2-bis(4-aminophenyl)hexafluoropropane, 2,2-bis(4-carboxyphenyl)hexafluoropropane, 2,2-bis(3,4-dimethylphenyl)hexafluoropropane, 2,2-bis(3-nitrophenyl)hexafluoropropane, 2,2-bis(4-methylphenyl)hexafluoropropane, 2,2-bis(4-isocyanatophenyl)hexafluoropropane, 2,2-bis(3-amino-4-hydroxyphenyl)hexafluoropropane, or 2,2-bis[4-(4-aminophenoxyphenyl)]hexafluoropropane. Thus, the formation of the dipole layer in the perovskite solar cell without holes (trans structure) can be promoted, the charge collection and transport efficiency of the dipole layer can be promoted, and the photoelectric conversion efficiency of the perovskite solar cell without holes (trans structure) can be improved.

[0014] According to embodiments of the present application, the perovskite solar cell further comprises an electron transport layer disposed on a side of the perovskite layer away from the dipole layer, the valeric acid derivative comprises at least one of 5-amino-5-oxopentanoic acid, 5-benzoylvaleric acid, 5-(benzoylamino) n-valeric acid, or 4-cyano-4-(phenylthiocarbamoylthio) valeric acid, and the hexafluoropropane derivative comprises at least one of 2,2-bis(4-aminophenyl) hexafluoropropane, 2,2-bis(4-carboxyphenyl) hexafluoropropane, 2,2-bis(3,4-dimethylphenyl) hexafluoropropane, 2,2-bis(3-nitrophenyl) hexafluoropropane, 2,2-bis(4-methylphenyl) hexafluoropropane, 2,2-bis(4-isocyanatophenyl) hexafluoropropane, 2,2-bis(3-amino-4-hydroxyphenyl) hexafluoropropane, or 2,2-bis[4-(4-aminophenoxyphenyl)] hexafluoropropane. In this way, the formation of the dipole layer in the electron-free (formal structure) perovskite solar cell can be facilitated, the charge collection and transport efficiency of the dipole layer can be facilitated, and the photoelectric conversion efficiency of the electron-free (formal structure) perovskite solar cell can be improved.

[0015] According to embodiments of the present application, the perovskite layer comprises ABX3, A comprises at least one of FA + , MA + , Cs + , or DMA + , B comprises at least one of Pb 2+ or Sn 2+ , and X comprises at least one of I - , Br - , Cl - , SCN - . In this way, the perovskite layer can be formed, a wide range of solar wavelengths can be absorbed, and light energy can be efficiently converted into electrical energy.

[0016] In a second aspect of the present application, a method for preparing the perovskite solar cell of the first aspect is provided. According to embodiments of the present application, the method comprises: forming a dipole layer on one side of a substrate, the dipole layer comprising a valeric acid derivative and a hexafluoropropane derivative; forming a perovskite layer on a side of the dipole layer away from the substrate; and forming an electrode layer on a side of the perovskite layer away from the dipole layer. In this way, the charge collection rate of the insulating dipole layer can be improved, the efficiency of the photo-generated charge transported from the perovskite layer to the electrode layer can be improved, and the photoelectric conversion efficiency of the perovskite solar cell can be improved.

[0017] According to embodiments of the present application, the method can further comprise at least one of the following additional technical features:

[0018] According to an embodiment of the present application, the method of forming the dipole layer comprises: mixing the valeric acid derivative, the hexafluoropropane derivative and a solvent into a slurry formed on one side of the substrate, and annealing to form the dipole layer. In this way, by adding the hexafluoropropane derivative in the process of forming the dipole layer, the charge collection rate of the dipole layer can be improved, and the photoelectric conversion efficiency of the perovskite solar cell can be improved.

[0019] According to an embodiment of the present application, the mass percentage of the valeric acid derivative is 0.5%-1% based on the total mass of the slurry. In this way, by setting the mass percentage of the valeric acid derivative in the above range, the insulation of the dipole layer can be improved.

[0020] According to an embodiment of the present application, the mass percentage of the hexafluoropropane derivative is 0.2%-0.5% based on the total mass of the slurry. In this way, by setting the mass percentage of the hexafluoropropane derivative in the above range, the content of the hexafluoropropane derivative in the dipole layer can be improved, and the charge collection rate of the dipole layer can be improved.

[0021] According to an embodiment of the present application, the solvent comprises at least one of isopropyl alcohol, methanol, ethanol, and dimethyl sulfoxide (DMSO). In this way, the above-mentioned kinds of solvents are helpful for the dissolution of the valeric acid derivative and the hexafluoropropane derivative.

[0022] According to an embodiment of the present application, the annealing is performed at a temperature of 80-120°C. In this way, the perovskite crystallization is facilitated in the above temperature range, and the quality of the perovskite thin film is improved.

[0023] According to an embodiment of the present application, the annealing is performed for a time of 5-15 min. In this way, the phase transition of the perovskite, i.e. from β phase to α phase, is facilitated in the above time range.

[0024] In a third aspect of the present application, a photovoltaic module is provided. According to an embodiment of the present application, the photovoltaic module comprises the perovskite solar cell of the first aspect. The photovoltaic module has all the features and advantages of the aforementioned perovskite solar cell, which will not be repeated here. In general, at least a higher photoelectric conversion efficiency is achieved.

[0025] Additional aspects and advantages of the present application will be in part apparent and in part pointed out hereinafter. BRIEF DESCRIPTION OF DRAWINGS

[0026] The above and / or additional aspects and advantages of the present application will become apparent and be readily appreciated from the following description, including the appended drawings.

[0027] Figure 1is a structural schematic of a perovskite solar cell according to an embodiment of the present application Figure 1 ;

[0028] Figure 2 is a structural schematic of a perovskite solar cell according to an embodiment of the present application Figure 2 ;

[0029] Figure 3 is a structural schematic of a perovskite solar cell according to an embodiment of the present application Figure 3 ;

[0030] Figure 4 is a structural schematic of a perovskite solar cell according to an embodiment of the present application Figure 4 ;

[0031] Figure 5 is a flow chart of preparing a perovskite solar cell according to an embodiment of the present application.

[0032] BRIEF DESCRIPTION OF DRAWINGS

[0033] 1: perovskite solar cell; 11: substrate; 12: dipole layer; 13: perovskite layer; 14: electrode layer; 15: hole transport layer; 16: electron transport layer; 17: buffer layer. DETAILED DESCRIPTION

[0034] Reference herein to "an embodiment" means that a particular feature, structure, or characteristic described in connection with the embodiment can be included in at least one embodiment of the application. The appearances of the phrase "in an embodiment" in various places in the specification are not necessarily all referring to the same embodiment, nor are they necessarily mutually exclusive of one another. It is expressly understood that any of the embodiments described herein can be incorporated into any other embodiment.

[0035] For the sake of brevity, only some of the numerous technical features of the application are specifically disclosed herein. However, it will be apparent to those skilled in the art from this disclosure that numerous other embodiments can be devised which, although not explicitly described herein, embody the principles of the application and are included within its spirit and scope. Moreover, nothing disclosed herein is intended to be dedicated to the public regardless of whether these embodiments are explicitly described herein.

[0036] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs; the terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the application; the use of the terms "including," "comprising," "having" and variations thereof herein is meant to encompass the items listed thereafter and equivalents thereof as well as additional items.

[0037] In the present document, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "upper", "lower", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", "circumferential" and the like indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings, and 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 particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as a limitation of the present application.

[0038] In the present document, the term "comprising" or "including" is an open-ended expression, i.e. including the content indicated in the present application, but not excluding other aspects.

[0039] It should be noted that the terms "first", "second" are only for the purpose of description, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of the technical features indicated. Therefore, the features defined with "first", "second" can include one or more of the features explicitly or implicitly. Further, in the description of the present application, unless otherwise specified, the meaning of "a plurality of" is two or more.

[0040] Unless otherwise specified, all embodiments and optional embodiments of the present application can be combined with each other to form new technical solutions.

[0041] Perovskite solar cells are solar cells that use an organic metal halide semiconductor of perovskite type as light-absorbing material, and belong to the third generation of solar cells, also known as new concept solar cells. Solar cells are a device that directly converts light energy into electrical energy through photoelectric effect or photochemical reaction. The working principle is that when sunlight shines on the p-n junction area of the semiconductor, a hole-electron pair (exciton) is formed, which is first separated into an electron and a hole under the action of the p-n junction electric field, and then transported to the cathode and anode, respectively. The photo-generated hole flows to the p region, and the photo-generated electron flows to the n region, which forms a circuit when connected, thereby forming a current. When a single solar cell is multiplied into a photovoltaic module, the problem of reverse bias resistance may be encountered when the cell is applied in the field.

[0042] Reverse bias refers to the phenomenon in a solar cell where the photogenerated voltage is lower than the cell's operating voltage. In a solar cell, when light shines on the cell surface, photons excite electrons to transition from the valence band to the conduction band, forming electron-hole pairs. These electrons and holes separate under the influence of an electric field, creating a current in the external circuit. Under normal operating conditions, the solar cell's operating voltage should be greater than the photogenerated voltage to generate effective electrical energy. However, if the solar cell is affected by shading, uneven illumination, or excessively high temperatures, the photogenerated voltage may exceed the cell's operating voltage, leading to reverse bias. Reverse bias degrades the performance of the solar cell and, in severe cases, may damage it.

[0043] This application proposes a perovskite solar cell including a dipole layer. The insulating dipole layer is used to ensure quasi-ohmic contact at the interface. At the same time, by adding a hexafluoropropane derivative to the dipole layer, the charge collection rate of the insulating dipole layer can be improved, and the efficiency of photogenerated charge transfer from the perovskite layer to the electrode layer can be improved, thereby reducing charge recombination and improving the photoelectric conversion efficiency of the perovskite solar cell.

[0044] Perovskite solar cells

[0045] This application discloses a perovskite solar cell. According to embodiments of this application, refer to... Figure 1 As shown, the perovskite solar cell 1 includes: a substrate 11; a dipole layer 12 disposed on one side of the substrate 11, the dipole layer 12 including a valeric acid derivative and a hexafluoropropane derivative; a perovskite layer 13 disposed on the side of the dipole layer 12 away from the substrate 11; and an electrode layer 14 disposed on the side of the perovskite layer 13 away from the dipole layer 12.

[0046] The perovskite solar cell proposed in this application uses valeric acid derivatives as the material for forming the dipole layer, which can improve the insulation and stability of the dipole layer. The material also includes hexafluoropropane derivatives, which can improve the charge collection rate of the insulating dipole layer and the efficiency of photogenerated charge transfer from the perovskite layer to the electrode layer, thereby reducing charge recombination and improving the photoelectric conversion efficiency of the perovskite solar cell. Simultaneously, the hexafluoropropane derivatives have a higher fluorine content, which increases the probability of fluorine reacting with organic ions in the perovskite layer, allowing the hexafluoropropane derivatives to adsorb onto the surface of the perovskite layer and promoting its growth. The hydrophobicity of the valeric acid and hexafluoropropane derivatives further reduces the probability of water corrosion of the perovskite layer, improving its stability.

[0047] In some embodiments of the present application, the mass ratio of the valeric acid derivative to the hexafluoropropane derivative in the dipole layer can be (5-10):(2-5). For example, it can be 5:2, 5:3, 5:4, 1:1, 3:1, 2:1, 3:2, 6:5, 7:2, 7:3, 7:4, 7:5, 4:1, 8:3, 8:5, 9:2, 9:4, 9:5, 5:1, 10:3, or the like, or a range consisting of any of the above values. In this way, by setting the mass ratio of the valeric acid derivative to the hexafluoropropane derivative within the above range, the charge collection and transport efficiency of the dipole layer can be improved while improving the insulation performance of the dipole layer, thereby improving the photoelectric conversion efficiency of the battery.

[0048] For example, the mass fraction of the valeric acid derivative can be 0.5%-1.5% based on the total mass of the dipole layer. For example, it can be 0.5%, 0.6%, 0.7%, 0.8%, 0.9%, 1%, 1.1%, 1.2%, 1.3%, 1.4%, 1.5%, or the like, or a range consisting of any of the above values. In this way, the charge collection and transport efficiency of the dipole layer can be improved, thereby improving the photoelectric conversion efficiency of the battery.

[0049] For example, the mass fraction of the hexafluoropropane derivative can be 0.1%-1% based on the total mass of the dipole layer. For example, it can be 0.1%, 0.2%, 0.3%, 0.4%, 0.5%, 0.6%, 0.7%, 0.8%, 0.9%, 1%, or the like, or a range consisting of any of the above values. In this way, the charge collection and transport efficiency of the dipole layer can be improved, thereby improving the photoelectric conversion efficiency of the battery.

[0050] In some embodiments of the present application, the thickness of the dipole layer can be 4-6 nm. For example, it can be 4 nm, 4.5 nm, 5 nm, 5.5 nm, or 6 nm, or the like, or a range consisting of any of the above values. In this way, the content of the valeric acid derivative and the hexafluoropropane derivative is increased, further improving the charge collection rate of the dipole layer, thereby improving the photoelectric conversion efficiency of the perovskite solar cell.

[0051] In some embodiments of the present application, the valeric acid derivative includes at least one of 3-aminovaleric acid, 5-aminovaleric acid, 5-(dimethylamino)valeric acid, 5-amino-5-oxovaleric acid, 5-aminovaleric acid hydrochloride, 5-(dimethylamino)valeric acid hydrochloride, 5-aminovaleric acid hydrogen iodide, 5-aminovaleric acid ethyl ester hydrochloride, 5-amino-5-oxovaleric acid, 5-benzoylvaleric acid, 5-(benzamido) n-valeric acid, or 4-cyano-4-(phenylthiocarbamoylthio) valeric acid. Thus, the valeric acid derivative of the above kind can promote the formation of the dipole layer, ensure the quasi-ohmic contact at the interface between the dipole layer and the perovskite layer, promote the perovskite solar cell to change from the Schottky / PN cascade heterojunction type to a single PN heterojunction device, reduce the loss of electrons in the transmission process, and improve the transmission efficiency of the electrons.

[0052] Specifically, when the valeric acid derivative contains a carbonyl group, the carbonyl group can react with Pb 2+ The metal chelation reaction occurs, thereby promoting the close connection between the perovskite layer and the dipole layer, providing an energy buffer layer for the transmission of photo-generated carriers, and being conducive to the transmission of charges and the collection of carriers.

[0053] In some embodiments of the present application, the hexafluoropropane derivative includes at least one of 2,2-bis(4-aminophenyl)hexafluoropropane, 2,2-bis(4-carboxyphenyl)hexafluoropropane, 2,2-bis(3,4-dimethylphenyl)hexafluoropropane, 2,2-bis(3-nitrophenyl)hexafluoropropane, 2,2-bis(4-methylphenyl)hexafluoropropane, 2,2-bis(4-isocyanic phenyl)hexafluoropropane, 2,2-bis(3-amino-4-hydroxyphenyl)hexafluoropropane, or 2,2-bis[4-(4-aminophenoxyphenyl)]hexafluoropropane. Thus, the hexafluoropropane derivative of the above kind has high symmetry and good solubility, which is conducive to the formation of a uniform dipole layer. Fluorine can react with organic ions in the perovskite layer on the one hand, so that the hexafluoropropane derivative is adsorbed on the lower surface of the perovskite layer, which can promote the formation of the perovskite layer and the close connection between the perovskite layer and the dipole layer, and promote the transmission of electrons; on the other hand, fluorine has hydrophobicity, which can avoid the hydrolysis of the perovskite layer after being adsorbed on the lower surface of the perovskite layer, thereby improving the stability of the perovskite layer; in addition, the hexafluoropropane derivative can offset a part of the insulation in the dipole layer, thereby improving the charge collection efficiency of the dipole layer.

[0054] In some embodiments of the present application, the substrate 11 can include, but is not limited to, transparent conductive glass or transparent conductive plastic prepared in various ways, for example, can include, but is not limited to, indium tin oxide (ITO) conductive glass, fluorine-doped tin oxide (FTO) conductive glass, ITO conductive plastic, FTO conductive plastic, and the like.

[0055] In some embodiments of the present application, the electrode layer 14 is a metal electrode. The metal electrode can be, for example, a silver electrode (Ag), a copper electrode (Cu), a gold electrode (Au), an aluminum electrode (Al), a molybdenum electrode (Mo), a chromium electrode (Cr), or the like.

[0056] In some embodiments of the present application, the preferred thickness of the electrode layer can be 60-100 nm. For example, it can be 60 nm, 65 nm, 70 nm, 75 nm, 80 nm, 85 nm, 90 nm, 95 nm, 100 nm, or the like, or it can be a range consisting of any of the above values.

[0057] In some embodiments of the present application, the perovskite solar cell further includes a hole transport layer 15, as shown in FIG. 1B. Figure 2 As shown in FIG. 1B, the hole transport layer 15 is disposed on the side of the perovskite layer 13 away from the dipole layer 12. At this time, the valeric acid derivative includes at least one of 3-aminopentanoic acid, 5-aminopentanoic acid, 5-(dimethylamino)pentanoic acid, 5-amino-5-oxopentanoic acid, 5-aminopentanoic acid hydrochloride, 5-(dimethylamino)pentanoic acid hydrochloride, 5-aminopentanoic acid hydrogen iodide, or 5-aminopentanoic acid ethyl ester hydrochloride; and the hexafluoropropane derivative includes at least one of 2,2-bis(4-aminophenyl)hexafluoropropane, 2,2-bis(4-carboxyphenyl)hexafluoropropane, 2,2-bis(3,4-dimethylphenyl)hexafluoropropane, 2,2-bis(3-nitrophenyl)hexafluoropropane, 2,2-bis(4-methylphenyl)hexafluoropropane, 2,2-bis(4-isocyanatophenyl)hexafluoropropane, 2,2-bis(3-amino-4-hydroxyphenyl)hexafluoropropane, or 2,2-bis[4-(4-aminophenoxyphenyl)]hexafluoropropane. Thereby, the formation of the dipole layer in the perovskite solar cell without holes (inverted structure) can be facilitated, the charge collection and transport efficiency of the dipole layer can be facilitated, and the photoelectric conversion efficiency of the perovskite solar cell without holes (inverted structure) can be improved.

[0058] In some embodiments of the present application, the material forming the hole transport layer can include at least one of 2,2',7,7'-tetrakis[N,N-bis(4-methoxyphenyl)amino]-9,9'-spirobifluorene (Spiro-OMeTAD), carbazole-based compounds, triphenylamine-based compounds, polytriazine (PTAA), nickel oxide (NiO x ), poly(3,4-ethylenedioxythiophene), poly(styrene sulfonate) (PEDOT:PSS).

[0059] In some embodiments of the present application, the thickness of the hole transport layer can be 50-80 nm. For example, it can be 50 nm, 55 nm, 60 nm, 65 nm, 70 nm, 75 nm, or 80 nm, or it can be a range consisting of any of the above values.

[0060] In some embodiments of this application, the perovskite solar cell further includes an electron transport layer 16, as referenced. Figure 3 As shown, the electron transport layer 16 is disposed on the side of the perovskite layer 13 away from the dipole layer 12. In this case, the valeric acid derivative includes at least one of 5-amino-5-oxovaleric acid, 5-benzoylvaleric acid, 5-(benzoylamino)-n-valeric acid, or 4-cyano-4-(phenylthiocarbamoylthio)valeric acid; the hexafluoropropane derivative includes at least one of 2,2-bis(4-aminophenyl)hexafluoropropane, 2,2-bis(4-carboxyphenyl)hexafluoropropane, 2,2-bis(3,4-xylyl)hexafluoropropane, 2,2-bis(3-nitrophenyl)hexafluoropropane, 2,2-bis(4-methylphenyl)hexafluoropropane, 2,2-bis(4-isocyanophenyl)hexafluoropropane, 2,2-bis(3-amino-4-hydroxyphenyl)hexafluoropropane, or 2,2-bis[4-(4-aminophenoxyphenyl)]hexafluoropropane. This can promote the formation of dipole layers in electron-free (formal structure) perovskite solar cells, improve the charge collection and transport efficiency of dipole layers, and enhance the photoelectric conversion efficiency of electron-free (formal structure) perovskite solar cells.

[0061] In some embodiments of this application, the material forming the electron transport layer may include [6,6]-phenyl-C 61 methyl butyrate (PC) 61 BM), [6,6]-phenyl-C 71 methyl butyrate (PC) 71 BM), Fullerene C 60 Fullerene C 70 At least one of tin dioxide and zinc oxide.

[0062] In some embodiments of this application, the thickness of the electron transport layer can be from 10 nm to 40 nm. For example, it can be 10 nm, 20 nm, 30 nm, or 40 nm, or any range of the above values.

[0063] In some embodiments of this application, the perovskite solar cell further includes a buffer layer 17, as referenced. Figure 4 As shown, the buffer layer 17 is disposed on the side of the electron transport layer 16 away from the perovskite layer 13. The buffer layer 17 can form an energy level gradient in the electron transport path, promoting electron transport; and inhibiting metal ion migration, thus protecting the perovskite absorber layer. The material forming the buffer layer includes at least one of copper bath (BCP) or tin dioxide (SnO2).

[0064] In some embodiments of the present application, the thickness of the buffer layer can be 1 nm to 10 nm. For example, it can be 1 nm, 3 nm, 5 nm, 7 nm, 9 nm or 10 nm, or a range consisting of any of the above values.

[0065] In some embodiments of the present application, the perovskite layer includes ABX3, A includes at least one of FA + , MA + , Cs + , or DMA + , B includes at least one of Pb 2+ or Sn 2+ , and X includes at least one of I - , Br - , Cl - , SCN - . Of course, it can be understood that the perovskite material of the present application is not limited to the above compounds, but can also be other perovskite materials considered appropriate by those skilled in the art.

[0066] In some embodiments of the present application, the thickness of the perovskite layer can be 500 nm to 700 nm. For example, it can be 500 nm, 550 nm, 600 nm, 650 nm or 700 nm, or a range consisting of any of the above values.

[0067] Method for preparing perovskite solar cell

[0068] The present application provides a method for preparing a perovskite solar cell. According to an embodiment of the present application, the method includes: forming a dipole layer on one side of a substrate, the dipole layer including a valeric acid derivative and a hexafluoropropane derivative; forming a perovskite layer on the side of the dipole layer away from the substrate; and forming an electrode layer on the side of the perovskite layer away from the dipole layer.

[0069] The method proposed in the present application uses a valeric acid derivative and a hexafluoropropane derivative to form a dipole layer in the process of preparing a perovskite solar cell. By adding a hexafluoropropane derivative to the dipole layer, the charge collection rate of the insulating dipole layer can be improved, the efficiency of the photo-generated charge transferred from the perovskite layer to the electrode layer can be improved, and thus the charge recombination can be reduced, and the photoelectric conversion efficiency of the perovskite solar cell can be improved.

[0070] The method for preparing a perovskite solar cell proposed in the present application will be described in detail below with reference to Figure 5 , which can include:

[0071] S10: Forming a dipole layer on one side of a substrate

[0072] In some embodiments of the present application, the method of forming the dipole layer comprises: mixing a valeric acid derivative and a hexafluoropropane derivative, a solvent into a slurry to form on one side of the substrate, annealing to form the dipole layer. In this way, by adding a hexafluoropropane derivative in the process of forming the dipole layer, the charge collection rate of the dipole layer can be improved, and the photoelectric conversion efficiency of the perovskite solar cell can be improved. At the same time, since the hexafluoropropane derivative has high symmetry, it has high solubility in the solvent, which can improve the uniformity of the distribution of the hexafluoropropane derivative in the dipole layer. Since the hexafluoropropane derivative has a large number of F atoms, when the perovskite layer is formed, F can react with the organic ions in the perovskite, which is conducive to the growth of the perovskite. The hydrophobicity of the hexafluoropropane derivative can also reduce the risk of corrosion of the perovskite layer by water and improve the stability of the perovskite layer.

[0073] In some embodiments of the present application, the mass fraction of the valeric acid derivative can be 0.5%-1% based on the total mass of the slurry. For example, it can be 0.5%, 0.6%, 0.7%, 0.8%, 0.9%, 1%, etc., or it can be a range composed of any of the above values. In this way, by making the mass fraction of the valeric acid derivative in the above range, the insulation of the dipole layer is improved.

[0074] In some embodiments of the present application, the mass fraction of the hexafluoropropane derivative can be 0.2%-0.5% based on the total mass of the slurry. For example, it can be 0.2%, 0.3%, 0.4%, 0.5%, etc., or it can be a range composed of any of the above values. In this way, by making the mass fraction of the hexafluoropropane derivative in the above range, the content of the hexafluoropropane derivative in the dipole layer is improved, and the charge collection rate of the dipole layer is improved.

[0075] In some embodiments of the present application, the solvent can include at least one of isopropyl alcohol, methanol, ethanol, DMSO. In this way, the solubility of the valeric acid derivative and the hexafluoropropane derivative is improved.

[0076] In some embodiments of the present application, the temperature of the annealing can be 80℃-120℃. For example, it can be 80℃, 85℃, 90℃, 95℃, 100℃, 105℃, 110℃, 115℃, 120℃, etc., or it can be a range composed of any of the above values. In this way, within the above temperature range, it is conducive to the crystallization of the perovskite, and the quality of the perovskite film is improved.

[0077] In some embodiments of the present application, the annealing time can be 5-15 minutes. For example, it can be 5 minutes, 6 minutes, 7 minutes, 8 minutes, 9 minutes, 10 minutes, 11 minutes, 12 minutes, 13 minutes, 14 minutes, 15 minutes, etc., or a range consisting of any of the above values. Thus, within the above time range, it is helpful for the perovskite to complete the phase transition, i.e., from the β phase to the α phase.

[0078] S20: Forming a perovskite layer on the side of the dipole layer away from the substrate

[0079] According to some embodiments of the present application, the method of forming the perovskite can include at least one of an evaporation method, a sputtering method, a chemical bath deposition method, a precursor liquid spin coating method, a precursor liquid doctor blade coating method, and a slot coating method.

[0080] S30: Forming an electrode layer on the side of the perovskite layer away from the dipole layer

[0081] According to some embodiments of the present application, the method of forming the electrode layer can include at least one of an evaporation method, a sputtering method, a chemical bath deposition method, a precursor liquid spin coating method, a precursor liquid doctor blade coating method, and a slot coating method.

[0082] In some embodiments of the present application, when the perovskite solar cell is a formal structure, the method can further include a step of forming a hole transport layer on the side of the perovskite layer away from the dipole layer.

[0083] In some embodiments of the present application, the method of forming the hole transport layer can include at least one of a chemical bath deposition method, a precursor liquid spin coating method, a precursor liquid doctor blade coating method, and a slot coating method.

[0084] In some embodiments of the present application, when the perovskite solar cell is a reverse structure, the method can further include a step of forming an electron transport layer on the side of the perovskite layer away from the dipole layer.

[0085] In some embodiments of the present application, the method of forming the electron transport layer can include at least one of an evaporation method, a sputtering method, a chemical bath deposition method, a precursor liquid spin coating method, a precursor liquid doctor blade coating method, and a slot coating method.

[0086] In some embodiments of the present application, when the perovskite solar cell is a reverse structure, the method can further include a step of forming a buffer layer on the side of the electron transport layer away from the perovskite layer.

[0087] In some embodiments of the present application, the method of forming the buffer layer can include at least one of an evaporation method, a sputtering method, a chemical bath deposition method, a precursor liquid spin coating method, a precursor liquid doctor blade coating method, and a slot coating method.

[0088] Photovoltaic module

[0089] A photovoltaic module is provided. According to embodiments of the present application, the photovoltaic module comprises the perovskite solar cell as previously described. The photovoltaic module has all the features and advantages of the perovskite solar cell as previously described, which will not be repeated here. In general, the photovoltaic module has at least higher photoelectric conversion efficiency.

[0090] For example, the photovoltaic module can comprise a plurality of perovskite solar cells connected in series and / or in parallel. The plurality of perovskite solar cells can be arranged at intervals or stacked together in a shingle form.

[0091] The scheme of the present application will be explained below in conjunction with the embodiments. Those skilled in the art will understand that the following embodiments are only used to illustrate the present application and should not be regarded as limiting the scope of the present application. If the specific technology or condition is not specified in the embodiments, it is carried out according to the technology or condition described in the literature in the art or according to the product instruction. If the reagent or instrument is not specified by the manufacturer, it is a conventional product that can be obtained by purchase.

[0092] Example 1

[0093] A hole-free (trans structure) perovskite solar cell is prepared, and the specific process is as follows:

[0094] Step 1: Put the ITO substrate into an ultrasonic cleaning instrument, and ultrasonically clean it with deionized water, alcohol, deionized water, and alcohol respectively, each for 15 min, and dry it with a N2 gun, and then perform UV-zone treatment for 20 min for standby;

[0095] Step 2: Dilute 5-amino-5-oxopentanoate and 2,2-bis(4-methylphenyl)hexafluoropropane in 1 mL of isopropanol solution, so that the mass fraction of 5-amino-5-oxopentanoate is 0.75%, and the mass fraction of 2,2-bis(4-methylphenyl)hexafluoropropane is 0.2%, and spin-coat it on the upper surface of the ITO after UV-zone treatment in step 1, with a spin-coating speed of 5000 rpm for 20 s, and anneal it at 100°C for 10 min, denoted as OAO layer, with a thickness of 6 nm;

[0096] Step 3: Dissolve 1.5 mol of FA 0.9 Cs 0.1 PbI3 in 1 ml of organic solvent with a volume ratio of dimethylformamide: dimethyl sulfoxide (DMF:DMSO) = 4:1, and stir thoroughly for 2 h to obtain a FA 0.9 Cs 0.1 PbI3 perovskite precursor solution;

[0097] Step 4: Take 100 μL of the FA prepared in step 3 0.9 Cs 0.1 The PbI3 perovskite precursor solution was dropped onto the surface of the OAO layer prepared in step 2, extracted using an antisolvent, and then annealed at 150°C for 20 min to obtain FA. 0.9 Cs 0.1 PbI3 perovskite thin film with a thickness of 600 nm;

[0098] Step 5: Take the FA obtained in Step 4 0.9 Cs 0.1 30 nm of C was thermally evaporated onto the surface of the PbI3 perovskite thin film. 60 As an electron transport layer;

[0099] Step 6: Perform copper bath (BCP) thermal evaporation on the electron transport layer from Step 5 again. The main function of BCP is to act as a hole blocking layer to prevent electron-hole recombination. The thickness is 6nm.

[0100] Step 7: The effective area of ​​the BCP barrier layer prepared in Step 6 is 0.071 cm². 2 A 100nm thick layer of silver was used as the metal anode to prepare a high-efficiency FA. 0.9 Cs 0.1 PbI3 perovskite solar cells.

[0101] Example 2

[0102] FA was prepared according to the method described in Example 1. 0.9 Cs 0.1 The PbI3 perovskite solar cell differs in step 2, specifically: 5-amino-5-oxovalerate and 2,2-bis(4-aminophenyl)hexafluoropropane are diluted in 1 mL of isopropanol solution, so that the mass percentage of 5-amino-5-oxovalerate is 0.75% and the mass percentage of 2,2-bis(4-aminophenyl)hexafluoropropane is 0.2%. This solution is then spin-coated onto the ITO surface treated with UV-zone in step 1 at a spin-coating speed of 5000 rpm for 20 s. After annealing at 100 °C for 10 min, an OAA layer with a thickness of 6 nm is formed.

[0103] Example 3

[0104] FA was prepared according to the method described in Example 1. 0.9 Cs 0.1A PbI3perovskite solar cell, except that in step 2, 5-aminovaleric acid and 2,2-bis(4-aminophenyl)hexafluoropropane were diluted in 1 mL of isopropanol solution, the mass fraction of 5-aminovaleric acid was 0.75%, and the mass fraction of 2,2-bis(4-aminophenyl)hexafluoropropane was 0.2%, and it was spin-coated on the upper surface of the ITO treated by UV-zone in step 1, the spin-coating speed was 5000 rpm for 20 s, and it was annealed at 100°C for 10 min, and it was recorded as the NAA layer, with a thickness of 6 nm.

[0105] Example 4

[0106] The FA was prepared according to the method described in Example 1 0.9 Cs 0.1 A PbI3perovskite solar cell, except that in step 2, 5-aminovaleric acid and 2,2-bis(4-aminophenyl)hexafluoropropane were diluted in 1 mL of isopropanol solution, the mass fraction of 5-aminovaleric acid was 0.75%, and the mass fraction of 2,2-bis(4-aminophenyl)hexafluoropropane was 0.2%, and it was spin-coated on the upper surface of the ITO treated by UV-zone in step 1, the spin-coating speed was 5000 rpm for 20 s, and it was annealed at 100°C for 10 min, and it was recorded as the NAA layer, with a thickness of 6 nm.

[0107] Example 5

[0108] The FA was prepared according to the method described in Example 1 0.9 Cs 0.1 A PbI3perovskite solar cell, except that in step 2, 5-aminovaleric acid and 2,2-bis(4-aminophenyl)hexafluoropropane were diluted in 1 mL of isopropanol solution, the mass fraction of 5-aminovaleric acid was 0.75%, and the mass fraction of 2,2-bis(4-aminophenyl)hexafluoropropane was 0.2%, and it was spin-coated on the upper surface of the ITO treated by UV-zone in step 1, the spin-coating speed was 5000 rpm for 20 s, and it was annealed at 100°C for 10 min, and it was recorded as the NAA layer, with a thickness of 6 nm.

[0109] Example 6

[0110] The FA was prepared according to the method described in Example 1 0.9 Cs 0.1A PbI3perovskite solar cell, except that in step 2, 5-aminopentanoic acid hydrochloride and 2,2-bis(4-carboxyphenyl)hexafluoropropane were diluted in 1 mL of isopropanol solution, the mass ratio of 5-aminopentanoic acid hydrochloride was 0.75%, and the mass ratio of 2,2-bis(4-carboxyphenyl)hexafluoropropane was 0.2%, and it was spin-coated on the upper surface of ITO treated by UV-zone in step 1, the spin-coating speed was 5000 rpm for 20 s, and 100°C annealing for 10 min, recorded as HAA layer, thickness was 6 nm.

[0111] Example 7

[0112] FA was prepared according to the method described in Example 1 0.9 Cs 0.1 A PbI3perovskite solar cell, except that in step 2, 5-aminopentanoic acid hydrochloride and 2,2-bis(4-carboxyphenyl)hexafluoropropane were diluted in 1 mL of isopropanol solution, the mass ratio of 5-aminopentanoic acid hydrochloride was 0.75%, and the mass ratio of 2,2-bis(4-carboxyphenyl)hexafluoropropane was 0.2%, and it was spin-coated on the upper surface of ITO treated by UV-zone in step 1, the spin-coating speed was 5000 rpm for 20 s, and 100°C annealing for 10 min, recorded as HAA layer, thickness was 6 nm.

[0113] Example 8

[0114] FA was prepared according to the method described in Example 1 0.9 Cs 0.1 A PbI3perovskite solar cell, except that in step 2, 5-aminopentanoic acid hydrochloride and 2,2-bis(4-carboxyphenyl)hexafluoropropane were diluted in 1 mL of isopropanol solution, the mass ratio of 5-aminopentanoic acid hydrochloride was 0.75%, and the mass ratio of 2,2-bis(4-carboxyphenyl)hexafluoropropane was 0.2%, and it was spin-coated on the upper surface of ITO treated by UV-zone in step 1, the spin-coating speed was 5000 rpm for 20 s, and 100°C annealing for 10 min, recorded as HAA layer, thickness was 6 nm.

[0115] Example 9

[0116] FA was prepared according to the method described in Example 1 0.9 Cs 0.1A PbI3perovskite solar cell, except that in step 2, 5-amino-5-oxopentanoate and 2,2-bis(4-carboxyphenyl)hexafluoropropane were diluted in 1 mL of isopropanol solution, the mass fraction of 5-amino-5-oxopentanoate was 0.5%, and the mass fraction of 2,2-bis(4-carboxyphenyl)hexafluoropropane was 0.2%, and it was spin-coated on the upper surface of the ITO treated by UV-zone in step 1, the spin-coating speed was 5000 rpm for 20 s, and 100°C annealing for 10 min, recorded as OAO-2 layer, thickness was 6 nm.

[0117] Example 10

[0118] FA was prepared according to the method described in Example 1 0.9 Cs 0.1 A PbI3perovskite solar cell, except that in step 2, 5-amino-5-oxopentanoate and 2,2-bis(4-carboxyphenyl)hexafluoropropane were diluted in 1 mL of isopropanol solution, the mass fraction of 5-amino-5-oxopentanoate was 1%, and the mass fraction of 2,2-bis(4-carboxyphenyl)hexafluoropropane was 0.2%, and it was spin-coated on the upper surface of the ITO treated by UV-zone in step 1, the spin-coating speed was 5000 rpm for 20 s, and 100°C annealing for 10 min, recorded as OAO-3 layer, thickness was 6 nm.

[0119] Example 11

[0120] FA was prepared according to the method described in Example 1 0.9 Cs 0.1 A PbI3perovskite solar cell, except that in step 2, 5-amino-5-oxopentanoate and 2,2-bis(4-carboxyphenyl)hexafluoropropane were diluted in 1 mL of isopropanol solution, the mass fraction of 5-amino-5-oxopentanoate was 0.75%, and the mass fraction of 2,2-bis(4-carboxyphenyl)hexafluoropropane was 0.3%, and it was spin-coated on the upper surface of the ITO treated by UV-zone in step 1, the spin-coating speed was 5000 rpm for 20 s, and 100°C annealing for 10 min, recorded as OAO-6 layer, thickness was 6 nm.

[0121] Example 12

[0122] FA was prepared according to the method described in Example 1 0.9 Cs 0.1PbI3 perovskite solar cell, except for step 2, specifically: 5-amino-5-oxopentanoate and 2,2-bis(4-carboxyphenyl)hexafluoropropane were diluted in 1 mL of isopropanol solution, the mass fraction of 5-amino-5-oxopentanoate was 0.75%, and the mass fraction of 2,2-bis(4-carboxyphenyl)hexafluoropropane was 0.5%, and it was spin-coated on the upper surface of ITO after UV-zone treatment in step 1, the spin-coating speed was 5000 rpm for 20 s, and it was annealed at 100°C for 10 min, and it was recorded as OAO-7 layer, the thickness was 6 nm.

[0123] Example 13

[0124] Prepare FA according to the method described in Example 1 0.9 Cs 0.1 PbI3 perovskite solar cell, except for step 2, specifically: 5-amino-5-oxopentanoate and 2,2-bis(4-carboxyphenyl)hexafluoropropane were diluted in 1 mL of isopropanol solution, the mass fraction of 5-amino-5-oxopentanoate was 0.5%, and the mass fraction of 2,2-bis(4-carboxyphenyl)hexafluoropropane was 0.5%, and it was spin-coated on the upper surface of ITO after UV-zone treatment in step 1, the spin-coating speed was 5000 rpm for 20 s, and it was annealed at 100°C for 10 min, and it was recorded as OAO-9 layer, the thickness was 6 nm.

[0125] Example 14

[0126] Prepare FA according to the method described in Example 1 0.9 Cs 0.1 PbI3 perovskite solar cell, except for step 2, specifically: 5-amino-5-oxopentanoate and 2,2-bis(4-carboxyphenyl)hexafluoropropane were diluted in 1 mL of isopropanol solution, the mass fraction of 5-amino-5-oxopentanoate was 1%, and the mass fraction of 2,2-bis(4-carboxyphenyl)hexafluoropropane was 0.5%, and it was spin-coated on the upper surface of ITO after UV-zone treatment in step 1, the spin-coating speed was 5000 rpm for 20 s, and it was annealed at 100°C for 10 min, and it was recorded as OAO-9 layer.

[0127] Example 15

[0128] Take the optimal scheme in the hole-free (trans structure) perovskite solar cell as an example, prepare the electron-free (formal structure) perovskite solar cell, the specific process is as follows:

[0129] Step 1: Put the ITO substrate in the ultrasonic cleaning instrument, ultrasonically clean with deionized water, alcohol, deionized water, alcohol respectively, each link time is 15 min, and blow dry with N2 gun, then perform UV-zone treatment for 20 min for standby;

[0130] Step 2: 5-amino-5-oxopentanoate and 2,2-bis(4-carboxyphenyl)hexafluoropropane were diluted in 1 mL isopropanol solution, the mass ratio of 5-amino-5-oxopentanoate was 1%, and the mass ratio of 2,2-bis(4-carboxyphenyl)hexafluoropropane was 0.5%, and it was spin-coated on the upper surface of ITO treated by UV-zone in step 1, the spin-coating speed was 5000 rpm for 20 s, and 100°C annealing was performed for 10 min, and the OAO(free-ETL) layer was recorded, with a thickness of 6 nm;

[0131] Step 3: 1.5 mol of FA 0.9 Cs 0.1 PbI3 was dissolved in 1 ml of organic solvent with a volume ratio of DMF:DMSO=4:1, and stirred for 2 h to obtain FA 0.9 Cs 0.1 PbI3 perovskite precursor solution;

[0132] Step 4: Take 100 μL of FA 0.9 Cs 0.1 PbI3 precursor solution prepared in step 3 was added dropwise to the upper surface of the OAO(free-ETL) layer prepared in step 2, and after extraction with an anti-solvent, 150°C annealing was performed for 20 min to obtain FA 0.9 Cs 0.1 PbI3 perovskite film with a thickness of 600 nm;

[0133] Step 5: First, 1 mol of lithium salt and 1 mol of cobalt salt were dissolved in 1 mL of acetonitrile, second, 0.072 mg of spiro-OMeTAD powder was dissolved in 1 ml of chlorobenzene, and finally 28 μL of TBP(4-tert-butylpyridine), 17 μL of lithium salt solution and 30 μL of cobalt salt solution were added to the spiro-OMeTAD pre-prepared solution to obtain a spiro-OMeTAD solution;

[0134] Step 6: The spiro-OMeTAD solution in step 5 was spin-coated onto the FA0.9Cs0.1PbI3 perovskite film prepared in step 5 at a spin-coating speed of 4000 rpm for 30 s to obtain a spiro-OMeTAD hole transport layer with a thickness of 50 nm without heating;

[0135] Step 7: The spiro-OMeTAD hole transport layer obtained in step 6 was placed in an oxygen tank for sufficient oxidation, and the oxidation time was 24 h;

[0136] Step 8: The effective area of the spiro hole transport layer oxidized in step 7 was 0.071 cm 2, thickness of 100 nm of silver, as the metal electrode, to prepare high-efficiency FA 0.9 Cs 0.1 PbI3 perovskite solar cell.

[0137] Comparative Example 1

[0138] A hole-free (inverted structure) perovskite solar cell without a dipole layer is prepared as follows:

[0139] Step 1: Place the ITO substrate in an ultrasonic cleaning instrument, and ultrasonically clean with deionized water, alcohol, deionized water, and alcohol, respectively, for 15 min each time, and dry with a N2 gun, and then perform UV-zone treatment for 20 min for standby;

[0140] Step 2: Dissolve 1.5 mol of FA 0.9 Cs 0.1 PbI3 in 1 ml of organic solvent with a volume ratio of DMF:DMSO = 4:1, and fully stir for 2 h to obtain a FA 0.9 Cs 0.1 PbI3 perovskite precursor solution;

[0141] Step 3: Take 100 μL of the FA 0.9 Cs 0.1 PbI3 precursor solution prepared in step 2, and drop it onto the upper surface of the ITO after UV-zone treatment in step 1, and perform extraction with an anti-solvent, and then anneal at 150°C for 20 min to obtain a FA 0.9 Cs 0.1 PbI3 perovskite thin film with a thickness of 600 nm;

[0142] Step 4: Hot evaporate 30 nm of C 0.9 Cs 0.1 onto the upper surface of the FA 60 PbI3 perovskite thin film obtained in step 3, to serve as an electron transport layer;

[0143] Step 5: Perform BCP hot evaporation again on the electron transport layer in step 4, and the BCP mainly serves as a hole blocking layer to prevent electron-hole recombination, with a thickness of 6 nm;

[0144] Step 6: Evaporate silver with an effective area of 0.071 cm 2 , thickness of 100 nm of silver, as the metal electrode, to prepare high-efficiency FA 0.9 Cs 0.1 PbI3 perovskite solar cell.

[0145] Comparative Example 2

[0146] FA was prepared according to the method described in Example 1 0.9 Cs 0.1 PbI3perovskite solar cell, except that only 5-amino-5-oxopentanoate was used to prepare the dipole layer, and the specific process is as follows:

[0147] Step 2: 5-amino-5-oxopentanoate was diluted in 1 mL of isopropanol solution, and the mass fraction of 5-amino-5-oxopentanoate was 0.75%, and it was spin-coated on the upper surface of ITO treated by UV-zone in step 1, the spin-coating speed was 5000 rpm for 20 s, and 100°C annealing for 10 min was used, and the layer was recorded as OA layer, the thickness was 6 nm.

[0148] The specific types and proportions of pentanoic acid derivatives and hexafluoropropane derivatives used in Examples 1-15 and Comparative Examples 1-2 are shown in Table 1.

[0149] Table 1

[0150]

[0151]

[0152] Performance test

[0153] 1. Calculation method of Voc (open circuit voltage)

[0154] In open circuit state. Unit: V, the size of Voc is generally determined by the physical properties and energy difference of different materials, and the energy level barrier or non-radiative recombination caused by defects between interfaces is also an important factor.

[0155] 2. Calculation method of Jsc (short circuit current)

[0156] In short circuit state, the current flowing per unit area (unit: mA / cm 2 ), the factors affecting Jsc include film thickness, film quality of each layer, material band gap, and incident light irradiation, etc.

[0157] 3. Calculation method of FF (fill factor)

[0158] FF is the ratio of the maximum output power of perovskite solar cell to the product of open circuit voltage and short circuit current density, that is: FF = Vmax*Jmax / Voc*Jsc

[0159] 4. Calculation method of PCE (electric-optical conversion efficiency)

[0160] The size of PCE is equal to the ratio of the maximum output power Pmax of the battery to the standard solar incident power, which can be expressed by the formula: PCE = J sc *V oc *FF / Pin

[0161] The test results of the perovskite solar cells in Examples 1-20, Comparative Example 1 and Comparative Example 2 are shown in Table 2. Compared with Comparative Example 1 and Comparative Example 2, the hole transport layer-free cells or electron transport layer-free cells prepared by using the combination of different kinds of valeric acid derivatives and different kinds of hexafluoropropane derivatives in Examples 1-7 and 15 can improve the photoelectric conversion efficiency of the cells; and in Examples 8-14, changing the mass ratio of the valeric acid derivatives and the mass ratio of the hexafluoropropane derivatives within a certain range can also improve the photoelectric conversion efficiency of the cells.

[0162] Table 2

[0163] Voc / V Jsc / mA*cm -2 ]]> FF / % PCE / % Example 1 1.07 24.32 79.43 20.67 Example 2 1.08 24.11 80.17 20.88 Example 3 1.11 24.80 82.33 22.67 Example 4 1.07 24.06 80.03 20.61 Example 5 1.08 24.43 79.67 21.02 Example 6 1.08 24.39 79.22 20.87 Example 7 1.10 24.48 81.02 21.82 Example 8 1.06 24.11 79.58 20.33 Example 9 1.07 24.15 79.20 20.46 Example 10 1.07 24.19 80 20.71 Example 11 1.08 24.09 79.4 20.68 Example 12 1.08 24.12 79.65 20.75 Example 13 1.11 24.62 82.2 22.46 Example 14 1.13 24.81 82.28 23.07 Example 15 1.09 24.10 79.89 20.99 Comparative Example 1 1.05 23.81 78.82 19.72 Comparative Example 2 1.07 24.02 78.91 20.28

[0164] In the description of the present specification, the description referring to the terms "one embodiment", "some embodiments", "an example", "a specific example", or "some examples" etc. means that the specific features, structures, materials or characteristics described in connection with the embodiment or example are included in at least one embodiment or example of the present application. In the present specification, the illustrative description of the above terms does not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described can be combined in any appropriate manner in any one or more embodiments or examples. In addition, the different embodiments or examples described in the present specification and the features of the different embodiments or examples can be combined and combined by those skilled in the art without contradiction.

[0165] Although the embodiments of the present application have been shown and described above, it should be understood that the above embodiments are exemplary and should not be construed as limiting the present application, and those skilled in the art can make changes, modifications, replacements and variations to the above embodiments within the scope of the present application.

Claims

1. A perovskite solar cell, characterized in that, include: Substrate; A dipole layer disposed on one side of the substrate, the dipole layer comprising a valeric acid derivative and a hexafluoropropane derivative; A perovskite layer is disposed on the side of the dipole layer away from the substrate; An electrode layer is disposed on the side of the perovskite layer away from the dipole layer; The valeric acid derivatives include at least one of 3-aminovaleric acid, 5-aminovaleric acid, 5-(dimethylamino)valeric acid, 5-amino-5-oxovaleric acid, 5-aminovaleric acid salt, 5-(dimethylamino)valeric acid salt, 5-aminovaleric acid hydroiodide, 5-aminovaleric acid ethyl ester hydrochloride, 5-benzoylvaleric acid, 5-(benzoylamino)n-valeric acid, or 4-cyano-4-(phenylthiocarbamoylthio)valeric acid. The hexafluoropropane derivatives include at least one of 2,2-bis(4-aminophenyl)hexafluoropropane, 2,2-bis(4-carboxyphenyl)hexafluoropropane, 2,2-bis(3,4-xylyl)hexafluoropropane, 2,2-bis(3-nitrophenyl)hexafluoropropane, 2,2-bis(4-methylphenyl)hexafluoropropane, 2,2-bis(4-isocyanatephenyl)hexafluoropropane, 2,2-bis(3-amino-4-hydroxyphenyl)hexafluoropropane, or 2,2-bis[4-(4-aminophenoxyphenyl)]hexafluoropropane.

2. The perovskite solar cell according to claim 1, characterized in that, The mass ratio of the valeric acid derivative to the hexafluoropropane derivative in the dipole layer is (5-10):(2-5).

3. The perovskite solar cell according to claim 1, characterized in that, The thickness of the dipole layer is 4nm~6nm.

4. The perovskite solar cell according to claim 1, characterized in that, The perovskite solar cell further includes a hole transport layer disposed on the side of the perovskite layer away from the dipole layer.

5. The perovskite solar cell according to claim 1, characterized in that, The perovskite solar cell further includes an electron transport layer disposed on the side of the perovskite layer away from the dipole layer.

6. The perovskite solar cell according to claim 1, characterized in that, The perovskite layer comprises ABX3, where A comprises FA. + MA + Cs + or DMA + At least one of them, B includes Pb 2+ or Sn 2+ At least one of them, X includes I - ,Br - Cl - SCN - At least one of them.

7. A method for preparing a perovskite solar cell according to any one of claims 1 to 6, characterized in that, include: A dipole layer is formed on one side of the substrate, the dipole layer comprising a valeric acid derivative and a hexafluoropropane derivative; A perovskite layer is formed on the side of the dipole layer away from the substrate; An electrode layer is formed on the side of the perovskite layer away from the dipole layer.

8. The method according to claim 7, characterized in that, The method for forming the dipole layer includes: mixing the valeric acid derivative, the hexafluoropropane derivative and a solvent into a slurry and forming it on one side of the substrate, and annealing it to form the dipole layer.

9. The method according to claim 8, characterized in that, At least one of the following conditions must be met: Based on the total mass of the slurry, the valeric acid derivative accounts for 0.5%-1% of the total mass. Based on the total mass of the slurry, the hexafluoropropane derivative accounts for 0.2%-0.5% of the total mass. The solvent includes at least one of isopropanol, methanol, ethanol, and dimethyl sulfoxide.

10. The method according to claim 8, characterized in that, The annealing temperature is 80℃~120℃; And / or, the annealing time is 5 min to 15 min.

11. A photovoltaic module, characterized in that, Including the perovskite solar cell according to any one of claims 1 to 6.

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