Perovskite solar cell, preparation method, photovoltaic system, power generation device and power utilization device

Abstract

The invention provides a perovskite solar cell, a preparation method, a photovoltaic system, a power generation device and a power utilization device. The perovskite solar cell comprises a first electrode, a charge extraction layer, a first passivation layer, a perovskite layer and a second electrode which are stacked in sequence. The material of the charge extraction layer comprises nickel oxide, the material of the first passivation layer comprises a reducing agent, and the reduction potential of the reducing agent is smaller than that of Ni < 3 + >. In the perovskite solar cell, through introduction of the first passivation layer, nickel ions with the valence of + 3 or more in the charge extraction layer can be reduced, so that degradation of a perovskite material is reduced, the stability of the perovskite layer is improved, and the service life of the perovskite solar cell is further prolonged.

Description

Technical Field

[0001] The present application relates to the technical field of solar cells, and in particular to a perovskite solar cell, a method for preparing a perovskite solar cell, a photovoltaic system, a power generation device, and an electricity-consuming device. Background Art

[0002] The statements herein merely provide background information related to the present application and do not necessarily constitute prior art.

[0003] Perovskite solar cells can convert solar energy into electrical energy and are relatively environmentally friendly. Nickel oxide is one of the most commonly used materials for the charge extraction layer in perovskite solar cells. However, the nickel ions with a valence of +3 or higher contained in nickel oxide can cause deprotonation of the perovskite material when in contact with the perovskite layer, leading to degradation of the perovskite material. This reduces the stability of the perovskite layer and, in turn, affects the lifespan of the perovskite solar cell. Summary of the Invention

[0004] The present application provides a perovskite solar cell, comprising a first electrode, a charge extraction layer, a first passivation layer, a perovskite layer, and a second electrode stacked in sequence; the charge extraction layer comprises nickel oxide, the first passivation layer comprises a reducing agent, and the reduction potential of the reducing agent is less than Ni 3+ reduction potential.

[0005] In the above perovskite solar cell, the nickel ions with a valence of +3 or above in the surface layer of the charge extraction layer can be reduced by introducing the first passivation layer and the reducing agent, thereby reducing the Ni 3+ Reacting with the perovskite material causes degradation of the perovskite material, thereby improving the stability of the perovskite layer and thereby increasing the service life of the perovskite solar cell.

[0006] In some embodiments, the reduction potential of the reducing agent is less than 0 V. 3+ The reduction of Ni on the surface of the charge extraction layer can 3+ Reduction to Ni 2+ , thereby reducing the surface Ni 3+ React with the perovskite layer, thereby improving the stability of the perovskite layer and further increasing the lifespan of the perovskite solar cell.

[0007] In some embodiments, the reducing agent includes at least one of formate, hypophosphite, hydrazine-containing compounds, hydroiodic acid, hydrosulfuric acid, nitrous acid, phosphorous acid, oxalic acid, and lactic acid. The reducing groups in these reducing agents (such as formate, hypophosphite, hydrazine, etc.) can reduce the surface Ni 3+ Reduction to Ni 2+, further improving the life of the perovskite solar cell. Optionally, the cations of the formate and hypophosphite independently include one of an inorganic cation or an organic cation; and / or, the hydrazine-containing compound is a substituted or unsubstituted C1~C20 alkane or substituted or unsubstituted aromatic hydrocarbon containing a hydrazine group. Further optionally, the inorganic cation includes Na + , K + 、Cs + NH4 + The organic cation comprises methylamine or formamidinium ion. Further optionally, the reducing agent comprises at least one of potassium formate, sodium formate, cesium formate, potassium hypophosphite, sodium hypophosphite, cesium hypophosphite and hydrazine benzene.

[0008] In some embodiments, the thickness of the first passivation layer is less than or equal to 10 nm. A thickness within this range of the first passivation layer can effectively function as the first passivation layer and reduce the impact of the first passivation layer on the battery series resistance, thereby maintaining good performance of the perovskite solar cell. Optionally, the thickness of the first passivation layer is 2 nm to 8 nm.

[0009] In some embodiments, the perovskite solar cell further includes a second passivation layer; the second passivation layer is located between the first passivation layer and the perovskite layer, and the material of the second passivation layer includes an organic amine. Providing the second passivation layer between the first passivation layer and the perovskite layer can improve the photoelectric conversion efficiency of the perovskite solar cell. The organic amine in the second passivation layer can complex with uncoordinated divalent metal ions in the perovskite layer, reducing the deep-level defect concentration in the perovskite layer, thereby improving the photoelectric conversion efficiency of the perovskite solar cell.

[0010] In some embodiments, the organic amine includes at least one of benzylamine, halogenated benzylamine, phenethylamine, halogenated phenethylamine, naphthylethylamine, and oleylamine iodide.

[0011] In some embodiments, the halogenated benzylamine includes at least one of o-fluorobenzylamine, m-fluorobenzylamine, p-fluorobenzylamine, and benzylamine iodide.

[0012] In some embodiments, the halogenated phenethylamine includes at least one of o-fluorophenethylamine, m-fluorophenethylamine, p-fluorophenethylamine, and phenethylamine iodine.

[0013] In some embodiments, the thickness of the second passivation layer is less than or equal to 15 nm. A thickness within this range allows the second passivation layer to effectively function and reduces the impact of the second passivation layer on the cell series resistance, thereby maintaining good performance of the perovskite solar cell. Optionally, the thickness of the second passivation layer is 2 nm to 8 nm.

[0014] In some embodiments, the charge extraction layer includes a hole transport layer or an electron transport layer.

[0015] A method for preparing a perovskite solar cell comprises the following steps:

[0016] Preparing a charge extraction layer on the surface of the first electrode, wherein the material of the charge extraction layer includes nickel oxide;

[0017] A first passivation layer is prepared on the surface of the charge extraction layer away from the first electrode, wherein the material of the first passivation layer includes a reducing agent, and the reduction potential of the reducing agent is less than Ni 3+ The reduction potential of

[0018] A second electrode is prepared on a surface of the first passivation layer away from the charge extraction layer.

[0019] A photovoltaic system comprises the perovskite solar cell or the perovskite solar cell prepared by the preparation method.

[0020] A power generation device comprises the perovskite solar cell or the perovskite solar cell prepared by the preparation method.

[0021] An electrical device comprises the perovskite solar cell or the perovskite solar cell prepared by the preparation method. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] To more clearly illustrate the technical solution of this application, the following is a brief introduction to the drawings used in this application. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on the drawings without inventive effort.

[0023] Figure 1 Schematic diagram of the structure of a perovskite solar cell in one embodiment of the present application.

[0024] Figure 2 This is a schematic structural diagram of a perovskite solar cell in another embodiment of the present application.

[0025] Figure 3 This is a schematic structural diagram of a perovskite solar cell in another embodiment of the present application.

[0026] Figure 4 This is a schematic structural diagram of a perovskite solar cell in another embodiment of the present application.

[0027] Description of the marks in the figure:

[0028] 100. Perovskite solar cell; 101. Transparent electrode; 102. Hole transport layer; 103. Perovskite layer; 104. Electron transport layer; 105. Metal electrode;

[0029] 200, perovskite solar cell; 201, transparent electrode; 202, electron transport layer; 203, perovskite layer; 204, hole transport layer; 205, metal electrode;

[0030] 300, perovskite solar cell; 301, transparent electrode; 302, hole transport layer; 303, perovskite layer; 304, electron transport layer; 305, metal electrode; 306, first passivation layer;

[0031] 400, perovskite solar cell; 401, transparent electrode; 402, hole transport layer; 403, perovskite layer; 404, electron transport layer; 405, metal electrode; 406, first passivation layer; 407, second passivation layer.

[0032] In order to better describe and illustrate the embodiments and / or examples of the inventions disclosed herein, reference may be made to one or more of the accompanying drawings. The additional details or examples used to describe the accompanying drawings should not be considered to limit the scope of the disclosed inventions, the presently described embodiments and / or examples, and any of the best modes currently understood for these inventions. DETAILED DESCRIPTION

[0033] Below, some embodiments of the present application are described in detail with appropriate reference to the accompanying drawings. However, unnecessary detailed descriptions may be omitted. For example, detailed descriptions of well-known matters and repeated descriptions of substantially identical structures may be omitted. This is to avoid making the following description unnecessarily lengthy and to facilitate understanding by those skilled in the art. In addition, the accompanying drawings and the following description are provided to enable those skilled in the art to fully understand the present application and are not intended to limit the subject matter described in the claims.

[0034] The details of one or more embodiments of the present application are set forth in the accompanying drawings and the description below. Other features, objects, and advantages of the present application will become apparent from the description, drawings, and claims.

[0035] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as those commonly understood by those skilled in the art of the present invention. The terms used in this specification of the present invention are only for the purpose of describing specific embodiments and are not intended to limit the present invention.

[0036] The "range" disclosed in this application is defined in the form of a lower limit and an upper limit. A given range is defined by selecting a lower limit and an upper limit, and the selected lower limit and upper limit define the boundaries of a particular range. The range defined in this way can be inclusive or exclusive of the end values, and can be arbitrarily combined, i.e., any lower limit can be combined with any upper limit to form a range. For example, if a range of 60 to 120 and 80 to 110 is listed for a particular parameter, it is understood that a range of 60 to 110 and 80 to 120 is also expected. In addition, if the minimum range values ​​listed are 1 and 2, and if the maximum range values ​​listed are 3, 4, and 5, then the following ranges can all be expected: 1 to 3, 1 to 4, 1 to 5, 2 to 3, 2 to 4, and 2 to 5. In this application, unless otherwise specified, the numerical range "a to b" represents an abbreviation of any real number combination between a and b, wherein a and b are both real numbers. For example, a numerical range of "0-5" indicates that all real numbers between "0-5" are listed herein, and "0-5" is simply an abbreviation for these numerical combinations. Furthermore, stating that a parameter is an integer ≥ 2 is equivalent to disclosing that the parameter is, for example, an integer of 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, etc.

[0037] Unless otherwise specified, all embodiments and optional embodiments of the present application can be combined with each other to form a new technical solution.

[0038] Unless otherwise specified, all technical features and optional technical features of this application can be combined with each other to form a new technical solution.

[0039] Unless otherwise specified, all steps of the present application may be performed sequentially or randomly, and in some embodiments are performed sequentially. For example, the method includes steps (a) and (b), which means that the method may include steps (a) and (b) performed sequentially, or may include steps (b) and (a) performed sequentially. For example, the method may further include step (c), which means that step (c) may be added to the method in any order, for example, the method may include steps (a), (b) and (c), or may include steps (a), (c) and (b), or may include steps (c), (a) and (b), etc.

[0040] Unless otherwise specified, the terms "include" and "comprising" used in this application may be open-ended or closed-ended. For example, "include" and "comprising" may mean that other components not listed may also be included or that only the listed components are included.

[0041] Unless otherwise specified, the term "or" is used in this application to be inclusive. For example, the phrase "M or N" means "M, N, or both M and N." More specifically, the condition "M or N" is satisfied by any of the following conditions: M is true or present, and N is false or absent; M is false or absent, and M is true or present; or both M and N are true, or both M and N are present.

[0042] If not otherwise specified, in this application, the term "room temperature" generally refers to 4°C to 30°C, preferably 25±5°C.

[0043] Unless otherwise indicated, the terms used in this application have the commonly understood meanings generally understood by those skilled in the art. Unless otherwise indicated, the numerical values ​​of the various parameters mentioned in this application can be measured using various measurement methods commonly used in the art. For example, the tests can be performed using the methods described in the examples of this application.

[0044] In perovskite solar cells, nickel oxide is one of the most widely used charge extraction layer materials. When nickel ions with a valence of +3 or above contained in nickel oxide come into contact with the perovskite layer, it will cause a deprotonation reaction of the perovskite material and degrade the perovskite material, resulting in a decrease in the stability of the perovskite layer, thereby affecting the life of the perovskite solar cell.

[0045] Based on this, an embodiment of the present application provides a perovskite solar cell. The perovskite solar cell includes a first electrode, a charge extraction layer, a first passivation layer, a perovskite layer, and a second electrode stacked in sequence; the charge extraction layer includes nickel oxide, the first passivation layer includes a reducing agent, and the reduction potential of the reducing agent is less than Ni 3+ In perovskite solar cells, the introduction of the first passivation layer and the reducing agent can reduce the nickel ions with a valence of +3 or above in the surface layer of the charge extraction layer, thereby reducing Ni 3+ The first passivation layer reacts with the perovskite material to cause degradation of the perovskite material, thereby improving the stability of the perovskite layer and thereby increasing the service life of the perovskite solar cell. Optionally, the first passivation layer is in direct contact with the charge extraction layer.

[0046] It is understood that the passivation layer can eliminate the surface defects of the perovskite layer and improve the performance of the perovskite layer. In this application, a reducing agent is introduced into the first passivation layer to reduce the Ni 3+ To reduce Ni 3+ React with the perovskite layer, thereby improving the stability of perovskite solar cells.

[0047] The redox potential of this application indicates the ease with which a substance is oxidized. The redox potential test adopts the redox potential determination (potential determination method) in the industry standard SL94-1994 of the People's Republic of China. Specifically:

[0048] (1) Inspection and calibration of platinum electrodes

[0049] Use a platinum electrode as the indicator electrode and connect it to the instrument's positive terminal. Use a saturated calomel electrode as the reference electrode and connect it to the instrument's negative terminal. When both electrodes are immersed in a standard solution with a fixed potential, their potential should match the standard. For example, when immersed in a standard solution of ferrous ammonium sulfate and ferrous ammonium sulfate, the redox potential at 25°C is +430 mV. If the measured potential differs by more than ±10 mV from the standard value, the platinum electrode needs to be cleaned or replaced.

[0050] (2) Sample measurement

[0051] ① Take a clean 500ml brown wide-mouth bottle and seal it tightly with a rubber stopper. Drill five holes in the bottle for inserting a platinum electrode, a saturated calomel (or silver chloride) electrode, a thermometer, and two glass tubes. The two glass tubes are for water inlet and outlet, respectively. The reagent inlet for the reference electrode should be above the stopper to prevent water sample from entering the reference electrode and facilitate reagent addition. Insert the electrode to the center of the redox potential measurement device bottle, ensuring it does not touch the bottom of the bottle. Connect the electrode to the instrument.

[0052] ② Use the siphon method to continuously deliver the solution to be tested into the measuring wide-mouth bottle. While the water is flowing, perform the measurement according to the instrument instructions.

[0053] It is understandable that the material of the first passivation layer also includes the product of the oxidation of the reducing agent and Ni 2+ When the reducing agent reacts with nickel ions with a valence of +3 or above, the reducing agent is oxidized and the nickel ions with a valence of +3 or above can be reduced to Ni 2+ .

[0054] It is understandable that Ni 3+ The reduction potential of Ni is 1.36V. 4+ The reduction potential of Ni is 1.678V. 2+ The reduction potential of the reducing agent is -0.257 V. In some embodiments, the reduction potential of the reducing agent is less than 1.36 V. Further, the reduction potential of the reducing agent is less than 0 V. By setting the reduction potential less than Ni in the first passivation layer 3+ The reducing agent with a reduction potential of 3+ Reduction to Ni 2+ , thereby reducing the surface Ni 3+React with the perovskite layer, thereby improving the stability of the perovskite layer and further increasing the lifespan of the perovskite solar cell.

[0055] In some embodiments, the reducing agent includes at least one of formate, hypophosphite, hydrazine-containing compounds, hydroiodic acid, hydrosulfuric acid, nitrous acid, phosphorous acid, oxalic acid, and lactic acid. The reducing groups (such as formate, hypophosphite, hydrazine, etc.) in the above reducing agents can reduce the surface Ni 3+ Reduction to Ni 2+ , further improving the lifespan of perovskite solar cells.

[0056] In some embodiments, the cations of formate and hypophosphite independently include one of an inorganic cation or an organic cation, and further optionally, the inorganic cation includes Na + , K + 、Cs + NH4 + The organic cations include methylamine and formamidine ion. Optionally, the formate and hypophosphite are potassium formate and potassium hypophosphite respectively.

[0057] In some embodiments, the hydrazine group-containing compound is a substituted or unsubstituted C1-C20 alkane or a substituted or unsubstituted aromatic hydrocarbon containing a hydrazine group.

[0058] In some embodiments, the reducing agent includes at least one of potassium formate, sodium formate, cesium formate, potassium hypophosphite, sodium hypophosphite, cesium hypophosphite, and hydrazinylbenzene.

[0059] In some embodiments, the thickness of the first passivation layer is less than or equal to 10 nm. The thickness of the first passivation layer within this range can better play the role of the first passivation layer, while reducing the impact of the introduction of the first passivation layer on the battery series resistance, which is conducive to maintaining good performance of the perovskite solar cell. Optionally, the thickness of the first passivation layer can be 1 nm, 2 nm, 3 nm, 4 nm, 5 nm, 6 nm, 7 nm, 8 nm, 9 nm, 10 nm, and any value within the range consisting of any two of the above values. Optionally, the thickness of the first passivation layer is 2 nm to 8 nm.

[0060] It is understood that the first passivation layer can be prepared by spin coating, coating, spraying, dipping, etc. For example, the material of the first passivation layer is prepared into a spin coating solution, which is then spin-coated on the surface of the charge extraction layer and then annealed to obtain the first passivation layer.

[0061] In some embodiments, the perovskite solar cell further comprises a second passivation layer. The second passivation layer is located between the first passivation layer and the perovskite layer, and the material of the second passivation layer comprises an organic amine. By providing the second passivation layer between the first passivation layer and the perovskite layer, the photoelectric conversion efficiency of the perovskite solar cell can be improved. The organic amine in the second passivation layer can complex with the uncoordinated divalent metal ions in the perovskite layer, reduce the deep energy level defect concentration of the perovskite layer, and thereby improve the photoelectric conversion efficiency of the perovskite solar cell. For example, the organic amine in the second passivation layer can complex with the uncoordinated Pb in the perovskite layer. 2+ Complexation reduces the deep level defect concentration of the perovskite layer, thereby improving the photoelectric conversion efficiency of the perovskite solar cell. Optionally, the second passivation layer is in direct contact with the perovskite layer.

[0062] In some embodiments, the organic amine in the second passivation layer includes at least one of benzylamine, halogenated benzylamine, phenethylamine, halogenated benzylamine, naphthylethylamine and oleylamine iodine. Alternatively, the halogenated benzylamine includes at least one of o-fluorobenzylamine, m-fluorobenzylamine, p-fluorobenzylamine and benzylamine iodine. Alternatively, the halogenated benzylamine includes at least one of o-fluorobenzylamine, m-fluorobenzylamine, p-fluorobenzylamine and phenethylamine iodine.

[0063] In some embodiments, the thickness of the second passivation layer is less than or equal to 15 nm. The thickness of the second passivation layer within this range can better play the role of the second passivation layer, while reducing the impact of the introduction of the second passivation layer on the battery series resistance, which is conducive to maintaining good performance of the perovskite solar cell. Optionally, the thickness of the second passivation layer can be 1 nm, 2 nm, 3 nm, 4 nm, 5 nm, 6 nm, 7 nm, 8 nm, 9 nm, 10 nm, 11 nm, 12 nm, 13 nm, 14 nm, 15 nm, and any value within the range consisting of any two of the above values. Optionally, the thickness of the second passivation layer is 2 nm to 8 nm.

[0064] It is understood that the second passivation layer can be prepared by evaporation, spin coating, coating, spraying, atomic deposition, etc. For example, the material of the second passivation layer can be vacuum-deposited onto the surface of the first passivation layer to obtain the second passivation layer.

[0065] It is understandable that the types of reducing groups in the first passivation layer and the types of organic amines in the second passivation layer in the present application can be tested by infrared spectroscopy, elemental analysis, etc.

[0066] It is understood that the perovskite layer comprises a material having a chemical formula of ABX3, wherein A comprises a methylamine cation (MA + ), formamidinium cation (FA + )、Li + 、Na+ , K + , Rb + 、Cs + At least one of, B includes Pb 2+ 、Sn 2+ 、Zn 2+ 、Ti 2+ 、Sb 2+ 、Bi 2+ 、Ni 2+ 、Fe 2+ 、Co 2+ 、Cu 2+ 、Ga 2+ 、Ge 2+ Mg 2+ , Ca 2+ 、Mn 2+ Cr 2+ and Mo 2+ At least one of, X comprises at least one of a halogen anion and a carboxylate ion.

[0067] In some embodiments, the charge extraction layer comprises a hole transport layer or an electron transport layer. Alternatively, the charge extraction layer is a hole transport layer.

[0068] Optionally, the hole transport layer comprises nickel oxide. Optionally, the hole transport layer may also include, but is not limited to, one or more of the following materials and their derivatives: 2,2',7,7'-tetrakis[N,N-di(4-methoxyphenyl)amino]-9,9'-spirobifluorene (Spiro-OMeTAD), polytriarylamine (PTAA), poly(3,4-ethylenedioxythiophene:polystyrenesulfonate) (PEDOT:PSS), WO3, and other materials that can transport holes and block electrons.

[0069] Optionally, the material of the electron transport layer includes nickel oxide. Optionally, the material of the electron transport layer may also include, but is not limited to, one or more of the following materials and their derivatives: imide compounds, quinone compounds, fullerenes and their derivatives, methoxytriphenylamine-fluoroformamidine (OMeTPA-FA), calcium titanate (CaTiO3), lithium fluoride (LiF), calcium fluoride (CaF2), poly (3,4-ethylenedioxythiophene): polystyrene sulfonic acid (PEDOT:PSS), poly 3-hexylthiophene (P3HT), triphenylamine with triptycene as the core (H101), 3,4 -ethylenedioxythiophene-methoxytriphenylamine (EDOT-OMeTPA), N-(4-phenylamino)carbazole-spirobifluorene (CzPAF-SBF), polythiophene, metal oxides, silicon oxide (SiO2), strontium titanate (SrTiO3), cuprous thiocyanate (CuSCN), etc.; wherein the metal element may include one or more of Mg, Cd, Zn, In, Pb, Mo, W, Sb, Bi, Cu, Hg, Ti, Ag, Mn, Fe, V, Sn, Zr, Sr, Ga, and Cr. Further optionally, the material of the electron transport layer includes [6,6]-phenyl-C61-butyric acid methyl ester (PC61BM), [6,6]-phenyl-C71-butyric acid methyl ester (PC71BM), fullerenes and their derivatives, as well as tin dioxide (SnO2), zinc oxide (ZnO), etc.

[0070] In some embodiments, in a perovskite solar cell, the hole transport layer contains nickel oxide, and the electron transport layer does not contain nickel oxide.

[0071] It is also understood that the first electrode can be a transparent electrode, and the second electrode can be a metal electrode, a metal-nonmetal hybrid electrode, a transparent conductive oxide, or the like. By configuring transparent and metal electrodes, both formal and inverted perovskite solar cells can be obtained. Optionally, the transparent electrode material includes at least one of fluorine-doped tin oxide (FTO), indium tin oxide (ITO), aluminum-doped zinc oxide (AZO), boron-doped zinc oxide (BZO), indium zinc oxide (IZO), and indium tungsten oxide (IWO). Optionally, the transparent electrode has a thickness of 100 nm to 1000 nm, and further optionally, a thickness of 300 nm to 800 nm. Optionally, the metal electrode material includes at least one of Au, Ag, Cu, Al, Ni, Cr, Bi, Pt, Mg, Mo, W, and alloys thereof. In the metal-nonmetal hybrid electrode, the metal material includes at least one of Au, Ag, Cu, Al, Ni, Cr, Bi, Pt, Mg, Mo, W, and alloys thereof, and the non-metallic material includes C. Optionally, the thickness of the metal electrode or the metal-nonmetal mixed electrode is 20nm~200nm, optionally, the thickness of the metal electrode or the metal-nonmetal mixed electrode is 60nm~100nm, further optionally, the thickness of the metal electrode or the metal-nonmetal mixed electrode is 70nm~90nm.

[0072] It is understood that perovskite solar cells also include a substrate. A transparent electrode is formed on the substrate. Substrates include glass substrates and flexible substrates. Flexible substrate materials include, but are not limited to, organic polymer materials. Furthermore, the flexible substrate material can be a mixture of one or more of the following materials, including but not limited to, polyvinyl alcohol (PVA), polyester (PET), polyimide (PI), polyethylene naphthalate (PEN), polydimethylsiloxane (PDMS), and the like, in varying proportions.

[0073] It is understandable that other functional layers, such as a buffer layer, can be introduced into the perovskite solar cell as required.

[0074] In some embodiments, a perovskite solar cell may be provided with a buffer layer of suitable energy level, which may play one or more of the following roles: reducing energy level barriers, promoting energy level matching, improving carrier extraction efficiency, passivating interface defect states, protecting the light absorption layer, inhibiting the oxidation and decomposition of water molecules and oxygen in the cell, improving photoelectric conversion efficiency, and improving the stability of the perovskite solar cell. Depending on the location of the buffer layer, the types of buffer layers may include a buffer layer between the hole transport layer and the anode, a buffer layer between the electron transport layer and the cathode, a buffer layer between the hole transport layer and the perovskite layer, and a buffer layer between the electron transport layer and the perovskite layer. Materials that can be used for the buffer layer in perovskite solar cells may include, but are not limited to, Cu2O, NiO, AZO, TiO2, etc.

[0075] It is understood that perovskite solar cells include formal perovskite solar cells and inverted perovskite solar cells. For formal perovskite solar cells, the formal perovskite solar cell includes a transparent electrode, an electron transport layer, a perovskite layer, a hole transport layer, and a metal electrode stacked in sequence. For inverted perovskite solar cells, the inverted perovskite solar cell includes a transparent electrode layer, a hole transport layer, a perovskite layer, an electron transport layer, and a metal electrode layer stacked in sequence. Figure 1 , which shows an inverted perovskite solar cell 100. The perovskite solar cell 100 includes a transparent electrode 101, a hole transport layer 102, a perovskite layer 103, an electron transport layer 104 and a metal electrode 105 stacked in sequence. Figure 2 , which shows a formal perovskite solar cell 200. The perovskite solar cell 200 includes a transparent electrode 201, an electron transport layer 202, a perovskite layer 203, a hole transport layer 204 and a metal electrode 205 stacked in sequence.

[0076] See also Figure 3 , which shows a perovskite solar cell 300. The perovskite solar cell 300 includes a transparent electrode 301, a hole transport layer 302, a first passivation layer 306, a perovskite layer 303, an electron transport layer 304 and a metal electrode 305 stacked in sequence. The hole transport layer 302 is made of nickel oxide, and the first passivation layer 306 is made of a reducing agent, the reduction potential of which is less than Ni 3+ The introduction of the first passivation layer 306 can reduce nickel ions with a valence of +3 or higher in the hole transport layer 302, thereby reducing the redox reaction between the nickel ions with a valence of +3 or higher and the perovskite layer 303, reducing the degradation of the perovskite material, improving the stability of the perovskite layer, and thereby increasing the service life of the perovskite solar cell 300. In addition, in the perovskite solar cell 300, the reduced degradation of the perovskite material can also improve the photoelectric conversion efficiency of the perovskite solar cell 300. Optionally, the thickness of the first passivation layer 306 is less than or equal to 10 nm. Further optionally, the thickness of the first passivation layer 306 is 2 nm to 8 nm.

[0077] See also Figure 4, which shows a perovskite solar cell 400. The perovskite solar cell 400 includes a transparent electrode 401, a hole transport layer 402, a first passivation layer 406, a second passivation layer 407, a perovskite layer 403, an electron transport layer 404 and a metal electrode 405 stacked in sequence. The hole transport layer 402 is made of nickel oxide, and the first passivation layer 406 is made of a reducing agent, the reduction potential of which is less than Ni 3+ The material of the second passivation layer 407 includes organic amines. Through the introduction of the first passivation layer 406, the nickel ions with a valence of +3 or above in the hole transport layer 402 can be reduced, thereby reducing the redox reaction between the nickel ions with a valence of +3 or above and the perovskite layer 403, reducing the degradation of the perovskite material, improving the stability of the perovskite layer, and thus improving the service life of the perovskite solar cell 400. Furthermore, the organic amine in the second passivation layer 407 can complex with the uncoordinated divalent metal ions in the perovskite layer 403, reduce the deep energy level defect concentration of the perovskite layer 403, and thus improve the photoelectric conversion efficiency of the perovskite solar cell 400. For example, the organic amine in the second passivation layer 407 can complex with the uncoordinated Pb in the perovskite layer 403. 2+ Complexation reduces the deep level defect concentration of the perovskite layer 403, thereby improving the photoelectric conversion efficiency of the perovskite solar cell 400. Optionally, the thickness of the second passivation layer 407 is less than or equal to 10 nm. Further optionally, the thickness of the second passivation layer 407 is 2 nm to 8 nm.

[0078] In some embodiments, the perovskite solar cell includes a first electrode, a hole transport layer, a perovskite layer, an electron transport layer, and a second electrode stacked in sequence. A first passivation layer is disposed between the hole transport layer and the perovskite layer, and / or a first passivation layer is disposed between the electron transport layer and the perovskite layer, and / or a second passivation layer is disposed between the hole transport layer and the perovskite layer, and / or a second passivation layer is disposed between the electron transport layer and the perovskite layer, and / or a first passivation layer and a second passivation layer are disposed between the hole transport layer and the perovskite layer, and the hole transport layer, the first passivation layer, the second passivation layer, and the perovskite layer are stacked in sequence, and / or a first passivation layer and a second passivation layer are disposed between the electron transport layer and the perovskite layer, and the electron transport layer, the first passivation layer, the second passivation layer, and the perovskite layer are stacked in sequence.

[0079] In some embodiments, in a perovskite solar cell, the band gap of the perovskite layer is 1.2 eV to 2.3 eV, and / or the thickness of the perovskite layer is 400 nm to 1000 nm.

[0080] Another embodiment of the present application provides a method for preparing a perovskite solar cell. The method for preparing a perovskite solar cell comprises the following steps: preparing a charge extraction layer on the surface of a first electrode, wherein the material of the charge extraction layer comprises nickel oxide; preparing a first passivation layer on the surface of the charge extraction layer away from the first electrode, wherein the material of the first passivation layer comprises a reducing agent, wherein the reduction potential of the reducing agent is less than Ni 3+ The second electrode is formed on a surface of the first passivation layer away from the charge extraction layer. Alternatively, the charge extraction layer can be formed by magnetron sputtering. The first passivation layer can be formed by spin coating, coating, spraying, immersion, etc. The second passivation layer can be formed by evaporation, spin coating, coating, spraying, atomic deposition, etc.

[0081] Another embodiment of the present application provides an electrical device, which includes the above-mentioned perovskite solar cell or the perovskite solar cell prepared by the above-mentioned preparation method.

[0082] Another embodiment of the present application provides a photovoltaic system, which includes the above-mentioned perovskite solar cell or the perovskite solar cell prepared by the above-mentioned preparation method.

[0083] Another embodiment of the present application provides a power generation device. The power generation device includes the aforementioned perovskite solar cell or a perovskite solar cell prepared using the aforementioned preparation method. The power generation device may be of a type including, but not limited to, an integrated power generation device. The power generation device may be located on, but not limited to, the roof or backplane of a vehicle.

[0084] Furthermore, the above-mentioned electrical devices may include mobile devices, such as mobile phones, laptop computers, etc., electric vehicles, electric trains, ships and satellites, power generation systems, etc., but are not limited thereto.

[0085] In order to make the technical problems, technical solutions and beneficial effects solved by this application clearer, the application will be further described in detail below with reference to the embodiments and drawings. Obviously, the described embodiments are only a part of the embodiments of this application, rather than all the embodiments. The following description of at least one exemplary embodiment is actually only illustrative and is in no way intended to limit the present application and its applications. Based on the embodiments in this application, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of this application.

[0086] If no specific techniques or conditions are specified in the examples, the experiments were carried out according to the techniques or conditions described in the literature in the field or according to the product instructions. All reagents or instruments used without specifying the manufacturer are commercially available conventional products.

[0087] Example 1

[0088] The preparation method of the perovskite solar cell in this embodiment is as follows:

[0089] S101: Preparation of FTO conductive glass electrodes: FTO glass with a specification of 2.0 cm × 2.0 cm is removed by laser etching at both ends of 0.35 cm of FTO to expose the glass substrate; the etched FTO conductive glass is ultrasonically cleaned several times with water, acetone, and isopropyl alcohol in sequence, and then blown dry with nitrogen for later use.

[0090] S102: Preparation of hole transport layer: FTO is treated with UV ozone, and then nickel oxide with a thickness of about 20 nm is magnetron sputtered, and annealed at 300° C. for 60 minutes to obtain a hole transport layer.

[0091] S103: Preparation of a first passivation layer: Prepare a 5 mg / mL hydrazine benzene ethanol solution, then spin-coat 100 μL of the solution on the hole transport layer at 4000 rpm. Anneal the solution at 100°C for 10 minutes to obtain a first passivation layer. The thickness of the first passivation layer is 5 nm.

[0092] S104: Preparation of the Perovskite Layer: A one-step process was used to prepare the perovskite layer. A perovskite precursor solution was spin-coated on the surface of the first passivation layer at 5000 rpm for 40 seconds. 300 μL of anisole antisolvent was added dropwise 10 seconds after the start of spin coating. The layer was then annealed at 120°C for 60 minutes to obtain a 500 nm thick perovskite layer. The perovskite layer was made of FAPbI3.

[0093] S105: Preparation of electron transport layer: Vapor-depositing a C60 electron transport layer with a thickness of 30 nm on the surface of the perovskite layer.

[0094] S106: Preparation of metal electrode: vapor-depositing an 80 nm thick Ag electrode on the surface of the electron transport layer.

[0095] Example 2

[0096] Compared with Example 1, the difference of this embodiment is that hydrazinobenzene is replaced by potassium formate in S103.

[0097] Example 3

[0098] Compared with Example 1, the difference of this example is that hydrazinobenzene is replaced by potassium hypophosphite in S103.

[0099] Examples 4 to 7

[0100] Compared with Example 1, Examples 4 to 7 are different in that the thickness of the first passivation layer is different. The thickness of the first passivation layer is shown in Table 1.

[0101] Example 8

[0102] The preparation method of the perovskite solar cell in this embodiment is as follows:

[0103] S101: Preparation of FTO conductive glass electrodes: FTO glass with a specification of 2.0 cm × 2.0 cm is removed by laser etching at both ends of 0.35 cm of FTO to expose the glass substrate; the etched FTO conductive glass is ultrasonically cleaned several times with water, acetone, and isopropyl alcohol in sequence, and then blown dry with nitrogen for later use.

[0104] S102: Preparation of hole transport layer: FTO is treated with UV ozone, and then nickel oxide with a thickness of about 20 nm is magnetron sputtered, and annealed at 300° C. for 60 minutes to obtain a hole transport layer.

[0105] S103: Preparation of a first passivation layer: Prepare a 5 mg / mL hydrazine benzene ethanol solution, then spin-coat 100 μL of the solution on the hole transport layer at 4000 rpm. Anneal the solution at 100°C for 10 minutes to obtain a first passivation layer. The thickness of the first passivation layer is 5 nm.

[0106] S104: Preparation of a second passivation layer: A second passivation layer made of naphthylethylamine is prepared on the surface of the first passivation layer by vacuum evaporation, with a thickness of 5 nm.

[0107] S105: Preparation of the Perovskite Layer: A one-step process was used to prepare the perovskite layer. A perovskite precursor solution was spin-coated on the surface of the second passivation layer at 5000 rpm for 40 seconds. 300 μL of anisole antisolvent was added dropwise 10 seconds after the start of spin coating. The layer was then annealed at 120°C for 60 minutes to obtain a 500 nm thick perovskite layer. The perovskite layer was made of FAPbI3.

[0108] S106: Preparation of electron transport layer: Vapor-depositing a C60 electron transport layer with a thickness of 30 nm on the surface of the perovskite layer.

[0109] S107: Preparation of metal electrode: vapor-deposit an 80 nm thick Ag electrode on the surface of the electron transport layer.

[0110] Examples 9-12

[0111] Compared with Example 8, Examples 9 to 12 are different in that the thickness of the second passivation layer is different. The thickness of the second passivation layer is shown in Table 1.

[0112] Example 13

[0113] Compared with Example 8, the difference of this example is that hydrazinobenzene is replaced by potassium formate in S103, and naphthylethylamine is replaced by benzylamine in S104.

[0114] Example 14

[0115] Compared with Example 8, the difference of this example is that naphthylethylamine is replaced by m-fluorophenylethylamine in S104.

[0116] Example 15

[0117] The preparation method of the perovskite solar cell in this embodiment is as follows:

[0118] S101: Preparation of FTO conductive glass electrodes: FTO glass with a specification of 2.0 cm × 2.0 cm is removed by laser etching at both ends of 0.35 cm of FTO to expose the glass substrate; the etched FTO conductive glass is ultrasonically cleaned several times with water, acetone, and isopropyl alcohol in sequence, and then blown dry with nitrogen for later use.

[0119] S102: Preparation of hole transport layer: FTO is treated with UV ozone, and then nickel oxide with a thickness of about 20 nm is magnetron sputtered, and annealed at 300° C. for 60 minutes to obtain a hole transport layer.

[0120] S103: Preparation of the First Passivation Layer: Prepare a spin coating solution containing ethanol as the solvent, 5 mg / mL hydrazinebenzene, and 3 mg / mL naphthylethylamine. Then, apply 100 μL of this solution to the hole transport layer surface by spin coating at 4000 rpm. Anneal at 100°C for 10 minutes to form the first passivation layer. The thickness of the first passivation layer is 8 nm.

[0121] S104: Preparation of the Perovskite Layer: A one-step process was used to prepare the perovskite layer. A perovskite precursor solution was spin-coated on the surface of the first passivation layer at 5000 rpm for 40 seconds. 300 μL of anisole antisolvent was added dropwise 10 seconds after the start of spin coating. The layer was then annealed at 120°C for 60 minutes to obtain a 500 nm thick perovskite layer. The perovskite layer was made of FAPbI3.

[0122] S105: Preparation of electron transport layer: Vapor-depositing a C60 electron transport layer with a thickness of 30 nm on the surface of the perovskite layer.

[0123] S106: Preparation of metal electrode: vapor-depositing an 80 nm thick Ag electrode on the surface of the electron transport layer.

[0124] Comparative Example 1

[0125] The preparation method of the perovskite solar cell in this comparative example is:

[0126] S101: Preparation of FTO conductive glass electrodes: FTO glass with a specification of 2.0 cm × 2.0 cm is removed by laser etching at both ends of 0.35 cm of FTO to expose the glass substrate; the etched FTO conductive glass is ultrasonically cleaned several times with water, acetone, and isopropyl alcohol in sequence, and then blown dry with nitrogen for later use.

[0127] S102: Preparation of hole transport layer: FTO is treated with UV ozone, and then nickel oxide with a thickness of about 20 nm is magnetron sputtered, and annealed at 300° C. for 60 minutes to obtain a hole transport layer.

[0128] S103: Preparation of the Perovskite Layer: A one-step process was used to prepare the perovskite layer. A perovskite precursor solution was spin-coated on the surface of the hole transport layer at 5000 rpm for 40 seconds. 300 μL of anisole antisolvent was added dropwise 10 seconds after the start of spin coating. The layer was then annealed at 120°C for 60 minutes to obtain a 500 nm thick perovskite layer. The perovskite layer was made of FAPbI3.

[0129] S104: Preparation of electron transport layer: Vapor-depositing a C60 electron transport layer with a thickness of 30 nm on the surface of the perovskite layer.

[0130] S105: Preparation of metal electrode: vapor-depositing an 80 nm thick Ag electrode on the surface of the electron transport layer.

[0131] Test Case

[0132] (1) The photoelectric conversion efficiency of the perovskite solar cells obtained in the examples and comparative examples was tested. The test method is:

[0133] Using Keithley 2400SMU, AM1.5G solar irradiation at 100mW / cm 2 The battery performance is tested under a light source, and the photoelectric conversion efficiency is calculated as follows:

[0134] PCE=Pout / Popt

[0135] =Voc×Jsc×(Vmpp×Jmpp) / (Voc×Jsc)

[0136] =Voc×Jsc×FF

[0137] Where Pout, Popt, Vmpp, Jmpp, Voc, and Jsc are the battery operating output power, incident light power, battery maximum power point voltage, battery maximum power point current, open circuit voltage, and short circuit current, respectively. The test results are shown in Table 1.

[0138] (2) The stability of the perovskite solar cells obtained in the examples and comparative examples was tested. The test method is:

[0139] The perovskite solar cell was placed at 65°C and 100 mW / cm 2 The researchers continuously irradiated the perovskite solar cell with a light source of 100 nm and tracked its photoelectric conversion efficiency over time. The time it took for the photoelectric conversion efficiency to decay to 80% of its initial efficiency was recorded as T80. The value of this parameter indicates the stability of the perovskite solar cell. The test results are shown in Table 1.

[0140] Table 1

[0141]

[0142] It can be seen from the comparison of Examples 1 to 15 with Comparative Example 1 in Table 1 that when the perovskite solar cell contains the first passivation layer, the cell has higher stability.

[0143] It can be seen from Examples 1 to 7 that when the thickness of the first passivation layer is within an appropriate range, the battery has higher stability.

[0144] It can be seen from Examples 1 and 8 to 14 that when the perovskite solar cell contains the first passivation layer and the second passivation layer, the cell has higher stability.

[0145] It can be seen from Example 8 and Example 15 that when hydrazinobenzene and naphthylethylamine are located in the first passivation layer and the second passivation layer, respectively, the battery has higher stability.

[0146] The technical features of the above-mentioned embodiments can be combined arbitrarily. In order to make the description concise, not all possible combinations of the technical features in the above-mentioned embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0147] The above-described embodiments merely represent several implementation methods of the present application. While the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the present invention. It should be noted that a person skilled in the art could make various modifications and improvements without departing from the spirit of the present application, all of which fall within the scope of protection of the present application. Therefore, the scope of protection of the present patent application shall be determined by the appended claims.

Claims

1. A perovskite solar cell, characterized in that The invention comprises a first electrode, a charge extraction layer, a first passivation layer, a perovskite layer and a second electrode stacked in sequence; the material of the charge extraction layer comprises nickel oxide, the material of the first passivation layer comprises a reducing agent, and the reduction potential of the reducing agent is less than Ni 3+ reduction potential.

2. The perovskite solar cell according to claim 1, characterized in that The reduction potential of the reducing agent is less than 0V.

3. The perovskite solar cell according to any one of claims 1 to 2, characterized in that The reducing agent includes at least one of formates, hypophosphites, hydrazine-containing compounds, hydroiodic acid, hydrosulfuric acid, nitrous acid, phosphorous acid, oxalic acid and lactic acid.

4. The perovskite solar cell according to claim 3, characterized in that The cations of the formate and hypophosphite independently include inorganic cations or organic cations; and / or the hydrazine-containing compound is a substituted or unsubstituted C1-C20 alkane or substituted or unsubstituted aromatic hydrocarbon containing a hydrazine group.

5. The perovskite solar cell according to claim 4, characterized in that The inorganic cations include Na + , K + 、Cs + NH4 + One or more of the organic cations include one or two of methylamine and formamidinium ion.

6. The perovskite solar cell according to any one of claims 1 to 5, characterized in that The reducing agent includes at least one of potassium formate, sodium formate, cesium formate, potassium hypophosphite, sodium hypophosphite, cesium hypophosphite and hydrazinylbenzene.

7. The perovskite solar cell according to any one of claims 1 to 6, wherein The thickness of the first passivation layer is less than or equal to 10 nm.

8. The perovskite solar cell according to claim 7, characterized in that The thickness of the first passivation layer is 2nm~8nm.

9. The perovskite solar cell according to any one of claims 1 to 8, wherein The perovskite solar cell further includes a second passivation layer; the second passivation layer is located between the first passivation layer and the perovskite layer, and a material of the second passivation layer includes organic amine.

10. The perovskite solar cell according to claim 9, characterized in that The organic amine includes at least one of benzylamine, halogenated benzylamine, phenethylamine, halogenated phenethylamine, naphthylethylamine and oleylamine iodide.

11. The perovskite solar cell according to claim 10, characterized in that The halogenated benzylamine includes at least one of o-fluorobenzylamine, m-fluorobenzylamine, p-fluorobenzylamine and benzylamine iodide; and / or, The halogenated phenethylamine includes at least one of o-fluorophenethylamine, m-fluorophenethylamine, p-fluorophenethylamine and phenethylamine iodine.

12. The perovskite solar cell according to any one of claims 9 to 11, wherein The thickness of the second passivation layer is less than or equal to 15 nm.

13. The perovskite solar cell according to claim 12, characterized in that The thickness of the second passivation layer is 2 nm to 8 nm.

14. The perovskite solar cell according to any one of claims 1 to 13, characterized in that The charge extraction layer includes a hole transport layer or an electron transport layer.

15. A method for preparing a perovskite solar cell, characterized in that: The steps include: Preparing a charge extraction layer on the surface of the first electrode, wherein the material of the charge extraction layer includes nickel oxide; A first passivation layer is prepared on the surface of the charge extraction layer away from the first electrode, wherein the material of the first passivation layer includes a reducing agent, and the reduction potential of the reducing agent is less than Ni 3+ The reduction potential of A second electrode is prepared on a surface of the first passivation layer away from the charge extraction layer.

16. A photovoltaic system, characterized in that: A perovskite solar cell comprising the perovskite solar cell according to any one of claims 1 to 14 or a perovskite solar cell prepared by the preparation method according to claim 15.

17. A power generation device, characterized in that: A perovskite solar cell comprising the perovskite solar cell according to any one of claims 1 to 14 or a perovskite solar cell prepared by the preparation method according to claim 15.

18. An electrical device, characterized in that: A perovskite solar cell comprising the perovskite solar cell according to any one of claims 1 to 14 or a perovskite solar cell prepared by the preparation method according to claim 15.

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