Solar cell and preparation method therefor, photovoltaic module, power generation apparatus, and electrical apparatus

Abstract

The present disclosure provides a solar cell and a preparation method therefor, a photovoltaic module, a power generation apparatus, and an electrical apparatus. The solar cell comprises: a first electrode and a second electrode, a perovskite light absorption layer disposed between the first electrode and the second electrode, and an electron transport layer disposed between the perovskite light absorption layer and the first electrode, and in contact with the perovskite light absorption layer. The electron transport layer comprises a fullerene derivative and an ionic compound represented by formula I, R1, R2, and R3 being independently selected from H or methyl, R4 being selected from electron withdrawing groups, R5 is selected from electron donating groups, and Y is selected from a halogen or a quasi-halogen. By means of providing the ionic compound represented by formula I in the electron transport layer comprising the fullerene derivative, the present solar cell is capable of doping / passivating the fullerene derivative in situ, reducing aggregation thereof, and increasing the conductivity thereof, which helps to improve the photoelectric performance of the solar cell.

Description

Solar cells and their manufacturing methods, photovoltaic modules, power generation devices and power consumption devices

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS

[0002] This disclosure is based on Chinese patent application number 202410358653.0, application date March 26, 2024, and invention name “Solar cells and methods for manufacturing the same, photovoltaic modules, power generation devices and power-using devices”, and claims the priority of the Chinese patent application. The entire content of the Chinese patent application is hereby incorporated into the present disclosure as a reference. Technical Field

[0003] The present disclosure relates to the field of battery technology, and in particular to a solar cell and a preparation method thereof, a photovoltaic module, a power generation device, and an electricity-consuming device. Background Art

[0004] In recent years, global energy shortages and environmental pollution have become increasingly prominent. As an ideal renewable energy source, solar cells have received increasing attention. Solar cells, also known as photovoltaic cells, are devices that convert light energy directly into electrical energy through the photoelectric effect or photochemical effect.

[0005] Perovskite solar cells (PSCs) are solar cells that use perovskite as a light-absorbing material. Compared with other solar cells, perovskite solar cells stand out in the solar cell field due to their low cost, high efficiency, and simple processing.

[0006] However, the poor stability and low photoelectric performance of perovskite solar cells in related technologies have hindered their practical application and industrial development. Therefore, how to improve the photoelectric performance of perovskite solar cells is a technical problem that needs to be solved urgently. Summary of the Invention

[0007] The present disclosure is made in response to the above-mentioned problems and aims to provide a solar cell and its preparation method, a photovoltaic module, a power generation device, and an electrical device. The solar cell, by providing an electron transport layer comprising a fullerene derivative and an ionic compound represented by Formula I, can reduce the aggregation of the fullerene derivative, increase the conductivity of the electron transport layer, and thus improve the photovoltaic performance of the solar cell.

[0008] To achieve the above objectives, the present disclosure provides a solar cell in a first aspect, comprising a first electrode and a second electrode, a perovskite light absorbing layer disposed between the first electrode and the second electrode, and an electron transport layer disposed between the perovskite light absorbing layer and the first electrode and in contact with the perovskite light absorbing layer; wherein the electron transport layer comprises a fullerene derivative and an ionic compound represented by Formula I:

[0009] wherein R1, R2, and R3 are independently selected from H or methyl, R4 is selected from an electron-withdrawing group, R5 is selected from an electron-donating group, and Y is selected from a halogen or a halogen-like group. This solar cell, by disposing the ionic compound represented by Formula I in an electron transport layer comprising a fullerene derivative, can reduce aggregation of the fullerene derivative, increase the conductivity of the electron transport layer, and thus improve the photoelectric performance of the solar cell.

[0010] In some embodiments, R4 is selected from -C(=O)R, -COOR, -SO3R, -CN, -CR'3, -NO2 or -R'; wherein R is selected from H or C1-C10 alkyl; and R' is selected from F, Cl, Br or I.

[0011] In some embodiments, R5 is selected from -OH or -SH. The above R5 has a small steric hindrance, which is conducive to the cation in the ionic compound represented by Formula I being embedded in the A vacancy of the perovskite light-absorbing layer.

[0012] In some embodiments, Y - Selected from F - 、Cl - Br - , I - 、SCN - 、BF4 - or HCO2 - .

[0013] In some embodiments, R1, R2 and R3 are methyl; R4 is selected from -COOH, -C(=O)H, -COOCH3, -CN, -CCl3, -NO2, -Cl; R5 is -OH; Y - Selected from Cl - , I - 、BF4 - 、SCN - .

[0014] When R1, R2 and R3 are methyl groups, the cation in the ionic compound shown in Formula I is a quaternary ammonium group, which is easily embedded in the A vacancy of the perovskite light-absorbing layer, reducing the carrier recombination sites, which is beneficial to further improve the open circuit voltage of the solar cell.

[0015] When R5 is selected from -OH, it is beneficial for the cation in the ionic compound represented by Formula I to be embedded in the A vacancy of the perovskite light-absorbing layer.

[0016] Y - Selected from Cl - , I - 、BF4 - 、SCN - In the case of the above Y - The ionic compounds are easy to synthesize.

[0017] In some embodiments, the ionic compound represented by Formula I includes one or more of (3-chloro-2-hydroxypropyl)trimethylammonium chloride, 3-carboxy-2-hydroxy-N,N,N-trimethylpropane-1-ammonium iodide, and L-carnenitrile. The ionic compound represented by Formula I can reduce the aggregation of fullerene derivatives, increase the conductivity of the electron transport layer, and thus improve the photoelectric performance of the solar cell.

[0018] In some embodiments, the fullerene derivative is selected from at least one of IC60BA, Bia-C60, ICMA, PC71BM, and PC61BM. These fullerene derivatives have high charge mobility, can effectively transfer photogenerated electrons, and reduce optical and electrical losses in the device. They can also form effective contact with the perovskite light-absorbing layer and reduce carrier (electron and hole) recombination at the interface.

[0019] In some embodiments, in the electron transport layer, the mass ratio of the fullerene derivative to the ionic compound represented by Formula I is 100:0.1-5. By controlling the mass ratio of the fullerene derivative to the ionic compound represented by Formula I within the above range, the fill factor, open circuit voltage, and / or photoelectric conversion efficiency of the solar cell can be improved.

[0020] In some embodiments, the mass ratio of the fullerene derivative to the ionic compound of Formula I is 100:1-2. By controlling the mass ratio of the fullerene derivative to the ionic compound of Formula I within the above range, the fill factor, open circuit voltage, and / or photoelectric conversion efficiency of the solar cell can be further improved.

[0021] In some embodiments, the perovskite light-absorbing layer includes at least one of the compounds represented by [A][B][X]3 and [A]2[C][D][X]6, wherein A includes at least one inorganic or organic monovalent cation, B includes at least one inorganic divalent cation, C includes at least one inorganic monovalent cation, D includes at least one inorganic trivalent cation, and X includes at least one monovalent anion. The electron transport layer provided in the present disclosure is applicable to solar cells comprising the above-mentioned perovskite materials. Therefore, it can be seen that the electron transport layer of the present disclosure has a wide range of applications and can be applied to materials commonly used in the art.

[0022] In some embodiments, the perovskite light absorbing layer comprises (FA x MA 1-x ) y Cs 1-y Pb(I z Br 1-z )3, where 0≤x≤1, 0≤y≤1, 0≤z≤1, and FA represents (H2N=CH-NH2) +, MA represents CH3NH3 + The band gap of the perovskite light-absorbing layer is adjustable and has good photoelectric properties.

[0023] In some embodiments, the solar cell further includes a hole-blocking layer disposed between the first electrode and the electron-transporting layer; and / or a hole-transporting layer disposed between the second electrode and the perovskite light-absorbing layer. The provision of the hole-transporting layer and / or the hole-blocking layer can further enhance the photovoltaic performance of the solar cell.

[0024] In some embodiments, at least one of the first electrode and the second electrode is a transparent electrode.

[0025] A second aspect of the present disclosure provides a method for preparing a solar cell, comprising:

[0026] providing a first electrode and a second electrode;

[0027] disposing a perovskite light absorbing layer between the first electrode and the second electrode;

[0028] An electron transport layer is arranged between the perovskite light absorbing layer and the first electrode and in contact with the perovskite light absorbing layer;

[0029] The electron transport layer includes a fullerene derivative and an ionic compound represented by formula I:

[0030] wherein R1, R2 and R3 are independently selected from H or methyl, R4 is selected from an electron-withdrawing group, R5 is selected from an electron-donating group, and Y is selected from a halogen or a halogen-like group.

[0031] In some embodiments, disposing an electron transport layer in contact with the perovskite light absorbing layer comprises:

[0032] A fullerene derivative is dissolved in a solvent to obtain a first solution having a fullerene derivative concentration of 10 mg / mL to 20 mg / mL; an ionic compound represented by Formula I is added to the first solution to obtain a second solution having a concentration of the ionic compound represented by Formula I of 0.02 mg / mL to 1.0 mg / mL; the second solution is applied to the perovskite light absorbing layer to obtain an electron transport layer.

[0033] In some embodiments, the concentration of the ionic compound represented by Formula I in the second solution is 0.2 mg / mL-0.4 mg / mL.

[0034] A third aspect of the present disclosure provides a photovoltaic module, which includes the solar cell according to the first aspect or the solar cell manufactured by the manufacturing method according to the second aspect.

[0035] Since the photovoltaic module of the present disclosure includes the solar cell provided by the present disclosure, it has at least the same advantages as the solar cell.

[0036] A fourth aspect of the present disclosure provides a power generation device, which includes the solar cell of the first aspect or the solar cell manufactured by the preparation method of the second aspect.

[0037] Since the power generation device of the present disclosure includes the solar cell provided by the present disclosure, it has at least the same advantages as the solar cell.

[0038] A fifth aspect of the present disclosure provides an electrical device, which includes the solar cell of the first aspect or the solar cell manufactured by the manufacturing method of the second aspect.

[0039] Since the electric device of the present disclosure includes the solar cell provided by the present disclosure, it has at least the same advantages as the solar cell. BRIEF DESCRIPTION OF THE DRAWINGS

[0040] FIG1 shows an exploded view of a solar cell according to an embodiment of the present disclosure.

[0041] FIG2 is a schematic diagram showing the interaction between the ionic compound represented by Formula I and the perovskite surface.

[0042] FIG3 shows an exploded view of a solar cell according to an embodiment of the present disclosure.

[0043] FIG4 shows a box plot of the photovoltaic performance parameters of the solar cells prepared in Examples 1-5.

[0044] Explanation of reference numerals: 10, 100: solar cell; 11: first electrode; 12: second electrode; 13: perovskite light absorbing layer; 14: electron transport layer; 15: hole transport layer; 16: hole blocking layer. DETAILED DESCRIPTION

[0045] Below, with appropriate reference to the accompanying drawings, a detailed description of the embodiments of the solar cell and its preparation method, photovoltaic module, power generation device, and power consumption device disclosed herein is specifically disclosed. However, there may be cases where unnecessary detailed descriptions are omitted. For example, there may be cases where detailed descriptions of well-known matters and repeated descriptions of actually the same structures are omitted. This is to avoid the following description from becoming unnecessarily lengthy and to facilitate understanding by those skilled in the art. In addition, the drawings and the following description are provided to enable those skilled in the art to fully understand the present disclosure and are not intended to limit the subject matter described in the claims.

[0046] " scope " disclosed in the present disclosure is limited in the form of lower limit and upper limit, and given range is limited by selecting a lower limit and an upper limit, and selected lower limit and upper limit define the boundary of special scope.The scope that this mode limits can be to include end value or not include end value, and can be combined arbitrarily, and promptly any lower limit can form a scope with any upper limit combination.For example, if the scope of 60-120 and 80-110 is listed for specific parameter, it is understood that the scope of 60-110 and 80-120 is also expected.In addition, if the minimum range value 1 and 2 listed, and if the maximum range value 3,4 and 5 listed, then the following scope can all be expected: 1-3, 1-4, 1-5, 2-3, 2-4 and 2-5.In the present disclosure, unless otherwise specified, numerical range " ab " represents the abbreviation of any real number combination between a and b, and wherein a and b are all 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, when a parameter is expressed as an integer ≥ 2, this 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.

[0047] Unless otherwise specified, all embodiments and optional embodiments of the present disclosure can be combined with each other to form new technical solutions.

[0048] Unless otherwise specified, all technical features and optional technical features disclosed herein can be combined with each other to form a new technical solution.

[0049] Unless otherwise specified, all steps of the present disclosure may be performed sequentially or randomly, preferably sequentially. For example, a method comprising steps (a) and (b) indicates that the method may comprise steps (a) and (b) performed sequentially, or may comprise steps (b) and (a) performed sequentially. For example, a method further comprising step (c) indicates that step (c) may be added to the method in any order, for example, the method may comprise steps (a), (b), and (c), or may comprise steps (a), (c), and (b), or may comprise steps (c), (a), and (b), etc.

[0050] Unless otherwise specified, the terms used in the present disclosure have the common meanings that are generally understood by those skilled in the art.

[0051] Unless otherwise specified, the numerical values ​​of the parameters mentioned in the present disclosure can be measured using various test methods commonly used in the art, for example, they can be measured according to the test methods given in the present disclosure.

[0052] In the present disclosure, the term "halogen" refers to an element of Group VIIA of the periodic table. Exemplarily, the halogen includes fluorine (F), chlorine (Cl), bromine (Br), and iodine (I).

[0053] In the present disclosure, the term "halogen-like" refers to an atomic group that is similar in nature to a halogen element in its free state. The anion of the halogen-like is also similar to the halogen ion. Exemplary, the anion of the halogen-like includes SCN - 、BF4 - 、HCO2 - 、SeCN - 、CN - wait.

[0054] In the present disclosure, the term "alkyl" refers to a straight or branched saturated hydrocarbon group. Alkyl groups may include C1-C10 alkyl, C1-C6 alkyl, or C1-C4 alkyl. Examples of C1-C10 alkyl groups include methyl, ethyl, propyl, butyl, pentyl, hexyl, heptyl, octyl, nonyl, or decyl. Examples of C1-C6 alkyl groups include methyl, ethyl, propyl, butyl, pentyl, or hexyl. Examples of C1-C4 alkyl groups include methyl, ethyl, isopropyl, n-propyl, tert-butyl, sec-butyl, or n-butyl.

[0055] As used herein, the term "layer" refers to any substantially layered structure. A layer may have a thickness that varies over the range of the layer. Typically, a layer has an approximately constant thickness. As used herein, the term "thickness" of a layer refers to the average thickness of the layer. The thickness of a layer can be measured by conventional methods in the art.

[0056] Unless otherwise specified, the term "disposed on" means that one component is provided or placed on another component. A first component may be provided or placed directly on a second component, or a third component may be interposed between the first and second components. For example, if a first layer is provided on a second layer, this includes the presence of a third layer between the first and second layers.

[0057] As used herein, the term "perovskite material" refers to a material having a three-dimensional crystal structure related to that of CaTiO3, or a material including a layer having a structure related to that of CaTiO3. Upon receiving incident light, electrons in the perovskite material are excited, transitioning from the valence band to the conduction band, generating electron-hole pairs.

[0058] Solar cells, also known as photovoltaic cells, are devices that convert light energy directly into electrical energy through the photoelectric or photochemical effect. Perovskite solar cells (PSCs) use perovskite materials as light-absorbing materials. Compared to other solar cells, perovskite solar cells have higher photoelectric conversion efficiency. Unless otherwise specified, solar cells refer to those whose light-absorbing layers contain perovskite materials, also known as perovskite solar cells.

[0059] Perovskite solar cells include electrodes, perovskite light-absorbing layers, electron transport layers, and hole transport layers.

[0060] The photoelectric conversion principle of solar cells is as follows: incident light enters one electrode, then reaches the perovskite light-absorbing layer and is absorbed by it. Under the excitation of the incident light, the perovskite light-absorbing layer generates hole-electron pairs. Under the action of the electric field, the holes and electrons are separated. The electrons are transmitted to one electrode through the electron transport layer, and at the same time, the holes are transmitted to the other electrode through the hole transport layer. Then, a loop is formed through the external circuit, which can be used to drive the load.

[0061] Fullerene derivatives (e.g., PCBM) have good solubility and high electron transport properties, can be manufactured at low temperatures, and have simple processes. Therefore, they are widely used in the electron transport layer of high-efficiency inverted perovskite solar cells.

[0062] However, fullerene derivatives tend to aggregate under photothermal conditions, deteriorating their electron transport properties and reducing the conductivity of the electron transport layer, thereby affecting the photoelectric performance of perovskite solar cells. Therefore, in-situ passivation / doping of fullerene derivatives is necessary to reduce their aggregation and improve their conductivity, thereby enhancing the photoelectric performance of perovskite solar cells.

[0063] Based on this, the present disclosure provides a solar cell and a method for preparing the same, as well as a photovoltaic module, power generation device, and power-consuming device comprising the solar cell. The solar cell in question employs an ionic compound represented by Formula I in an electron transport layer to in-situ passivate / dope a fullerene derivative, thereby reducing aggregation of the fullerene derivative and increasing the conductivity of the electron transport layer, thereby enhancing the photovoltaic performance of the solar cell.

[0064] solar cells

[0065] The solar cell includes a first electrode and a second electrode, a perovskite light-absorbing layer arranged between the first electrode and the second electrode, and an electron transport layer arranged between the perovskite light-absorbing layer and the first electrode and in contact with the perovskite light-absorbing layer; wherein the electron transport layer includes a fullerene derivative and an ionic compound represented by formula I:

[0066] wherein R1, R2 and R3 are independently selected from H or methyl, R4 is selected from an electron-withdrawing group, R5 is selected from an electron-donating group, and Y is selected from a halogen or a halogen-like group.

[0067] The solar cell disclosed herein can achieve in-situ passivation / doping of the fullerene derivative by disposing the ionic compound of Formula I in the electron transport layer containing the fullerene derivative, thereby reducing the aggregation of the fullerene derivative under photothermal conditions, maintaining its charge transport capability, and thus maintaining the photoelectric performance and stability of the solar cell. Specifically, -NR1R2R3 in the ionic compound of Formula I + Some of them can be embedded in the A vacancies on the perovskite surface, while the electron-donating group R5 at the β position can further interact with the incompletely coordinated fullerene derivatives on the perovskite surface. The electron-withdrawing group R4 at the γ position has strong electron-attracting ability, promoting the unidirectional arrangement of the fullerene derivatives, reducing the aggregation of the fullerene derivatives, increasing their conductivity, and improving the contact impedance between the electron transport layer and the perovskite. At the same time, the electron-withdrawing group R4 can also interact with the B vacancies on the perovskite surface, thereby further improving the performance of the solar cell, such as the fill factor (FF) and / or the photoelectric conversion efficiency (PCE). In addition, the anions in the ionic compound shown in Formula I can also enter the perovskite crystal structure, passivating surface defects and increasing the open circuit voltage of the battery.

[0068] Figure 1 shows a schematic diagram of the structure of a solar cell according to one embodiment of the present disclosure. The solar cell 10 includes a first electrode 11 and a second electrode 12, a perovskite light absorbing layer 13 disposed between the first electrode 11 and the second electrode 12, and an electron transport layer 14 disposed between the perovskite light absorbing layer 13 and the first electrode 11 and in contact with the perovskite light absorbing layer.

[0069] In the present disclosure, the first electrode 11 and the second electrode 12 represent regions or layers composed of or substantially composed of a conductive material. The conductive material refers to a material with high electrical conductivity. The conductive material may include a transparent conductive material, a metal and its alloys, a carbon elemental material, and the like. Exemplarily, the transparent conductive material includes tin oxide, indium tin oxide (ITO), fluorine-doped tin oxide (FTO), indium-doped zinc oxide (IZO), aluminum-doped zinc oxide (AZO), boron-doped zinc oxide (BZO), antimony-doped tin oxide (ATO), indium-doped tungsten oxide (IWO), and the like. Exemplarily, the metal and its alloys include at least one of gold, silver, copper, aluminum, nickel, chromium, bismuth, platinum, magnesium, molybdenum, and tungsten. Exemplarily, the carbon elemental material includes at least one of graphite, graphene, and carbon nanotubes.

[0070] In some embodiments, at least one of the first electrode 11 and the second electrode 12 is a transparent electrode, that is, at least one of the first electrode 11 and the second electrode 12 includes the transparent conductive material.

[0071] In some embodiments, the second electrode 12 is a transparent electrode (also referred to as a bottom electrode). When the second electrode 12 is a transparent electrode, the second electrode 12 first receives incident light. In this embodiment, the thickness of the second electrode 12 is in the range of 20 nm to 80 nm.

[0072] In some embodiments, the second electrode 12 includes a glass substrate and a transparent conductive material disposed on the glass substrate. Exemplarily, the second electrode 12 includes, but is not limited to, an FTO transparent conductive glass substrate layer. The surface of the FTO transparent conductive glass substrate layer containing the FTO may be referred to as the conductive surface, and the surface not containing the FTO may be referred to as the glass surface. In some embodiments, an electron transport layer is disposed on the side adjacent to the conductive surface.

[0073] In some embodiments, the first electrode 11 serves as a top electrode and receives incident light last. In this embodiment, the thickness of the first electrode 11 is in a range of 60 nm to 140 nm.

[0074] The perovskite light-absorbing layer 13 is disposed between the first electrode 11 and the second electrode 12 and is capable of generating electron-hole pairs based on excitation by incident light. The present disclosure does not specifically limit the band gap of the perovskite light-absorbing layer 13, and the band gap of the perovskite light-absorbing layer 13 conventionally used in the art can be used. For example, the band gap of the perovskite light-absorbing layer 13 can be in the range of 1.17Ev to 2.30eV. In the present disclosure, there is no specific limitation on the band gap measurement method. For example, the band gap measurement method may include: first, obtaining an ultraviolet absorption curve through ultraviolet absorption spectroscopy testing; and then calculating the band gap of the perovskite light-absorbing layer 13 through the Tauc equation.

[0075] The present disclosure does not impose any particular limitation on the thickness of the perovskite light absorption layer 13 , and the thickness of the perovskite light absorption layer 13 conventionally used in the art can be adopted. For example, the thickness of the perovskite light absorption layer 13 is in the range of 500 nm to 800 nm.

[0076] The perovskite light absorbing layer 13 includes a perovskite material. In some embodiments, the perovskite material includes at least one of the compounds represented by [A][B][X]3 and [A]2[C][D][X]6, wherein A includes at least one inorganic or organic monovalent cation, B includes at least one inorganic divalent cation, C includes at least one inorganic monovalent cation, D includes at least one inorganic trivalent cation, and X includes at least one monovalent anion.

[0077] Exemplary organic monovalent cations include (H2N=CH-NH2) + (abbreviated as FA), CH3NH3 + (abbreviated as MA) at least one.

[0078] Exemplary inorganic monovalent cations include Li + 、Na + , K + , Rb + 、Cs + 、Cu + 、Ag + 、Au + or Hg + At least one of .

[0079] Exemplary inorganic divalent cations include Pb 2+ 、Sn 2+ 、Be 2+ Mg 2+ , Ca 2+ 、Sr 2+ 、Ba 2+ 、Zn 2+ 、Ge 2+ 、Fe 2+ 、Co 2+ 、Ni 2+ 、Cd 2+ 、Cu 2+ 、Mn 2+ 、Pd 2+ 、Yb 2+ or Eu 2+ At least one of .

[0080] Exemplary inorganic trivalent cations include Bi 3+ 、Sb 3+ Cr 3+ 、Fe 3+ 、Co 3+ 、Ga 3+ 、As 3+ 、Ru 3+ , Rh 3+ 、In 3+ 、Ir 3+ 、Au 3+ or Al 3+ At least one of .

[0081] Exemplary monovalent anions include: F - 、Cl - Br - , I - 、SCN - 、CNO -、OCN - 、OSCN - SH - OH - 、CN - 、SeCN - At least one of .

[0082] The electron transport layer provided in the present disclosure is applicable to solar cells comprising the above-mentioned perovskite light-absorbing layer. It can be seen that the electron transport layer provided in the present disclosure has a wide range of applications and can be applied to common materials in this field.

[0083] In some embodiments, the perovskite light absorbing layer comprises (FA x MA 1-x ) y Cs 1-y Pb(I z Br 1-z )3, where 0≤x≤1, 0≤y≤1, 0≤z≤1, and FA represents (H2N=CH-NH2) + , MA represents CH3NH3 + For example, in some embodiments, the perovskite light absorbing layer includes (FA 0.98 MA 0.02 ) 0.95 Cs 0.05 Pb(I 0.98 Br 0.02 )3. CH3NH3PbI3(MAPbI3), (H2N=CH-NH2)PbI3(FAPbI3), (FA 0.83 MA 0.17 ) 0.95 Cs 0.05 Pb(I 0.83 Br 0.17 )3, at least one of CsPbI3, CsPbI2Br, and CsPbIBr2. The perovskite light-absorbing layer has an adjustable band gap and good photoelectric properties.

[0084] In the present disclosure, the electron transport layer 14 is disposed between the perovskite light absorbing layer 13 and the first electrode 11 and contacts the perovskite light absorbing layer 13 , and includes a fullerene derivative and an ionic compound represented by Formula I.

[0085] In some embodiments, in the ionic compound of Formula I, R1, R2, and R3 are methyl groups. As shown in FIG2 , the cation in the ionic compound of Formula I is a quaternary ammonium group, which easily embeds into the A vacancy in the perovskite light-absorbing layer, reducing the number of carrier (electron and hole) recombination sites, thereby further improving the open-circuit voltage of the solar cell.

[0086] In some embodiments, in the ionic compound shown in Formula I, R4 is selected from -C(=O)R, -COOR, -SO3R, -CN, -CR'3, -NO2 or -R'. In some embodiments, R4 is selected from -COOR, -CN or -R'. Wherein, R is selected from hydrogen (H) or alkyl. Alternatively, R is selected from H or C1-C10 alkyl, further optionally, R is selected from H or C1-C4 alkyl. Exemplarily, alkyl includes methyl, ethyl, propyl, butyl, pentyl, hexyl, heptyl, octyl, nonyl, decyl and the like. In this embodiment, R' is selected from halogen, alternatively, R' is selected from F, Cl, Br or I, further optionally, R' is selected from F or Cl.

[0087] In some embodiments, in the ionic compound of Formula I, R5 is selected from -OH or -SH. Alternatively, R5 is selected from -OH. The above R5 has a small steric hindrance, which facilitates the insertion of the cation in the ionic compound of Formula I into the A vacancy of the perovskite light-absorbing layer.

[0088] In some embodiments, in the ionic compound represented by Formula I, Y - Selected from F - 、Cl - Br - , I - 、SCN - 、BF4 - 、HCO2 - .

[0089] In some embodiments, Y - Selected from Cl - 、BF4 - 、SCN - 、F - The above Y - The small ionic radius facilitates its entry into the X vacancy in the perovskite light-absorbing layer.

[0090] In some embodiments, Y - Selected from Cl - 、BF4 - 、SCN - The above Y - It has a small ionic radius, which is conducive to its entry into the X vacancy of the perovskite light absorption layer, and contains the above Y - The ionic compounds are easy to synthesize.

[0091] In some embodiments, Y - Selected from Cl - Br - , I - 、BF4 - 、SCN - . Contains the above Y -The ionic compounds are easy to synthesize.

[0092] In some embodiments, in the ionic compound of Formula I, R1, R2, and R3 are methyl; R4 is selected from -COOH, -C(=O)H, -COOCH3, -CN, -CCl3, -NO2, -Cl, especially -CN, -Cl, or -COOH; R5 is -OH; Y - Selected from Cl - , I - 、BF4 - 、SCN - .

[0093] In some embodiments, the ionic compound represented by Formula I is selected from at least one of (3-chloro-2-hydroxypropyl)trimethylammonium chloride (CHCl), 3-carboxy-2-hydroxy-N,N,N-trimethylpropane-1-ammonium iodide (LI), and L-carnenitrile (3ChTCl). The ionic compound represented by Formula I can reduce the aggregation of fullerene derivatives and increase the conductivity of the electron transport layer, thereby improving the photoelectric performance of the solar cell.

[0094] The chemical formula of CHCl is:

[0095] The chemical formula of LI is:

[0096] The chemical formula of 3ChTCl is:

[0097] In some embodiments, the fullerene derivative is selected from at least one of indene-C60 bisadduct (IC60BA), fullerene-C60 (Bia-C60), indene-C60 monoadduct (ICMA), [6,6]-phenyl-C71-butyric acid isomethyl ester (PC71BM), and [6,6]-phenyl-C61-butyric acid methyl ester (PC61BM). These fullerene derivatives have high charge mobility, can effectively transfer photogenerated charges, and reduce optical and electrical losses in devices. They can also form effective contact with the perovskite light-absorbing layer and reduce interfacial carrier recombination.

[0098] In some embodiments, in the electron transport layer, the mass ratio of the fullerene derivative to the ionic compound of Formula I is 100:0.1-5, optionally 100:1-2. Exemplary mass ratios include 100:0.1, 100:1, 100:2, 100:3, 100:4, 100:5, or any range consisting of two such values, but are not limited thereto. By controlling the mass ratio of the fullerene derivative to the ionic compound of Formula I within the aforementioned range, the fill factor, open circuit voltage, and photoelectric conversion efficiency of the solar cell can be further improved.

[0099] The present disclosure does not impose any particular limitation on the thickness of the electron transport layer 14 , and the thickness of the electron transport layer conventionally used in the art can be adopted. For example, the thickness of the electron transport layer is in the range of 15 nm to 30 nm.

[0100] In some embodiments, the solar cell further includes a hole transport layer disposed between the second electrode and the perovskite light-absorbing layer. The hole transport layer has the function of extracting and transporting holes, and is used to transfer holes generated by the perovskite light-absorbing layer 13 to the adjacent electrode and prevent holes from diffusing in the opposite direction. This can enhance the dissociation of electrons and holes, further improving the photovoltaic performance of the solar cell.

[0101] The present disclosure does not specifically limit the hole transport material used in the hole transport layer, and hole transport materials commonly used in the art can be used. For example, the hole transport material includes nickel oxide (NiO x , 1≤x≤2), cuprous iodide (CuI), cuprous oxide (Cu2O), cuprous thiocyanate (CuSCN), 2,2',7,7'-tetrakis[N,N-di(4-methoxyphenyl)amino]-9,9'-spirobifluorene (Spiro-OMeTAD), 2,2',7,7'-tetrakis(di-p-tolylamino)spiro-9,9'-bifluorene (Spiro-TTB), poly[bis(4-phenyl)(2,4,6-trimethylphenyl)amine] (PTAA), phosphate-based single molecules or polymers, carbazole-based single molecules or polymers, sulfonic acid-based single molecules or polymers, triphenylamine-based single molecules or polymers, etc.

[0102] The present disclosure does not impose any particular limitation on the thickness of the hole transport layer, and the thickness of the hole transport layer conventionally used in the art can be adopted. For example, the thickness of the hole transport layer is in the range of 1 nm to 200 nm.

[0103] In some embodiments, the solar cell further includes a hole blocking layer disposed between the first electrode and the electron transport layer. The hole blocking layer can further reduce non-radiative recombination of electrons and holes, thereby further improving the photovoltaic performance of the solar cell.

[0104] The hole blocking layer includes a hole blocking material. The present disclosure has no particular limitation on the hole blocking material. For example, the hole blocking material may include SnO z (1.5≤z≤2), 2,9-dimethyl-4,7-diphenyl-1,10-phenanthroline (BCP), etc.

[0105] The present disclosure does not impose any particular limitation on the thickness of the hole blocking layer, and the thickness of the hole blocking layer conventionally used in the art can be adopted. For example, the thickness of the hole blocking layer is in the range of 10 nm to 30 nm.

[0106] Figure 3 shows an exploded view of a solar cell according to one embodiment of the present disclosure. In this embodiment, the solar cell 100 includes a second electrode 12, a hole transport layer 15, a perovskite light absorbing layer 13, an electron transport layer 14, a hole blocking layer 16, and a first electrode 11, which are sequentially arranged along the direction of light incidence. In this embodiment, the first electrode 11, the second electrode 12, the perovskite light absorbing layer 13, the electron transport layer 14, the hole transport layer 15, and the hole blocking layer 16 are as described above and will not be repeated here.

[0107] Those skilled in the art will understand that FIG3 is merely an example of an embodiment in which a solar cell includes a hole blocking layer and a hole transport layer. In some embodiments, a solar cell may include only a hole blocking layer without a hole transport layer. In some embodiments, a solar cell may include only a hole transport layer without a hole blocking layer.

[0108] The present disclosure also provides a method for preparing a solar cell, comprising:

[0109] providing a first electrode and a second electrode;

[0110] disposing a perovskite light absorbing layer between the first electrode and the second electrode;

[0111] An electron transport layer is arranged between the perovskite light absorbing layer and the first electrode and in contact with the perovskite light absorbing layer;

[0112] The electron transport layer includes a fullerene derivative and an ionic compound represented by formula I:

[0113] wherein R1, R2 and R3 are independently selected from H or methyl, R4 is selected from an electron-withdrawing group, R5 is selected from an electron-donating group, and Y is selected from a halogen or a halogen-like group.

[0114] The present disclosure does not impose any specific limitation on the arrangement of the first electrode and the second electrode. For example, the first electrode and the second electrode may be arranged by an evaporation method.

[0115] The present disclosure does not specifically limit the method for disposing the perovskite light absorbing layer. For example, the perovskite light absorbing layer can be disposed by a precursor liquid spin coating method, a precursor liquid slit coating method, a precursor liquid blade coating method, and the like.

[0116] In some embodiments, disposing the perovskite light absorbing layer may include spin coating the perovskite precursor solution at a rotation speed of 5000 rpm for 25 seconds, and then annealing at 150° C. for 20 minutes to obtain the perovskite light absorbing layer.

[0117] In some embodiments, an antisolvent (e.g., chlorobenzene) is rapidly added dropwise 5-10 seconds before the end of spin coating to control perovskite crystallization. After spin coating, the perovskite is annealed at 150° C. for 20 minutes to obtain a uniform, dense, smooth, and transparent perovskite light-absorbing layer.

[0118] In some embodiments, disposing an electron transport layer in contact with the perovskite light absorbing layer comprises:

[0119] dissolving the fullerene derivative in a solvent to obtain a first solution having a concentration of the fullerene derivative of 10 mg / mL to 20 mg / mL;

[0120] adding the ionic compound of Formula I to the first solution to obtain a second solution having a concentration of the ionic compound of Formula I of 0.02 mg / mL to 1.0 mg / mL, optionally, a concentration of the ionic compound of Formula I of 0.2 mg / mL to 0.4 mg / mL;

[0121] The second solution is applied on the perovskite light-absorbing layer to form an electron transport layer.

[0122] In the present disclosure, there is no specific limitation on the type of the solvent, as long as the solvent does not cause much damage to the perovskite light-absorbing layer and can dissolve the fullerene derivative. Exemplarily, the solvent includes chlorobenzene.

[0123] In some embodiments, the concentration of the fullerene derivative in the first solution is 10 mg / mL to 20 mg / mL. For example, the concentration of the fullerene derivative is 10 mg / mL, 12 mg / mL, 14 mg / mL, 16 mg / mL, 18 mg / mL, 20 mg / mL, or a range between any two of these values, but is not limited thereto.

[0124] In some embodiments, the concentration of the ionic compound of Formula I in the second solution is 0.02 mg / mL to 1 mg / mL. Alternatively, the concentration of the ionic compound of Formula I is 0.2 mg / mL to 0.4 mg / mL. Exemplarily, the concentration of the ionic compound of Formula I is 0.02 mg / mL, 0.2 mg / mL, 0.3 mg / mL, 0.4 mg / mL, 0.6 mg / mL, 0.8 mg / mL, 1 mg / mL, or a range between any two of these values, but is not limited thereto.

[0125] In some embodiments, the mass ratio of the fullerene derivative to the ionic compound of Formula I in the second solution is 100:0.1-5, optionally 100:1-2. Exemplarily, the mass ratio is 100:0.1, 100:1, 100:1.2, 100:1.4, 100:1.6, 100:1.8, 100:2, or a range between any two of these values, but is not limited thereto.

[0126] In some embodiments, the second solution may be applied to the perovskite light absorbing layer by spin coating.

[0127] In some embodiments, the spin coating speed is 2000 rpm to 4000 rpm. For example, the spin coating speed is 2000 rpm, 2500 rpm, 3000 rpm, 3500 rpm, 4000 rpm, or a range between any two values, but is not limited thereto.

[0128] In some embodiments, the spin coating time is 25 s to 30 s. Exemplarily, the spin coating time is 25 s, 26 s, 27 s, 28 s, 29 s, 30 s, or a range between any two values, but is not limited thereto.

[0129] In some embodiments, the second solution after spin coating is heat treated to obtain an electron transport layer. In some embodiments, the heat treatment temperature is 80°C to 120°C, and the heat treatment time is 5 min to 15 min. Exemplarily, the heat treatment temperature is 80°C, 90°C, 100°C, 110°C, 120°C or a value between the ranges consisting of any two values, but is not limited thereto. Exemplarily, the heat treatment time is 5 min, 6 min, 7 min, 8 min, 9 min, 10 min, 11 min, 12 min, 13 min, 14 min, 15 min or a value between the ranges consisting of any two values, but is not limited thereto.

[0130] The preparation methods of the other functional layers (hole blocking layer and hole transport layer) of the solar cell are not particularly limited and can be prepared by methods commonly used in the art, such as electrochemical deposition, chemical vapor deposition, physical epitaxial growth, vacuum thermal evaporation, atomic layer deposition, magnetron sputtering, etc.

[0131] The present disclosure also provides a photovoltaic module. The photovoltaic module includes the aforementioned solar cell. In some embodiments, the photovoltaic module may further include a welding ribbon connecting multiple solar cells, a junction box for current transmission, and a battery packaging component.

[0132] In some embodiments, the battery packaging component includes photovoltaic glass. The photovoltaic glass covers the solar cells and protects them. Photovoltaic glass also has excellent light transmittance and high hardness, making it adaptable to large temperature swings between day and night and adverse weather conditions.

[0133] In some embodiments, the battery packaging component includes an ethylene-vinyl acetate copolymer (EVA) film, which is disposed between the photovoltaic glass and the solar cell to bond the photovoltaic glass and the solar cell.

[0134] In some embodiments, the battery packaging component includes a photovoltaic backsheet, which protects the solar cells.

[0135] Optionally, the material of the photovoltaic backsheet can be a polyvinyl fluoride composite film or a thermoplastic elastic material. The material of the photovoltaic backsheet has the properties of insulation, waterproofness, and aging resistance.

[0136] In some embodiments, the battery packaging component includes a solar aluminum frame, which is made of aluminum alloy and has the characteristics of high strength and corrosion resistance, and can support and protect the solar cell.

[0137] The present disclosure also provides a power generation device, comprising the solar cell provided in the above embodiment.

[0138] The present disclosure also provides an electrical device including the solar cell provided in the above embodiment.

[0139] In some embodiments, the electrical device may also include lighting equipment, energy storage equipment, etc., and the embodiments of the present disclosure include but are not limited to the above. For example, the electrical device may include a solar water heater, a solar street light, a solar photovoltaic generator, etc.

[0140] Example

[0141] The following examples are provided. The examples described below are illustrative and are intended only to explain the present disclosure and are not to be construed as limiting the present disclosure. Unless otherwise specified, all reagents used were commercially available and all equipment used was conventional.

[0142] Example 1

[0143] A solar cell was prepared by the following steps.

[0144] Cleaning and treatment of the second electrode:

[0145] Use a digital multimeter to distinguish the conductive and glass surfaces of a 2.0 cm × 2.0 cm piece of FTO transparent conductive glass. Place the FTO transparent conductive glass on a glass cleaning rack and record the orientation of the conductive surface. Place the glass cleaning rack containing the FTO transparent conductive glass in an ultrasonic cleaner and clean the glass with a surfactant, deionized water, isopropyl alcohol, and anhydrous ethanol for 20 minutes, respectively. Finally, dry the glass in a 70°C oven for 5 minutes. Treat the FTO transparent conductive glass with an ultraviolet ozone (UV-O3) cleaner under a fume hood for 20 minutes and cool to room temperature before use.

[0146] Set up the hole transport layer:

[0147] Weigh 15 mg of nickel oxide (NiOx, 1 ≤ X ≤ 2) nanoparticles and disperse them in 1 mL of deionized water. Shake for 20 minutes until the nickel oxide nanoparticles are evenly dispersed. Filter the resulting dispersion through a hydrophobic PTFE syringe filter (25 mm diameter, 0.22 μm pore size) to retain nickel oxide nanoparticles with a particle size of 7 to 15 nm. Take 150 μL of this dispersion and spin coat it on the conductive surface of FTO transparent conductive glass using a spin coater at 3000 rpm for 25 seconds. After spin coating, place the coating on a hot plate and anneal at 140°C for 20 minutes, then cool it to room temperature to form a 50 nm thick hole transport layer.

[0148] Set up the perovskite light absorbing layer:

[0149] Weigh 480.31 mg of formamidine hydroiodide (FAI), 31.39 mg of methylammonium iodide (MAI), 6.38 mg of methylammonium bromide (MABr), 38.97 mg of cesium iodide (CsI), 22.57 mg of lead bromide (PbBr2) and 1452.18 mg of lead iodide (PbI2), and dissolve them in 2 mL of a mixture of N,N-dimethylformamide (DMF) and dimethyl sulfoxide (DMSO) (the volume ratio of DMF to DMSO is 4:1) to obtain a perovskite precursor solution.

[0150] Then oscillate in the dark for 5 hours. After the oscillation is completed, use a filter head (the diameter of the needle filter is 25 mm, and the pore size of the filter is 0.22 μm) to remove impurities in the perovskite precursor solution. Take 150 μL of the perovskite precursor solution and spin coat it on the hole transport layer at a speed of 5000 rpm for 45 seconds. After 35 seconds of spin coating, 200 μL of chlorobenzene is quickly added to regulate the crystallization of the perovskite. After spin coating, anneal at 150 ° C for 20 minutes to obtain a uniform, dense, smooth and transparent perovskite light-absorbing layer with a thickness of 550 nm (FA 0.98 MA 0.02 ) 0.95 Cs 0.05 Pb(I 0.98 Br 0.02 )3.

[0151] Set up the electron transport layer:

[0152] Dissolve 40 mg of PC61BM ([6,6]-phenyl-C61-butyric acid methyl ester) in 2 mL of chlorobenzene to prepare 2 mL of a 20 mg / mL PC61BM chlorobenzene solution. Then, add 0.4 mg of (3-chloro-2-hydroxypropyl)trimethylammonium chloride (CHCl) to the resulting solution to obtain a CHCl-PC61BM solution with a CHCl concentration of 0.2 mg / mL.

[0153] 90 μL of CHCl-PC61BM solution was spin-coated on the perovskite light-absorbing layer at 4000 rpm for 30 seconds. The solution was then annealed at 100°C for 10 minutes to form a 30 nm thick electron transport layer on the perovskite light-absorbing layer.

[0154] Set up the hole blocking layer:

[0155] On the electron transport layer, a SnO2 hole blocking layer with a thickness of 15 nm was prepared by atomic layer deposition.

[0156] Set up the first electrode:

[0157] On the hole blocking layer, copper (Cu) with a thickness of 140 nm was evaporated as the first electrode. Before evaporation, the vacuum was first evacuated to 1.0×10 -4 Pa, followed by 5 minutes of pre-evaporation. During the evaporation process, when the copper thickness is between 0-20nm, the Cu evaporation rate is about 0.5A / s; when the copper thickness is between 20nm-140nm, the Cu evaporation rate is about 6A / s.

[0158] Thus, the solar cell of Example 1 was obtained.

[0159] Example 2

[0160] A solar cell was prepared in the same manner as in Example 1, except that during the process of setting the electron transport layer, the amount of CHCl added was adjusted to 0.6 mg to prepare a CHCl-PC61BM solution with a CHCl concentration of 0.3 mg / mL.

[0161] Example 3

[0162] A solar cell was prepared in the same manner as in Example 1, except that during the process of setting the electron transport layer, the amount of CHCl added was adjusted to 0.8 mg to prepare a CHCl-PC61BM solution with a CHCl concentration of 0.4 mg / mL.

[0163] Example 4

[0164] A solar cell was prepared in the same manner as in Example 1, except that 0.2 mg of (R)-3-carboxy-2-hydroxy-N,N,N-trimethylpropane-1-ammonium iodide (LI) was used instead of 0.2 mg of CHCl during the formation of the electron transport layer.

[0165] Example 5

[0166] A solar cell was prepared in the same manner as in Example 1, except that 0.2 mg of L-carnelian nitrile (3ChTCl) was used instead of 0.2 mg of CHCl during the formation of the electron transport layer.

[0167] Comparative Example 1

[0168] A solar cell was prepared in the same manner as in Example 1, except that CHCl was not added during the formation of the electron transport layer.

[0169] Comparative Example 2

[0170] A solar cell was prepared in the same manner as in Example 1, except that 0.2 mg of choline chloride (CHOCl) was used instead of CHCl during the formation of the electron transport layer.

[0171] Among them, the chemical formula of choline chloride is:

[0172] Comparative Example 3

[0173] A solar cell was prepared in the same manner as in Example 1, except that 0.2 mg of (3-chloropropyl)-trimethylammonium chloride (3CTMCl) was used instead of 0.2 mg of CHCl during the formation of the electron transport layer.

[0174] Comparative Example 4

[0175] A solar cell was prepared in the same manner as in Example 1, except that 0.2 mg of 2-hydroxypropyltrimethylammonium chloride (2MeCl) was used instead of 0.2 mg of CHCl during the formation of the electron transport layer.

[0176] Comparative Example 5

[0177] A solar cell was prepared in the same manner as in Example 1, except that 0.2 mg of 2-hydroxy-N,N,N-trimethylethylammonium tetrafluoroborate (CHOBF) was used instead of 0.2 mg of CHCl during the formation of the electron transport layer.

[0178] Solar cell performance testing

[0179] Using a solar simulator under standard test conditions: total irradiance 100mW / cm 2 , the spectral intensity is AM1.5G to test the photoelectric performance parameters of solar cells. out 、P in 、V mpp 、J mpp 、V OC 、J SC Then, the photoelectric conversion efficiency (PCE) is calculated based on the following formula: PCE = P out / P in=V OC ×J SC ×(V mpp ×J mpp ) / (V OC ×J SC =V OC ×J SC ×FF / P in ;

[0180] Among them, P out 、P in 、V mpp 、J mpp , FF, V OC 、J SC They are the battery operating output power, incident light power, battery maximum power point voltage, battery maximum power point current, fill factor, short-circuit current, and open-circuit voltage.

[0181] The solar cells obtained in Examples 1-5 and Comparative Examples 1-5 were tested under the above test conditions. The test results of Examples 1-5 and Comparative Examples 1-5 are shown in Table 1 below.

[0182] Table 1

[0183] It can be seen from the data in Table 1 that, compared with the solar cells of Comparative Examples 1-5, the ionic compound represented by Formula I is provided in the electron transport layer of the cells of Examples 1-5, thereby improving the photoelectric performance of the cells.

[0184] Four solar cells were prepared according to the methods described in Examples 1-5. The performance of these solar cells was tested using the aforementioned testing methods, and a box plot of the photovoltaic performance parameters of the solar cells prepared in Examples 1-5 was plotted (see Figure 4). It can be seen that the solar cells prepared in Examples 1-5 exhibited good reproducibility.

[0185] It should be noted that the present disclosure is not limited to the above-mentioned embodiments. The above-mentioned embodiments are merely examples, and within the scope of the technical solution of the present disclosure, embodiments having substantially the same structure as the technical concept and exerting the same effects are all included in the technical scope of the present disclosure. In addition, within the scope of the present disclosure, various modifications that can be imagined by those skilled in the art to the embodiments, and other methods constructed by combining some of the constituent elements of the embodiments are also included in the scope of the present disclosure.

Claims

1. A solar cell, comprising: a first electrode and a second electrode, a perovskite light absorbing layer disposed between the first electrode and the second electrode, an electron transport layer disposed between the perovskite light absorbing layer and the first electrode and in contact with the perovskite light absorbing layer; Wherein, the electron transport layer comprises a fullerene derivative and an ionic compound represented by formula I: wherein R1, R2 and R3 are independently selected from H or methyl, R4 is selected from an electron-withdrawing group, R5 is selected from an electron-donating group, and Y is selected from a halogen or a halogen-like group.

2. The solar cell according to claim 1, wherein R4 is selected from -C(=O)R, -COOR, -SO3R, -CN, -CR'3, -NO2 or -R'; wherein R is selected from H or C1-C10 alkyl; R' is selected from F, Cl, Br or I.

3. The solar cell according to claim 1 or 2, wherein R5 is selected from -OH or -SH.

4. The solar cell according to any one of claims 1 to 3, wherein Y - Selected from F - 、Cl - Br - , I - 、SCN - 、BF4 - or HCO2 - .

5. The solar cell according to any one of claims 1 to 4, wherein R1, R2 and R3 are methyl groups; R4 is selected from -COOH, -C(=O)H, -COOCH3, -CN, -CCl3, -NO2, -Cl; R5 is -OH; Y - Selected from Cl - , I - 、BF4 - 、SCN - .

6. The solar cell according to claim 1 or 2, wherein: The ionic compound represented by formula I includes one or more of (3-chloro-2-hydroxypropyl)trimethylammonium chloride, 3-carboxyl-2-hydroxy-N,N,N-trimethylpropane-1-ammonium iodide, and L-carnitrile.

7. The solar cell according to any one of claims 1 to 6, wherein The fullerene derivative is selected from at least one of IC60BA, Bia-C60, ICMA, PC71BM, and PC61BM.

8. The solar cell according to any one of claims 1 to 7, wherein In the electron transport layer, the mass ratio of the fullerene derivative to the ionic compound represented by formula I is 100:0.1-5.

9. The solar cell according to claim 8, wherein The mass ratio of the fullerene derivative to the ionic compound represented by formula I is 100:1-2.

10. The solar cell according to any one of claims 1 to 9, wherein The perovskite light-absorbing layer comprises at least one of the compound represented by [A][B][X]3 and the compound represented by [A]2[C][D][X]6, Wherein, A comprises at least one inorganic or organic monovalent cation, B comprises at least one inorganic divalent cation, C comprises at least one inorganic monovalent cation, D comprises at least one inorganic trivalent cation, and X comprises at least one monovalent anion.

11. The solar cell according to claim 10, wherein The perovskite light absorbing layer comprises: (FA x MA 1-x ) y Cs 1-y Pb(I z Br 1-z )3, where 0≤x≤1, 0≤y≤1, 0≤z≤1, and FA represents (H2N=CH-NH2) + , MA represents CH3NH3 + .

12. The solar cell according to any one of claims 1 to 11, wherein The solar cell further comprises: a hole blocking layer disposed between the first electrode and the electron transport layer; and / or A hole transport layer is disposed between the second electrode and the perovskite light absorbing layer.

13. The solar cell according to any one of claims 1 to 12, wherein At least one of the first electrode and the second electrode is a transparent electrode.

14. A method for preparing a solar cell, comprising: providing a first electrode and a second electrode; disposing a perovskite light absorbing layer between the first electrode and the second electrode; disposing an electron transport layer between the perovskite light absorbing layer and the first electrode and in contact with the perovskite light absorbing layer; Wherein, the electron transport layer comprises a fullerene derivative and an ionic compound represented by formula I: wherein R1, R2 and R3 are independently selected from H or methyl, R4 is selected from an electron-withdrawing group, R5 is selected from an electron-donating group, and Y is selected from a halogen or a halogen-like group.

15. The preparation method according to claim 14, wherein The electron transport layer arranged in contact with the perovskite light absorbing layer comprises: dissolving the fullerene derivative in a solvent to obtain a first solution having a fullerene derivative concentration of 10 mg / mL to 20 mg / mL; adding the ionic compound of Formula I to the first solution to obtain a second solution having a concentration of the ionic compound of Formula I of 0.02 mg / mL to 1.0 mg / mL; The second solution is applied on the perovskite light absorbing layer to obtain the electron transport layer.

16. The preparation method according to claim 15, wherein The concentration of the ionic compound represented by formula I in the second solution is 0.2 mg / mL-0.4 mg / mL. 17 . A photovoltaic module, comprising the solar cell according to claim 1 or the solar cell prepared by the preparation method according to claim 14 .

18. A power generation device, comprising the solar cell according to any one of claims 1 to 13 or the solar cell produced by the preparation method according to any one of claims 14 to 16.

19. An electrical device, comprising the solar cell according to any one of claims 1 to 13 or the solar cell produced by the method according to any one of claims 14 to 16.

Images