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 cell and method of manufacturing the same, photovoltaic module, power generation device, and power consumption device

[0001] Cross-reference to Related Applications

[0002] The present disclosure is based on and claims priority to Chinese Patent Application No. 202410358653.0, filed on March 26, 2024, entitled “Solar cell and method of manufacturing the same, photovoltaic module, power generation device, and power consumption device”, the entire contents of which are incorporated herein by reference. TECHNICAL FIELD

[0003] The present disclosure relates to the technical field of batteries, and in particular to a solar cell, a method of manufacturing the same, a photovoltaic module, a power generation device, and a power consumption device. BACKGROUND

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

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

[0006] However, the stability of perovskite solar cells in the related art is poor, and the photoelectric performance is low, which hinders 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. SUMMARY

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

[0008] To achieve the above-mentioned purpose, the present disclosure provides a solar cell in a first aspect, the solar cell comprising 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 comprises fullerene derivatives and an ionic compound represented by Formula I:

[0009] wherein R1, R2and R3are independently selected from H or methyl, R4is selected from an electron-withdrawing group, R5is selected from an electron-donating group, and Y is selected from halogen or halogen-like. The solar cell is capable of reducing the aggregation of the fullerene derivative, increasing the conductivity of the electron transport layer, and improving the photoelectric performance of the solar cell by disposing the ionic compound of Formula I in the electron transport layer comprising the fullerene derivative.

[0010] In some embodiments, R4is 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, R5is selected from -OH or -SH. The above R5has small steric hindrance, which is conducive to the cation in the ionic compound of Formula I to embed into the A-site of the perovskite light-absorbing layer.

[0012] In some embodiments, Y is selected from Cl - - - - - - - - .

[0013] In some embodiments, R1, R2and R3are methyl; R4is selected from -COOH, -C(=O)H, -COOCH3, -CN, -CCl3, -NO2, -Cl; R5is -OH; and Y is selected from Cl - - - - - .

[0014] When R1, R2and R3are methyl, the cation in the ionic compound of Formula I is quaternary ammonium group, which is easy to embed into the A-site of the perovskite light-absorbing layer, reduce the carrier recombination sites, and further improve the open-circuit voltage of the solar cell.

[0015] When R5is selected from -OH, the cation in the ionic compound of Formula I is easy to embed into the A-site of the perovskite light-absorbing layer.

[0016] When Y is selected from Cl - - - - - , the ionic compound comprising the above Y - is easy to synthesize. ​​​​​​​​​​​​​​​

[0017] In some embodiments, the ionic compound of Formula I includes one or more of (3-chloro-2-hydroxypropyl)trimethylammonium chloride, 3-carboxy-2-hydroxy-N,N,N- trimethylpropan-1-aminium iodide, L-camphor-10-sulfonic acid. The ionic compound of Formula I can reduce the aggregation of the fullerene derivative, increase the conductivity of the electron transport layer, and 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. The fullerene derivative has a high charge mobility, can effectively transfer photo-generated electrons, reduce optical and electrical losses in the device, and form an effective contact with the perovskite light-absorbing layer and reduce the recombination of carriers (electrons and holes) at the interface.

[0019] In some embodiments, the mass ratio of the fullerene derivative to the ionic compound of Formula I in the electron transport layer is 100:0.1-5. By controlling the mass ratio of the fullerene derivative to the ionic compound of Formula I in 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 in 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 a compound of Formula [A][B][X]3, a compound of Formula [A]2[C][D][X]6, wherein A includes at least one of an 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 by the present disclosure is suitable for a solar cell containing the above perovskite material, and thus the electron transport layer of the present disclosure has a wide range of applications and can be applied to commonly used materials in the field.

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

[0023] In some embodiments, the solar cell further comprises a hole blocking layer arranged between the first electrode and the electron transport layer; and / or a hole transport layer arranged between the second electrode and the perovskite light-absorbing layer. By arranging the hole transport layer and / or the hole blocking layer, the photoelectric performance of the solar cell is further improved.

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

[0025] The 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] arranging a perovskite light-absorbing layer between the first electrode and the second electrode;

[0028] arranging an electron transport layer in contact with the perovskite light-absorbing layer between the perovskite light-absorbing layer and the first electrode;

[0029] The electron transport layer comprises 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 halogen or halogen-like.

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

[0032] dissolving the fullerene derivative in a solvent to obtain a first solution with a fullerene derivative concentration of 10 mg / mL-20 mg / mL; adding the ionic compound represented by Formula I to the first solution to obtain a second solution with an ionic compound represented by Formula I concentration of 0.02 mg / mL-1.0 mg / mL; and applying the second solution on the perovskite light-absorbing layer to obtain the electron transport layer.

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

[0034] The third aspect of the present disclosure provides a photovoltaic module, which comprises the solar cell of the first aspect or the solar cell prepared by the method of the second aspect.

[0035] The photovoltaic module of the present disclosure comprises the solar cell provided by the present disclosure, and thus has at least the same advantages as the solar cell.

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

[0037] The power generation device of the present disclosure comprises the solar cell provided by the present disclosure, and thus has at least the same advantages as the solar cell.

[0038] The fifth aspect of the present disclosure provides a power consumption device, which comprises the solar cell of the first aspect or the solar cell prepared by the preparation method of the second aspect.

[0039] The power consumption device of the present disclosure comprises the solar cell provided by the present disclosure, and thus has at least the same advantages as the solar cell. BRIEF DESCRIPTION OF DRAWINGS

[0040] FIG. 1 shows an exploded view of a solar cell according to an embodiment of the present disclosure.

[0041] FIG. 2 shows a schematic diagram of the interaction between an ionic compound of Formula I and a perovskite surface.

[0042] FIG. 3 shows an exploded view of a solar cell according to an embodiment of the present disclosure.

[0043] FIG. 4 shows a box plot of the photoelectric performance parameters of the solar cells prepared in Examples 1-5.

[0044] Reference Signs: 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] Hereinafter, specific embodiments of a solar cell and a preparation method thereof, a photovoltaic module, a power generation device, and a power consumption device of the present disclosure are specifically disclosed with appropriate reference to the accompanying drawings. However, there will be cases where unnecessary detailed descriptions are omitted. For example, there will be cases where detailed descriptions of matters that are well known, repeated descriptions of substantially identical structures are omitted. This is to avoid the following description from becoming unnecessarily lengthy and to facilitate the understanding of those skilled in the art. In addition, the accompanying drawings and the following description are provided so that those skilled in the art can fully understand the present disclosure, and are not intended to limit the subject matter recited in the claims.

[0046] The ranges disclosed herein are defined by their lower and upper endpoints, and given that a range is defined by selecting a lower endpoint and an upper endpoint, the selected lower and upper endpoints define the boundaries of the particular range. Ranges defined in this manner can be inclusive or exclusive of the endpoints, and can be arbitrarily combined, i.e., any lower endpoint can be combined with any upper endpoint to form a range. For example, if ranges of 60-120 and 80-110 are listed, it is understood that ranges of 60-110 and 80-120 are also contemplated. Furthermore, if minimum range values of 1 and 2 are listed, and if maximum range values of 3, 4, and 5 are listed, then the following ranges are all contemplated: 1-3, 1-4, 1-5, 2-3, 2-4, and 2-5. In the present disclosure, unless otherwise stated, a numerical range "a-b" indicates a shorthand way of describing all of the individual real combinations of values that are within the range of a to b, where a and b are both real numbers. For example, the numerical range "0-5" indicates that all of the real numbers between 0 and 5 have been listed herein, and "0-5" is merely a shorthand way of describing these numerical combinations. In addition, when a parameter is stated to be an integer ≥ 2, it is equivalent to disclose 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 of the present disclosure can be combined with each other to form new technical solutions.

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

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

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

[0052] In the present disclosure, the term "halogen" refers to the elements in Group VIIA of the Periodic Table. Illustratively, halogens include fluorine (F), chlorine (CI), bromine (Br), and iodine (I).

[0053] In the present disclosure, the term "pseudohalogen" refers to an atomic group that in the free state resembles the halogen elements in their elemental nature. The anion of a pseudohalogen also resembles the halogen ions. Illustratively, the anion of a pseudohalogen includes SCN - , BF4 - , HCO2 - , SeCN - , CN - , and the like.

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

[0055] The term "layer" as used in the present disclosure refers to any substantially layer-like structure. The layer can have a thickness that varies over the extent of the layer. Typically, the layer has a thickness that is approximately constant. The "thickness" of a layer as used in the present disclosure refers to the average thickness of the layer. The thickness of a layer can be measured by methods conventional in the art.

[0056] The term "disposed on" if not specifically stated refers to having one component provided or placed on another component. The first component can be provided or placed directly on the second component, or there can be a third component interposed between the first component and the second component. For example, if a first layer is disposed on a second layer, this includes the case where there is an intervening third layer between the first layer and the second layer.

[0057] As used in the present disclosure, the term "perovskite material" refers to a material having a three-dimensional crystal structure related to that of CaTiO3, or a layer material including a structure related to that of CaTiO3. When receiving incident light, electrons in the perovskite material are excited, and the electrons transition from a valence band to a conduction band, producing an electron-hole pair.

[0058] A solar cell, also known as a photovoltaic cell, is a device that converts light energy directly into electricity through the photoelectric effect or photochemical effect. Perovskite solar cells (PSCs) are solar cells that use perovskite materials as light-absorbing materials. Compared with other solar cells, perovskite solar cells have high photoelectric conversion efficiency. In the following text, unless otherwise specified, solar cell refers to a solar cell whose light-absorbing layer contains perovskite materials, which can also be called perovskite solar cell.

[0059] The perovskite solar cell includes an electrode, a perovskite light-absorbing layer, an electron transport layer, and a hole transport layer.

[0060] The photoelectric conversion principle of the solar cell is as follows: incident light is incident from an electrode, then reaches the perovskite light-absorbing layer and is absorbed by it, and under the excitation of the incident light, the perovskite light-absorbing layer generates hole-electron pairs, which are separated under the action of an electric field. The electrons are transported to one electrode via the electron transport layer, while the holes are transported to the other electrode via the hole transport layer, and then a loop is formed via an external circuit, which can be used to drive a load to work.

[0061] Fullerene derivatives (for example, PCBM) have good solubility and high electron transport performance, can be manufactured at low temperature, and have simple process, and therefore are widely used in the electron transport layer of high-efficiency inverted perovskite solar cells.

[0062] However, fullerene derivatives tend to aggregate under photo-thermal conditions, which deteriorates the electron transport performance of the fullerene derivatives, reduces the conductivity of the electron transport layer, and thus affects the photoelectric performance of the perovskite solar cell. Therefore, it is necessary to in-situ passivate / dope the fullerene derivatives to reduce the aggregation of the fullerene derivatives, improve the conductivity thereof, and thus improve the photoelectric performance of the perovskite solar cell.

[0063] Based on this, the present disclosure provides a solar cell and a preparation method thereof, as well as a photovoltaic module, a power generation device, and a power consumption device comprising the solar cell. The solar cell in-situ passivates / dopes the fullerene derivatives by disposing an ionic compound represented by Formula I in the electron transport layer, thereby reducing the aggregation of the fullerene derivatives, increasing the conductivity of the electron transport layer, and further improving the photoelectric performance of the solar cell.

[0064] Solar cell

[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, R2and R3are independently selected from H or methyl, R4is selected from an electron-withdrawing group, R5is selected from an electron-donating group, and Y is selected from halogen or halogen-like.

[0067] The solar cell of the present disclosure 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 photo-thermal conditions, maintaining the charge transport ability of the fullerene derivative, and further maintaining the photoelectric performance and stability of the solar cell. Specifically, the -NR1R2R3 + The electron-donating group R5at the β position can further interact with the uncoordinated fullerene derivative on the perovskite surface, and the electron-withdrawing group R4at the γ position has strong electron-withdrawing ability, promotes the one-way arrangement of the fullerene derivative, reduces the aggregation of the fullerene derivative, increases the conductivity of the fullerene derivative, and improves the contact resistance between the electron transport layer and the perovskite. In addition, the electron-withdrawing group R4can also interact with the B-vacancy 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 anion in the ionic compound of Formula I can also enter the perovskite crystal structure, passivate surface defects, and improve the open-circuit voltage of the cell.

[0068] FIG. 1 shows a schematic diagram of the structure of a solar cell according to an 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 arranged between the first electrode 11 and the second electrode 12, and an electron transport layer 14 arranged 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 a region or a layer composed of or substantially composed of a conductive material. The conductive material refers to a material having high electrical conductivity. The conductive material can include a transparent conductive material, a metal and an alloy thereof, a carbon elemental material, etc. 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), etc. Exemplarily, the metal and the alloy thereof include at least one of gold, silver, copper, aluminum, nickel, chromium, bismuth, platinum, magnesium, molybdenum, tungsten. Exemplarily, the carbon elemental material includes at least one of graphite, graphene, carbon nanotubes.

[0070] In some embodiments, at least one of the first electrode 11 and the second electrode 12 is a transparent electrode, i.e., at least one of the first electrode 11 and the second electrode 12 comprises a transparent conductive material as described above.

[0071] In some embodiments, the second electrode 12 is a transparent electrode (may also be 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 comprises a glass substrate and a transparent conductive material disposed on the glass substrate. For example, the second electrode 12 comprises a FTO transparent conductive glass substrate layer, but is not limited thereto. The surface of the FTO transparent conductive glass substrate layer on the side of the FTO can be referred to as a conductive surface, and the surface on the side without the FTO can be referred to as a glass surface. In some embodiments, the electron transport layer is disposed on the side adjacent to the conductive surface.

[0073] In some embodiments, the first electrode 11 is a top electrode and is the last to receive incident light. In this embodiment, the thickness of the first electrode 11 is in the 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 can generate electron-hole pairs based on excitation of incident light. The disclosure does not make special limitations on the band gap of the perovskite light-absorbing layer 13, and the band gap of the perovskite light-absorbing layer 13 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 1.17 eV to 2.30 eV. In the disclosure, the method for measuring the band gap is not particularly limited. For example, the method for measuring the band gap can include: first, obtaining an ultraviolet absorption curve by ultraviolet absorption spectrum test; and then calculating the band gap of the perovskite light-absorbing layer 13 by Tauc equation.

[0075] The disclosure does not make special limitations on the thickness of the perovskite light-absorbing layer 13, and the thickness of the perovskite light-absorbing layer 13 used in the art can be used. For example, the thickness of the perovskite light-absorbing layer 13 is in the range of 500 nm to 800 nm.

[0076] The perovskite light-absorbing layer 13 comprises a perovskite material. In some embodiments, the perovskite material comprises at least one of a compound represented by [A][B][X]3, a compound represented by [A]2[C][D][X]6, wherein A comprises at least one of an 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.

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

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

[0079] For example, 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 them.

[0080] For example, 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 them.

[0081] For example, monovalent anions include: F - Cl - ,Br - I - SCN - CNO -, OCN - , OSCN - , SH - , OH - , CN - , SeCN - .

[0082] The electron transport layer provided by the present disclosure is applicable to the solar cell containing the above-mentioned perovskite light-absorbing layer, and thus it can be seen that the electron transport layer of the present disclosure is widely applicable and can be applied to common materials in the 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, wherein 0≤x≤1, 0≤y≤1, 0≤z≤1, FA represents (H2N=CH-NH2) + , and MA represents CH3NH3 + . For example, in some embodiments, the perovskite light-absorbing layer comprises (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, CsPbI3, CsPbI2Br, CsPbIBr2. The above-mentioned perovskite light-absorbing layer has adjustable band gap and good photoelectric performance.

[0084] In the present disclosure, the electron transport layer 14 is arranged between the perovskite light-absorbing layer 13 and the first electrode 11 and in contact with the perovskite light-absorbing layer 13, and comprises a fullerene derivative and an ionic compound shown in formula I.

[0085] In some embodiments, in the ionic compound shown in formula I, R1, R2 and R3 are methyl groups. As shown in FIG. 2, the cation in the ionic compound shown in formula I is a quaternary ammonium group, which is easy to be embedded in the A vacancy of the perovskite light-absorbing layer, reduces the carrier (electron and hole) recombination sites, and is conducive to further improving the open-circuit voltage of the solar cell.

[0086] In some embodiments, in the ionic compound represented by 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 an alkyl group. Optionally, R is selected from H or a C1-C10 alkyl group, and more preferably, R is selected from H or a C1-C4 alkyl group. Exemplarily, alkyl groups include methyl, ethyl, propyl, butyl, pentyl, hexyl, heptyl, octyl, nonyl, decyl, etc. In this embodiment, R' is selected from a halogen, and optionally, R' is selected from F, Cl, Br, or I, and more preferably, R' is selected from F or Cl.

[0087] In some embodiments, in the ionic compound shown in Formula I, R5 is selected from -OH or -SH. Optionally, R5 is selected from -OH. The aforementioned R5 has small steric hindrance, which is beneficial for the cation in the ionic compound shown in Formula I to intercalate into the A vacancy of the perovskite light-absorbing layer.

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

[0089] In some implementations, Y - Selected from Cl - BF4 - SCN - F - The aforementioned Y - Having a small ionic radius is advantageous for it to enter the X vacancy in the perovskite light-absorbing layer.

[0090] In some implementations, Y - Selected from Cl - BF4 - SCN - The aforementioned Y - Having a small ionic radius facilitates its entry into the X vacancy of the perovskite light-absorbing layer, and also contains the aforementioned Y... - Ionic compounds are easy to synthesize.

[0091] In some implementations, Y - Selected from Cl - ,Br - I - BF4 - SCN - Includes the above Y. -The ionic compound of Formula I is easy to synthesize.

[0092] In some embodiments, the ionic compound of Formula I is selected from at least one of (3-chloro-2-hydroxypropyl)trimethylammonium chloride (CHCl), 3-carboxy-2-hydroxy-N,N,N-trimethylpropan-1-aminium iodide (L-I), and L-camphor-10-sulfonic acid (3ChTCl). The ionic compound of Formula I can reduce the aggregation of the fullerene derivative, increase the conductivity of the electron transport layer, and improve the photoelectric performance of the solar cell. - selected from Cl - , I - , BF4 - , SCN - .

[0093] In some embodiments, the ionic compound of Formula I is selected from at least one of (3-chloro-2-hydroxypropyl)trimethylammonium chloride (CHCl), 3-carboxy-2-hydroxy-N,N,N-trimethylpropan-1-aminium iodide (L-I), and L-camphor-10-sulfonic acid (3ChTCl). The ionic compound of Formula I can reduce the aggregation of the fullerene derivative, increase the conductivity of the electron transport layer, and improve the photoelectric performance of the solar cell.

[0094] wherein the chemical formula of CHCl is:

[0095] wherein the chemical formula of L-I is:

[0096] wherein 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 (PC71 BM), and [6,6]-phenyl-C61 -butyric acid methyl ester (PC61 BM). The fullerene derivative has a high charge mobility, can effectively transfer photo-generated charges, reduce optical and electrical losses in the device, and form an effective contact with the perovskite light-absorbing layer and reduce the interface carrier recombination.

[0098] In some embodiments, the mass ratio of the fullerene derivative to the ionic compound of Formula I in the electron transport layer is 100:0.1-5, and optionally, the mass ratio is 100:1-2. For example, the mass ratio is 100:0.1, 100:1, 100:2, 100:3, 100:4, 100:5, or any value between the values of any two of the above values, but is not limited thereto. By controlling the mass ratio of the fullerene derivative to the ionic compound of Formula I in the above 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 particularly limit the thickness of the electron transport layer 14, and the thickness of the electron transport layer 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 comprises a hole transport layer arranged 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 transport the holes generated by the excitation of the perovskite light-absorbing layer 13 to the adjacent electrode, and prevent the holes from diffusing in the opposite direction, which can enhance the dissociation effect of electrons and holes, and further improve the photoelectric performance of the solar cell.

[0101] The present disclosure does not particularly limit the hole transport material used in the hole transport layer, and the hole transport material used in the art can be adopted. 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-bis(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), phosphonic monomer or polymer, carbazolyl monomer or polymer, sulfonic monomer or polymer, triphenylamine monomer or polymer, etc.

[0102] The present disclosure does not particularly limit the thickness of the hole transport layer, and the thickness of the hole transport layer 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 comprises a hole blocking layer arranged between the first electrode and the electron transport layer. By arranging the hole blocking layer, the non-radiative recombination of electrons and holes can be further reduced, thereby further improving the photoelectric performance of the solar cell.

[0104] The hole blocking layer comprises a hole blocking material. The present disclosure does not particularly limit the hole blocking material, and for example, the hole blocking material can include SnO z (1.5≤z≤2), 2,9-dimethyl-4,7-diphenyl-1,10-phenanthroline (BCP), etc.

[0105] The present disclosure does not particularly limit the thickness of the hole blocking layer, and the thickness of the hole blocking layer 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] FIG. 3 shows an exploded view of a solar cell according to an embodiment of the present disclosure. In this embodiment, the solar cell 100 comprises, in order from the direction of light incidence, 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. 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 described again here.

[0107] Those skilled in the art will understand that FIG. 3 is merely an example of an embodiment in which the solar cell comprises a hole blocking layer and a hole transport layer. In some embodiments, the solar cell can comprise only a hole blocking layer and not a hole transport layer. In some embodiments, the solar cell can comprise only a hole transport layer and not a hole blocking layer.

[0108] An embodiment of the present disclosure also provides a method for preparing a solar cell, comprising:

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

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

[0111] arranging an electron transport layer in contact with the perovskite light-absorbing layer between the perovskite light-absorbing layer and the first electrode;

[0112] wherein the electron transport layer comprises 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 make specific limitations on the embodiments of arranging the first electrode and the second electrode. For example, the first electrode and the second electrode can be arranged using a vapor deposition method.

[0115] The present disclosure does not make specific limitations on the embodiments of arranging the perovskite light-absorbing layer. For example, the perovskite light-absorbing layer can be arranged using a precursor solution spin coating method, a precursor solution slot coating method, a precursor solution doctor blade coating method, or the like.

[0116] In some embodiments, arranging the perovskite light-absorbing layer can comprise spin coating a perovskite precursor solution at a rotation speed of 5000 rpm for 25 s. After spin coating, annealing at 150°C for 20 min to obtain the perovskite light-absorbing layer.

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

[0118] In some embodiments, the arranging the 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 with a concentration of the fullerene derivative of 10-20 mg / mL;

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

[0121] applying the second solution on the perovskite light-absorbing layer to obtain the electron transport layer.

[0122] In the present disclosure, the type of the solvent is not specifically limited, and the solvent can satisfy the requirements of small damage to the perovskite light-absorbing layer and the ability to dissolve the fullerene derivative. For example, the solvent includes chlorobenzene.

[0123] In some embodiments, the concentration of the fullerene derivative in the first solution is 10-20 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 value within a range between any two of the values, but is not limited thereto.

[0124] In some embodiments, the concentration of the ion compound of Formula I in the second solution is 0.02-1 mg / mL. Optionally, the concentration of the ion compound of Formula I is 0.2-0.4 mg / mL. For example, the concentration of the ion 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 value within a range between any two of the values, but is not limited thereto.

[0125] In some embodiments, the mass ratio of the fullerene derivative to the ion compound of Formula I in the second solution is 100:0.1-5, optionally, the mass ratio is 100:1-2. For example, 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 value within a range between any two of the values, but is not limited thereto.

[0126] In some embodiments, the second solution can be applied on 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 any value within the range between any two values, but not limited thereto.

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

[0129] In some embodiments, the second solution after spin coating is heat treated to obtain the electron transport layer. In some embodiments, the heat treatment temperature is 80℃ to 120℃, and the heat treatment time is 5 min to 15 min. For example, the heat treatment temperature is 80℃, 90℃, 100℃, 110℃, 120℃ or any value within the range between any two values, but not limited thereto. For example, 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 any value within the range between any two values, but not limited thereto.

[0130] The preparation method of other functional layers (hole blocking layer, hole transport layer) of the solar cell is not particularly limited, and the preparation method commonly used in the art can be used. For example, electrochemical deposition method, chemical vapor deposition method, physical epitaxial growth method, vacuum thermal evaporation method, atomic layer deposition method, and magnetron sputtering method.

[0131] The embodiments of the present disclosure also provide a photovoltaic module. The photovoltaic module comprises the above-mentioned solar cell. In some embodiments, the photovoltaic module can further comprise a solder strip connecting a plurality of solar cells, a junction box for current transmission, and a cell packaging component.

[0132] In some embodiments, the cell packaging component comprises photovoltaic glass. The photovoltaic glass covers the above-mentioned solar cell and plays a role of protecting the solar cell. At the same time, the photovoltaic glass has very good light transmittance and very high hardness, and can adapt to large diurnal temperature difference and harsh weather environment.

[0133] In some embodiments, the cell packaging component comprises an ethylene-vinyl acetate copolymer (EVA) film arranged between the photovoltaic glass and the solar cell, and used for bonding the photovoltaic glass and the solar cell.

[0134] In some embodiments, the battery packaging component comprises a photovoltaic backsheet. The photovoltaic backsheet serves to protect the solar cell.

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

[0136] In some embodiments, the battery packaging component comprises a solar aluminum frame, which comprises an aluminum alloy material and has the characteristics of high strength and corrosion resistance. It can serve to support and protect the solar cell.

[0137] The present disclosure also provides a power generation device comprising the solar cell provided by the above embodiments.

[0138] The present disclosure also provides a power consumption device comprising the solar cell provided by the above embodiments.

[0139] In some embodiments, the power consumption device can further comprise lighting equipment, energy storage equipment, etc. The present disclosure includes but is not limited to the above. For example, the power consumption device can comprise a solar water heater, a solar street lamp, a solar photovoltaic generator, etc.

[0140] Embodiments

[0141] Hereinafter, embodiments of the present disclosure are described. The embodiments described below are exemplary and are only used to explain the present disclosure and cannot be understood as a limitation of the present disclosure. Unless otherwise specified, the reagents used are commercially available and the equipment used is conventional equipment.

[0142] Embodiment 1

[0143] The solar cell is prepared by the following steps.

[0144] Cleaning and treatment of the second electrode:

[0145] A digital multimeter is used to distinguish the conductive surface and the glass surface of the 2.0 cm x 2.0 cm FTO transparent conductive glass. The FTO transparent conductive glass is placed on a glass cleaning rack, and the conductive surface is recorded. The glass cleaning rack with the FTO transparent conductive glass is placed in an ultrasonic cleaner, and the glass is cleaned with surfactant, deionized water, isopropanol and anhydrous ethanol for 20 min, and finally dried in a 70°C oven for 5 min. The FTO transparent conductive glass is treated with an ultraviolet ozone (UV-O3) cleaning machine under a fume hood for 20 min, and cooled to room temperature for use.

[0146] Setting the hole transport layer:

[0147] Take 15 mg of nickel oxide (NiOx, 1≤X≤2) nanoparticles, disperse in 1 mL of deionized water, shake for 20 min until the nickel oxide nanoparticles are uniformly dispersed, then filter the obtained dispersion with a hydrophobic PTFE needle filter (the diameter of the needle filter is 25 mm, and the filter mesh size is 0.22 μm) to retain nickel oxide nanoparticles with a particle size of 7 nm to 15 nm. Take 150 μL of the obtained dispersion and spin-coat it on the conductive surface of the FTO transparent conductive glass in a spin coater at a speed of 3000 rpm for 25 s. After spin-coating, place it on a hot stage and anneal it at 140°C for 20 min, then naturally cool it to room temperature to obtain a hole transport layer with a thickness of 50 nm.

[0148] Setting up the perovskite light-absorbing layer:

[0149] Take 480.31 mg of formamidinium hydriodide (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] Subsequently, avoid light and shake for 5 h. After shaking is complete, use a filter head (the diameter of the needle filter is 25 mm, and the filter mesh size 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 s. At 35 s of spin-coating, quickly add 200 μL of chlorobenzene to control perovskite crystallization. After spin-coating is complete, anneal it at 150°C for 20 min to obtain a uniform, dense, and smooth 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] Setting 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 a 2 mL PC61BM chlorobenzene solution with a concentration of 20 mg / mL. Then add 0.4 mg of CHCl ((3-chloro-2-hydroxypropyl)trimethylammonium chloride) to the obtained solution to obtain a CHCl-PC61BM solution with a CHCl concentration of 0.2 mg / mL.

[0153] Take 90 μL of CHCl-PC61BM solution and spin-coat it onto the perovskite light-absorbing layer at 4000 rpm for 30 s. Then, anneal at 100 °C for 10 min to form an electron transport layer with a thickness of 30 nm on the perovskite light-absorbing layer.

[0154] Set a hole-blocking layer:

[0155] A 15 nm thick SnO2 hole-blocking layer was prepared on the electron transport layer by atomic layer deposition.

[0156] Set the first electrode:

[0157] A 140 nm thick layer of metallic copper (Cu) was deposited on the hole-blocking layer as the first electrode. Before deposition, a vacuum of 1.0 × 10⁻⁶ was first applied. -4 Pa, then pre-deposited for 5 minutes. During the deposition process, when the copper thickness is in the 0-20 nm range, the Cu evaporation rate is approximately 0.5 A / s; when the copper thickness is in the 20 nm-140 nm range, the Cu evaporation rate is approximately 6 A / s.

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

[0159] Example 2

[0160] Except for adjusting the amount of CHCl added to 0.6 mg during the electron transport layer setup to prepare a CHCl-PC61BM solution with a CHCl concentration of 0.3 mg / mL, the solar cell was prepared in the same manner as in Example 1.

[0161] Example 3

[0162] Except for adjusting the amount of CHCl added to 0.8 mg during the electron transport layer setup to prepare a CHCl-PC61BM solution with a CHCl concentration of 0.4 mg / mL, the solar cell was prepared in the same manner as in Example 1.

[0163] Example 4

[0164] The 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-iodide (LI) was used instead of 0.2 mg of CHCl during the electron transport layer setup.

[0165] Example 5

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

[0167] Comparative Example 1

[0168] A solar cell was prepared in the same manner as in Example 1 except that 0.2 mg of CHCl was not added during the process of setting 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 process of setting the electron transport layer.

[0171] wherein 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 process of setting 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 process of setting 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-trimethylethanaminium tetrafluoroborate (CHOBF) was used instead of 0.2 mg of CHCl during the process of setting the electron transport layer.

[0178] Performance test of solar cell

[0179] The photoelectric performance parameters of the solar cell were tested under standard test conditions: total irradiance 100 mW / cm 2 , and spectral intensity AM1.5G using a solar simulator. P out , P in , V mpp , J mpp , V OC , J SC Then, the photoelectric conversion efficiency (PCE) was 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] wherein, P out , P in , V mpp , J mpp , FF, V OC , J SC are the battery working output power, incident light power, battery maximum power point voltage, battery maximum power point current, fill factor, short-circuit current, open-circuit voltage, respectively.

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

[0182] Table 1

[0183] As can be seen from the data in Table 1, compared with the solar cells of Comparative Examples 1-5, the solar cells of Examples 1-5, in which the ion compound represented by Formula I is arranged in the electron transport layer, achieve the improvement of the photoelectric performance of the cells.

[0184] Four solar cells were respectively prepared according to the methods of Examples 1-5. The performances of these solar cells were tested by the above-mentioned test methods, and the box plot of the photoelectric performance parameters of the solar cells prepared in Examples 1-5 was drawn, as shown in Figure 4. It can be seen that the solar cells of Examples 1-5 have good reproducibility.

[0185] It should be noted that the present disclosure is not limited to the above-mentioned embodiments. The above-mentioned embodiments are only examples, and embodiments having the same technical idea and substantially the same function and effect within the scope of the technical solutions of the present disclosure are all included in the technical scope of the present disclosure. In addition, within the scope of the main idea of the present disclosure, various modifications that can be thought of by those skilled in the art, and other ways constructed by combining part of the components 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 arranged between the first electrode and the second electrode, an electron transport layer arranged between the perovskite light absorbing layer and the first electrode and in contact with the perovskite light absorbing layer; The electron transport layer comprises a fullerene derivative and an ionic compound shown in formula I: wherein R 1, R 2 and R 3 are independently selected from H or methyl, R 4 is selected from an electron withdrawing group, R 5 is selected from an electron donating group, and Y is selected from halogen or halogen-like.

2. The solar cell according to claim 1, wherein, R 4 is selected from -C(=O)R, -COOR, -SO 3R, -CN, -CR' 3, -NO 2 or -R'; wherein R is selected from H or C 1-C 10 alkyl; R' is selected from F, Cl, Br or I.

3. The solar cell according to claim 1 or 2, wherein R 5 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 of any one of claims 1-4, wherein R 1, R 2 and R 3 are methyl; R 4 is selected from -COOH, -C(=O)H, -COOCH 3, -CN, -CCl 3, -NO 2, -Cl; R 5 is -OH; Y - selected from CI - , I - , BF4 - , SCN - .

6. The solar cell according to claim 1 or 2, wherein the ionic compound of Formula I comprises one or more of (3-chloro-2-hydroxypropyl)trimethylammonium chloride, 3-carboxy-2-hydroxy-N,N,N-trimethylpropan-1-aminium iodide, L-carnitine.

7. The solar cell according to any one of claims 1 to 6, wherein, the fullerene derivative is selected from at least one of IC 60 BA, Bia-C 60, ICMA, PC 71 BM, PC 61 BM.

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

9. The solar cell of claim 8, wherein, a mass ratio of the fullerene derivative to the ionic compound of 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 a compound of Formula [A][B][X] 3, a compound of Formula [A] 2[C][D][X] 6, wherein A comprises at least one of inorganic or organic monovalent cations, 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 of 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, wherein 0≤x≤1, 0≤y≤1, 0≤z≤1, FA represents (H2N=CH-NH2) + , and 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 arranged between the first electrode and the electron transport layer; and / or a hole transport layer arranged between the second electrode and the perovskite light absorbing layer. 13.The solar cell of any one of claims 1-12, wherein at least one of the first electrode, the second electrode is a transparent electrode. 14.A method for preparing a solar cell, comprising: providing a first electrode and a second electrode; arranging a perovskite light absorbing layer between the first electrode and the second electrode; arranging an electron transport layer in contact with the perovskite light absorbing layer between the perovskite light absorbing layer and the first electrode; The electron transport layer comprises a fullerene derivative and an ionic compound shown in formula I: wherein R 1, R 2 and R 3 are independently selected from H or methyl, R 4 is selected from an electron withdrawing group, R 5 is selected from an electron donating group, and Y is selected from halogen or halogen-like.

15. The method of making according to claim 14, wherein, arranging the electron transport layer in contact with the perovskite light absorbing layer comprises: dissolving the fullerene derivative in a solvent to obtain a first solution with a concentration of the fullerene derivative of 10-20 mg / mL; adding an ionic compound represented by Formula I 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; applying the second solution to the perovskite light-absorbing layer to obtain the electron transport layer.

16. The method of manufacturing according to claim 15, wherein, The concentration of the ionic compound represented by Formula I in the second solution is 0.2 mg / mL to 0.4 mg / mL.

17. A photovoltaic module comprising the solar cell of any one of claims 1 to 13 or prepared by the method of any one of claims 14 to 16.

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

19. An electric device comprising the solar cell of any one of claims 1 to 13 or prepared by the method of any one of claims 14 to 16.

Images