Solar cell, photovoltaic module, power generation device, electric device, and polymer

Abstract

The present disclosure provides a solar cell, a photovoltaic module, a power generation device, an electric device, and a polymer. The solar cell comprises a first electrode, a hole transport layer, a perovskite light-absorbing layer, and a second electrode that are stacked in sequence. The hole transport layer comprises a self-assembled monolayer, the self-assembled monolayer comprises a polymer, and the polymer comprising repeating units of formula (I). In formula (I), ArD represents an aromatic electron-donating unit; ArA represents an aromatic electron-withdrawing unit; L represents a linking group having two linking sites; A represents an oxyacid group or a corresponding salt thereof; and m is an integer from 0 to 10.

Description

Solar cell, photovoltaic module, power generation device, power consumption device and polymer

[0001] Cross Reference to Related Applications

[0002] The present disclosure is based on and claims priority to Chinese Patent Application No. 202411342307.X, filed on September 24, 2024, entitled “Solar cell, photovoltaic module, power generation device, power consumption device and polymer”, 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 photovoltaic module, a power generation device, a power consumption device and a polymer. 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 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, which hinders their practical application and industrial development. Therefore, how to improve the stability of perovskite solar cells is still a technical problem 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 photovoltaic module, a power generation device, a power consumption device and a polymer. The solar cell has improved photoelectric conversion efficiency and stability.

[0008] To achieve the above-mentioned purpose, the present disclosure provides a solar cell, the solar cell comprising: a first electrode, a hole transport layer, a perovskite light-absorbing layer and a second electrode which are sequentially stacked; wherein the hole transport layer comprises a self-assembled monolayer, the self-assembled monolayer comprises a polymer, and the polymer comprises a repeating unit of formula (I):

[0009] In formula (I), ArD represents an aromatic electron-donating unit; ArA represents an aromatic electron-withdrawing unit; L represents a linking group having two linking sites; A represents an oxygen-containing acid group or a corresponding salt thereof; and m is an integer from 0 to 10. In the solar cell of the present disclosure, the self-assembled monolayer comprises a polymer, so that the self-assembled monolayer can maintain a good morphology under high temperature and light conditions, which is conducive to improving the stability of the solar cell. Meanwhile, the donor-acceptor (D-A) interaction in the self-assembled monolayer is conducive to improving the charge transport capability of the self-assembled monolayer, and thus is conducive to improving the photoelectric conversion efficiency of the solar cell.

[0010] In some embodiments, the repeating unit of formula (I) satisfies one or more of the following conditions:

[0011] (1) ArD is selected from any one of the following structural formulas represented by ArD1 to ArD9:

[0012] In each of the structural formulas represented by ArD1 to ArD9, the dotted bond represents a single bond connected to L, and R D are each independently selected from any one of a single bond, hydrogen, halogen, -OR', -OC(=O)R', -NHC(=O)R', -NR'2, R', halogen-substituted R', -SR', and -PR'2, provided that in each of the structural formulas represented by ArD1 to ArD9, there is and only one R D is a single bond;

[0013] In each of the structural formulas represented by ArD7 to ArD9, Y is each independently selected from any one of -CR2-, -NR-, -O-, -SiR2-, -PR-, -S-, -As-, and -Se;

[0014] In the structural formula represented by ArD7, k is an integer from 1 to 3;

[0015] (2) ArA is selected from any one of the following structural formulas represented by ArA1 to ArA8:

[0016] In each of the structural formulas represented by ArA1 to ArA8, Z is each independently selected from CR or N, provided that in each of the structural formulas represented by ArA1 to ArA8, there is and only one Z is N, wherein in formula , the dotted bond represents a single bond connected to the adjacent ArD group;

[0017] In each of the structural formulas represented by ArA4 to ArA8, Y' is independently selected from any one of -CR2-, -NR-, -O-, -SiR2-, -PR-, -S-, -As-, -Se-, -C(=O)-, -C(=S)-, -C(=NR)-, and -C(=CR2)-;

[0018] (3) L is selected from -CR2-, -CR2-CR2-, -NR-, -O-, -SiR2-, -PR-, -S-, -C(=O)-, -C(=S)-, -C(=NR)-, -C(=CR2)-, or any one or a combination of more than one of the structural formulas represented by L1 to L8;

[0019] In each of the structural formulas represented by L1 to L8, Z is independently selected from CR or N;

[0020] In each of the structural formulas represented by L2, L5 to L7, Y is independently selected from any one of -CR2-, -NR-, -O-, -SiR2-, -PR-, -S-, -As-, -Se-, -C(=O)-, -C(=S)-, -C(=NR)-, and -C(=CR2)-;

[0021] (4) A is selected from any one of -COOH, -PO(OH)2, -PHO(OH), -SO2(OH), and -B(OH)2;

[0022] In the above R-containing groups, R is independently selected from any one of hydrogen, halogen, R', halogen-substituted R', -OR', -OC(=O)R', -NHC(=O)R', -NR'2, -SR', and -PR'2;

[0023] In the above R'-containing groups, R' is independently selected from any one of substituted or unsubstituted phenyl, thienyl, and C1 to C10 alkyl.

[0024] By selecting one or more of the above groups, the stability and charge transport ability of the self-assembled monolayer are more favorably improved, and thus the stability and photoelectric conversion efficiency of the solar cell are more favorably improved.

[0025] In some embodiments, the repeating unit of formula (I) satisfies one or more of the following conditions:

[0026] (1) ArD is selected from any one of the structural formulas represented by ArD10 to ArD21:

[0027] In each of the structural formulas represented by ArD10 to ArD21, R Deach independently selected from any one of hydrogen, halogen, -OR', -OC(=O)R', -NHC(=O)R', -NR'2, R', halogen-substituted R', -SR', -PR'2; R" is a single bond;

[0028] In each of the structural formulas represented by ArD19 to ArD21, Y is each independently selected from any one of -CR2-, -NR-, -O-, -S-, -Se-;

[0029] In the structural formula represented by ArD19, k is an integer from 1 to 3;

[0030] (2) ArA is selected from any one of the structural formulas represented by ArA9 to ArA15:

[0031] In each of the structural formulas represented by ArA11 to ArA15, Y' is each independently selected from any one of -NR-, -O-, -S-, -Se-, -C(=O)-;

[0032] In each of the structural formulas represented by ArA11, ArA12, ArA15, Z is each independently selected from CR or N;

[0033] (3) L is selected from -CR2-, -CR2-CR2-, -NR-, -O-, -C(=O)-, or a combination of any one or more of the structural formulas represented by L9 to L11,

[0034] In each of the structural formulas represented by L9 to L11, Y is each independently selected from any one of -CR2-, -NR-, -O-, -S-, -Se-;

[0035] (4) A is selected from -COOH or -PO(OH)2;

[0036] (5) m is an integer from 0 to 5,

[0037] In the above group containing R, R is as defined in the above embodiments,

[0038] In the above group containing R', R' is as defined in the above embodiments.

[0039] Thus, it is more conducive to improve the stability and charge transport ability of the self-assembled monolayer, thereby more conducive to improve the stability and photoelectric conversion efficiency of the solar cell.

[0040] In some embodiments, the polymer of Formula (I) satisfies one or more of the following conditions:

[0041] (1) ArD is selected from any one of the structural formulas represented by ArD11, ArD16, and ArD19;

[0042] (2) ArA is selected from any one of the structural formulas represented by ArA9, ArA12, and ArA15;

[0043] (3) L is selected from any one or a combination of more than one of -CR2-, -CR2-CR2-, or L9.

[0044] In some embodiments, the repeating unit of formula (I) comprises one or more of the repeating units represented by formulas U1-U5:

[0045] In some embodiments, the polymer has a degree of polymerization of an integer from 2 to 100000.

[0046] In some embodiments, the self-assembled monolayer has a thickness of 0.25 nm to 5 nm. In this way, it is beneficial to form a monolayer film.

[0047] In some embodiments, the hole transport layer further comprises a metal oxide layer, the metal oxide layer is located between the self-assembled monolayer and the first electrode, and the metal oxide layer has a thickness of 10 nm to 100 nm. In this way, it is more beneficial to improve the stability of the solar cell.

[0048] In some embodiments, the solar cell comprises a first electrode, a hole transport layer, a perovskite light-absorbing layer, an electron transport layer, and a second electrode which are sequentially stacked, wherein the first electrode is a transparent electrode. In this way, a transsolar cell is obtained.

[0049] The second aspect of the present disclosure provides a photovoltaic module, the photovoltaic module comprising the solar cell provided in the first aspect.

[0050] The third aspect of the present disclosure provides a power generation device, the power generation device comprising the solar cell provided in the first aspect.

[0051] The fourth aspect of the present disclosure provides a power consumption device, the power consumption device comprising the solar cell provided in the first aspect.

[0052] The photovoltaic module, the power generation device, and the power consumption device of the present disclosure comprise the solar cell provided in the present disclosure, and thus at least have the same advantages as the solar cell.

[0053] The fifth aspect of the present disclosure provides a polymer, the polymer comprising a repeating unit of formula (I):

[0054] In formula (I), ArD represents an aromatic electron-donating unit; ArA represents an aromatic electron-withdrawing unit; L represents a linking group having two linking sites; A represents an oxygen-containing acid group or a corresponding salt thereof; and m is an integer from 0 to 10.

[0055] In the self-assembled monolayer of the perovskite solar cell, the polymer is included, and the self-assembled monolayer can maintain a good morphology under high temperature and light conditions, thereby being conducive to improving the stability of the self-assembled monolayer, and further being conducive to improving the stability of the solar cell. At the same time, the donor-acceptor (D-A) interaction in the self-assembled monolayer is conducive to improving the charge transport capability of the self-assembled monolayer, and further being conducive to improving the photoelectric conversion efficiency of the solar cell.

[0056] In some embodiments, the repeating unit of formula (I) satisfies one or more of the following conditions:

[0057] (1) ArD is selected from any one of the following ArD1 to ArD9:

[0058] In each of the structural formulas represented by ArD1 to ArD9, the dotted bond represents a single bond connected to L, and R D are each independently selected from any one of a single bond, hydrogen, halogen, -OR', -OC(=O)R', -NHC(=O)R', -NR'2, R', halogen-substituted R', -SR', and -PR'2, provided that in each of the structural formulas represented by ArD1 to ArD9, there are and only two R D are single bonds;

[0059] In each of the structural formulas represented by ArD7 to ArD9, Y is each independently selected from any one of -CR2-, -NR-, -O-, -SiR2-, -PR-, -S-, -As-, and -Se;

[0060] In the structural formula represented by ArD7, k is an integer from 1 to 3;

[0061] (2) ArA is selected from any one of the following ArA1 to ArA8:

[0062] In each of the structural formulas represented by ArA1 to ArA8, Z is each independently selected from CR or N, provided that in each of the structural formulas represented by ArA1 to ArA8, there are and only two Zs that are and at least one Z is N, wherein, in formula the dotted bond represents a single bond connected to an adjacent ArD group;

[0063] In each of the structural formulas represented by ArA4 to ArA8, Y' is independently selected from any one of -CR2-, -NR-, -O-, -SiR2-, -PR-, -S-, -As-, -Se-, -C(=O)-, -C(=S)-, -C(=NR)-, and -C(=CR2)-;

[0064] (3) L is selected from -CR2-, -CR2-CR2-, -NR-, -O-, -SiR2-, -PR-, -S-, -C(=O)-, -C(=S)-, -C(=NR)-, -C(=CR2)-, or any one or a combination of more than one of the structural formulas represented by L1 to L8;

[0065] In each of the structural formulas represented by L1 to L8, Z is independently selected from CR or N;

[0066] In each of the structural formulas represented by L2, L5 to L7, Y is independently selected from any one of -CR2-, -NR-, -O-, -SiR2-, -PR-, -S-, -As-, -Se-, -C(=O)-, -C(=S)-, -C(=NR)-, and -C(=CR2)-;

[0067] (4) A is selected from any one of -COOH, -PO(OH)2, -PHO(OH), -SO2(OH), and -B(OH)2;

[0068] In the above R-containing groups, R is independently selected from any one of hydrogen, halogen, R', halogen-substituted R', -OR', -OC(=O)R', -NHC(=O)R', -NR'2, -SR', and -PR'2;

[0069] In the above R'-containing groups, R' is independently selected from any one of substituted or unsubstituted phenyl, thienyl, and C1 to C10 alkyl.

[0070] By selecting one or more of the above groups, the stability and charge transport ability of the self-assembled monolayer are more favorably improved, and thus the stability and photoelectric conversion efficiency of the solar cell are more favorably improved.

[0071] In some embodiments, the repeating unit of formula (I) satisfies one or more of the following conditions:

[0072] (1) ArD is selected from any one of the structural formulas represented by ArD10 to ArD21:

[0073] In each of the structural formulas represented by ArD10 to ArD21, R Deach independently selected from any one of hydrogen, halogen, -OR', -OC(=O)R', -NHC(=O)R', -NR'2, R', halogen-substituted R', -SR', -PR'2; R" is a single bond;

[0074] In each of the structural formulas represented by ArD19 to ArD21, Y is each independently selected from any one of -CR2-, -NR-, -O-, -S-, -Se-;

[0075] In the structural formula represented by ArD19, k is an integer from 1 to 3;

[0076] (2) ArA is selected from any one of the structural formulas represented by ArA9 to ArA15:

[0077] In each of the structural formulas represented by ArA11 to ArA15, Y' is each independently selected from any one of -NR-, -O-, -S-, -Se-, -C(=O)-;

[0078] In each of the structural formulas represented by ArA11, ArA12, ArA15, Z is each independently selected from CR or N;

[0079] (3) L is selected from -CR2-, -CR2-CR2-, -NR-, -O-, -C(=O)-, or a combination of any one or more of the structural formulas represented by L9 to L11,

[0080] In each of the structural formulas represented by L9 to L11, Y is each independently selected from any one of -CR2-, -NR-, -O-, -S-, -Se-;

[0081] (4) A is selected from -COOH or -PO(OH)2;

[0082] (5) m is an integer from 0 to 5,

[0083] In the above group containing R, R is as defined in the above embodiments,

[0084] In the above group containing R', R' is as defined in the above embodiments.

[0085] Therefore, it is more conducive to improve the stability and charge transport ability of the self-assembled monolayer, thereby more conducive to improving the stability and photoelectric conversion efficiency of the solar cell.

[0086] In some embodiments, the repeating unit of formula (I) satisfies one or more of the following conditions:

[0087] (1) ArD is selected from any one of the structural formulas represented by ArD11, ArD16, and ArD19;

[0088] (2) ArA is selected from any one of the structural formulas represented by ArA9, ArA12, and ArA15;

[0089] (3) L is selected from any one or a combination of more than one of -CR2-, -CR2-CR2-, or L9.

[0090] In some embodiments, the repeating unit of formula (I) comprises one or more of the repeating units represented by formulas U1 to U5:

[0091] In some embodiments, the polymer has a degree of polymerization of an integer from 2 to 100,000.

[0092] The solar cell of the present disclosure comprises a self-assembled monolayer comprising a polymer comprising a repeating unit of formula (I). The self-assembled monolayer comprising the polymer can maintain a good morphology under high temperature and light conditions, thereby being conducive to improving the stability of the self-assembled monolayer, and further being conducive to improving the stability of the solar cell. Meanwhile, the donor-acceptor (D-A) interaction within the self-assembled monolayer is conducive to improving the charge transport capability of the self-assembled monolayer, and further being conducive to improving the photoelectric conversion efficiency of the solar cell. BRIEF DESCRIPTION OF DRAWINGS

[0093] FIG. 1 shows a structural schematic diagram of a solar cell according to an embodiment of the present disclosure.

[0094] FIG. 2 shows a structural schematic diagram of a solar cell according to an embodiment of the present disclosure.

[0095] BRIEF DESCRIPTION OF DRAWINGS DETAILED DESCRIPTION

[0096] Hereinafter, embodiments of the solar cell, the photovoltaic module, the power generation device, the power consumption device, and the polymer of the present disclosure are specifically disclosed with appropriate reference to the accompanying drawings. However, there will be cases where unnecessary detailed description is omitted. For example, there will be cases where detailed description of matters that are well known, repeated description of substantially the same structure, is 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 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.

[0097] The ranges disclosed herein are defined by their lower and upper limit. Any range listed is defined to include both endpoints and also to include any integer or fraction between the end points. For example, a range from 60-120 and a range from 80-110 should be considered to include a range from 60-110 and a range from 80-120. Also, a minimum range value of 1 and 2, and a maximum range value of 3, 4 and 5, the following ranges are all contemplated: 1-3, 1-4, 1-5, 2-3, 2-4 and 2-5. In the present disclosure, a numerical range "a-b" indicates a shorthand way of describing each and every integer and fraction between the endpoints a and b, wherein a and b are both real numbers. For example, the numerical range "0-5" indicates that all real numbers between "0-5" have been listed herein, and "0-5" is merely a shorthand way of describing those numerical combinations. Also, when a parameter is stated to be an integer > 2, it is equivalent to disclose that the parameter is, for example, an integer 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, etc.

[0098] If not specifically explained, all the embodiments and optional embodiments of the present disclosure can be combined with each other to form new technical solutions.

[0099] If not specifically explained, all the technical features and optional technical features of the present disclosure can be combined with each other to form new technical solutions.

[0100] If not specifically explained, all the steps of the present disclosure can be performed in sequence or randomly, and preferably in sequence. For example, the method comprises steps (a) and (b), which means that the method can comprise steps (a) and (b) performed in sequence, or steps (b) and (a) performed in sequence. For example, the method also comprises step (c), which means 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.

[0101] The term "alkyl" refers to branched and straight-chain saturated aliphatic hydrocarbon groups and has the indicated number of carbon atoms, for example, C1-C20 alkyl groups having 1 to 20 carbon atoms. The term "C1-C10 alkyl" as used herein denotes alkyl groups having 1 to 10 carbon atoms, for example C1-C2, C1-C3, C1-C4, C1-C5, C1-C6 alkyl groups. Examples of alkyl groups include, but are not limited to, methyl, ethyl, n-propyl, i-propyl, n-butyl, t-butyl.

[0102] The term "halogen" includes one or more of F, CI, Br, I.

[0103] The term "aryl" refers to a monovalent, all-carbon monocyclic or fused polycyclic group having a conjugated pi-electron system. The term "six- to ten-membered aryl" refers to a 6- to 10-membered, all-carbon monocyclic or fused polycyclic group having a conjugated pi-electron system. Examples of aryl groups include, but are not limited to, phenyl, naphthyl, and the like.

[0104] The term "phenyl" refers to a structure represented by the formula .

[0105] The term "thienyl" refers to a structure represented by the formula .

[0106] The term "aromatic electron-withdrawing unit" or "ArA" refers to a unit of a monocyclic, polycyclic, or fused polycyclic structure having a conjugated pi-electron system, wherein the unit contains a group that is more likely to withdraw an electron from the bonding atom side than a hydrogen atom. Specific examples of electron-withdrawing groups include, but are not limited to, -N=, the nitrogen atom of which is sp 2 hybridized, and the lone pair of which does not participate in conjugation, and the electronegativity of the nitrogen element is stronger than that of the carbon atom, thereby exhibiting an electron-withdrawing property. Other specific examples of electron-withdrawing groups also include halogen atoms (-F, -CI, -Br, -I), a trifluoromethyl group (-CF3), a nitro group (-NO2), a cyano group (-CN), an acyl group, a sulfonyl group, and the like, but are not limited thereto.

[0107] The term "aromatic electron-donating unit" or "ArD" refers to a unit of a monocyclic, polycyclic, or fused polycyclic structure having a conjugated pi-electron system, wherein the unit contains a group that is more likely to donate an electron from the bonding atom side than a hydrogen atom. Specific examples of electron-donating groups include, but are not limited to, -NR-, -PR-, -O-, or -S-, the atoms of which are sp 3 hybridized, and each of which contains a lone pair of electrons, the lone pair of electrons of which is conjugated with the aromatic ring, thereby exhibiting an electron-donating property; other specific examples of electron-donating groups also include -OH, a thiol group (-SH), an alkoxy group, an alkyl sulfide group, an aryl sulfide group, an amino group (-NH2), a morpholino group, a piperidyl group, a methyl group, and the like, but are not limited thereto.

[0108] The term "electrode" refers to a region or layer composed of or consisting essentially of an electrode material.

[0109] The term "layer" as used in the present disclosure refers to any substantially layer-like structure. A layer can have a thickness that varies over the extent of the layer. Typically, a 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. For example, a Zygo NewView 9000 model white light interferometer can be employed.

[0110] The term "arranged / disposed on" if not specifically stated otherwise refers to providing or disposing one component on another component. The first component can be provided or disposed 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 that there is an intermediate third layer between the first layer and the second layer.

[0111] The term "perovskite material" as used in the present disclosure refers to a material having a three-dimensional crystal structure related to that of CaTiO3, or a layer material comprising 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 to generate electron-hole pairs.

[0112] A solar cell, also referred to as a photovoltaic cell, is a device that converts light energy directly into electricity by the photovoltaic effect or photochemical effect. A perovskite solar cell is a solar cell that uses a perovskite material as a light-absorbing material. Compared with other solar cells, a perovskite solar cell has a high photoelectric conversion efficiency. Hereinafter, a solar cell refers to a solar cell whose light-absorbing layer contains a perovskite material, which can also be referred to as a perovskite solar cell.

[0113] The principle of photoelectric conversion of a solar cell is as follows: incident light (for example, sunlight) enters the interior of the device, and then reaches and is absorbed by a perovskite light-absorbing layer. Under the excitation of incident light, the perovskite light-absorbing layer generates hole-electron pairs, and under the action of an electric field, the holes and electrons are separated, the electrons are transported to one electrode, and the holes are transported to the other electrode. Subsequently, a loop is formed via an external circuit, which can be used to drive a load to work.

[0114] In a perovskite solar cell, the presence of perovskite surface defects can cause non-radiative recombination of charge carriers, thereby adversely affecting the photoelectric performance and stability of the cell. To address this problem, in the related art, a self-assembled monolayer (SAM) is provided on the lower surface of the perovskite layer as a lower passivation layer to passivate the lower surface of the perovskite layer, in an attempt to passivate the perovskite layer. In the related art, a self-assembled small molecule as shown in the following formula (II) is typically used to form a self-assembled monolayer.

[0115] The self-assembled small molecule comprises three parts of a terminal group Ar, a carbon chain L1, and a head group A. The self-assembled small molecule forming the SAM is highly oriented, the head group A is combined with the surface of the substrate, and the terminal group Ar is in contact with the perovskite lower interface to passivate the surface defects of the perovskite, so that the perovskite solar cell has a larger open-circuit voltage, short-circuit current density, and fill factor, and a higher photoelectric conversion efficiency.

[0116] However, the self-assembled small molecule is connected to the substrate by hydrogen bonding, and the small molecules in the self-assembled monolayer rely on van der Waals forces and / or π-π interactions. Therefore, the morphology stability of the self-assembled monolayer under high temperature and light conditions is poor, which affects the stability of the solar cell. In addition, the charge transport capacity of the existing self-assembled monolayer is limited, and the photoelectric conversion efficiency needs to be improved. Therefore, it is still necessary to provide a technology to improve the morphology stability and charge transport capacity of the self-assembled monolayer under high temperature and light conditions, so as to improve the photoelectric performance and stability of the perovskite solar cell.

[0117] Based on this, the present disclosure provides a solar cell, a photovoltaic module comprising the solar cell, a power generation device, a power consumption device, and a polymer. The present disclosure and optional embodiments are described in more detail below.

[0118] Solar cell

[0119] The first aspect of the present disclosure provides a solar cell. The solar cell comprises a first electrode, a hole transport layer, a perovskite light-absorbing layer, and a second electrode which are sequentially stacked; wherein the hole transport layer comprises a self-assembled monolayer, the self-assembled monolayer comprises a polymer, and the polymer comprises a repeating unit of formula (I):

[0120] In formula (I), ArD represents an aromatic electron-donating unit; ArA represents an aromatic electron-withdrawing unit; L represents a linking group having two linking sites; A represents an oxygen-containing acid group or a corresponding salt thereof; and m is an integer from 0 to 10.

[0121] In the solar cell of the present disclosure, the hole transport layer comprises a self-assembled monolayer, and the self-assembled monolayer comprises a polymer, and the polymer comprises a repeating unit of formula (I). In the repeating unit of formula (I), an aromatic electron-donating unit (ArD) and an aromatic electron-withdrawing unit (ArA) are included, thereby forming a polymer with a main chain having a donor-acceptor interaction. The self-assembled monolayer comprising the polymer can maintain a good morphology under high temperature and light conditions, thereby being conducive to improving the stability of the self-assembled monolayer, and further being conducive to improving the stability of the solar cell. Meanwhile, the donor-acceptor (D-A) interaction in the self-assembled monolayer improves the energy band structure of the self-assembled monolayer material, and is conducive to improving the charge transport capability of the self-assembled monolayer, and further being conducive to improving the photoelectric conversion efficiency of the solar cell. Thus, the solar cell of the present disclosure has improved photoelectric performance and stability.

[0122] The polymer comprising the repeating unit of formula (I) in the solar cell of the present disclosure can be determined by instruments and methods known in the art. For example, by matrix-assisted laser desorption / ionization time-of-flight mass spectrometry (MALDI-TOF) determination, if the main peaks in the mass spectrum are in an arithmetic progression distribution, and the difference between adjacent main peaks is the relative molecular mass of the repeating unit of the polymer, it is indicated that the solar cell contains the polymer comprising the repeating unit of formula (I) of the present disclosure.

[0123] In some embodiments, ArD is selected from any one of the structural formulae represented by ArD1 to ArD9:

[0124] In each of the structural formulae represented by ArD1 to ArD9, the dashed bond represents a single bond connected to L, and R D each independently is selected from any one of a single bond, hydrogen, halogen, -OR’, -OC(=O)R’, -NHC(=O)R’, -NR’2, R’, halogen-substituted R’, -SR’, -PR’2, provided that in each of the structural formulae represented by ArD1 to ArD9, there are and only two R D is a single bond.

[0125] In each of the structural formulae represented by ArD7 to ArD9, Y is each independently selected from any one of -CR2-, -NR-, -O-, -SiR2-, -PR-, -S-, -As-, -Se-. Alternatively, Y is each independently selected from -CR2- or -S-.

[0126] In the structural formula represented by ArD7, k is an integer from 1 to 3. Exemplarily, k can be 1, 2 or 3. Alternatively, k can be 1.

[0127] In some embodiments, ArA is selected from any one of the following structural formulae of ArA1-ArA8:

[0128] In each of the structural formulae of ArA1-ArA8, each Z is independently selected from CR or N, provided that in each of the structural formulae of ArA1-ArA8, there is and only one Z is and at least one Z is N, wherein in the formula the dashed bond represents a single bond to an adjacent ArD group.

[0129] In each of the structural formulae of ArA4-ArA8, each Y' is independently selected from any one of -CR2-, -NR-, -O-, -SiR2-, -PR-, -S-, -As-, -Se-, -C(=O)-, -C(=S)-, -C(=NR)-, -C(=CR2)-. Alternatively, each Y' is independently selected from -S-.

[0130] In some embodiments, L is selected from -CR2-, -CR2-CR2-, -NR-, -O-, -SiR2-, -PR-, -S-, -C(=O)-, -C(=S)-, -C(=NR)-, -C(=CR2)-, or a combination of any one or more of the following L1-L8:

[0131] In each of the structural formulae of L1-L8, each Z is independently selected from CR or N. Alternatively, each Z is independently selected from CR, wherein R is hydrogen.

[0132] In each of the structural formulae of L2, L5-L7, each Y is independently selected from any one of -CR2-, -NR-, -O-, -SiR2-, -PR-, -S-, -As-, -Se-, -C(=O)-, -C(=S)-, -C(=NR)-, or -C(=CR2)-.

[0133] Alternatively, L is selected from -CR2-, -CR2-CR2-, or a combination of any one or more of L1. Alternatively, R is hydrogen. Alternatively, in the structural formula of L1, each Z is selected from CR, wherein R is hydrogen.

[0134] In some embodiments, A is selected from any one of -COOH, -PO(OH)2, -PHO(OH), -SO2(OH), or -B(OH)2. Alternatively, A is selected from -COOH or -PO(OH)2.

[0135] In the above R-containing groups, each R is independently selected from any one of hydrogen, halogen, R', halogen-substituted R', -OR', -OC(=O)R', -NHC(=O)R', -NR'2, -SR', -PR'2.

[0136] In the above R'-containing groups, each R' is independently selected from any one of substituted or unsubstituted phenyl, thienyl, C1-C10 alkyl. Exemplarily, in the case that R' has a substituent, the substituent can each independently include one or more of hydroxyl, nitro, cyano, carboxyl, ester, C1-C10 alkyl, C1-C10 alkoxy, 6- to 10-membered aryl.

[0137] By including a polymer containing one or more of the above groups, it is more advantageous to improve the stability and charge transport ability of the self-assembled monolayer, thereby more advantageously improving the photoelectric performance and stability of the solar cell.

[0138] In some embodiments, ArD is selected from any one of the following structural formulas of ArD10-ArD21:

[0139] In each of the structural formulas of ArD10-ArD21, each R D is independently selected from any one of hydrogen, halogen, -OR', -OC(=O)R', -NHC(=O)R', -NR'2, R', halogen-substituted R', -SR', -PR'2; R" is a single bond. Alternatively, each R D is selected from hydrogen.

[0140] In each of the structural formulas of ArD19-ArD21, each Y is independently selected from any one of -CR2-, -NR-, -O-, -S-, -Se-. Alternatively, each Y is independently selected from -CR2- or -S-, wherein R is selected from R', and R' is selected from C1-C10 alkyl.

[0141] In the structural formula of ArD19, k is an integer from 1 to 3. Alternatively, k can be 1, 2, or 3.

[0142] In some embodiments, ArA is selected from any one of the following structural formulas of ArA9-ArA15:

[0143] In each of the structural formulas of ArA11-ArA15, each Y' is independently selected from any one of -NR-, -O-, -S-, -Se-, -C(=O)-. Alternatively, each Y' is independently selected from -S-.

[0144] In each of the structural formulas represented by ArA11, ArA12, ArA15, Z is independently selected from CR or N.

[0145] In some embodiments, L is selected from -CR2-, -CR2-CR2-, -NR-, -O-, -C(=O)-, or a combination of any one or more of the structural formulas represented by L9-L11:

[0146] Optionally, L is selected from -CR2-, -CR2-CR2-, or a combination of any one or more of L9, wherein R is selected from hydrogen.

[0147] In each of the structural formulas represented by L9-L11, Y is independently selected from -CR2-, -NR-, -O-, -S-, -Se-.

[0148] In some embodiments, A is selected from -COOH or -PO(OH)2.

[0149] In some embodiments, m is an integer from 0 to 5. Illustratively, m is 0, 1, 2, 3, 4, 5, or a value within a range defined by any two of these values.

[0150] In the above R-containing groups, R is as defined in the above embodiments.

[0151] In the above R'-containing groups, R' is as defined in the above embodiments.

[0152] Thus, it is more advantageous to improve the stability and photoelectric performance of the solar cell.

[0153] In some embodiments, ArD is selected from any one of the structural formulas represented by ArD11, ArD16, ArD19. Wherein, ArD11, ArD16, ArD19 are as defined above.

[0154] In some embodiments, ArA is selected from any one of the structural formulas represented by ArA9, ArA12, ArA15. Wherein, ArA9, ArA12, ArA15 are as defined above.

[0155] In some embodiments, L is selected from -CR2-, -CR2-CR2-, or a combination of any one or more of L9. Optionally, in the formulas -CR2-, -CR2-CR2-, R is selected from hydrogen. Wherein, L9 is as defined above.

[0156] In some embodiments, ArD is selected from any one of the structural formulas represented by ArD22 to ArD25:

[0157] wherein R" is a single bond.

[0158] In some embodiments, ArA is selected from any one of the structural formulas represented by ArA16 to ArA19:

[0159] In some embodiments, L is selected from -CH2-, -CH2-CH2- or a combination of any one or more of L9. Wherein L9 is as defined above. Alternatively, L is -CH2- and m is 4, or L is a combination of -CH2-CH2- and L9 and m is 1.

[0160] In some embodiments, the repeating unit of formula (I) comprises one or more of the repeating units represented by formulae U1 to U5:

[0161] In some embodiments, the polymer has a degree of polymerization of an integer from 2 to 100000. Illustratively, the polymer has a degree of polymerization of an integer from 2 to 10000, 2 to 5000, 2 to 3000, 2 to 2000, 2 to 1000, 2 to 500, 2 to 300, 2 to 200, 2 to 100, 2 to 50, 2 to 30, 2 to 20, 3 to 10000, 3 to 5000, 3 to 3000, 3 to 2000, 3 to 1000, 3 to 500, 3 to 300, 3 to 200, 3 to 100, 3 to 50, 3 to 30, 3 to 20, 4 to 10000, 4 to 5000, 4 to 3000, 4 to 2000, 4 to 1000, 4 to 500, 4 to 300, 4 to 200, 4 to 100, 4 to 50, 4 to 30, 4 to 20.

[0162] In some embodiments, the self-assembled monolayer has a thickness of 0.25 nm to 5 nm. Illustratively, the self-assembled monolayer can have a thickness of 0.25 nm, 0.5 nm, 1 nm, 2 nm, 3 nm, 4 nm, 5 nm or a value within a range between any two of the values. Controlling the thickness of the self-assembled monolayer within the above range is advantageous for forming a monolayer film, promoting the alignment of the polymer molecules within the self-assembled monolayer, thereby facilitating the binding of the A groups in formula (I) to the surface of the substrate and the contact of the ArD-ArA ends to the surface of the perovskite light absorbing layer, and thus enhancing the binding of the self-assembled monolayer to the substrate and / or passivating the perovskite light absorbing layer.

[0163] In some embodiments, the hole transport layer further comprises a metal oxide layer between the self-assembled monolayer and the first electrode. Thereby, the stability of the solar cell is further improved. The metal oxide is not particularly limited as long as it is a metal oxide that is generally used as a hole transport material. Illustratively, the metal oxide comprises one or more of nickel oxide, molybdenum oxide, tungsten oxide.

[0164] In some embodiments, the thickness of the metal oxide layer is in the range of 10 nm to 100 nm. Illustratively, the thickness of the metal oxide layer can be 10 nm, 15 nm, 20 nm, 25 nm, 30 nm, 35 nm, 40 nm, 45 nm, 50 nm, 55 nm, 60 nm, 65 nm, 70 nm, 75 nm, 80 nm, 85 nm, 90 nm, 95 nm, 100 nm, or a value in the range between any two of the values. Controlling the thickness of the metal oxide layer in the above range is advantageous for charge transport, thereby improving the stability of the solar cell while maintaining the photoelectric performance of the solar cell.

[0165] In some embodiments, the first electrode and the second electrode are used for collecting electrons / holes.

[0166] In some embodiments, one of the first electrode and the second electrode is a transparent electrode. The transparent electrode is the electrode that first receives the incident light. Illustratively, the transparent electrode can comprise a transparent conductive material. The transparent conductive material is not particularly limited in the present disclosure. Illustratively, the transparent conductive material comprises one or more of 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, indium-doped tungsten oxide (IWO), indium-doped chromium oxide (ICrO), indium-doped titanium oxide (ITiO), graphene.

[0167] In some embodiments, the other of the first electrode and the second electrode can comprise the transparent conductive material described above or other conductive material. The other conductive material is not particularly limited in the present disclosure. For example, the other conductive material comprises one or more of metals and alloys thereof, elemental carbon materials. Illustratively, the metals and alloys thereof comprise one or more of gold, silver, copper, aluminum, nickel, chromium, bismuth, platinum, magnesium, molybdenum, tungsten. Illustratively, the elemental carbon materials comprise one or more of graphite, graphene, carbon nanotubes. Illustratively, the organic conductive material comprises one or more of poly(3,4-ethylenedioxythiophene), polythiophene, polyacetylene.

[0168] In some embodiments, the first electrode is a transparent electrode, or also referred to as a front electrode; and the second electrode is an electrode formed of other conductive material as described above, or also referred to as a back electrode. Exemplarily, the thickness of each of the first electrode and the second electrode is in a range from 10 nm to 1000 nm.

[0169] The perovskite light-absorbing layer is disposed between the first electrode and the second electrode, and can generate electron-hole pairs based on excitation of incident light. The present disclosure does not particularly limit the band gap of the perovskite light-absorbing layer, and the band gap of the perovskite light-absorbing layer used in the art can be adopted. Exemplarily, the band gap of the perovskite light-absorbing layer can be in a range from 1.20 eV to 2.30 eV. In the present disclosure, the method for measuring the band gap is not particularly limited. Exemplarily, 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 by Tauc equation. The present disclosure does not particularly limit the thickness of the perovskite light-absorbing layer, and the thickness of the perovskite light-absorbing layer used in the art can be adopted. Exemplarily, the thickness of the perovskite light-absorbing layer is in a range from 200 nm to 1000 nm.

[0170] The perovskite light-absorbing layer includes a perovskite material. In some embodiments, the perovskite material includes at least one of a compound represented by [A][B][X]3, a compound represented by [A]2[C][D][X]6, wherein A includes at least one of inorganic or organic monovalent cations, 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.

[0171] Exemplarily, the organic monovalent cation includes one or more of (NR1R2R3R4) + , (R1R2N=CR3R4) + , (R1R2N-C(R5)=NR3R4) + , or (R1R2N-C(NR5R6)=NR3R4) + , wherein R1, R2, R3, R4, R5, and R6 are each independently selected from H, substituted or unsubstituted C1-C20 alkyl, or substituted or unsubstituted aryl. Optionally, the organic monovalent cation includes one or more of (H2N=CH-NH2) + (shorthand FA), CH3NH3 + (shorthand MA).

[0172] Exemplarily, the inorganic monovalent cation includes Li + , Na + , K + , Rb + , Cs + , Cu+ Ag + Au + or Hg + .

[0173] Exemplarily, the inorganic divalent cations include at least one of 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+ .

[0174] Exemplarily, the inorganic trivalent cations include at least one of 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+ .

[0175] Exemplarily, the monovalent anions include at least one of F - Cl - Br - I - SCN - CNO - OCN - OSCN - SH - OH - CN - SeCN - .

[0176] In some embodiments, the perovskite light-absorbing layer includes Cs 0.05 FA 0.95 PbBr 0.15 I 2.85, Cs 0.1 MA 0.15 FA 0.75 PbCl 0.15 I 2.85 , MAPbI3, FAPbI3, (FA 0.83 MA 0.17 ) 0.95 Cs 0.05 Pb(I 0.83 Br 0.17 )3, CsPbI3, CsPbI2Br, CsPbIBr2, wherein FA represents (H2N=CH-NH2) + , MA represents CH3NH3 + . Optionally, the perovskite light-absorbing layer comprises Cs 0.05 FA 0.95 PbBr 0.15 I 2.85 . The above-mentioned lead-based perovskite material is commonly used in perovskite solar cells, which makes the solar cells have good reproducibility.

[0177] In some embodiments, the solar cell comprises a first electrode, a hole transport layer, a perovskite light-absorbing layer, an electron transport layer and a second electrode which are sequentially stacked.

[0178] In some embodiments, the solar cell comprises a first electrode, a hole transport layer, a perovskite light-absorbing layer, an electron transport layer and a second electrode which are sequentially stacked, wherein the first electrode is a transparent electrode.

[0179] The electron transport layer has the function of transporting electrons, which is used to transport the electrons generated by the excitation of the perovskite light-absorbing layer to the adjacent electrode and prevent the transport of holes.

[0180] The electron transport material employed by the present disclosure for the electron transport layer is not particularly limited and can employ the electron transport material commonly used in the art. For example, the electron transport material comprises at least one of an imide compound, a quinone compound, a fullerene and a derivative thereof, a metal oxide, a semiconductor material oxide, a titanate, a fluoride and a derivative thereof, and a material obtained by doping or passivation thereof. Illustratively, the imide compound comprises at least one of phthalimide, succinimide, N-bromosuccinimide, glutarimide or maleimide. Illustratively, the quinone compound comprises at least one of benzoquinone, naphthoquinone, phenanthraquinone or anthraquinone. Illustratively, the metal element in the metal oxide comprises at least one of Mg, Cd, Zn, In, Pb, W, Sb, Bi, Hg, Ti, Ag, Mn, Fe, V, Sn, Zr, Sr, Ga or Cr. Illustratively, the fullerene and the derivative thereof comprise fullerene C 60 , fullerene C70 [6,6]-phenyl C 61 methyl butyrate (PC 61 BM), [6,6]-phenyl C 71 methyl butyrate (PC 71 BM), etc. Optionally, the metal oxide includes at least one of tin dioxide (Sn02), titanium dioxide (Ti02). Illustratively, the semiconductor material oxide includes silicon oxide. Illustratively, the titanate includes at least one of strontium titanate, calcium titanate. Illustratively, the fluoride includes at least one of lithium fluoride, calcium fluoride.

[0181] In some embodiments, the electron transport layer includes at least one of the following materials and derivatives thereof and materials obtained by doping or passivation thereof: [6,6]-phenyl C 61 methyl butyrate (PC 61 BM), [6,6]-phenyl C 71 methyl butyrate (PC 71 BM), indene-C 60 bisadduct (ICBA), fullerene C 60 , fullerene C 70 tin dioxide, zinc oxide (ZnO), perylene diimide (PDI)-based material, naphthalene diimide (NDI)-based material, etc.

[0182] The present disclosure does not particularly limit the thickness of the electron transport layer, and the thickness of the electron transport layer used in the art can be adopted. Illustratively, the thickness of the electron transport layer can be 5 nm to 100 nm.

[0183] 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 to the adjacent electrode and prevent the transport of electrons.

[0184] In addition to the self-assembled monolayer of the polymer including the repeating unit of formula (I), the hole transport layer of the present disclosure can also include other hole transport materials or other hole transport material layers. The other hole transport materials are not particularly limited, and the hole transport materials used in the art can be adopted. Illustratively, the other hole transport materials can include at least one of cuprous iodide (Cul), cuprous oxide (Cu20), 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).

[0185] In some embodiments, the perovskite solar cell further comprises a hole blocking layer disposed between the electron transport layer and the second electrode. By disposing the hole blocking layer, the electron extraction performance and the hole blocking performance can be improved.

[0186] The hole blocking layer comprises a hole blocking material. The hole blocking material is not particularly limited in the present disclosure, and exemplarily, the hole blocking material can comprise one or more of SnO2, ZnO, CeO x , bathocuproine (BCP, 2,9-dimethyl-4,7-diphenyl-1,10-phenanthroline), etc.

[0187] The thickness of the hole blocking layer is not particularly limited in the present disclosure, and the thickness of the hole blocking layer commonly used in the art can be adopted. Exemplarily, the thickness of the hole blocking layer can be 0.5 nm to 20 nm.

[0188] In some embodiments, the perovskite solar cell further comprises a passivation layer disposed on at least one surface of the perovskite light-absorbing layer, thereby facilitating the reduction of defects at the interface and further improving the performance of the solar cell.

[0189] The passivation layer can comprise passivation agents commonly used in the art for passivating the perovskite light-absorbing layer, such as organic small molecules, organic salts, inorganic salts, polymers, etc. The organic small molecule passivation agents include but are not limited to phenethylamine, ethylenediamine, pyridine, butanethiol, 2,5-thiophenedicarboxylic acid, etc. The organic salt passivation materials include but are not limited to piperazine iodine, phenethylamine hydroiodide, dodecylhydroiodide, guanidine bromide, thiophene ethylamine hydroiodide, ethylenediamine hydroiodide, oleylamine iodine. The inorganic salt passivation materials include but are not limited to zinc chloride, potassium chloride, gallium chloride. The polymer passivation materials include but are not limited to polymethyl methacrylate, polyethylene oxide, polyacrylonitrile, polyvinyl alcohol.

[0190] FIG. 1 shows a structural schematic diagram of a solar cell according to an embodiment of the present disclosure. In this embodiment, the solar cell 10 comprises a first electrode 11, a hole transport layer 151, a perovskite light-absorbing layer 13, an electron transport layer 152 and a second electrode 12 disposed in sequence along the direction of light incidence, wherein the hole transport layer 151 comprises a self-assembled monolayer. The first electrode 11, the hole transport layer 151, the self-assembled monolayer, the perovskite light-absorbing layer 13, the electron transport layer 152 and the second electrode 12 are as described above, and will not be described here again.

[0191] FIG. 2 shows a structural schematic diagram of a solar cell according to an embodiment of the present disclosure. In this embodiment, the solar cell 100 comprises, in sequence along the direction of light incidence, a first electrode 11, a hole transport layer 151, a perovskite light-absorbing layer 13, an electron transport layer 152, and a second electrode 12, wherein the hole transport layer 151 comprises a metal oxide layer 1511 and a self-assembled monolayer 1512. The first electrode 11, the hole transport layer 151, the metal oxide layer 1511, the self-assembled monolayer 1512, the perovskite light-absorbing layer 13, the electron transport layer 152, and the second electrode 12 are as described above and will not be described again here.

[0192] Those skilled in the art will understand that, in FIGS. 1 and 2, the hole transport layer 151 is only illustratively shown as being disposed on the side surface of the perovskite light-absorbing layer 13 facing the first electrode 11, and the electron transport layer 152 is disposed on the side surface of the perovskite light-absorbing layer 13 facing the second electrode 12. In some embodiments, the positions at which the hole transport layer 151 and the electron transport layer 152 are disposed can be interchanged, i.e., the electron transport layer 152 is disposed on the side surface of the perovskite light-absorbing layer 13 facing the first electrode 11, and the hole transport layer 151 is disposed on the side surface of the perovskite light-absorbing layer 13 facing the second electrode 12.

[0193] In some embodiments, the perovskite solar cell of the present disclosure can be obtained by a preparation method described as follows. The preparation method comprises the following steps:

[0194] Step S1: providing a transparent conductive glass substrate as the first electrode, and performing pretreatments such as etching, cleaning, and drying on the transparent conductive glass substrate for standby use;

[0195] Optional step S2: preparing a metal oxide layer on the pretreated transparent conductive glass substrate;

[0196] Step S3: preparing a self-assembled monolayer on the transparent conductive glass substrate or, if present, the metal oxide layer;

[0197] Step S4: preparing a perovskite light-absorbing layer on the self-assembled monolayer;

[0198] Optional step S5: preparing a passivation layer on the perovskite light-absorbing layer;

[0199] Step S5: preparing an electron transport layer on the perovskite light-absorbing layer or, if present, the passivation layer;

[0200] Optional step S6: preparing a hole blocking layer on the electron transport layer;

[0201] Step S7: preparing a metal electrode as the second electrode on the electron transport layer or, if present, the hole blocking layer; and

[0202] Step S8, encapsulating the stacked structure obtained through steps S1 to S7 to obtain the perovskite solar cell.

[0203] The preparation method of each functional layer of the solar cell, such as the first electrode, the metal oxide layer, the self-assembled monolayer, the perovskite light-absorbing layer, the passivation layer, the electron transport layer, the hole blocking layer, and the second electrode, is not particularly limited and can include a preparation method commonly used in the art, such as a chemical bath deposition method, an electrochemical deposition method, a chemical vapor deposition method, a physical epitaxial growth method, a vacuum thermal evaporation method, an atomic layer deposition method, a magnetron sputtering method, a spin coating method, a slot coating method, a doctor blade coating method, a mechanical pressing method, and the like.

[0204] In some embodiments, the perovskite solar cell further comprises a substrate layer disposed on the side of the first electrode away from the hole transport layer, for supporting the perovskite solar cell. The substrate layer can be, but is not limited to, a glass substrate or a flexible substrate. In some embodiments, the material of the flexible substrate layer can be, for example, but is not limited to, an organic polymer material, and further can be mixed in different proportions by one or more of the following materials: polyvinyl alcohol (PVA), polyester (PET), polyimide (PI), polyethylene naphthalate glycol (PEN), polydimethylsiloxane (PDMS), and the like.

[0205] Photovoltaic module

[0206] The embodiments of the present disclosure further provide a photovoltaic module comprising the solar cell provided by the above-mentioned embodiments. In some embodiments, the photovoltaic module further comprises a solder strip connecting the plurality of solar cells, a junction box for current transmission, and a cell encapsulation component.

[0207] In some embodiments, the cell encapsulation 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 differences and harsh weather environments.

[0208] In some embodiments, the cell encapsulation component comprises an ethylene-vinyl acetate copolymer (EVA) film, which is disposed between the photovoltaic glass and the solar cell and is used for bonding the photovoltaic glass and the solar cell.

[0209] In some embodiments, the cell encapsulation component comprises a photovoltaic backsheet. The photovoltaic backsheet plays a role of protecting the solar cell.

[0210] Optionally, the material of the photovoltaic backsheet can comprise a polyvinyl fluoride composite film or a thermoplastic elastomer. The material of the photovoltaic backsheet has the characteristics of insulation, waterproofness, and aging resistance.

[0211] In some embodiments, the battery packaging component includes a solar aluminum frame, which is made of an aluminum alloy material and has high strength and corrosion resistance, and can support and protect the solar cell.

[0212] Power generation device

[0213] The embodiments of the present disclosure also provide a power generation device, which includes the solar cell provided by the above-mentioned embodiments.

[0214] Power consumption device

[0215] The embodiments of the present disclosure also provide a power consumption device, which includes the solar cell provided by the above-mentioned embodiments.

[0216] In some embodiments, the power consumption device includes a lighting device, an energy storage device, etc., but is not limited thereto. For example, the power consumption device includes a solar water heater, a solar street lamp, a solar photovoltaic generator, etc.

[0217] Polymer

[0218] The embodiments of the present disclosure also provide a polymer. The polymer includes a repeating unit of formula (I):

[0219] In formula (I), ArD represents an aromatic electron-donating unit; ArA represents an aromatic electron-withdrawing unit; L represents a linking group having two linking sites; A represents an oxygen-containing acid group or a corresponding salt thereof; and m is an integer from 0 to 10.

[0220] The polymer of the present disclosure includes a repeating unit of formula (I). In the repeating unit of formula (I), an aromatic electron-donating unit (ArD) and an aromatic electron-withdrawing unit (ArA) are included, thereby forming a polymer having a main chain with donor-acceptor interaction. The polymer is included in a self-assembled monolayer of a perovskite solar cell, and the self-assembled monolayer can maintain a good morphology under high temperature and light conditions, thereby being conducive to improving the stability of the self-assembled monolayer and further being conducive to improving the stability of the solar cell. At the same time, the donor-acceptor (D-A) interaction in the self-assembled monolayer improves the energy band structure of the self-assembled monolayer material, which is conducive to improving the charge transport capability of the self-assembled monolayer and further being conducive to improving the photoelectric conversion efficiency of the solar cell. Therefore, the polymer of the present disclosure included in the self-assembled monolayer of the solar cell is conducive to improving the photoelectric performance and stability of the solar cell.

[0221] Polymers comprising repeat units of Formula (I) can be determined by instruments and methods known in the art. For example, by matrix-assisted laser desorption ionization time-of-flight mass spectrometry (MALDI-TOF) determination, the presence of a polymer comprising repeat units of Formula (I) is indicated if the main peaks in the mass spectrum are in an arithmetic sequence, and the difference between adjacent main peaks is the relative molecular mass of the repeat unit of the polymer.

[0222] In some embodiments, ArD is selected from any one of the structural formulas represented by ArD1 to ArD9:

[0223] In each of the structural formulas represented by ArD1 to ArD9, the dashed bond represents a single bond to L, R D each independently is selected from any one of a single bond, hydrogen, halogen, -OR’, -OC(=O)R’, -NHC(=O)R’, -NR’2, R’, halogen-substituted R’, -SR’, -PR’2, provided that in each of the structural formulas represented by ArD1 to ArD9, there are and only two R D is a single bond.

[0224] In each of the structural formulas represented by ArD7 to ArD9, Y is each independently selected from any one of -CR2-, -NR-, -O-, -SiR2-, -PR-, -S-, -As-, -Se-. Alternatively, Y is each independently selected from -CR2- or -S-.

[0225] In the structural formula represented by ArD7, k is an integer from 1 to 3. Illustratively, k can be 1, 2, or 3. Alternatively, k can be 1.

[0226] In some embodiments, ArA is selected from any one of the structural formulas represented by ArA1 to ArA8:

[0227] In each of the structural formulas represented by ArA1 to ArA8, Z is each independently selected from CR or N, provided that in each of the structural formulas represented by ArA1 to ArA8, there are and only two Z’s are and at least one Z is N, wherein, in the formula the dashed bond represents a single bond to an adjacent ArD group.

[0228] In each of the structural formulas represented by ArA4to ArA8, each Y' is independently selected from any one of -CR2-, -NR-, -O-, -SiR2-, -PR-, -S-, -As-, -Se-, -C(=O)-, -C(=S)-, -C(=NR)-, -C(=CR2)-. Alternatively, each Y' is independently selected from -S-.

[0229] In some embodiments, L is selected from -CR2-, -CR2-CR2-, -NR-, -O-, -SiR2-, -PR-, -S-, -C(=O)-, -C(=S)-, -C(=NR)-, -C(=CR2)-, or a combination of any one or more of the structural formulas represented by L1to L8:

[0230] In each of the structural formulas represented by L1to L8, each Z is independently selected from CR or N. Alternatively, each Z is independently selected from CR, wherein R is hydrogen.

[0231] In each of the structural formulas represented by L2, L5to L7, each Y is independently selected from any one of -CR2-, -NR-, -O-, -SiR2-, -PR-, -S-, -As-, -Se-, -C(=O)-, -C(=S)-, -C(=NR)-, or -C(=CR2)-.

[0232] Alternatively, L is selected from -CR2-, -CR2-CR2-, or a combination of any one or more of L1. Alternatively, R is hydrogen. Alternatively, in the structural formula represented by L1, each Z is selected from CR, wherein R is hydrogen.

[0233] In some embodiments, A is selected from any one of -COOH, -PO(OH)2, -PHO(OH), -SO2(OH), or -B(OH)2. Alternatively, A is selected from -COOH or -PO(OH)2.

[0234] In the above R-containing groups, each R is independently selected from any one of hydrogen, halogen, R', halogen-substituted R', -OR', -OC(=O)R', -NHC(=O)R', -NR'2, -SR', -PR'2.

[0235] In the above R'-containing groups, each R' is independently selected from any one of substituted or unsubstituted phenyl, thienyl, C1to C10alkyl. Illustratively, where R' has a substituent, the substituent can each independently include one or more of hydroxyl, nitro, cyano, carboxyl, ester, C1to C10alkyl, C1to C10alkoxy, 6- to 10-membered aryl.

[0236] By including a polymer containing one or more of the above groups, it is more advantageous to improve the stability and charge transport ability of the self-assembled monolayer, thereby more advantageously improving the photoelectric performance and stability of the solar cell.

[0237] In some embodiments, ArD is selected from any one of the following structural formulas of ArD10-ArD21:

[0238] In each of the structural formulas of ArD10-ArD21, R D each independently is selected from any one of hydrogen, halogen, -OR', -OC(=O)R', -NHC(=O)R', -NR'2, R', halogen-substituted R', -SR', -PR'2; R" is a single bond. Alternatively, R D is selected from hydrogen.

[0239] In each of the structural formulas of ArD19-ArD21, Y each independently is selected from any one of -CR2-, -NR-, -O-, -S-, -Se-. Alternatively, Y each independently is selected from -CR2- or -S-, wherein R is selected from R', R' is selected from C1-C10 alkyl.

[0240] In the structural formula of ArD19, k is an integer from 1 to 3. Alternatively, k can be 1, 2, or 3.

[0241] In some embodiments, ArA is selected from any one of the following structural formulas of ArA9-ArA15:

[0242] In each of the structural formulas of ArA11-ArA15, Y' each independently is selected from any one of -NR-, -O-, -S-, -Se-, -C(=O)-. Alternatively, Y' each independently is selected from -S-.

[0243] In each of the structural formulas of ArA11, ArA12, ArA15, Z each independently is selected from CR or N.

[0244] In some embodiments, L is selected from -CR2-, -CR2-CR2-, -NR-, -O-, -C(=O)-, or a combination of any one or more of the structural formulas of L9-L11:

[0245] Alternatively, L is selected from -CR2-, -CR2-CR2-, or a combination of any one or more of L9, wherein R is selected from hydrogen.

[0246] In each of the structural formulae shown in L9 to L11, Y is independently selected from any one of -CR2-, -NR-, -O-, -S-, -Se-.

[0247] In some embodiments, A is selected from -COOH or -PO(OH)2.

[0248] In some embodiments, m is an integer from 0 to 5. Illustratively, m is 0, 1, 2, 3, 4, 5, or a value within a range defined by any two of these values.

[0249] In the above R-containing groups, R is as defined in the above embodiments.

[0250] In the above R'-containing groups, R' is as defined in the above embodiments.

[0251] Thus, it is more advantageous to improve the stability and photoelectric performance of the solar cell.

[0252] In some embodiments, ArD is selected from any one of the structural formulae shown in ArD11, ArD16, ArD19. Wherein, ArD11, ArD16, ArD19 are as defined above.

[0253] In some embodiments, ArA is selected from any one of the structural formulae shown in ArA9, ArA12, ArA15. Wherein, ArA9, ArA12, ArA15 are as defined above.

[0254] In some embodiments, L is selected from any one or more combinations of -CR2-, -CR2-CR2-, or L9. Alternatively, in the formulae -CR2-, -CR2-CR2-, R is selected from hydrogen. Wherein, L is as defined above.

[0255] In some embodiments, ArD is selected from any one of the structural formulae shown in ArD22 to ArD25:

[0256] Wherein, R" is a single bond.

[0257] In some embodiments, ArA is selected from any one of the structural formulae shown in ArA16 to ArA19:

[0258] In some embodiments, L is selected from any one or more combinations of -CH2-, -CH2-CH2-, or L9. Wherein, L9 is as defined above. Alternatively, L is -CH2- and m is 4, or L is a combination of -CH2-CH2- and L9 and m is 1.

[0259] In some embodiments, the repeating unit of formula (I) comprises one or more of the repeating units shown in formulae U1-U5:

[0260] In some embodiments, the polymer has a degree of polymerization of an integer from 2 to 100,000.

[0261] Examples

[0262] Hereinafter, examples of the present disclosure will be described. The examples described below are exemplary and are for the purpose of explanation of the present disclosure only and are not to be understood as limiting the present disclosure. In the examples, specific techniques or conditions not otherwise described are performed according to the techniques or conditions described in the literature in the field or according to the product manual. The reagents or instruments not otherwise described by the manufacturer are all conventional products that can be obtained commercially.

[0263] Example 1

[0264] Preparation of polymer P1

[0265] 1. Preparation of compound 2

[0266] Compound 1 (CAS No.: 6825-20-3, 1 mmol), 1,4-dibromobutane (8 mL), 50% mass fraction potassium hydroxide aqueous solution (KOH(aq), 5 mL), tetrabutylammonium bromide (TBAB, 5% mmol) were mixed, heated at 70°C for 20 hours under nitrogen protection, and then separated by silica gel chromatography column (petroleum ether: dichloromethane = 1:1) to obtain compound 2 with a yield of about 83%.

[0267] Compound 2 was subjected to nuclear magnetic hydrogen spectrum test, and the results were as follows: 1 H NMR (400 MHz, CDCl3, ppm): 8.15 (d, J = 1.9 Hz, 2H), 7.55-7.52 (m, 2H), 7.25 (d, J = 2.1 Hz, 2H), 4.30 (t, J = 7.3 Hz, 2H), 3.37 (t, J = 6.4 Hz, 2H), 2.07-1.99 (m, 2H), 1.91-1.85 (m, 2H).

[0268] 2. Preparation of compound 3

[0269] Compound 2 (1 mmol), triethyl phosphite (P(OEt)3, 10 mL) were mixed and heated at 180 °C for 12 h under nitrogen atmosphere. The unreacted triethyl phosphite was removed by distillation under reduced pressure. Compound 3 was obtained by silica gel column chromatography (dichloromethane:methanol = 10:1) with a yield of about 45%.

[0270] Compound 3 was tested by1H NMR and the results were as follows: 1 H NMR (400 MHz, CDC13, ppm): 8.12 (d, J = 2.1 Hz, 2H), 7.54-7.52 (m, 2H), 7.25 (d, J = 8.9 Hz, 2H), 4.25 (t, J = 7.9 Hz, 2H), 4.06-3.96 (m, 4H), 1.96-1.61 (m, 6H), 1.25 (t, J = 7.1 Hz, 6H).

[0271] 3. Preparation of compound 5

[0272] Compound 3 (1 mmol), compound 4 (CAS No.: 934365-16-9, 2.1 mmol), tetrakis(triphenylphosphine)palladium (10% mmol), toluene (10 mL) and aqueous potassium carbonate solution (2 M, 10 mL) were mixed and heated at 110 °C for 48 h under nitrogen atmosphere. The solid residue was obtained by Soxhlet extraction with n-hexane and methanol vapor, respectively, for 12 h each to give compound 5 with a yield of about 68%.

[0273] Compound 5 was tested by1H NMR and the results were as follows: 1 H NMR (400 MHz, CDC13, ppm): 8.64-7.31 (m, 8H), 4.67-4.24 (m, 2H), 4.24-3.86 (m, 4H), 2.20-1.45 (m, 6H), 1.40-1.10 (m, 6H).

[0274] 4. Preparation of polymer P1

[0275] Compound 5 (1 mmol, molar amount calculated by relative molecular mass of repeating unit) was dissolved in 20 mL of 1,4-dioxane, and then trimethylsilyl bromide (TMSBr, 0.72 mL) was added dropwise. After stirring at room temperature for 18 h, methanol (MeOH, 8 mL) was added, and then stirred for another 3 h. Then 40 mL of deionized water (H2O) was added, and then stirred at room temperature for 12 h. The filtrate was collected by filtration to obtain polymer P1 with a yield of about 56%.

[0276] The polymer P1 was subjected to GPC testing (EcoSEC HLC-8320 GPC, solvent tetrahydrofuran), with the following results: number average molecular weight Mn = 2431, weight average molecular weight Mw = 3281 and dispersion index PDI = 1.35.

[0277] Preparation of a solar cell

[0278] 1. Providing a first electrode

[0279] FTO conductive glass substrate (i.e. fluorine-doped Sn02transparent metal oxide) with size of 2.0 x 2.0 cm was used. The FTO on both ends was removed by laser etching for 0.35 cm to expose the glass substrate. The substrate was cleaned with deionized water, acetone and isopropanol in sequence. After drying under nitrogen gun, the cleaned substrate was irradiated in a UV-ozone machine for 20 minutes and was ready for use.

[0280] 2. Preparation of a hole transport layer

[0281] 100 μL of methanol solution (10 mg / mL) of nano-nickel oxide (NiO x , 1≤x≤1.5) was dropped onto the FTO conductive glass substrate and spin-coated at a speed of 2000 rpm for 30 seconds. The substrate was annealed at 100°C for 10 minutes to obtain a nickel oxide layer with a thickness of 30 nm.

[0282] 100 μL of methanol solution (0.3 mg / mL) of polymer P1 was dropped onto the nickel oxide layer and spin-coated at a speed of 3000 rpm for 30 seconds. The substrate was annealed at 100°C for 10 minutes to obtain a self-assembled monolayer with a thickness of 5 nm.

[0283] The nickel oxide layer and the self-assembled monolayer together constitute a hole transport layer.

[0284] 3. Preparation of a perovskite light-absorbing layer

[0285] Lead iodide (726 mg), formamidinium iodide (240 mg), cesium iodide (19 mg) and lead bromide (11 mg) were dissolved in 1000 μL of a mixed solvent of N,N-dimethylformamide (DMF) and dimethyl sulfoxide (DMSO) (volume ratio of DMF to DMSO = 4:1) and stirred for 3 hours. The perovskite precursor solution was obtained by filtration through a 0.22 μm organic filter membrane. 100 μL of the perovskite precursor solution was dropped onto the self-assembled monolayer and spin-coated at a speed of 3000 rpm for 30 seconds. The obtained thin film was annealed at 100°C for 30 minutes to obtain a perovskite light-absorbing layer with a thickness of 900 nm of Cs 0.05 FA 0.95 PbBr 0.15 I 2.85 .

[0286] 4. Preparation of the electron transport layer

[0287] 100 μL of PC was dropped on the perovskite light-absorbing layer, and spin-coated at a speed of 1500 rpm for 30 seconds to obtain an electron transport layer with a thickness of 35 nm. 61 A chlorobenzene solution (20 mg / mL) of BM was dropped on the perovskite light-absorbing layer, and spin-coated at a speed of 1500 rpm for 30 seconds, and annealed at 100°C for 10 minutes to obtain an electron transport layer with a thickness of 35 nm.

[0288] 5. Preparation of the hole blocking layer

[0289] A saturated solution of 2,9-dimethyl-4,7-diphenyl-1,10-phenanthroline BCP in isopropanol (30 μL) was filtered through a filter head, and dropped on the electron transport layer, and spin-coated at a speed of 5000 rpm for 30 seconds, and annealed at 100°C for 10 minutes to obtain a hole blocking layer with a thickness of 15 nm.

[0290] 6. Preparation of the second electrode

[0291] A copper electrode with a thickness of 80 nm was evaporated on the hole blocking layer as the second electrode under high vacuum.

[0292] The layered structure obtained through steps 1 to 6 was encapsulated to obtain a perovskite solar cell.

[0293] Example 2

[0294] Preparation of polymer P2

[0295] 1. Preparation of compound 7

[0296] Compound 3 (1 mmol), compound 6 (CAS No.: 934365-16-9, 2.1 mmol), tetrakis(triphenylphosphine)palladium (10% mmol), toluene (10 mL) and an aqueous potassium carbonate solution (2 M, 10 mL) were mixed, heated at 110°C for 48 hours under nitrogen protection, and then extracted with n-hexane and methanol vapor in a Soxhlet extractor for 12 hours for each solvent to obtain a solid residue of compound 7 with a yield of about 59%.

[0297] Compound 7 was subjected to nuclear magnetic hydrogen spectrum test, and the results were as follows: 1 H NMR (400 MHz, CDCl3, ppm): δ 8.96-7.38 (m, 6H), 4.63-3.83 (m, 6H), 2.28-1.33 (m, 6H), 1.41-1.18 (m, 6H).

[0298] 2. Preparation of polymer P2

[0299] Compound 7 (1 mmol, molar amount calculated by relative molecular mass of repeating unit) was dissolved in 20 mL of 1,4-dioxane, and then trimethylsilyl bromide (TMSBr, 0.72 mL) was added dropwise. After stirring at room temperature for 18 h, methanol (MeOH, 8 mL) was added, and after stirring for another 3 h, 40 mL of deionized water (H2O) was added. After stirring at room temperature for 12 h, the filtrate was collected to obtain polymer P2, with a yield of about 45%.

[0300] The GPC test (EcoSEC HLC-8320 GPC, solvent: tetrahydrofuran) was performed on polymer P2, and the results were as follows: Mn = 1973, Mw = 2900, PDI = 1.47.

[0301] A solar cell was prepared in the same manner as in Example 1, except that in the preparation of the hole transport layer, polymer P2 was used instead of polymer P1.

[0302] Example 3

[0303] Preparation of polymer P3

[0304] 1. Preparation of compound 10

[0305] Compound 8 (CAS No.: 267221-88-5, 1 mmol), compound 9 (CAS No.: 40640-98-0, 1.1 mmol), tetrakis(triphenylphosphine)palladium (5% mmol), toluene (30 mL), and aqueous potassium carbonate solution (2 M, 30 mL) were mixed, and after heating at 110°C for 48 h under nitrogen protection, compound 10 was obtained by silica gel chromatography column (petroleum ether: dichloromethane = 1:1) with a yield of about 68%.

[0306] The hydrogen nuclear magnetic resonance spectrum test was performed on compound 10, and the results were as follows: 1 H NMR (400 MHz, DMSO-d6, ppm): δ 7.62 (d, J = 7.2 Hz, 2H), 7.55 (d, J = 7.2 Hz, 2H), 7.37-7.24 (m, 8H), 7.08-7.00 (m, 6H), 4.03-3.98 (m, 2H), 2.86-2.81 (m, 2H), 2.58-2.53 (m, 2H), 1.09-1.05 (m, 3H).

[0307] 2. Preparation of compound 11

[0308] Compound 10 (1 mmol), N-bromosuccinimide (NBS, 2 mmol) were dissolved in chloroform (30 mL), and stirred at room temperature for 12 h in the dark. Compound 11 was obtained by silica gel chromatography (petroleum ether: dichloromethane = 2:1) with a yield of about 94%.

[0309] The compound 11 was tested by nuclear magnetic hydrogen spectrum, and the results were as follows: 1 H NMR (400 MHz, DMSO-d6) δ 7.62 (d, J = 7.2 Hz, 2H), 7.55 (d, J = 7.2 Hz, 2H), 7.38-7.32 (m, 6H), 7.08-7.06 (m, 4H), 7.00-6.97 (m, 2H), 4.03-3.98 (m, 2H), 2.86-2.81 (m, 2H), 2.58-2.53 (m, 2H), 1.09-1.05 (m, 3H).

[0310] 3. Preparation of compound 12

[0311] Compound 11 (1 mmol), compound 4 (2.1 mmol), tetrakis(triphenylphosphine)palladium (10% mmol), toluene (10 mL) and aqueous potassium carbonate solution (2 M, 10 mL) were mixed, and heated at 110°C for 48 h under nitrogen protection. The solid residue was obtained by Soxhlet extraction with n-hexane and methanol vapor for 12 h each, and the yield of compound 12 was about 68%.

[0312] The compound 12 was tested by nuclear magnetic hydrogen spectrum, and the results were as follows: 1 H NMR (400 MHz, CDCl3, ppm): δ 8.15-7.01 (m, 18H), 4.69-2.97 (m, 6H), 1.41-1.18 (m, 3H).

[0313] 4. Preparation of polymer P3

[0314] Compound 12 (1 mmol, the molar amount was calculated based on the relative molecular mass of the repeating unit) was dissolved in 20 mL of 1,4-dioxane, and then trimethylsilyl bromide (TMSBr, 0.72 mL) was added dropwise. After stirring at room temperature for 18 h, methanol (MeOH, 8 mL) was added, and then stirred for another 3 h. Then 40 mL of deionized water (H2O) was added, and stirred at room temperature for 12 h. After filtration, the filter residue was collected to obtain polymer P3 with a yield of about 56%.

[0315] The GPC test (EcoSEC HLC-8320 GPC, solvent: tetrahydrofuran) was performed on the polymer P3, and the results were as follows: Mn = 2910, Mw = 4714, PDI = 1.62.

[0316] A solar cell was prepared in the same manner as in Example 1, except that in the preparation of the hole transport layer, the polymer P1 was replaced by the polymer P3.

[0317] Example 4

[0318] Preparation of polymer P4

[0319] 1. Preparation of compound 14

[0320] Compound 13 (CAS No.: 1333316-35-0, 1 mmol), 1,4-dibromobutane (8 mL), 50% mass fraction potassium hydroxide aqueous solution (5 mL), tetrabutylammonium bromide (TBAB, 5% mmol) were mixed, and after heating at 70°C for 20 hours under nitrogen protection, compound 14 was obtained by silica gel chromatography column (petroleum ether: dichloromethane = 1:1) after separation, with a yield of about 87%.

[0321] The hydrogen nuclear magnetic resonance spectrum test was performed on compound 14, and the results were as follows: 1 H NMR (400 MHz, CDCl3, ppm): 8.15 (d, J = 1.9 Hz, 2H), 7.55-7.52 (m, 2H), 7.25 (d, J = 2.1 Hz, 2H), 4.30 (t, J = 7.3 Hz, 2H), 3.37 (t, J = 6.4 Hz, 2H), 2.07-1.99 (m, 2H), 1.91-1.85 (m, 2H), 1.61 (s, 6H).

[0322] 2. Preparation of compound 15

[0323] Compound 14 (1 mmol), triethyl phosphite (P(OEt)3, 10 mL) were mixed, and after heating at 180°C for 12 hours under nitrogen protection, the unreacted triethyl phosphite was removed by reduced pressure distillation, and compound 15 was obtained by silica gel chromatography column (petroleum ether: dichloromethane = 1:1) after separation, with a yield of about 45%.

[0324] The hydrogen nuclear magnetic resonance spectrum test was performed on compound 15, and the results were as follows: 1H NMR (400 MHz, CDC13, ppm): 8.12 (d, J = 2.1 Hz, 2H), 7.54-7.52 (m, 2H), 7.25 (d, J = 8.9 Hz, 2H), 4.25 (t, J = 7.9 Hz, 2H), 4.06-3.96 (m, 4H), 1.96-1.61 (m, 15H), 1.25 (t, J = 7.1 Hz, 6H).

[0325] 3. Preparation of compound 17

[0326] Compound 15 (1 mmol), compound 16 (CAS No.: 156367-17-8, 2.1 mmol), tetrakis(triphenylphosphine)palladium (10% mmol), toluene (10 mL) and aqueous potassium carbonate solution (2 M, 10 mL) were mixed, heated at 110 °C for 48 h under nitrogen protection, then extracted with n-hexane and methanol steam in a Soxhlet extractor, 12 h for each solvent, to obtain a solid residue as compound 17, with a yield of about 36%.

[0327] Compound 17 was tested by nuclear magnetic hydrogen spectrum, and the results were as follows: 1 H NMR (400 MHz, CDC13, ppm): 8.12 (d, J = 2.1 Hz, 2H), 7.54-7.52 (m, 2H), 7.25 (d, J = 8.9 Hz, 2H), 4.25 (t, J = 7.9 Hz, 2H), 4.06-3.96 (m, 4H), 1.96-1.61 (m, 15H), 1.25 (t, J = 7.1 Hz, 6H).

[0328] 4. Preparation of polymer P4

[0329] Compound 17 (1 mmol, molar amount calculated by relative molecular mass of repeating unit) was dissolved in 20 mL of 1,4-dioxane, and then trimethylsilyl bromide (TMSBr, 0.72 mL) was added dropwise. After stirring at room temperature for 18 h, methanol (MeOH, 8 mL) was added, and after stirring for another 3 h, 40 mL of deionized water was added. After stirring at room temperature for 12 h, the filter residue was collected to obtain polymer P4, with a yield of about 47%.

[0330] Polymer P4 was tested by GPC (EcoSEC HLC-8320 GPC, solvent: tetrahydrofuran), and the results were as follows: Mn = 1756, Mw = 2739, PDI = 1.56.

[0331] Solar cells were prepared in the same manner as in Example 1, except that in the preparation of the hole transport layer, polymer P4 was used instead of polymer P1.

[0332] Example 5

[0333] Preparation of polymer P5

[0334] 1. Preparation of compound 19

[0335] Compound 18 (1 mmol), 1,4-dibromobutane (8 mL), 50% mass fraction potassium hydroxide aqueous solution (5 mL), tetrabutylammonium bromide (TBAB, 5% mmol) were mixed, and after heating at 70°C for 20 hours under nitrogen protection, compound 19 was obtained by silica gel chromatography column (petroleum ether: dichloromethane = 1:1) after separation, with a yield of about 83%.

[0336] Compound 19 was tested by nuclear magnetic hydrogen spectrum, and the results were as follows: 1 H NMR (400 MHz, CDCl3, ppm): 8.16 (d, J = 1.9 Hz, 2H), 7.57-7.53 (m, 2H), 7.26 (d, J = 2.1 Hz, 2H), 4.31 (t, J = 7.2 Hz, 2H), 3.37 (t, J = 6.4 Hz, 2H), 2.07-1.99 (m, 2H), 1.91-1.85 (m, 2H).

[0337] 2. Preparation of compound 20

[0338] Compound 19 (1 mmol), triethyl phosphite (P(OEt)3, 10 mL) were mixed, and after heating at 180°C for 12 hours under nitrogen protection, unreacted triethyl phosphite was removed by reduced pressure distillation, and compound 20 was obtained by silica gel chromatography column (dichloromethane:methanol = 10:1) after separation, with a yield of about 45%.

[0339] Compound 20 was tested by nuclear magnetic hydrogen spectrum, and the results were as follows: 1 H NMR (400 MHz, CDCl3, ppm): 8.12 (d, J = 2.1 Hz, 2H), 7.54-7.52 (m, 2H), 7.25 (d, J = 8.9 Hz, 2H), 4.25 (t, J = 7.9 Hz, 2H), 4.06-3.96 (m, 4H), 1.96-1.61 (m, 6H), 1.25 (t, J = 7.1 Hz, 6H).

[0340] 3. Preparation of compound 22

[0341] Compound 20 (1 mmol), compound 21 (CAS No.: 1622217-15-5, 2.1 mmol), tetrakis(triphenylphosphine)palladium (10% mmol), toluene (10 mL) and aqueous potassium carbonate solution (2 M, 10 mL) were mixed, heated at 110 °C for 48 h under nitrogen protection, then extracted with n-hexane and methanol steam in a Soxhlet extractor, 12 h for each solvent extraction, to obtain a solid residue as compound 22, with a yield of about 41%.

[0342] Compound 22 was tested by nuclear magnetic hydrogen spectrum, and the results were as follows: 1 H NMR (400 MHz, CDCl3, ppm): 8.64-7.31 (m, 8H), 4.67-4.24 (m, 2H), 4.24-3.86 (m, 4H), 2.20-1.45 (m, 6H), 1.40-1.10 (m, 15H).

[0343] 4. Preparation of polymer P5

[0344] Compound 22 (1 mmol, molar amount calculated by relative molecular mass of repeating unit) was dissolved in 20 mL of 1,4-dioxane, and then trimethylsilyl bromide (TMSBr, 0.72 mL) was added dropwise. After stirring at room temperature for 18 h, methanol (MeOH, 8 mL) was added, and after stirring for another 3 h, 40 mL of deionized water (H2O) was added. After stirring at room temperature for 12 h, the filtrate was collected by filtration, to obtain polymer P5, with a yield of about 56%.

[0345] Polymer P5 was tested by GPC (EcoSEC HLC-8320 GPC, solvent: tetrahydrofuran), and the results were as follows: Mn = 1943, Mw = 3226, PDI = 1.66.

[0346] Solar cells were prepared in the same manner as in Example 1, except that in the preparation of the hole transport layer, polymer P1 was replaced by polymer P5.

[0347] Example 6

[0348] Solar cells were prepared in the same manner as in Example 1, except that in the preparation of the hole transport layer, no nickel oxide layer was prepared, and the self-assembled monolayer of polymer P1 was directly disposed on the FTO surface.

[0349] Example 7

[0350] Solar cells were prepared in the same manner as in Example 2, except that in the preparation of the hole transport layer, no nickel oxide layer was prepared, and the self-assembled monolayer of polymer P2 was directly disposed on the FTO surface.

[0351] Comparative Example 1

[0352] A solar cell was prepared according to the same method as in Example 1, except that in the preparation of the hole transport layer, no self-assembled monolayer was prepared.

[0353] Comparative Example 2

[0354] A solar cell was prepared according to the same method as in Example 1, except that in the preparation of the hole transport layer, the polymer P1 was replaced by compound 23 (CAS No.: 20999-36-4) shown in the following formula.

[0355] Comparative Example 3

[0356] A solar cell was prepared according to the same method as in Example 1, except that in the preparation of the hole transport layer, the polymer P1 was replaced by compound 24 shown in the following formula. Compound 24 was prepared according to the preparation method disclosed in Ren, Zhijun et al. “Poly(carbazole phosphonic acid) as a versatile hole-transporting material for p-i-n perovskite solar cells and modules.” Joule 7.12 (2023): 2894-2904 (https: / / doi.org / 10.1016 / j.joule.2023.10.014).

[0357] Test of photoelectric performance of solar cells

[0358] The test method of initial photoelectric conversion efficiency at room temperature (25°C) is as follows.

[0359] According to the international standard IEC61215, the intensity of the light source was corrected to 1 sun intensity, AM 1.5, using a solar simulator of light flux. The solar cell was tested by reverse scanning using a Keithley 2400 source meter, and the open circuit voltage V OC , short circuit current density J SC and fill factor FF were measured, and the initial photoelectric conversion efficiency (PCE0) of the solar cell was calculated by the following formula:

[0360] Where P input represents the incident light power density.

[0361] Test of stability of solar cells

[0362] The stability of the measured cells was tested at 85°C using the above-mentioned light-flame solar simulator. The photovoltaic conversion efficiency (PCE) after heating at 85°C for 1000h was continuously monitored at the maximum output voltage and recorded. 1000 @85°C).

[0363] Efficiency retention = photovoltaic conversion efficiency after heating at 85°C for 1000h / initial photovoltaic conversion efficiency x 100%.

[0364] The performance and stability test results of the solar cells of Examples 1-7 and Comparative Examples 1-3 are shown in Table 1 below.

[0365] Table 1

[0366] According to the above results, compared with Comparative Example 1 which does not include a self-assembled monolayer in the hole transport layer, and Comparative Examples 2 and 3 in which the self-assembled monolayer in the hole transport layer uses a compound outside the scope of the present disclosure, Examples 1-7 all significantly improve the stability of the solar cells and improve the initial photovoltaic conversion efficiency.

[0367] 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 substantially the same configuration and playing the same role and effect within the scope of the technical solutions of the present disclosure are all included within 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 are applied to the embodiments, and other ways constructed by combining part of the constituent elements in the embodiments are also included within the scope of the present disclosure.

Claims

1. A solar cell comprising a first electrode, a hole transport layer, a perovskite light absorbing layer, and a second electrode, which are sequentially stacked. wherein The hole transport layer comprises a self-assembled monolayer, the self-assembled monolayer comprising a polymer, the polymer comprising repeat units of formula (I): In formula (I), ArD represents an aromatic electron-donating unit; ArA represents an aromatic electron-withdrawing unit; L represents a linking group having two linking sites; A represents an oxygen-containing acid group or a corresponding salt thereof; m is an integer from 0 to 10.

2. The solar cell of claim 1, wherein, The repeating unit of formula (I) satisfies one or more of the following conditions: (1) ArD is selected from any one of the following structural formulas of ArD1 to ArD9: In each of the structural formulas shown in ArD1 to ArD9, the dotted bond represents a single bond to L, R D each independently is selected from any one of a single bond, hydrogen, halogen, -OR', -OC(=0)R', -NHC(=0)R', -NR'2, R', halogen-substituted R', -SR', -PR'2, provided that in each of the structural formulas shown in ArD1 to ArD9, there is and there is only one R D is a single bond; In each of the structural formulas represented by ArD7 to ArD9, Y is independently selected from any one of -CR2-, -NR-, -O-, -SiR2-, -PR-, -S-, -As-, -Se-; In the structural formula represented by ArD7, k is an integer from 1 to 3; (2) ArA is selected from any one of the following ArA1 to ArA8: In each of the structural formulas represented by ArA1to ArA8, each Z is independently selected from CR or N, with the proviso that in each of the structural formulas represented by ArA1to ArA8, there are and only two Z are and at least one Z is N, wherein, in the formula In the structural formula represented by ArD7, k is an integer from 1 to 3; In each of the structural formulas represented by ArA4 to ArA8, Y' is independently selected from any one of -CR2-, -NR-, -O-, -SiR2-, -PR-, -S-, -As-, -Se-, -C(=O)-, -C(=S)-, -C(=NR)-, -C(=CR2)-; (3) L is selected from -CR2-, -CR2-CR2-, -NR-, -0-, -SiR2-, -PR-, -S-, -C(=0)-, -C(=S)-, -C(=NR)-, -C(=CR2)-, or any one or a combination of more of the following L1to L8: In each of the structural formulas represented by L1 to L8, Z is independently selected from CR or N; In each of the structural formulas represented by L2, L5 to L7, Y is independently selected from any one of -CR2-, -NR-, -O-, -SiR2-, -PR-, -S-, -As-, -Se-, -C(=O)-, -C(=S)-, -C(=NR)-, or -C(=CR2)-; (4) A is selected from any one of -COOH, -PO(OH)2, -PHO(OH), -SO2(OH), or -B(OH)2; In the above group containing R, R is independently selected from any one of hydrogen, halogen, R', halogen-substituted R', -OR', -OC(=O)R', -NHC(=O)R', -NR'2, -SR', -PR'2; In the above group containing R', R' is independently selected from any one of substituted or unsubstituted phenyl, thienyl, C1-C10 alkyl.

3. The solar cell according to claim 1 or 2, wherein The repeating unit of formula (I) satisfies one or more of the following conditions: (1) ArD is selected from any one of the following structural formulas of ArD10 to ArD21: In each of the structural formulas shown in ArD10 to ArD21, R D each is independently selected from any one of hydrogen, halogen, -OR', -OC(=0)R', -NHC(=0)R', -NR'2, R', halogen-substituted R', -SR', -PR'2; R" is a single bond; In each of the structural formulas represented by ArD19 to ArD21, Y is independently selected from any one of -CR2-, -NR-, -O-, -S-, -Se-; In the structural formula represented by ArD19, k is an integer from 1 to 3; (2) ArA is selected from any one of the following structural formulas of ArA9 to ArA15: In each of the structural formulas represented by ArA11 to ArA15, Y' is independently selected from any one of -NR-, -O-, -S-, -Se-, -C(=O)-; In each of the structural formulas represented by ArA11, ArA12, ArA15, Z is independently selected from CR or N; (3) L is selected from -CR2-, -CR2-CR2-, -NR-, -O-, -C(=O)- or any one or a combination of more of the structural formulae indicated by L9to L11, In each of the structural formulas represented by L9 to L11, Y is independently selected from any one of -CR2-, -NR-, -O-, -S-, -Se-; (4) A is selected from -COOH or -PO(OH)2; (5) m is an integer from 0 to 5, in the above R-containing group, R is as defined in claim 2, in the above R'-containing group, R' is as defined in claim 2.

4. The solar cell of claim 3, wherein, The repeating unit of formula (I) satisfies one or more of the following conditions: (1) ArD is selected from any one of the structural formulas represented by ArD11, ArD16, ArD19; (2) ArA is selected from any one of the structural formulas represented by ArA9, ArA12, ArA15; (3) L is selected from any one or a combination of more than one of -CR2-, -CR2-CR2- or L9.

5. The solar cell according to any one of claims 1 to 4, wherein, The repeating units of formula (I) include one or more of the repeating units of formulae U1-U5:

6. The solar cell according to any one of claims 1 to 5, wherein, The polymer has a degree of polymerization of an integer from 2 to 100000.

7. The solar cell according to any one of claims 1 to 6, wherein, The self-assembled monolayer has a thickness of 0.25 nm to 5 nm.

8. The solar cell according to any one of claims 1 to 7, wherein, The hole transport layer further comprises a metal oxide layer, the metal oxide layer is located between the self-assembled monolayer and the first electrode, and the thickness of the metal oxide layer is 10 nm to 100 nm.

9. The solar cell according to any one of claims 1 to 8, wherein, The solar cell comprises a first electrode, a hole transport layer, a perovskite light-absorbing layer, an electron transport layer and a second electrode which are sequentially stacked, wherein the first electrode is a transparent electrode.

10. A photovoltaic module comprising the solar cell of any one of claims 1 to 9.

11. A power generation device comprising the solar cell of any one of claims 1 to 9.

12. A power consumption device comprising the solar cell of any one of claims 1 to 9.

13. A polymer comprising repeat units of formula (I): ###0002### (I) in formula (I), ArD represents an aromatic electron-donating unit; ArA represents an aromatic electron-withdrawing unit; L represents a linking group having two linking sites; A represents an oxygen-containing acid group or a corresponding salt thereof; m is an integer from 0 to 10.

14. The polymer of claim 13, wherein, The repeating unit of formula (I) satisfies one or more of the following conditions: (1) ArD is selected from any one of the following structural formulas of ArD1 to ArD9: In each of the structural formulas shown in ArD1 to ArD9, the dotted bond represents a single bond to L, R D each independently is selected from any one of a single bond, hydrogen, halogen, -OR', -OC(=0)R', -NHC(=0)R', -NR'2, R', halogen-substituted R', -SR', -PR'2, with the proviso that in each of the structural formulas shown in ArD1 to ArD9, there is and there is only one R D is a single bond; in each of the structural formulas represented by ArD7 to ArD9, Y is independently selected from any one of -CR2-, -NR-, -O-, -SiR2-, -PR-, -S-, -As-, -Se-; in the structural formula represented by ArD7, k is an integer from 1 to 3; (2) ArA is selected from any one of the following ArA1 to ArA8: In each of the structural formulas represented by ArA1to ArA8, each Z is independently selected from CR or N, with the proviso that in each of the structural formulas represented by ArA1to ArA8, there are and only two Z are and at least one Z is N, wherein, in the formula in the structural formula represented by ArD7, k is an integer from 1 to 3; in each of the structural formulas represented by ArA4 to ArA8, Y' is independently selected from any one of -CR2-, -NR-, -O-, -SiR2-, -PR-, -S-, -As-, -Se-, -C(=O)-, -C(=S)-, -C(=NR)-, -C(=CR2)-; (3) L is selected from -CR2-, -CR2-CR2-, -NR-, -0-, -SiR2-, -PR-, -S-, -C(=0)-, -C(=S)-, -C(=NR)-, -C(=CR2)-, or any one or a combination of more of the following L1to L8: in each of the structural formulas represented by L1 to L8, Z is independently selected from CR or N; in each of the structural formulas represented by L2, L5 to L7, Y is independently selected from any one of -CR2-, -NR-, -O-, -SiR2-, -PR-, -S-, -As-, -Se-, -C(=O)-, -C(=S)-, -C(=NR)- or -C(=CR2)-; (4) A is selected from any one of -COOH, -PO(OH)2, -PHO(OH), -SO2(OH) or -B(OH)2; In the above R-containing groups, R is independently selected from any one of hydrogen, halogen, R', halogen-substituted R', -OR', -OC(=O)R', -NHC(=O)R', -NR'2, -SR', -PR'2. In the above R'-containing groups, R' is independently selected from any one of substituted or unsubstituted phenyl, thienyl, C1-C10 alkyl.

15. The polymer of claim 13 or 14, wherein, The repeating unit of formula (I) satisfies one or more of the following conditions: (1) ArD is selected from any one of the following structural formulas of ArD10 to ArD21: In each of the structural formulas shown in ArD10 to ArD21, R D each is independently selected from any one of hydrogen, halogen, -OR', -OC(=0)R', -NHC(=0)R', -NR'2, R', halogen-substituted R', -SR', -PR'2; R" is a single bond; In each of the structural formulas represented by ArD19 to ArD21, Y is independently selected from any one of -CR2-, -NR-, -O-, -S-, -Se-; In the structural formula represented by ArD19, k is an integer from 1 to 3; (2) ArA is selected from any one of the following structural formulas of ArA9to ArA15: In each of the structural formulas represented by ArA11 to ArA15, Y' is independently selected from any one of -NR-, -O-, -S-, -Se-, -C(=O)-; In each of the structural formulas represented by ArA11, ArA12, ArA15, Z is independently selected from CR or N; (3) L is selected from -CR2-, -CR2-CR2-, -NR-, -O-, -C(=O)- or any one or a combination of more of the structural formulae indicated by L9to L11, In each of the structural formulas represented by L9 to L11, Y is independently selected from any one of -CR2-, -NR-, -O-, -S-, -Se-; (4) A is selected from -COOH or -PO(OH)2; (5) m is an integer from 0 to 5, In the above R-containing groups, R is as defined in claim 14, In the above R'-containing groups, R' is as defined in claim 14.

16. The polymer of claim 15, wherein, The repeating unit of formula (I) satisfies one or more of the following conditions: (1) ArD is selected from any one of the structural formulas represented by ArD11, ArD16, ArD19; (2) ArA is selected from any one of the structural formulas represented by ArA9, ArA12, ArA15; (3) L is selected from any one or a combination of more than one of -CR2-, -CR2-CR2- or L9.

17. The polymer of any one of claims 13 to 16, wherein, The repeating units of formula (I) include one or more of the repeating units of formulae U1-U5:

18. The polymer of any one of claims 13 to 17, wherein, The polymer has a degree of polymerization of an integer from 2 to 100000.

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