Solar cell, tandem solar cell, photovoltaic device, electric device, and power generation device

Abstract

The present application discloses a solar cell, a tandem solar cell, a photovoltaic device, an electric device, and a power generation device. The solar cell comprises a first electrode, a first hole transport layer, a first light absorption layer, a first hole transport layer and a second electrode, wherein the first light absorption layer and the first hole transport layer are disposed between the first electrode and the second electrode; the first hole transport layer is disposed between the first electrode and the first light absorption layer; and the first hole transport layer comprises a first hole transport material and an insulating additive, the first hole transport material comprising a first polymer material, and the insulating additive comprising a second polymer material. The first hole transport layer of the present application comprises the insulating additive, which can improve the solution viscosity and film formation property of the first hole transport layer, thereby improving the coverage of the first hole transport layer on a covered film layer. In this way, the problem of electron-hole recombination caused by direct contact between the first light absorption layer and the first electrode is ameliorated, and therefore the photoelectric conversion efficiency of the solar cell can be improved.

Description

Solar cells, tandem solar cells, photovoltaics, electricity consumption and generation devices

[0001] Cross-reference to related applications

[0002] This application claims priority to Chinese patent application 202510192606.8, filed on February 20, 2025, entitled “Solar Cells, Photovoltaic Devices, Electrical Appliances and Power Generation Devices”, the entire contents of which are incorporated herein by reference. Technical Field

[0003] This application relates to the field of solar cell technology, and in particular to solar cells, tandem solar cells, photovoltaic devices, electrical appliances, and power generation devices. Background Technology

[0004] In perovskite solar cells, the hole transport layer is typically located on one side of the electrode layer, with a perovskite material forming the light absorption layer on the side of the hole transport layer facing away from the electrode. However, because the hole transport layer may not completely cover the electrode layer or the light absorption layer, direct contact between the light absorption layer and the electrode layer can occur, leading to significant carrier recombination losses and resulting in poor solar cell conversion efficiency and short lifespan. Summary of the Invention

[0005] In view of the above-mentioned technical problems, this application provides a solar cell, a tandem solar cell, a photovoltaic device, an electrical device, and a power generation device to improve the coverage of the hole transport layer on the electrode layer or the light absorption layer, thereby improving the photoelectric conversion efficiency and lifespan of the solar cell.

[0006] The first technical solution adopted in this application is: to provide a solar cell, the solar cell including at least a first electrode, a first hole transport layer, a first light absorption layer and a second electrode stacked together, the first light absorption layer and the first hole transport layer being disposed between the first electrode and the second electrode, the first hole transport layer being disposed between the first electrode and the first light absorption layer, wherein the first hole transport layer includes a first hole transport material and an insulating additive, the first hole transport material including a first polymer material, and the insulating additive including a second polymer material.

[0007] In the technical solution of this application embodiment, the first hole transport layer includes a first hole transport material and an insulating additive. Both the first hole transport material and the insulating additive are polymer materials, which can improve the solution viscosity and film-forming properties of the first hole transport layer. This increases the coverage of the first hole transport layer on the covered film layer (such as the first electrode or the first light absorption layer), reducing the problem of electron-hole recombination caused by direct contact between the first light absorption layer and the first electrode, thus improving the performance of the solar cell. Furthermore, the first hole transport material is used for hole transport and to block the reverse flow of electrons. The first hole transport material includes a first polymer material, and the insulating additive includes a second polymer material. The second polymer material and the first polymer material are blended to form the first hole transport layer. This results in the first hole transport layer near the surface of the first light absorption layer being partly composed of the first polymer material capable of transporting holes and partly composed of the insulating second polymer material. This further reduces the electrical contact area between the first light absorption layer and the first hole transport layer, reducing carrier recombination induced by interface defects, thereby improving the photoelectric conversion efficiency of the solar cell.

[0008] In some embodiments, the volume resistivity of the insulating additive is 1×10⁻⁶. 10 Ω m~1×10 18 Ω m.

[0009] In the technical solution of this application embodiment, the resistivity of the insulating additive is within the above-mentioned range, indicating that the second polymer material in the insulating additive exhibits good insulation properties. After the insulating second polymer material is blended with the first polymer material, a first hole transport layer is formed. The surface portion of the first hole transport layer near the first light absorption layer is composed of the first polymer material that can transport holes, and the portion is composed of the insulating second polymer material. This reduces the area of ​​the electrical contact interface between the first light absorption layer and the first hole transport layer, reduces carrier recombination induced by interface defects, and thus improves the photoelectric conversion efficiency of the solar cell.

[0010] In some embodiments, the weight-average molecular weight of the insulating additive is greater than or equal to 20 kDa and less than or equal to 4 million Da.

[0011] In the technical solution of this application embodiment, the weight-average molecular weight of the insulating additive is within the aforementioned range. This can improve the solution viscosity and film-forming properties of the first hole transport layer, thereby increasing the coverage of the first hole transport layer on the covered film layer (such as the first electrode or the first light-absorbing layer). This reduces the problem of electron-hole recombination caused by direct contact between the first light-absorbing layer and the first electrode, which is beneficial to improving the performance of the solar cell. Simultaneously, the weight-average molecular weight of the insulating additive within the aforementioned range results in stronger interaction between the insulating additive and the electrode layer. Furthermore, the low solubility of the insulating additive prevents it from easily dissolving and diffusing into the subsequently prepared light-absorbing layer. This provides good stability when mixed with the first hole transport material to form the first hole transport layer, which is beneficial to improving the photoelectric conversion efficiency of the solar cell.

[0012] In some implementations, the polydispersity index (PDI) of the insulating additive is less than or equal to 5.

[0013] In the technical solution of this application embodiment, the polydispersity index (PDI) of the insulating additive is within the above range, the molecular weight distribution of the insulating additive is narrow, the content of small molecule components is reduced, and the insulating additive is not easily dissolved and diffused into the first light absorption layer prepared subsequently, which can reduce the impact on the growth of perovskite crystals.

[0014] In some implementations, the hydrophilic-lipophilic balance value of the insulating additive is in the range of 9 to 35.

[0015] In the technical solution of this application embodiment, the hydrophilic-lipophilic balance value of the insulating additive is within the above-mentioned range, and the insulating additive exhibits good hydrophilicity, thereby making the first hole transport layer exhibit good hydrophilicity. The surface of the first hole transport layer has a large number of polar groups. The polar groups on the surface of the first hole transport layer can interact with the first light absorption layer material to form interactions including hydrogen bonds, π-π interactions, and electrostatic forces (ion-ion interactions, ion-dipole interactions, dipole-dipole interactions), which enhances the interaction force between the interface of the first hole transport layer and the first light absorption layer material. This is beneficial to the growth of the thin film of the first light absorption layer on the surface of the first hole transport layer, improves the quality of the thin film of the first light absorption layer, and thus improves the photoelectric conversion efficiency and service life of the solar cell.

[0016] In some embodiments, the molecular structure of the second polymer material includes one or more of the following: organic acid group, hydroxyl group, amino group, carboxyl group, sulfonic acid group, phosphate group, ether group, amide group, and sulfoxide group.

[0017] In the technical solution of this application embodiment, the second polymer material is selected from the above-mentioned materials, which makes the insulating additive exhibit good hydrophilicity, thereby making the first hole transport layer exhibit good hydrophilicity, enhancing the interaction force between the interface of the first hole transport layer and the material of the first light absorption layer, which is conducive to the growth of the thin film of the first light absorption layer on the surface of the first hole transport layer, improving the quality of the first light absorption layer film, thereby improving the photoelectric conversion efficiency and service life of the solar cell.

[0018] In some embodiments, the second polymer material comprises one or more of synthetic polymers, starch, protein, and cellulose; the synthetic polymers include copolymers formed from one or more of polyacrylic acid (PAA), polystyrene sulfonic acid (PSS), polyacrylamide (PAM), polyvinyl alcohol (PVA), polyethylene glycol (PEG, PEO), poly(N-vinylpyrrolidone) (PVP), poly(2-hydroxypropyl methacrylamide) (PHPMA), polyethyleneimine (PEI), and poly(2-(methacryloyloxy)ethylphosphorylcholine) (PMPC).

[0019] In the technical solution of this application embodiment, the second polymer material is selected from the aforementioned materials, which makes the insulating additive material exhibit better insulation properties. This insulating additive, when blended with the first hole transport material, forms the first hole transport layer. The surface portion of the first hole transport layer near the first light absorption layer is the first hole transport material capable of transporting holes, and the remaining portion is the insulating additive. This reduces the area of ​​the electrical contact interface between the first light absorption layer and the first hole transport layer, lowering interface carrier recombination induced by interface defects, thereby improving the photoelectric conversion efficiency of the solar cell. Furthermore, the second polymer material is selected from the aforementioned materials, which makes the insulating additive exhibit better hydrophilicity, thus making the first hole transport layer exhibit better hydrophilicity. This enhances the interaction force between the interface of the first hole transport layer and the first light absorption layer material, which is beneficial for the growth of the thin film of the first light absorption layer on the surface of the first hole transport layer, improving the quality of the first light absorption layer film, thereby improving the photoelectric conversion efficiency and lifespan of the solar cell.

[0020] In some embodiments, the weight-average molecular weight of the first hole transport material is 500 to 50,000.

[0021] In the technical solution of this application embodiment, the weight-average molecular weight of the first hole transport material is within the above-mentioned range, the interaction between the first hole transport material and the electrode layer is stronger, and the solubility of the first hole transport material is low, so the first hole transport material is not easy to dissolve and diffuse into the subsequently prepared first light absorption layer, which is beneficial to the stability of the first hole transport layer and improves the performance of the solar cell.

[0022] In some embodiments, the molecular structure of the first polymer material includes one or more of aniline, carbazole, acridine, thiophenazine, phenoxazine, benzothiazolyl, and thiophene.

[0023] In the technical solution of this application embodiment, the first polymer material is selected from the above-described structure, which can effectively transport holes, thereby improving the photoelectric performance of the solar cell.

[0024] In some embodiments, the first hole transport material comprises a polymer of N4,N4′-bis(naphthyl-1-yl)-N4,N4′-bis(4-vinylphenyl)biphenyl-4,4′-diamine, poly[bis(4-phenyl)(2,4,6-trimethylphenyl)amine], poly3-hexylthiophene, poly(3,4-ethylenedioxythiophene):polystyrene sulfonic acid, or one or more of the repeating units shown in formula (I):

[0025] Formula (I),

[0026] In formula (I),

[0027] M includes substituted or unsubstituted aniline, substituted or unsubstituted carbazolyl, substituted or unsubstituted acridine, substituted or unsubstituted thiophenazinyl or substituted or unsubstituted phenoxazinyl;

[0028] R is a single bond or a bridging group;

[0029] Y includes H or one or both of the oxygen-containing groups.

[0030] In the technical solution of this application embodiment, the first hole transport material is selected from the above-mentioned materials, which can play a good role in transporting holes and can effectively extract and transport photogenerated holes, thereby improving the photoelectric performance of the solar cell. Furthermore, selecting the repeating unit described in formula (I) as the first hole transport material helps to enhance its interaction force with the interface below the first hole transport layer, thereby improving the stability and lifespan of the solar cell.

[0031] In some implementations, equation (I) satisfies one or more of the following conditions:

[0032] (1) The repeating unit shown in equation (I) includes one or more of the repeating units shown in equations (I-1) to (I-6):

[0033] Formula (I-1), Formula (I-2), Formula (I-3), Formula (I-4), Formula (I-5), Equation (I-6); where,

[0034] R1 to R 12 Each of the following is independently selected from one or more of the following: hydrogen atom, halogen atom, nitrogen-containing group, hydroxyl group, substituted or unsubstituted C1-C5 alkyl group, substituted or unsubstituted C1-C5 alkoxy group, substituted or unsubstituted C1-C5 amide group, substituted or unsubstituted C1-C5 ester group, substituted or unsubstituted C1-C5 carboxyl group, substituted or unsubstituted C6-C30 aryl group, or substituted or unsubstituted C5-C30 heterocyclic aryl group; the curve " " represents the connection key with adjacent repeating units;

[0035] (2) The bridging group includes one or more of the following: oxygen atom, sulfur atom, substituted or unsubstituted alkylene group, substituted or unsubstituted alkenyl group, substituted or unsubstituted heteroalkylene group, substituted or unsubstituted aromatic group, or substituted or unsubstituted heterocyclic group;

[0036] In cases where the bridging group includes a substituted or unsubstituted alkylene group, a substituted or unsubstituted alkenyl group, or a substituted or unsubstituted heteroalkylene group, and the above group is substituted by a substituent group, the substituent group includes one or more of a halogen group, an amine group, an alkylthion group, an oxygen-containing substituent group, an aromatic group, or an aromatic heterocyclic group, and the number of carbon atoms is 1 to 10 when the substituent group includes a carbon atom.

[0037] In cases where the bridging group includes a substituted or unsubstituted aromatic group or a substituted or unsubstituted heterocyclic group, and the above group is substituted by a substituent group, the substituent group includes one or more of halogen groups, amine groups, alkyl thio groups, oxygen-containing substituent groups or C1 to C5 alkyl groups.

[0038] (3) The oxygen-containing group includes one or more of the following: carboxylic acid group, phosphite group, phosphate group, sulfonic acid group, silicate group, siloxane group, borate group, carboxylic acid ester group, phosphate ester group, sulfonate group, silicate group, borate group, carboxylate group, phosphite group, phosphate group, borate group or silicate group.

[0039] In the technical solution of this application embodiment, the first hole transport material includes the repeating unit shown in formula (I). The material has an energy level that matches the perovskite material and a high hole mobility, which can enhance the charge transport properties of the first hole transport material and improve the performance of the perovskite solar cell.

[0040] In some embodiments, the first hole transport material includes one or more of polyphosphate carbazole, polycarboxylic acid carbazole, and poly[bis(4-phenyl)(2,4,6-trimethylphenyl)amine].

[0041] In the technical solution of this application embodiment, the first hole transport material is selected from the above-mentioned materials, which can play a good role in transporting holes, effectively extracting and transporting photogenerated holes, thereby improving the photoelectric performance of the solar cell.

[0042] In some embodiments, the repeating units of polycarbazole polyphosphate or polycarbazole polycarboxylate are as shown in formula (I-3), wherein Y in polycarbazole polyphosphate is selected from one or more of phosphate groups, phosphate ester groups, and phosphate groups; Y in polycarbazole polycarboxylate is selected from one or more of carboxylic acid groups, carboxylic acid ester groups, and carboxylate groups. In the technical solution of the embodiments of this application, the first hole transport material is selected from the above-mentioned materials, which can play a good role in transporting holes, effectively extracting and transporting photogenerated holes, thereby improving the photoelectric performance of the solar cell.

[0043] In some embodiments, the first polymer material comprises one or more of poly[4-(3,6-dimethyl-9H-carbazole-9-yl)butyl]phosphonic acid, poly[4-(9H-carbazole-9-yl)butyl]phosphonic acid, poly[2-(3,6-dimethoxy-9H-carbazole-9-yl)ethyl]phosphonic acid, poly[2-(3,6-dimethyl-9H-carbazole-9-yl)ethyl]phosphonic acid, poly[2-(9H-carbazole-9-yl)ethyl]phosphonic acid, poly[2-(3,6-dibromo-9H-carbazole-9-yl)ethyl]phosphonic acid, poly[4-(3,6-dimethyl-9H-carbazole-9-yl)butyl]phosphonic acid, and poly[bis(4-phenyl)(2,4,6-trimethylphenyl)amine]; and / or, the second polymer material comprises one or both of polyacrylic acid and polyethyleneimine.

[0044] In the technical solution of this application embodiment, when the first polymer material and the second polymer material are selected from the above materials to form the first hole transport layer, the first hole transport layer exhibits good hydrophilicity, which enhances the interaction force between the interface of the first hole transport layer and the material of the first light absorption layer. This is beneficial to the growth of the thin film of the first light absorption layer on the surface of the first hole transport layer, improves the quality of the first light absorption layer film, and thus improves the photoelectric conversion efficiency and lifespan of the solar cell. Furthermore, the second polymer material exhibits good insulation properties. When this insulating second polymer material is blended with the first polymer material, the first hole transport layer is formed. The surface portion of the first hole transport layer near the first light absorption layer is composed of the first polymer material that can transport holes, and the portion is composed of the insulating second polymer material. This reduces the area of ​​the electrical contact interface between the first light absorption layer and the first hole transport layer, reduces the interface carrier recombination induced by interface defects, and thus improves the photoelectric conversion efficiency of the solar cell.

[0045] In some embodiments, the first hole transport material forms the hole transport region, the insulating additive forms the insulating region, and the hole transport region and the insulating region exhibit a microscopic phase separation structure.

[0046] In the technical solution of this application embodiment, holes can only be transported from the hole transport region and cannot be transported from the insulating region. The hole transport region and the insulating region exhibit a microscopic phase separation structure, which reduces the area of ​​the electrical contact interface between the first light absorption layer and the first hole transport layer, and suppresses the interface carrier recombination induced by interface defects. The second polymer material can improve the solution viscosity and film-forming properties of the first hole transport layer, thereby increasing the coverage of the first hole transport layer on the solar cell substrate and reducing the problem of carrier recombination caused by direct contact between the first light absorption layer and the solar cell substrate, thus improving the photoelectric conversion efficiency of the solar cell.

[0047] In some embodiments, the mass ratio of the first hole transport material to the insulating additive in the first hole transport layer is 1:5 to 5:1.

[0048] In the technical solution of this application embodiment, the mass ratio of the first hole transport material to the insulating additive in the first hole transport layer is within the aforementioned range. This facilitates the formation of a composite first hole transport layer with superior performance, significantly improving solution viscosity and film-forming properties, increasing coverage on the solar cell substrate, and reducing the problem of carrier recombination caused by direct contact between the first light absorption layer and the solar cell substrate. Furthermore, the improved hydrophilicity of the first hole transport layer is beneficial for the subsequent growth of the first light absorption layer film on the first hole transport layer, improving the quality of the perovskite film, thereby enhancing the photoelectric conversion efficiency and lifespan of the solar cell.

[0049] In some implementations, the thickness of the first hole transport layer is 1 nm to 30 nm.

[0050] In the technical solution of this application embodiment, the thickness of the first hole transport layer is within the above-mentioned range, which can better transport holes and block electrons, thereby improving the photoelectric conversion efficiency of the solar cell.

[0051] In some embodiments, the first light-absorbing layer comprises a perovskite material having the general formula ABX3 or A2CDX6, wherein A ions comprise inorganic or organic or mixed organic-inorganic cations; B ions comprise inorganic cations; C ions comprise inorganic or organic or mixed organic-inorganic cations; D ions comprise inorganic cations; and X ions comprise inorganic or organic or mixed organic-inorganic anions.

[0052] In the technical solution of this application embodiment, the first light absorption layer includes the above-mentioned first perovskite material, which has high photoelectric conversion efficiency, low preparation cost, and can be mass-produced by solution method, which is beneficial to reduce the manufacturing cost of solar cells. The band gap of the first perovskite material can be adjusted by adjusting the type and ratio of elements, thereby optimizing photoelectric performance and adapting to different application needs.

[0053] In some embodiments, the first perovskite material satisfies one or more of the following conditions: (1) A ions include FA. + MA + Gu + Cs + 、Rb + DMA + (1) One or more of the following; (2) B ions include Pb 2+ Sn 2+ Ge² + Mn² + One or more of them; (3) C ions include Ag + Cu + Au + FA + Gu + One or more of them; (4) D ions include Bi 3+ Sb 3+ And In 3+ One or more of them; (5) X ions include Cl - ,Br - I - SCN - CNO - OCN - OSCN - SH - OH - CN - SeCN - COO - One or more of them.

[0054] In the technical solution of this application embodiment, the first light absorption layer includes the above-mentioned first perovskite material, which has high photoelectric conversion efficiency, low preparation cost, and can be mass-produced by solution method, which is beneficial to reduce the manufacturing cost of solar cells. The band gap of the first perovskite material can be adjusted by adjusting the type and ratio of elements, thereby optimizing photoelectric performance and adapting to different application needs.

[0055] In some embodiments, the solar cell further includes a second hole transport layer located on the side of the first hole transport layer away from the first light absorption layer and between the first electrode and the first hole transport layer.

[0056] In the technical solution of this application embodiment, the second hole transport layer is located on the side of the first hole transport layer away from the first light absorption layer, and the combination of the first hole transport layer and the second hole transport layer can improve the hole mobility.

[0057] In some implementations, the second hole transport layer comprises nickel oxide.

[0058] In the technical solution of this application embodiment, nickel oxide is used as the second hole transport layer, which can improve hole mobility on the one hand, and increase the anchoring points of the first hole transport layer material on the other hand, thereby improving the performance and stability of the solar cell.

[0059] In some implementations, the solar cell is a reverse solar cell.

[0060] In the technical solution of this application embodiment, the inverted solar cell improves the efficiency of the solar cell by optimizing the cell structure, making it easier for electrons to pass through the entire cell. The inverted solar cell of this application embodiment utilizes the aforementioned hydrophilic first hole transport layer, which facilitates the subsequent growth of the first light absorption layer film, improves the quality of the perovskite film, and thus enhances the photoelectric conversion efficiency and lifespan of the solar cell.

[0061] The second technical solution adopted in this application is: to provide a tandem solar cell, the tandem solar cell including the solar cell described in any of the above, as well as an intermediate layer and a second light-absorbing layer, the intermediate layer being disposed on the side of the first light-absorbing layer near the second electrode, the second light-absorbing layer being disposed between the intermediate layer and the second electrode, and the second light-absorbing layer and the first light-absorbing layer having different band gaps.

[0062] In the embodiments of this application, by setting a second light-absorbing layer and a first light-absorbing layer with different band gaps, the tandem solar cell can effectively absorb light of different wavelengths, broadening the spectral range of absorbed light and thus further improving the photoelectric conversion efficiency of the tandem solar cell. Furthermore, the tandem solar cell provided in the embodiments of this application possesses at least the same advantages as the solar cell provided in the first aspect.

[0063] In one embodiment, the intermediate layer is an interconnect layer; or, the intermediate layer includes a third electrode, an insulating layer, and a fourth electrode stacked together, with the third electrode disposed between the first light-absorbing layer and the insulating layer, and the fourth electrode disposed between the insulating layer and the second light-absorbing layer.

[0064] In the embodiments of this application, when the intermediate layer is an interconnect layer, the tandem solar cell can form a monolithic integrated tandem cell. The two cell sections are connected through the interconnect layer to achieve current matching between the two cell sections. The size is relatively smaller, and it can absorb light of different wavelengths, thus broadening the absorption spectrum range of the tandem solar cell and improving the photoelectric conversion efficiency of the tandem solar cell. When the intermediate layer includes a third electrode, an insulating layer, and a fourth electrode stacked together, the tandem solar cell can form a mechanically tandem cell. The two cell sections are isolated by the insulating layer so that the charge carriers are not directly connected in parallel. No current matching is required between the two. At the same time, each cell section is provided with separate positive and negative electrodes to lead out current, which can flexibly realize circuit adjustment.

[0065] The third technical solution adopted in this application is: to provide a photovoltaic device, including any of the above-mentioned solar cells or any of the above-mentioned tandem solar cells.

[0066] Since the photovoltaic device of this application includes the solar cell provided in this application, it has at least the same advantages as the solar cell.

[0067] The fourth technical solution adopted in this application is: to provide an electrical device, including any of the above-mentioned solar cells or any of the above-mentioned tandem solar cells or the above-mentioned photovoltaic devices.

[0068] Since the power-consuming device of this application includes the solar cell provided in this application, it has at least the same advantages as the solar cell.

[0069] The fifth technical solution adopted in this application is: to provide a power generation device, including any of the above-mentioned solar cells or any of the above-mentioned tandem solar cells or the above-mentioned photovoltaic devices.

[0070] Since the power generation device of this application includes the solar cell provided in this application, it has at least the same advantages as the solar cell.

[0071] The above description is merely an overview of the technical solution of this application. In order to better understand the technical means of this application and to implement it in accordance with the contents of the specification, and to make the above and other objects, features and advantages of this application more obvious and understandable, specific embodiments of this application are given below. Attached Figure Description

[0072] Various other advantages and benefits will become apparent to those skilled in the art upon reading the detailed description of the preferred embodiments below. The accompanying drawings are for illustrative purposes only and are not intended to limit the scope of this application. Furthermore, the same reference numerals denote the same parts throughout the drawings. In the drawings:

[0073] Figure 1 is a schematic diagram of the structure of an inverted perovskite solar cell, provided by related technologies.

[0074] Figure 2 is a schematic diagram of the structure of the solar cell provided in an embodiment of this application;

[0075] Figure 3 is a schematic diagram of the structure of the first light absorption layer, the first hole transport layer, and the first electrode layer of the solar cell provided in the embodiment of this application.

[0076] Figure 4 is a scanning electron microscope image of the crystallization of the first light-absorbing layer provided in the embodiment of this application;

[0077] Figure 5 is a scanning electron microscope image of the crystallization of the light absorption layer in the related technology;

[0078] Figure 6 is a schematic diagram of the contact angle of the first hole transport layer provided in an embodiment of this application;

[0079] Figure 7 is a schematic diagram of a stacked solar cell provided in an embodiment of this application;

[0080] Figure 8 is a schematic diagram of another stacked solar cell provided in an embodiment of this application;

[0081] Figure 9 is a schematic diagram of another stacked solar cell provided in an embodiment of this application;

[0082] Figure 10 is a schematic diagram of the structure of the photovoltaic device provided in the embodiments of this application;

[0083] Figure 11 is a schematic diagram of the structure of the electrical device provided in an embodiment of this application;

[0084] Figure 12 is a schematic diagram of the structure of the power generation device provided in the embodiment of this application.

[0085] Marker explanation:

[0086] 100-Solar cell, 101-First electrode, 102-First hole transport layer, 103-First light absorption layer, 104-First electron transport layer, 105-Second electrode, 1000-Photovoltaic device, 2000-Electrical device, 3000-Power generation device, 200-Stacked solar cell, 20-Intermediate layer, 201-Interconnect layer, 202-Third electrode, 203-Insulating layer, 204-Fourth electrode, 30-Second light absorption layer. Embodiments of the present invention

[0087] The embodiments of the technical solution of this application will now be described in detail with reference to the accompanying drawings. These embodiments are only used to more clearly illustrate the technical solution of this application and are therefore merely examples, and should not be used to limit the scope of protection of this application.

[0088] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application pertains; the terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit the application; the terms “comprising” and “having”, and any variations thereof, in the specification, claims, and foregoing description of the drawings are intended to cover non-exclusive inclusion.

[0089] In the description of the embodiments of this application, technical terms such as "first" and "second" are used only to distinguish different objects and should not be construed as indicating or implying relative importance or implicitly specifying the number, specific order, or primary and secondary relationship of the indicated technical features. In the description of the embodiments of this application, "multiple" means two or more, unless otherwise explicitly defined.

[0090] In this document, the term "embodiment" means that a particular feature, structure, or characteristic described in connection with an embodiment may be included in at least one embodiment of this application. The appearance of this phrase in various places throughout the specification does not necessarily refer to the same embodiment, nor is it a separate or alternative embodiment mutually exclusive with other embodiments. It will be explicitly and implicitly understood by those skilled in the art that the embodiments described herein can be combined with other embodiments.

[0091] In the description of the embodiments in this application, the term "and / or" is merely a description of the relationship between related objects, indicating that three relationships can exist. For example, A and / or B can represent: A existing alone, A and B existing simultaneously, and B existing alone. Additionally, the character " / " in this document generally indicates that the preceding and following related objects have an "or" relationship.

[0092] In perovskite solar cells, the hole transport layer is typically located on one side of the electrode layer, with a perovskite material forming the light absorption layer on the side of the hole transport layer facing away from the electrode. However, because the hole transport layer may not completely cover the electrode layer or the light absorption layer, direct contact between the light absorption layer and the electrode layer can occur, leading to significant carrier recombination losses and resulting in poor solar cell conversion efficiency and short lifespan.

[0093] Referring to Figure 1, which is a schematic diagram of the structure of an inverted perovskite solar cell provided by related technologies, the hole transport layer of an inverted perovskite solar cell is located on a transparent conductive substrate. In order to reduce interfacial recombination loss and series resistance of the cell, the thickness of the hole transport layer is required to be less than 20 nm. This often results in the hole transport layer not completely covering the transparent conductive substrate and poor conformability (thick film at depressions and thin film at protrusions). This leads to direct contact between the perovskite photoactive layer and the transparent electrode, resulting in large interfacial carrier recombination loss and poor solar cell performance.

[0094] Please refer to Figure 2, which is a schematic diagram of the structure of a solar cell provided in an embodiment of this application.

[0095] Therefore, this application provides a solar cell 100, which includes at least a first electrode 101, a first hole transport layer 102, a first light absorption layer 103, and a second electrode 105 stacked together. The first light absorption layer 103 and the first hole transport layer 102 are disposed between the first electrode 101 and the second electrode 105. The first hole transport layer 102 is disposed between the first electrode 101 and the first light absorption layer 103. The first hole transport layer 102 includes a first hole transport material and an insulating additive. The first hole transport material includes a first polymer material, and the insulating additive includes a second polymer material.

[0096] In the technical solution of this application embodiment, the first hole transport layer 102 includes a first hole transport material and an insulating additive; wherein, both the first hole transport material and the insulating additive include polymer materials, which can improve the solution viscosity and film-forming properties of the first hole transport layer 102, thereby increasing the coverage of the first hole transport layer 102 on the covered film layer (such as the first electrode 101 or the first light absorption layer 103), reducing the problem of electron and hole recombination caused by direct contact between the first light absorption layer 103 and the first electrode 101, which is beneficial to improving the performance of the solar cell 100. The first hole transport material is used for hole transport and to block the reverse flow of electrons. The first hole transport material includes a first polymer material, and the insulating additive includes a second polymer material. The second polymer material and the first polymer material are blended to form a first hole transport layer 102. The surface of the first hole transport layer 102 near the first light absorption layer 103 is partly composed of the first polymer material that can transport holes and partly composed of the insulating second polymer material. This further reduces the area of ​​the electrical contact interface between the first light absorption layer 103 and the first hole transport layer 102, reduces the carrier recombination induced by interface defects, and thus improves the photoelectric conversion efficiency of the solar cell 100.

[0097] The reverse testing method for the first hole transport layer 102 in the solar cell 100 is as follows:

[0098] First, the first light absorption layer 103 and the film layer on the side away from the first hole transport layer 102 are removed with adhesive tape to expose the first light absorption layer 103. Then, the first light absorption layer 103 is washed away with a solvent (such as DMF (N,N-dimethylformamide)) to expose the first hole transport layer 102.

[0099] The samples obtained by the above method were then analyzed using AFM-IR (Atomic Force Microscopy-Infrared Spectroscopy) and liquid chromatography to determine the types and distribution of functional groups. It should be noted that dimethyl sulfoxide (DMSO) was used to dissolve the material of the first hole transport layer 102 for liquid chromatography testing. Specific functional groups in the first hole transport material, such as aniline, carbazole, acridine, thiophenazine, phenoxazine, benzothiazolium, and thiophene, exhibit characteristic absorption peaks in the infrared spectrum. The infrared characteristic absorption peaks of the insulating additive are located significantly different from those of the first hole transport material. This detection method not only distinguishes the presence of the two materials but also reveals their in-plane distribution within the perovskite film. For example, the carbazole:NH stretching vibration peak is located at approximately 3000-3600 cm⁻¹. -1 The C=C double bond stretching vibration peak is at 1600-1700 cm⁻¹. -1 The CN stretching vibration peak is at 1450 cm⁻¹ -1 Triphenylamine: CH stretching vibration peak at 3000-3100 cm⁻¹ -1 The vibrational peaks of the benzene ring skeleton are at 1450-1600 cm⁻¹ -1 Thiophene: CH stretching vibration peak at 3000-3100 cm⁻¹ -1 The peak of C=S stretching vibration is at 1000-1100 cm⁻¹ -1 For example, the second polymer material includes polyacrylic acid, such as the carboxyl group (-COOH) as the main functional group of polyacrylic acid, in the range of 3300-2500 cm⁻¹. -1 A broad and strong absorption peak appears at 1700-1680 cm⁻¹, corresponding to the stretching vibration of the OH group associated with the carboxyl group. -1 A strong absorption peak appears at the point corresponding to the stretching vibration of C=O. Based on the above, two materials are distinguished. According to the functional groups of the materials, it can be determined which material has hole transport characteristics. The HOMO and LUMO energy levels of the material can be tested to verify the hole transport characteristics of the material. The other material is tested using conductive atomic force microscopy to confirm its insulation properties.

[0100] Among them, solar cell 100 refers to a device that directly converts light energy into electrical energy through the photovoltaic effect. Generally speaking, solar cell 100 includes first-generation solar cells represented by crystalline silicon solar cells, second-generation solar cells represented by thin-film solar cells made of direct bandgap semiconductors such as copper indium gallium selenide (CIGS), gallium arsenide (GaAs), and cadmium telluride (CdTe), and third-generation solar cells represented by dye-sensitized solar cells (DSSCs), organic photovoltaic cells (OPVs), and perovskite solar cells (PSCs).

[0101] Taking a single-junction perovskite solar cell as an example, the perovskite solar cell includes a first electrode 101, a first hole transport layer 102, a first light absorption layer 103, and a second electrode 105 stacked together. At least one of the first electrode 101 and the second electrode 105 is a light-transmitting electrode, allowing incident photons to pass through it and be absorbed by the first light absorption layer 103. In some embodiments, one of the first electrode 101 and the second electrode 105 is a light-transmitting electrode layer, and the other is a metal electrode layer. The metal electrode layer reduces the resistivity of the solar cell 100 and improves its efficiency. The first light absorption layer 103 is a core component of the solar cell, its main function being to absorb solar energy and convert it into electrical energy. It should be noted that the single-junction perovskite solar cell described above can be used alone or in devices such as perovskite-perovskite tandem cells, perovskite-crystalline silicon tandem cells, or perovskite-heterojunction tandem cells.

[0102] In some embodiments, the volume resistivity of the insulating additive is 1×10⁻⁶. 10 Ω m~1×10 18 Ω m. Optional: 1×10 14 Ω m~1×10 18 Ω m.

[0103] When a voltage is applied across a material, free charges (such as electrons or ions) within the material move directionally under the influence of the electric field, forming an electric current. Resistivity is a measure of how much a material impedes this directional movement of charges. The volume resistivity is measured using the four-probe method. Four equally spaced probes are placed on the material surface. A known current is passed through the two outer probes, while the voltage drop is measured on the two inner probes. According to Ohm's law, the resistivity is calculated by measuring the current and voltage.

[0104] In the technical solution of this application embodiment, the resistivity of the insulating additive is within the above-mentioned range, indicating that the second polymer material in the insulating additive exhibits good insulation properties. After the insulating second polymer material is blended with the first polymer material, a first hole transport layer 102 is formed. The surface portion of the first hole transport layer 102 near the first light absorption layer 103 is the first polymer material for transporting holes, and the portion is the insulating second polymer material. Referring to FIG3, the area of ​​the electrical contact interface between the first light absorption layer 103 and the first hole transport layer 102 is reduced, the carrier recombination induced by interface defects is reduced, thereby improving the photoelectric conversion efficiency of the solar cell 100.

[0105] In some embodiments, the weight-average molecular weight of the insulating additive is greater than or equal to 20 kDa and less than or equal to 4 million Da.

[0106] Weight-average molecular weight refers to the molecular weight obtained by statistical averaging based on mass.

[0107] Weight-average molecular weight (Mw) was determined using static light scattering (SEC-MALS) as follows: First, the sample was dissolved and injected into a size exclusion chromatography (SEC) column to separate different components based on molecular size. The separated components then entered a multi-angle light scattering detector, where the intensity of the scattered light was measured by laser irradiation. Combined with concentration information obtained from a differential refractive index detector, the Zimm equation was used for calculation. The weight-average molecular weight (Mw) was obtained through dual extrapolation of concentration and angle.

[0108] In the technical solution of this application embodiment, the weight-average molecular weight of the insulating additive is within the above-mentioned range, which can improve the solution viscosity and film-forming properties of the first hole transport layer 102. This increases the coverage of the first hole transport layer 102 on the covered film layer (such as the first electrode 101 or the first light absorption layer 103), reducing the problem of electron and hole recombination caused by direct contact between the first light absorption layer 103 and the first electrode 101, which is beneficial to improving the performance of the solar cell 100. At the same time, the weight-average molecular weight of the insulating additive is within the above-mentioned range, resulting in stronger interaction between the insulating additive and the electrode layer. Furthermore, the insulating additive has low solubility, making it less likely to dissolve and diffuse into the subsequently prepared first light absorption layer 103. This provides good stability when the insulating additive is mixed with the first hole transport material to form the first hole transport layer 102, which is beneficial to improving the photoelectric conversion efficiency of the solar cell 100.

[0109] In some implementations, the polydispersity index (PDI) of the insulating additive is less than or equal to 5.

[0110] Molecular weight distribution is characterized by the polydispersity index (PDI). Molecular weight distribution is a statistical characteristic of the relative quantities of polymers with different molecular weights within a polymer; the ratio of weight-average molecular weight to number-average molecular weight is called the polydispersity index. The molecular weight distribution of a polymer can be measured by gel permeation chromatography (GPC), and Mw and Mn can be calculated to obtain the PDI. In the technical solution of this application embodiment, the polydispersity index (PDI) of the insulating additive is within the above-mentioned range. This indicates a narrower molecular weight distribution of the insulating additive, reducing the content of small molecule components. The insulating additive is less likely to dissolve and diffuse into the subsequently prepared first light-absorbing layer 103, thus reducing its impact on perovskite crystal growth. The polydispersity index (PDI) of the insulating additive can be 1, 2, 3, 4, 5, or a range consisting of any two of the above values, such as 1~3, 3~5, 2~4, etc.

[0111] In some implementations, the hydrophilic-lipophilic balance value of the insulating additive is in the range of 9 to 35.

[0112] The hydrophilic-lipophilic balance (HLB) value is used to characterize the hydrophilicity and lipophilicity of additives. The HLB value is a relative value; it is defined that paraffin wax (completely hydrophilic) has an HLB value of 0, while polyethylene glycol (completely hydrophilic) has an HLB value of 20. Based on this standard, HLB values ​​for other surfactants (or additives) are determined. The smaller the HLB value, the stronger the lipophilicity; conversely, the larger the value, the stronger the hydrophilicity.

[0113] HLB is measured by determining the equilibrium partition coefficient of a surfactant in an oil-water two-phase system. The specific steps are as follows: First, the oil phase (e.g., n-octanol) and the aqueous phase are mutually saturated to ensure equilibrium. Then, the surfactant is dissolved separately in both the oil and aqueous phases to prepare solutions of known concentrations. These solutions are then mixed and shaken under constant temperature to allow the surfactant to reach equilibrium in both phases. After separating the two phases, the concentrations of the surfactant in the oil and aqueous phases are measured separately, and the partition coefficient K is calculated as K = Coil phase / Caqueous phase. Finally, based on the negative correlation between the partition coefficient and the HLB value (HLB = 20 - 10 × logK), the HLB value is calculated.

[0114] In the technical solution of this application embodiment, the hydrophilic-lipophilic balance value of the insulating additive is within the above-mentioned range, and the insulating additive exhibits good hydrophilicity, thereby making the first hole transport layer 102 exhibit good hydrophilicity. The surface of the first hole transport layer 102 has a large number of polar groups. The polar groups on the surface of the first hole transport layer 102 can interact with the first light absorption layer material to form interactions including hydrogen bonds, π-π interactions, and electrostatic forces (ion-ion interactions, ion-dipole interactions, dipole-dipole interactions), which enhances the interaction force between the interface of the first hole transport layer 102 and the material of the first light absorption layer 103. This is beneficial to the growth of the thin film of the first light absorption layer 103 on the surface of the first hole transport layer 102, improves the quality of the thin film of the first light absorption layer 103, and thus improves the photoelectric conversion efficiency and service life of the solar cell 100. The hydrophilic-lipophilic balance value of the insulating additive can be 9, 10, 12, 15, 16, 18, 20, 24, 28, 32, 35, or any range of two of the above values, such as 9~15, 15~20, 20~28, 28~35, etc.

[0115] For example, the first light-absorbing layer 103 comprises a perovskite material. Figure 4 shows a scanning electron microscope (SEM) image of the crystallization of the first light-absorbing layer 103 formed on the surface of the first hole transport layer 102. The first hole transport layer 102 comprises a first hole transport material and an insulating additive, allowing for more controllable perovskite nucleation and crystallization. The perovskite surface exhibits no obvious macroscopic defects, resulting in a high-quality film of the first light-absorbing layer 103. Figure 5 shows a SEM image of the crystallization of the light-absorbing layer in a related technology. The perovskite crystallization in the light-absorbing layer is disordered, and a large number of white lead iodide particles appear on the surface. Comparing Figures 4 and 5 reveals that designing an insulating additive with good hydrophilicity is beneficial for improving the film quality of the first light-absorbing layer 103 on the surface of the first hole transport layer 102. It should be noted that the first hole transport material used in Figure 5 is the same as that used in Figure 4, and the material of the light-absorbing layer used in Figure 5 is the same as that used in the first light-absorbing layer 103 in Figure 4.

[0116] Referring to Figure 6, when only the first hole transport material is used without the use of insulating additives to form a single-component hole transport layer, the contact angle is 77°. When both the first hole transport material and the insulating additive are used to form a composite material system (first hole transport layer 102), the contact angle decreases to 32°. This indicates that the insulating additive has good hydrophilicity, which makes the composite first hole transport layer 102 formed by the first hole transport material and the insulating additive exhibit good hydrophilicity.

[0117] In some embodiments, the molecular structure of the second polymer material includes one or more of the following: organic acid group, hydroxyl group, amino group, carboxyl group, sulfonic acid group, phosphate group, ether group, amide group, and sulfoxide group.

[0118] In the technical solution of this application embodiment, the second polymer material is selected from the above-mentioned materials, which makes the insulating additive exhibit good hydrophilicity, thereby making the first hole transport layer 102 exhibit good hydrophilicity, enhancing the interaction force between the interface of the first hole transport layer 102 and the material of the first light absorption layer 103, which is conducive to the growth of the thin film of the first light absorption layer 103 on the surface of the first hole transport layer 102, improving the quality of the thin film of the first light absorption layer 103, thereby improving the photoelectric conversion efficiency and service life of the solar cell 100.

[0119] In some embodiments, the second polymer material includes one or more of synthetic polymers, starch, protein, and cellulose; the synthetic polymer includes one or more of polyacrylic acid (PAA), polystyrene sulfonic acid (PSS), polyacrylamide (PAM), polyvinyl alcohol (PVA), polyethylene glycol (PEG or PEO), poly(N-vinylpyrrolidone) (PVP), poly(2-hydroxypropyl methacrylamide) (PHPMA), poly(ethyleneimine) (PEI), and poly(2-(methacryloyloxy)ethylphosphorylcholine) (PMPC), or copolymers of two or more of them.

[0120] In this application, the term "starch" refers to a polysaccharide composed of glucose units linked by α-1,4-glycosidic bonds, including amylose and amylopectin; "protein" refers to a biological macromolecule composed of amino acids linked by peptide bonds; and the term "cellulose" is a polysaccharide composed of glucose units linked by β-1,4-glycosidic bonds.

[0121] The insulating additive can be one or more polymers selected from polyacrylic acid (PAA), polystyrene sulfonic acid (PSS), polyacrylamide (PAM), polyvinyl alcohol (PVA), polyethylene glycol (PEG or PEO), poly(N-vinylpyrrolidone) (PVP), poly(2-hydroxypropyl methacrylamide) (PHPMA), poly(ethyleneimine) (PEI), and poly(2-(methacryloyloxy)ethylphosphorylcholine) (PMPC). It can also be a copolymer of two polymers selected from polyacrylic acid (PAA), polystyrene sulfonic acid (PSS), polyacrylamide (PAM), polyvinyl alcohol (PVA), polyethylene glycol (PEG or PEO), poly(N-vinylpyrrolidone) (PVP), poly(2-hydroxypropyl methacrylamide) (PHPMA), poly(ethyleneimine) (PEI), and poly(2-(methacryloyloxy)ethylphosphorylcholine) (PMPC).

[0122] In the technical solution of this application embodiment, the second polymer material is selected from the above-mentioned materials. On the one hand, the insulating additive material exhibits good insulation properties. After being blended with the first hole transport material, this insulating additive forms the first hole transport layer 102. The surface portion of the first hole transport layer 102 near the first light absorption layer 103 is the first hole transport material capable of transporting holes, and the other portion is the insulating additive, which reduces the area of ​​the electrical contact interface between the first light absorption layer 103 and the first hole transport layer 102, reduces carrier recombination induced by interface defects, and thus improves the photoelectric conversion efficiency of the solar cell 100. On the other hand, the above-mentioned insulating additive exhibits good hydrophilicity, which in turn makes the first hole transport layer 102 exhibit good hydrophilicity, enhances the interaction force between the interface of the first hole transport layer 102 and the material of the first light absorption layer 103, facilitates the growth of the thin film of the first light absorption layer 103 on the surface of the first hole transport layer 102, improves the quality of the thin film of the first light absorption layer 103, and thus improves the photoelectric conversion efficiency and service life of the solar cell 100.

[0123] In some embodiments, the insulating additive includes one or more of proteins, cellulose, polyacrylic acid (PAA), polyethylene glycol, and polyvinyl alcohol (PVA).

[0124] In the technical solution of this application embodiment, the insulating additive uses the commonly used materials with organic acid radicals or hydroxyl groups, which have good hydrophilicity and insulation properties, and can also reduce the manufacturing cost of solar cell 100.

[0125] In some embodiments, the weight-average molecular weight of the first hole transport material is 500 to 50,000.

[0126] In the technical solution of this application embodiment, the weight-average molecular weight of the first hole transport material is within the above-mentioned range. The interaction between the first hole transport material and the electrode layer is stronger, and the solubility of the first hole transport material is low. This does not affect the preparation, and the first hole transport material is not easily dissolved and diffused into the subsequently prepared first light-absorbing layer 103, which is beneficial to the stability of the first hole transport layer 102 and improves the performance of the solar cell. The weight-average molecular weight of the first hole transport material can be 500, 1000, 2500, 5600, 6800, 10000, 15000, 25000, 30000, 40000, 50000, etc., or a range composed of any two of the above values, such as 500~2500, 2500~6800, 6800~15000, 15000~30000, 30000~50000, etc.

[0127] In some embodiments, the molecular structure of the first polymer material includes one or more of aniline, carbazole, acridine, thiophenazine, phenoxazine, benzothiazolyl, and thiophene.

[0128] In the technical solution of this application embodiment, the first polymer material is selected from the above structure, which can play a good role in transporting holes and can effectively extract and transport photogenerated holes, thereby improving the photoelectric performance of the solar cell 100.

[0129] In some embodiments, the first hole transport material comprises a polymer of N4,N4′-bis(naphthyl-1-yl)-N4,N4′-bis(4-vinylphenyl)biphenyl-4,4′-diamine, poly[bis(4-phenyl)(2,4,6-trimethylphenyl)amine], poly3-hexylthiophene, poly(3,4-ethylenedioxythiophene):polystyrene sulfonic acid (PEDOT:PSS), or one or more of the repeating units shown in formula (I):

[0130] Formula (I),

[0131] In formula (I),

[0132] M includes substituted or unsubstituted aniline, substituted or unsubstituted carbazolyl, substituted or unsubstituted acridine, substituted or unsubstituted thiophenazinyl or substituted or unsubstituted phenoxazinyl;

[0133] R is a single bond or a bridging group;

[0134] Y includes H or one or both of the oxygen-containing groups.

[0135] In the technical solution of this application embodiment, the first hole transport material is selected from the above-mentioned materials, which can play a good role in transporting holes and can effectively extract and transport photogenerated holes, thereby improving the photoelectric performance of the solar cell. Furthermore, selecting the repeating unit described in formula (I) as the first hole transport material helps to enhance its interaction force with the interface below the first hole transport layer, thereby improving the stability and lifespan of the solar cell.

[0136] When R represents a single bond, the hole-transporting group M can be connected to the Y group via a single bond, for example, M can be connected to a hydrogen atom or M can be connected to an oxygen-containing group.

[0137] When R represents a bridging group, the hole transport group M can be connected to the Y group through the bridging group. For example, M can be connected to an oxygen-containing group through the bridging group, or M can be connected to a hydrogen atom through the bridging group.

[0138] Organic polymers formed by the organic combination of M, R, and Y can form aggregates with ordered structures through intermolecular interactions. They possess strong self-assembly capabilities, which is beneficial for obtaining flat self-assembled structures, thereby improving the photoelectric conversion efficiency and stability of solar cells. Furthermore, the oxygen-containing groups can bind to metal ions, such as transparent conductive oxides or trivalent nickel ions, thus passivating and anchoring the metal ions. The hole-transporting group M enables the organic polymer to possess energy levels compatible with other functional layer materials in the solar cell, further enhancing the photoelectric conversion efficiency and stability of the solar cell.

[0139] In some embodiments, the repeating unit shown in formula (I) includes one or more of the repeating units shown in formulas (I-1) to (I-6):

[0140] Formula (I-1), Formula (I-2), Formula (I-3), Formula (I-4), Formula (I-5), Formula (I-6);

[0141] Among them, R1 to R 12 Each of the following is independently selected from one or more of the following: hydrogen atom, halogen atom, nitrogen-containing group, hydroxyl group, substituted or unsubstituted C1-C5 alkyl group, substituted or unsubstituted C1-C5 alkoxy group, substituted or unsubstituted C1-C5 amide group, substituted or unsubstituted C1-C5 ester group, substituted or unsubstituted C1-C5 carboxyl group, substituted or unsubstituted C6-C30 aryl group, or substituted or unsubstituted C5-C30 heterocyclic aryl group; the curve " "" represents the connection key with the adjacent repeating unit.

[0142] The term "C1-C5 alkyl" refers to an alkyl group containing 1-5 carbon atoms, including straight-chain alkyl or branched-chain alkyl.

[0143] The term "alkoxy group" refers to a group in which an alkyl group is connected to an oxygen atom by a single bond. For example, an alkoxy group can be a C1-C5 alkoxy group or a C2-C4 alkoxy group. In some embodiments, an alkoxy group may include methoxy, ethoxy, propoxy, butoxy, isobutoxy, sec-butoxy, tert-butoxy, cyclobutoxy, pentoxy, isopentoxy, neopentoxy, tert-pentoxy, and cyclopentoxy.

[0144] The term "amide group" refers to the group formed when the hydroxyl group in a carboxyl group is replaced by an amino or amine group. C1-C5 amide groups include formamido, acetamido, propionamido, butyrylamino, isobutyrylamino, sec-butyrylamino, tert-butyrylamino, cyclobutyrylamino, pentamido, isovaleramino, neopentamido, tert-pentamido, and cyclopentamido.

[0145] The term "ester group" refers to the functional group of an ester in a carboxylic acid derivative. C1-C5 ester groups include methyl ester, ethyl ester, propyl ester, butyl ester, isobutyl ester, sec-butyl ester, tert-butyl ester, cyclobutyl ester, pentyl ester, isopentyl ester, neopentyl ester, tert-pentyl ester, and cyclopentyl ester.

[0146] The term "carboxyalkyl" refers to a group in which an alkyl group and a carboxyl group are linked by a single bond, i.e., a group in which at least one hydrogen atom on the alkyl group is replaced by a carboxyl group. In some embodiments, C1-C5 carboxyalkyl groups include carboxymethyl, carboxyethyl, carboxypropyl, carboxybutyl, carboxyisobutyl, carboxysec-butyl, carboxyter-butyl, carboxycyclobutyl, carboxypentyl, carboxyisopentyl, carboxyneopentyl, carboxyter-pentyl, and carboxycyclopentyl.

[0147] The term "aryl" refers to a closed aromatic ring or ring system. C6-C30 aryl refers to a system containing 6-30 carbon atoms for ring formation. In some embodiments, aryl includes phenyl, naphthyl, phenanthryl, anthraceneyl, biphenyl, triphenylene, pyrene, spirobisfluorene, yl, peryl, indole, and azulel, etc.

[0148] The term "heterocyclic aryl" refers to an aromatic ring group containing heteroatoms (such as nitrogen, oxygen, sulfur, etc.) in its ring structure. That is, the ring structure of a heterocyclic aryl group not only contains carbon atoms but also at least one heteroatom. C5-C30 heterocyclic aryl groups refer to groups containing 5-30 ring atoms, such as pyridine groups and thiophene groups.

[0149] The term "halogen atom" refers to fluorine, chlorine, bromine, iodine, etc.

[0150] The term "nitrogen-containing group" refers to a group containing nitrogen atoms, such as an amino group, which includes alkylamino groups, and alkylamino groups include -NH-alkyl, -N(alkyl)2, -N(alkyl)3, and -N(alkyl)3 includes trimethylamino, triethylamino, or tripropylamino, etc., wherein each alkyl group has 1 to 5 carbon atoms; the two alkyl groups in -N(alkyl)2 can be the same or different; the three alkyl groups in -N(alkyl)3 can be the same or different.

[0151] From R1 to R 12 When substituents are present, the substituents may be one or more of the following: C1-C5 alkyl groups, halogen atoms, carboxyl groups, hydroxyl groups, etc.

[0152] In the technical solution of this application embodiment, the first hole transport material is selected from the materials shown in formulas (I-1) to (I-6), which can play a good role in transporting holes and can effectively extract and transport photogenerated holes, thereby improving the photoelectric performance of the solar cell 100.

[0153] For example, the repeating unit shown in equation (I-1) includes one or more of the repeating units shown in equations (I-11) to (I-16).

[0154] Formula (I-11), Formula (I-12)

[0155] Formula (I-13), Formula (I-14), Formula (I-15), Formula (I-16), Equation (I-17); where, curve " "" represents the connection key with the adjacent repeating unit.

[0156] In one embodiment, the M group comprises one or more of the structures shown in formula (I-21) to (I-27) with or without substitution.

[0157] Formula (I-21), Formula (I-22), Formula (I-23), Formula (I-24), Formula (I-25), Formula (I-26), Equation (I-27). In the equation,

[0158] Indicates the connection point between M and R; curve " "" indicates the connection point between the repeating units.

[0159] In some embodiments, the M group comprises one or more of the structures shown in formula (I-31) to (I-39) with or without substitution. Formula (I-31), Formula (I-32), Formula (I-33), Formula (I-34), Formula (I-35), Formula (I-36), Formula (I-37), Formula (I-38), Formula (I-39).

[0160] In the formula,

[0161] Indicates the connection point between M and R; curve " "" indicates the connection point between the repeating units.

[0162] In some embodiments, the M group comprises one or more of the structures shown in substituted or unsubstituted formulas (1-41) to those shown in substituted or unsubstituted formulas (1-44): Formula (I-41), Formula (I-42), Formula (I-43), Formula (I-44).

[0163] In the formula,

[0164] Indicates the connection point between M and R; curve " "" indicates the connection point between the repeating units.

[0165] In some embodiments, the M group comprises one or more of the structures shown in substituted or unsubstituted formulas (1-51) to those shown in substituted or unsubstituted formulas (1-54). Formula (I-51), Formula (I-52), Formula (I-53), Formula (I-54),

[0166] In the formula,

[0167] Indicates the connection point between M and R; curve " "" indicates the connection point between the repeating units.

[0168] In some embodiments, the M group comprises one or more of the structures shown in formulas (1-61) to (1-63) with or without substituted ... Formula (I-61), Formula (I-62), Formula (I-63),

[0169] In the formula,

[0170] Indicates the connection point between M and R; curve " "" indicates the connection point between the repeating units.

[0171] In some embodiments, the bridging group includes one or more of the following: an oxygen atom, a sulfur atom, a substituted or unsubstituted alkylene group, a substituted or unsubstituted alkenyl group, a substituted or unsubstituted heteroalkylene group, a substituted or unsubstituted aromatic group, or a substituted or unsubstituted heterocyclic group.

[0172] In cases where the bridging group includes a substituted or unsubstituted alkylene group, a substituted or unsubstituted alkenyl group, or a substituted or unsubstituted heteroalkylene group, and the above group is substituted by a substituent group, the substituent group includes one or more of a halogen group, an amine group, an alkylthion group, an oxygen-containing substituent group, an aromatic group, or an aromatic heterocyclic group, and the number of carbon atoms is 1 to 10 when the substituent group includes a carbon atom.

[0173] In cases where the bridging group includes a substituted or unsubstituted aromatic group or a substituted or unsubstituted heterocyclic group, and the aforementioned group is substituted by a substituent group, the substituent group includes one or more of a halogen group, a nitrogen-containing group, an alkyl-sulfur group, an oxygen-containing substituent group, or a C1 to C5 alkyl group.

[0174] Bridging groups can reduce steric hindrance or improve hole transport capability when polymers are applied to perovskite solar cells.

[0175] The term "heteroalkylene" refers to a group in which at least one carbon atom of the alkylene group is replaced by a heteroatom, including oxygen, sulfur, nitrogen or phosphorus atoms, etc. C1 to C8 heteroalkylene may include heteromethylene, heteroethylene, heteropropylene, heterobutylene, heteropentylene, heterohexylene, heteroheptylene or heterooctylene; exemplary C1 to C8 heteroalkylene may include methyleneoxy, ethoxy, propylthio or butylthio.

[0176] The term "alkenyl" refers to a group containing a carbon-carbon double bond. For example, alkenyl groups can be C1 to C8 alkenyl groups, such as propenyl (-CH=CH-CH2-) and butenyl (-CH2-CH=CH-CH2-).

[0177] The term "alkanethium group" refers to an alkyl group containing a sulfur atom. Alkanethium groups include C1 to C5 alkanethium groups, specifically including methyl thio group, ethyl thio group, propyl thio group, butyl thio group, pentyl thio group, etc.

[0178] In some embodiments, the bridging group may be a substituted or unsubstituted alkylene group or a substituted or unsubstituted alkenyl group, which can reduce the steric hindrance of the polymer.

[0179] In some embodiments, the bridging group may be a substituted or unsubstituted aromatic group or a substituted or unsubstituted heterocyclic group, which can improve the dipole of the first polymer monomer, making the work function of the molecular film formed after the first polymer self-assembly more compatible with the perovskite layer. When applied to the preparation of solar cells, higher photoelectric conversion efficiency of solar cells can be obtained.

[0180] In some embodiments, the oxygen-containing group includes one or more of the following: carboxylic acid group, phosphite group, phosphate group, sulfonic acid group, silicate group, siloxane group, borate group, carboxylic acid ester group, phosphate ester group, sulfonate group, silicate group, borate group, carboxyl group, phosphite group, phosphate group, borate group, or silicate group. The oxygen-containing group has an anchoring effect on metal ions, which can enhance the bonding force between the first hole transport layer and the underlying film layer (such as an electrode layer or other hole transport layer), thereby improving the stability of the device.

[0181] In some embodiments, the first hole transport material includes one or more of polyphosphate carbazole, polycarboxylic acid carbazole, and poly[bis(4-phenyl)(2,4,6-trimethylphenyl)amine].

[0182] The repeating units of polycarbazole polyphosphate or polycarboxylic acid carbazole are shown in formula (I-3), wherein Y in the polycarbazole polyphosphate is selected from one or more of phosphate groups, phosphate groups, or phosphate ester groups. Y in the polycarboxylic acid carbazole is selected from one or more of carboxylic acid groups, carboxylic acid ester groups, or carboxylic acid groups. In the technical solution of this application embodiment, the first hole transport material is selected from the above materials, which can play a good role in transporting holes, effectively extracting and transporting photogenerated holes, thereby improving the photoelectric performance of the solar cell.

[0183] In some embodiments, the first polymer material comprises one or more of poly[4-(3,6-dimethyl-9H-carbazole-9-yl)butyl]phosphonic acid, poly[4-(9H-carbazole-9-yl)butyl]phosphonic acid, poly[2-(3,6-dimethoxy-9H-carbazole-9-yl)ethyl]phosphonic acid, poly[2-(3,6-dimethyl-9H-carbazole-9-yl)ethyl]phosphonic acid, poly[2-(9H-carbazole-9-yl)ethyl]phosphonic acid, poly[2-(3,6-dibromo-9H-carbazole-9-yl)ethyl]phosphonic acid, poly[4-(3,6-dimethyl-9H-carbazole-9-yl)butyl]phosphonic acid, and poly[bis(4-phenyl)(2,4,6-trimethylphenyl)amine]; and / or, the second polymer material comprises one or more of polyacrylic acid, polyethyleneimine, or polyethylene glycol.

[0184] In the technical solution of this application embodiment, when the first polymer material and the second polymer material are selected from the above materials to form the first hole transport layer, the first hole transport layer exhibits good hydrophilicity, which enhances the interaction force between the interface of the first hole transport layer and the material of the first light absorption layer. This is beneficial to the growth of the thin film of the first light absorption layer on the surface of the first hole transport layer, improves the quality of the first light absorption layer film, and thus improves the photoelectric conversion efficiency and lifespan of the solar cell. Furthermore, the second polymer material exhibits good insulation properties. When this insulating second polymer material is blended with the first polymer material, the first hole transport layer is formed. The surface portion of the first hole transport layer near the first light absorption layer is composed of the first polymer material that can transport holes, and the portion is composed of the insulating second polymer material. This reduces the area of ​​the electrical contact interface between the first light absorption layer and the first hole transport layer, reduces the interface carrier recombination induced by interface defects, and thus improves the photoelectric conversion efficiency of the solar cell.

[0185] Specifically, in some embodiments, the first hole transport material includes a polymer of [4-(3,6-dimethoxy-9H-carbazole-9-yl)butyl]phosphonic acid (MeO-4PACz), a polymer of [4-(9H-carbazole-9-yl)butyl]phosphonic acid (4PACz), a polymer of [4-(3,6-dibromo-9H-carbazole-9-yl)butyl]phosphonic acid (Br-4PACz), or a polymer of [2-(3,6-dimethoxy-9H-carbazole-9-yl)ethyl]phosphonic acid (MeO-4PACz). Polymers of MeO-2PACz, polymers of [2-(3,6-dimethyl-9H-carbazole-9-yl)ethyl]phosphonic acid (Me-2PACz), polymers of [2-(9H-carbazole-9-yl)ethyl]phosphonic acid (2PACz), polymers of [2-(3,6-dibromo-9H-carbazole-9-yl)ethyl]phosphonic acid (Br-2PACz), and poly(3,6-dimethyl-9H-carbazole-9-yl)butyl]phosphonic acid (M4P) are one or more of these.

[0186] In the technical solution of this application embodiment, the first hole transport material uses the commonly used carbazole-containing material, which effectively extracts and transports photogenerated holes while also reducing the manufacturing cost of the solar cell 100.

[0187] In some embodiments, the first polymer material comprises M4P (poly[4-(3,6-dimethyl-9H-carbazole-9-yl)butylphosphonic acid) and the second polymer material comprises polyacrylic acid (PAA); or, the first polymer material comprises M4P (poly[4-(3,6-dimethyl-9H-carbazole-9-yl)butylphosphonic acid) and the second polymer material comprises polyethyleneimine; or, the first polymer material comprises poly[bis(4-phenyl)(2,4,6-trimethylphenyl)amine] and the second polymer material comprises polyacrylic acid; or, the first polymer material comprises M4P (poly[4-(3,6-dimethyl-9H-carbazole-9-yl)butylphosphonic acid) and the second polymer material comprises polyethylene glycol.

[0188] In the technical solution of this application embodiment, when the first polymer material and the second polymer material are selected from the above materials to form the first hole transport layer 102, the first hole transport layer 102 exhibits good hydrophilicity, enhancing the interaction force between the interface of the first hole transport layer 102 and the material of the first light absorption layer 103. This is beneficial to the growth of the thin film of the first light absorption layer 103 on the surface of the first hole transport layer 102, improving the quality of the thin film of the first light absorption layer 103, thereby improving the photoelectric conversion efficiency and lifespan of the solar cell 100. Furthermore, the second polymer material exhibits good insulation properties. When this insulating second polymer material is blended with the first polymer material, the first hole transport layer 102 is formed. The surface portion of the first hole transport layer 102 near the first light absorption layer 103 is composed of the first polymer material capable of transporting holes, and the portion is composed of the insulating second polymer material. This reduces the area of ​​the electrical contact interface between the first light absorption layer 103 and the first hole transport layer 102, reducing interface carrier recombination induced by interface defects, thereby improving the photoelectric conversion efficiency of the solar cell 100.

[0189] In some embodiments, referring to FIG3, a first hole transport material forms a hole transport region, an insulating additive forms an insulating region, and the hole transport region and the insulating region exhibit a microscopic phase separation structure.

[0190] The microscopic phase separation structure refers to the spontaneous formation of different phase regions (hole transport region and insulating region) at the microscopic scale (typically nanometer to micrometer level) in the first hole transport layer 102 due to factors such as the difference in interaction between the first hole transport material and the insulating additive. The hole transport region and the insulating region are spatially separated but coexist, forming a specific structural morphology with a certain regularity or disorder. The first hole transport material and the insulating additive undergo phase separation at the microscopic scale due to thermodynamic incompatibility and other reasons, forming their respective aggregated regions.

[0191] In the technical solution of this application embodiment, holes can only be transported from the hole transport region and cannot be transported from the insulating region. The hole transport region and the insulating region exhibit a microscopic phase separation structure, which reduces the area of ​​the electrical contact interface between the first light absorption layer 103 and the first hole transport layer 102. Interface carrier recombination induced by interface defects is suppressed. The second polymer material can improve the solution viscosity and film-forming properties of the first hole transport layer, thereby increasing the coverage of the first hole transport layer 102 on the substrate of the solar cell 100. This reduces the problem of carrier recombination caused by direct contact between the first light absorption layer 103 and the substrate of the solar cell 100, thereby improving the photoelectric conversion efficiency of the solar cell 100.

[0192] It should be noted that the hole transport region and the insulating region exhibit a microscopic phase separation structure, which can be detected by the aforementioned AFM-IR (atomic force microscopy-infrared spectroscopy) instrument.

[0193] In some embodiments, the mass ratio of the first hole transport material to the insulating additive in the first hole transport layer 102 is 1:5 to 5:1.

[0194] In the technical solution of this application embodiment, in the first hole transport layer 102, the mass ratio of the first hole transport material to the insulating additive is within the above-mentioned range, which is beneficial to forming a first hole transport layer 102 with better performance. This results in the surface portion of the first hole transport layer 102 near the first light absorption layer 103 being a first polymer material capable of transporting holes, and the remaining portion being an insulating second polymer material. This reduces the area of ​​the electrical contact interface between the first light absorption layer 103 and the first hole transport layer 102, reducing interface carrier recombination induced by interface defects, thereby improving the photoelectric conversion efficiency of the solar cell 100. The mass ratio of the first hole transport material to the insulating additive can be 1:5, 1:2, 1:1, 2:1, 3:1, 4:1, 5:1, etc., or a range consisting of any two of the above values, such as 1:5~2:1, 2:1~4:1, 4:1~5:1, 1:2~3:1, 1:1~4:1, 2:1~5:1, etc.

[0195] In some implementations, the thickness of the first hole transport layer 102 is 1 nm to 30 nm.

[0196] The thickness of the first hole transport layer 102 refers to the average vertical distance between the surface of the first hole transport layer 102 near the first light absorption layer 103 and the surface of the first hole transport layer 102 away from the first light absorption layer 103. The thickness of the first hole transport layer 102 is measured by cross-sectional measurement using a high-resolution scanning electron microscope to obtain the calibrated thickness.

[0197] In the technical solution of this application embodiment, the thickness of the first hole transport layer 102 is within the above-mentioned range, which can better transport holes and block electrons, with less interface recombination loss and lower resistance, thereby improving the photoelectric conversion efficiency of the solar cell 100. The thickness of the first hole transport layer 102 can be 1nm, 2nm, 5nm, 10nm, 15nm, 20nm, 23nm, 25nm, 28nm, 30nm, etc., or a range consisting of any two of the above values, such as 1nm~10nm, 10nm~23nm, 23nm~30nm, 5nm~20nm, 15nm~25nm, etc.

[0198] In some embodiments, the first light-absorbing layer 103 includes a first perovskite material, the general formula of which is ABX3 or A2CDX6, wherein A ions include inorganic or organic or mixed organic-inorganic cations; B ions include inorganic cations; C ions include inorganic or organic or mixed organic-inorganic cations; D ions include inorganic cations; and X ions include inorganic or organic or mixed organic-inorganic anions.

[0199] In the technical solution of this application embodiment, the first light absorption layer 103 includes the above-mentioned first perovskite material, which has high photoelectric conversion efficiency, low preparation cost, and can be mass-produced by solution method, which is beneficial to reduce the manufacturing cost of solar cell 100. The band gap of the first perovskite material can be adjusted by adjusting the type and ratio of elements, thereby optimizing photoelectric performance and adapting to different application needs.

[0200] In some embodiments, the first perovskite material satisfies one or more of the following conditions: (1) A ions include FA. + (Formamidinium cation, CH(NH2)2) + MA + (Methylamine cation, CH3NH3) + ), Gu + (Guidinium cation), Cs + 、Rb + DMA + (Dimethylammonium cation, (CH3)2NH2) + (1) One or more of the following; (2) B ions include Pb 2+ Sn 2+ Ge² + Mn² + One or more of them; (3) C ions include Ag + Cu + Au + FA + Gu + One or more of them; (4) D ions include Bi 3+ Sb3+ And In 3+ One or more of them; (5) X ions include Cl - ,Br - I - SCN - CNO - OCN - OSCN - SH - OH - CN - SeCN - COO - One or more of them.

[0201] In the technical solution of this application embodiment, the first light absorption layer 103 includes the above-mentioned first perovskite material, which has high photoelectric conversion efficiency, low preparation cost, and can be mass-produced by solution method, which is beneficial to reduce the manufacturing cost of solar cell 100. The band gap of the first perovskite material can be adjusted by adjusting the type and ratio of elements, thereby optimizing photoelectric performance and adapting to different application needs.

[0202] In some embodiments, the solar cell 100 further includes a second hole transport layer located on the side of the first hole transport layer 102 away from the first light absorption layer 103 and between the first electrode 101 and the first hole transport layer 102.

[0203] In the technical solution of this application embodiment, the second hole transport layer is located on the side of the first hole transport layer 102 away from the first light absorption layer 103. The combination of the first hole transport layer 102 and the second hole transport layer can improve the hole mobility.

[0204] The material of the second hole transport layer may include, but is not limited to, one or more of the following materials and their derivatives: 2,2',7,7'-tetratetra[N,N-di(4-methoxyphenyl)amino]-9,9'-spirodifluorene (Spiro-OMeTAD), polytriarylamine (PTAA), poly(3,4-ethylenedioxythiophene):polystyrene sulfonate (PEDOT:PSS), WO3, nickel oxide, CuSCN, CuI, vanadium pentoxide (V2O5), molybdenum trioxide (MoO3), cuprous oxide (Cu2O), stannous oxide (SnO), and stannous sulfide (SnS).

[0205] In some implementations, the second hole transport layer comprises nickel oxide.

[0206] In the technical solution of this application embodiment, nickel oxide is used as the second hole transport layer, which can improve hole mobility on the one hand, and increase the anchoring points of the first hole transport layer 102 material on the other hand, thereby improving the performance and stability of the solar cell 100.

[0207] In some embodiments, the solar cell 100 further includes a first electron transport layer 104 disposed between the first light absorption layer 103 and the second electrode 105. Specifically, the solar cell 100 includes a first electrode 101, a first hole transport layer 102, a first light absorption layer 103, a first electron transport layer 104, and a second electrode 105 stacked sequentially.

[0208] In some embodiments, as shown in FIG1, the solar cell 100 is a reverse solar cell 100. The reverse cell includes, from bottom to top, a first electrode 101, a first hole transport layer 102, a first light absorption layer 103, a first electron transport layer 104, and a second electrode 105 arranged sequentially. The direction from bottom to top is the light incident direction, that is, light is incident from the first electrode 101.

[0209] In the technical solution of this application embodiment, the inverted solar cell 100 improves the efficiency of the solar cell 100 by optimizing the cell structure, making it easier for electrons to flow through the entire cell. The inverted solar cell 100 of this application embodiment utilizes the first hole transport layer 102 containing insulating additives. These insulating additives can increase the solution viscosity and film-forming properties of the first hole transport layer 102, thereby increasing the coverage of the first hole transport layer 102 on the electrodes of the solar cell 100 and reducing the problem of electron-hole recombination caused by direct contact between the first light absorption layer 103 and the solar cell electrodes. Furthermore, the surface portion of the first hole transport layer 102 near the first light absorption layer 103 is made of a first polymer material capable of transporting holes, and the remaining portion is made of an insulating second polymer material. This reduces the area of ​​the electrical contact interface between the first light absorption layer 103 and the first hole transport layer 102, reducing interface carrier recombination induced by interface defects, thereby improving the photoelectric conversion efficiency of the solar cell 100.

[0210] The first electron transport layer 104 serves to transport electrons and block holes. In some embodiments, the first electron transport layer 104 may include, but is not limited to, one or more of the following materials and their derivatives: imide compounds, quinone compounds, fullerenes and their derivatives, metal oxides, semiconductor material oxides, titanates, and fluorides. Imide compounds include one or more of perylene imide and its derivatives, naphthylimide and its derivatives, phthalimide, succinimide, N-bromosuccinimide, glutarimide, or maleimide. Quinone compounds include one or more of benzoquinone, naphthylquinone, phenanthrenequinone, or anthraquinone. Fullerenes and their derivatives include methyl [6,6]-phenyl C61 butyrate (PC... 61 BM), [6,6]-phenyl C71-butyrate methyl ester (PC) 71 Metal oxides include one or more of the following: BM, fullerene C60 (C60), and fullerene C70 (C70). Metal elements in metal oxides include one or more of the following: magnesium (Mg), nickel (Ni), cadmium (Cd), zinc (Zn), indium (In), lead (Pb), molybdenum (Mo), tungsten (W), antimony (Sb), bismuth (Bi), copper (Cu), mercury (Hg), titanium (Ti), silver (Ag), manganese (Mn), iron (Fe), vanadium (V), tin (Sn), zirconium (Zr), strontium (Sr), gallium (Ga), and chromium (Cr). Semiconductor material oxides include silicon oxide. Titanates include one or two of the following: strontium titanate and calcium titanate. Fluorides include one or two of the following: lithium fluoride and calcium fluoride.

[0211] The function of the first electrode 101 is to extract photogenerated charge carrier holes. The first electrode 101 includes one or more of organic conductive materials, inorganic conductive materials, or organic-inorganic mixed conductive materials. It may include one or more of transparent conductive metal oxides, carbon, metals and their alloys, including one or more of tin-doped indium oxide (ITO), lanthanide-doped indium oxide, fluorine-doped tin oxide (FTO), antimony-doped tin oxide, boron-doped zinc oxide (BZO), aluminum-doped zinc oxide (AZO), zinc-doped indium oxide (IZO), gallium-doped zinc oxide (GZO), tungsten-doped indium oxide (IWO), Au, Ag, Cu, Al, Ni, Cr, Bi, Pt, Mg, Mo, W and their alloys, graphite, graphene, and carbon nanotubes.

[0212] The material of the second electrode 105 can be an organic, inorganic, or organic-inorganic mixed conductive material. In some embodiments, the second electrode 105 may include a transparent conductive oxide, a metal, etc. The transparent conductive oxide includes one or more of the following: tin-doped indium oxide (ITO), lanthanide-doped indium oxide, fluorine-doped tin oxide (FTO), antimony-doped tin oxide, boron-doped zinc oxide (BZO), aluminum-doped zinc oxide (AZO), zinc-doped indium oxide (IZO), gallium-doped zinc oxide (GZO), and tungsten-doped indium oxide (IWO). The metal includes one or more of the following: Au, Ag, Cu, Al, Ni, Cr, Bi, Pt, and Mg.

[0213] It should be noted that the materials of the first electrode 101 and the second electrode 105 may be the same or different. At least one of the first electrode 101 and the second electrode 105 is a transparent electrode so that light can enter through the transparent electrode.

[0214] In some embodiments, the solar cell 100 further includes a light-transmitting substrate located on the side of the first electrode 101 away from the first light-absorbing layer 103 to support the solar cell, or located on the side of the second electrode 105 away from the first light-absorbing layer 103 to support the solar cell. The substrate layer can be, but is not limited to, a rigid substrate or a flexible substrate. The rigid substrate is transparent glass, and the flexible substrate material can be, for example (but not limited to), an organic polymer material. Further, it can be a mixture of one or more of the following materials in different proportions: including but not limited to polyvinyl alcohol (PVA), polyester (PET), polyimide (PI), polyethylene naphthalate (PEN), polydimethylsiloxane (PDMS), etc. In some embodiments, the substrate is located on the side of the first electrode 101 away from the first light-absorbing layer 103 to support the solar cell.

[0215] It should be noted that corresponding modification layers can be inserted between the layers. For example, a passivation layer can be inserted between the first light-absorbing layer 103 and the first hole transport layer 102, and / or between the first light-absorbing layer 103 and the first electron transport layer 104, to passivate defects in the first light-absorbing layer 103 and further improve the performance of the solar cell 100. Alternatively, a hole-blocking layer can be inserted on the side of the first electron transport layer 104 away from the first light-absorbing layer 103; the material may include copper bath (2,9-dimethyl-4,7-diphenyl-1,10-phenanthroline, BCP), tin oxide, etc.

[0216] In one specific embodiment, the solar cell includes at least a first light-absorbing layer and a first hole-transporting layer. The first hole-transporting layer includes a first hole-transporting material and an insulating additive. The first hole-transporting material includes a first polymer material, and the insulating additive includes a second polymer material. The volume resistivity of the insulating additive is 1×10⁻⁶.10 Ωm~1×10 18 The weight-average molecular weight of the insulating additive is greater than or equal to 20 kDa and less than or equal to 4 million Da. The polydispersity index (PDI) of the insulating additive is less than or equal to 5. The hydrophilic-lipophilic balance value of the insulating additive ranges from 9 to 35. The second polymer material includes one or more of synthetic polymers, starch, protein, and cellulose; the synthetic polymers include copolymers formed from one or more of polyacrylic acid (PAA), polystyrene sulfonic acid (PSS), polyacrylamide (PAM), polyvinyl alcohol (PVA), polyethylene glycol (PEG, PEO), poly(N-vinylpyrrolidone) (PVP), poly(2-hydroxypropyl methacrylamide) (PHPMA), poly(ethyleneimine) (PEI), and poly(2-(methacryloyloxy)ethylphosphorylcholine) (PMPC). The weight-average molecular weight of the first hole transport material is 500 to 50,000. The first hole transport material includes a polymer of N4,N4′-bis(naphthyl-1-yl)-N4,N4′-bis(4-vinylphenyl)biphenyl-4,4′-diamine, poly[bis(4-phenyl)(2,4,6-trimethylphenyl)amine], poly3-hexylthiophene, poly(3,4-ethylenedioxythiophene):polystyrene sulfonic acid (PEDOT:PSS), or a repeating unit as shown in formula (I): Formula (I). In Formula (I), M includes substituted or unsubstituted aniline, substituted or unsubstituted carbazole, substituted or unsubstituted acridine, substituted or unsubstituted thiophenazine, or substituted or unsubstituted phenoxazine; R is a single bond or bridging group; Y includes H or one or both of oxygen-containing groups. In the first hole transport layer, the mass ratio of the first hole transport material to the insulating additive is 1:5 to 5:1.

[0217] This application also provides a method for preparing a solar cell 100, the method comprising: providing a first electrode 101; coating a first hole transport layer solution onto one side of the first electrode 101 to form a first hole transport layer 102; coating a perovskite precursor solution onto one side of the first hole transport layer 102 to form a first light absorption layer 103; and forming a second electrode 105 onto one side of the first light absorption layer 103. The first hole transport layer 102 comprises a first hole transport material and an insulating additive. The first hole transport material comprises a first polymer material, and the insulating additive comprises a second polymer material. The first hole transport layer 102 is prepared by blending the first polymer material and the second polymer material in a mass ratio of 1:5 to 5:1, and dissolving them in a suitable solvent to obtain a hole transport solution. The solvent includes, but is not limited to, one or more of chloroform, dichloromethane, chlorobenzene, toluene, xylene, methanol, ethanol, dimethyl sulfoxide, and N,N-dimethylformamide, blended to obtain a mixed solvent.

[0218] In one specific embodiment, the inverted solar cell structure comprises, in sequence, a first electrode layer, a first hole transport layer, a first light absorption layer, an upper passivation layer, an electron transport layer, and a second electrode layer. The materials and processes of each layer are as follows:

[0219] First electrode layer: The etched 20mm×20mm transparent conductive oxide glass (TCO), which can be fluorine-doped tin oxide (FTO) with a sheet resistance of 5Ω / sq~20Ω / sq, is ultrasonically treated with cleaning agent, deionized water, and ethanol for 15 minutes in sequence. Before use, it is dried with a nitrogen gas gun and treated with ultraviolet ozone for 15 minutes.

[0220] Hole transport layer fabrication: Hole transport layer fabrication includes one or more hole transport layer films.

[0221] First, a second hole transport layer is formed. This second hole transport layer includes a second hole transport material (optional, it may not be necessary). This second hole transport material includes one or more of the following: 2,2',7,7'-tetratetra[N,N-di(4-methoxyphenyl)amino]-9,9'-spirodifluorene (Spiro-OMeTAD), polytriarylamine (PTAA), poly(3,4-ethylenedioxythiophene):polystyrene sulfonate (PEDOT:PSS), WO3, nickel oxide, CuSCN, CuI, vanadium pentoxide (V2O5), molybdenum trioxide (MoO3), cuprous oxide (Cu2O), stannous oxide (SnO), and stannous sulfide (SnS). Typically, metal oxide or sulfide films with a thickness of 2 nm to 30 nm are prepared using processes such as magnetron sputtering, sol-gel method, or atomic layer deposition. Here, a nickel oxide film with a thickness of 18 nm can be optionally prepared by radio frequency magnetron sputtering.

[0222] A first hole transport layer is formed on a second hole transport layer (if any). The hole transport solution containing the first polymer material and the second polymer material is applied to an FTO substrate (or the second hole transport layer) on nickel oxide by processes such as immersion, dip-coating, spin coating, slot coating, spraying, inkjet printing, roll-to-roll printing, etc., to obtain a composite first hole transport layer 102 film. This film can be annealed at 80°C to 150°C for 1 minute to 30 minutes to obtain the first hole transport layer.

[0223] In the technical solution of this application embodiment, the solar cell 100 is prepared using the preparation method provided above.

[0224] Referring to FIG. 7, the present application further provides a tandem solar cell 200, which includes the solar cell 100 provided in the above embodiment, an intermediate layer 20, and a second light absorption layer 30. The intermediate layer 20 is disposed on a side of the first light absorption layer 103 close to the second electrode 105, and the second light absorption layer 30 is disposed between the intermediate layer 20 and the second electrode 105. The second light absorption layer 30 has a different bandgap from the first light absorption layer 103. Thus, by providing the second light absorption layer 30 and the first light absorption layer 103 with different bandgaps, the tandem solar cell 200 can effectively absorb light of different wavelengths, broaden the spectral range of light absorbed by the tandem solar cell 200, and improve the photoelectric conversion efficiency of the tandem solar cell 200.

[0225] In some embodiments, the bandgap of the first light absorption layer 103 is Eg1, where 1.1 eV ≤ Eg1 ≤ 1.6 eV; the bandgap of the second light absorption layer 30 is Eg2, where 1.65 eV < Eg2 ≤ 2.2 eV. The setting of the bandgaps of the first light absorption layer 103 and the second light absorption layer 30 can effectively absorb short-wavelength and long-wavelength light, and improve the photoelectric conversion efficiency of the tandem solar cell 200. In this embodiment, the battery part corresponding to the first light absorption layer 103 is a narrow-bandgap solar cell, and the battery part corresponding to the second light absorption layer 30 is a wide-bandgap solar cell.

[0226] In some embodiments, the second light absorption layer 30 includes a layer of the following compounds: a second perovskite material, crystalline silicon, an organic active layer, copper zinc tin sulfide, copper zinc tin selenide, copper zinc tin selenosulfide, copper indium gallium selenide, copper indium gallium diselenide, or copper indium selenide. The above materials can absorb light of different wavelengths with the first light absorption layer 103 to broaden the spectral range of light absorbed by the tandem solar cell 200 and improve the photoelectric conversion efficiency of the tandem solar cell 200. In the present application, the definition of the second perovskite material is the same as that of the first perovskite material type above, but the specific components are different to obtain a second light absorption layer 30 with a different bandgap, which is used to absorb light of different wavelengths with the first light absorption layer 103, broaden the absorption spectral range of the tandem solar cell 200, and improve the photoelectric conversion efficiency of the tandem solar cell 200. Exemplarily, the second light absorption layer 30 includes a second perovskite material, and thus a perovskite-perovskite tandem solar cell is obtained. In another example, the second light absorption layer 30 includes a crystalline silicon material, and thus a perovskite-crystalline silicon tandem solar cell is obtained.

[0227] The organic active layer is usually composed of a blend of an electron donor and an electron acceptor material. Common electron donor materials include poly(3-hexylthiophene) (P3HT), wide-bandgap polymer donor PM6, high-efficiency polymer donor D18, etc. Common electron acceptor materials include fullerene-based acceptors (such as PC61BM, PC71BM, etc.), non-fullerene acceptors (such as Y6 series materials, indacenodithiophene-based, BTP series, etc.). Exemplarily, the organic active layer includes PM6:Y6, P3HT:PC61BM, D18:BTP-eC9, etc.

[0228] In some specific embodiments, in the tandem solar cell 200, the first electrode 101 is a transparent electrode. Thus, light can enter the tandem solar cell 200 from the first electrode 101. Further, the bandgap of the second light absorption layer 30 is Eg2, where 1.1 eV ≤ Eg2 ≤ 1.6 eV; the bandgap of the first light absorption layer 103 is Eg1, where 1.65 eV < Eg1 ≤ 2.2 eV. Thus, when light enters from the first electrode 101, it first passes through the first light absorption layer 103, and the first light absorption layer 103 absorbs short-wavelength light (such as light in the ultraviolet to visible light band), and then enters the second light absorption layer 30, where the second light absorption layer 30 absorbs long-wavelength light (such as light in the near-infrared band). Thus, on the one hand, different wavelengths of light can be utilized to a greater extent, improving the photoelectric conversion efficiency of the tandem solar cell 200. On the other hand, the first light absorption layer 103, as the light absorption layer of the top cell, absorbs ultraviolet-visible light, protecting the second light absorption layer 30, which is the light absorption layer of the bottom cell.

[0229] In one embodiment, referring to FIG. 8, the intermediate layer 20 is an interconnect layer 201. The tandem solar cell 200 includes a first electrode 101, a first hole transport layer 102, a first light absorption layer 103, an intermediate layer 20 (interconnect layer 201), a second light absorption layer 30, and a second electrode 105 stacked in sequence. Thus, the two cell parts are connected through the interconnect layer 201 to achieve current matching between the two cell parts, with a relatively smaller size, capable of absorbing different wavelengths of light, broadening the absorption spectrum range of the tandem solar cell, and improving the photoelectric conversion efficiency of the tandem solar cell.

[0230] In one embodiment, the interconnect layer 201 is selected from a composite layer or a tunneling layer. The composite layer is used to recombine and annihilate electrons generated from the first light-absorbing layer 103 and holes generated from the second light-absorbing layer 30, thereby forming a low-ohmic tunnel recombination between the first battery section containing the first light-absorbing layer 103 and the second battery section containing the second light-absorbing layer 30, ensuring connectivity between the two battery sections. The tunneling layer is located between the two battery sections and its main function is to achieve efficient electron and hole transport. Through the tunneling effect, the tunneling layer allows electrons and holes to be transported from one battery section to another, thereby reducing energy loss due to electron thermal relaxation and improving the photoelectric conversion efficiency of the battery.

[0231] In one embodiment, the composite layer comprises one or more of a metallic material, a transparent conductive material, and a carbon material. Further, the transparent conductive material comprises, but is not limited to, one or more of tin-doped indium oxide (ITO), lanthanide-doped indium oxide, fluorine-doped tin oxide (FTO), antimony-doped tin oxide, boron-doped zinc oxide (BZO), aluminum-doped zinc oxide (AZO), zinc-doped indium oxide (IZO), gallium-doped zinc oxide (GZO), and tungsten-doped indium oxide (IWO). Further, the metallic material comprises, but is not limited to, one or more of gold, copper, silver, platinum, aluminum, and iron. Further, the carbon material comprises one or more of graphite, graphene, and carbon nanotubes.

[0232] In one embodiment, the thickness of the composite layer is 0.1nm-200nm. For example, it can be 0.1nm, 0.8nm, 1nm, 2nm, 10nm, 30nm, 50nm, 90nm, 100nm, 130nm, 150nm, 160nm, 200nm, etc., or within the range of any two of the above point values ​​as end values.

[0233] In one embodiment, the components of the tunneling layer include, but are not limited to, PEDOT, transparent conductive materials, etc. Further, the components of the transparent conductive material include, but are not limited to, one or more of the following: tin-doped indium oxide (ITO), lanthanide-doped indium oxide, fluorine-doped tin oxide (FTO), antimony-doped tin oxide, boron-doped zinc oxide (BZO), aluminum-doped zinc oxide (AZO), zinc-doped indium oxide (IZO), gallium-doped zinc oxide (GZO), and tungsten-doped indium oxide (IWO).

[0234] In one specific embodiment, the tandem solar cell 200 includes a first electrode 101, a first hole transport layer 102, a first light absorption layer 103, a first electron transport layer 104, a composite layer or tunneling layer, a third hole transport layer, a second light absorption layer 30, a second electron transport layer, and a second electrode 105, all stacked together. It should be noted that the tandem solar cell 200 may simultaneously include the third hole transport layer, the second electron transport layer, the first hole transport layer 102, and the first electron transport layer 104, or it may include only one or more of these elements; this is not limited here. The arrangement of the third hole transport layer, the second electron transport layer, the first hole transport layer 102, and the first electron transport layer 104 helps to extract and transport electrons or holes generated by the first light absorption layer 103 or the second light absorption layer 30, thereby enhancing the extraction and transport effect of electrons and holes and improving the performance of the tandem solar cell 200. Furthermore, the hole transport layer includes a hole transport material as defined above; the material of the third hole transport layer may be the same as or different from the material of the first hole transport layer 102. The electron transport layer includes an electron transport material as defined above; the material of the second electron transport layer may be the same as or different from the material of the first electron transport layer 104.

[0235] In one embodiment, as shown in FIG9, the intermediate layer 20 includes a third electrode 202, an insulating layer 203, and a fourth electrode 204 stacked together; the third electrode 202 is disposed between the first light-absorbing layer 103 and the insulating layer 203, and the fourth electrode 204 is disposed between the insulating layer 203 and the second light-absorbing layer 30. Specifically, the stacked solar cell 200 includes a first electrode 101, a first hole transport layer 102, a first light-absorbing layer 103, a third electrode 202, an insulating layer 203, a fourth electrode 204, a second light-absorbing layer 30, and a second electrode 105 stacked together. Thus, the stacked solar cell 200 forms a mechanically stacked cell. The two cell sections are isolated by the insulating layer 203 so that the charge carriers are not directly connected in parallel, and no current matching is required between them. At the same time, each cell section is provided with separate positive and negative electrodes to lead out current, which allows for flexible adjustment of the circuit.

[0236] In one embodiment, the material of the insulating layer 203 includes, but is not limited to, glass or an insulating adhesive. Further, the glass is transparent glass; further, the insulating adhesive is a transparent adhesive.

[0237] In one embodiment, since the third electrode 202 and the fourth electrode 204 are located in the middle of the tandem solar cell 200, in order to further increase the light energy utilization of the tandem solar cell 200 and enable the remaining light after absorption by one sub-cell to enter the next sub-cell, the third electrode 202 and the fourth electrode 204 can be set as light-transmitting electrodes, and the material can be one or more of the above-mentioned transparent conductive oxides.

[0238] In one specific embodiment, the tandem solar cell 200 includes a first electrode 101, a first hole transport layer, a first light absorption layer 103, a first electron transport layer 104, a third electrode 202, an insulating layer 203, a fourth electrode 204, a third hole transport layer, a second light absorption layer 30, a second electron transport layer, and a second electrode 105 stacked together. Thus, the first electrode 101, the first hole transport layer, the first light absorption layer 103, the first electron transport layer 104, and the third electrode 202 form a first cell section, and the fourth electrode 204, the third hole transport layer, the second light absorption layer 30, the second electron transport layer, and the second electrode 105 form a second cell section. The first cell section and the second cell section are electrically isolated by the insulating layer 203. Each cell section has two electrodes, for a total of four electrodes. The circuits of the two sub-cells are independent of each other, forming a four-terminal tandem solar cell. Therefore, the current of the tandem solar cell can be adjusted.

[0239] In other embodiments, the tandem solar cell 200 may also include tandem solar cells composed of 3, 4, or 5 cells, such as 3-junction solar cells, 4-junction solar cells, 5-junction solar cells, etc., which may be mechanical tandem cells, monolithic integrated tandem cells, or hybrid tandem cells composed of both, without limitation here.

[0240] Referring to Figure 10, this application also provides a photovoltaic device 1000, including the solar cell 100 of any of the above.

[0241] Referring to Figure 11, this application also provides an electrical device 2000, including any of the above-mentioned solar cells 100 or photovoltaic devices 1000.

[0242] In this application, the solar cell 100 serves as the power source for the aforementioned electrical device 2000; alternatively, the solar cell 100 can serve as an energy storage unit for the aforementioned electrical device 2000. As an example, the electrical device 2000 can be a lighting element, a display element, or an automobile, etc. The electrical device 2000 can be, but is not limited to, mobile phones, tablets, laptops, electric toys, power tools, electric vehicles, electric cars, ships, spacecraft, etc. Among these, electric toys can include stationary or mobile electric toys, such as game consoles, electric car toys, electric ship toys, and electric airplane toys, etc., and spacecraft can include airplanes, rockets, space shuttles, and spacecraft, etc.

[0243] Referring to Figure 12, this application also provides a power generation device 3000, including the solar cell 100 or the photovoltaic device 1000 described above. The power generation device 3000 may include the solar cell 100 and an energy storage device, which may be a secondary battery.

[0244] To make the technical problems, technical solutions, and beneficial effects solved by the embodiments of this application clearer, the following will provide a more detailed description in conjunction with the embodiments and accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of this application, and not all of them. The following description of at least one exemplary embodiment is merely illustrative and is in no way intended to limit this application or its applications. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0245] The features and performance of this application will be further described in detail below with reference to the embodiments.

[0246] Example 1:

[0247] (1) Preparation of the first electrode layer: The 20mm×20mm fluorine-doped SnO2 conductive glass (FTO, sheet resistance of 8Ω / sq) after etching was ultrasonically cleaned in detergent, deionized water and ethanol for 15min each. After cleaning, it was dried with a nitrogen gun and treated with ultraviolet ozone for 15min.

[0248] (2) Preparation of hole transport layer:

[0249] Preparation of the second hole transport layer:

[0250] A nickel oxide film was prepared by radio frequency magnetron sputtering to obtain a second hole transport layer with a thickness of 18 nm. During sputtering, a small amount of oxygen was introduced to adjust the nickel-oxygen ratio of the nickel oxide, that is, the ratio of trivalent nickel to divalent nickel was 1 / 3.

[0251] Preparation of the first hole transport layer:

[0252] A first hole transport layer was prepared on the second hole transport layer. M4P and polyacrylic acid were dissolved in DMSO (dimethyl sulfoxide) solvent to obtain a mixed solution with an M4P concentration of 0.3 mg / mL and a polyacrylic acid concentration of 0.15 mg / mL. This solution was then prepared by spin coating at 4000 rpm without annealing, resulting in a first hole transport layer with a thickness of 7 nm. The mass ratio of M4P to polyacrylic acid was 2:1.

[0253] (3) Preparation of the first light-absorbing layer: 1934.7 mg of FAI (formamidinium hydroiodide), 324.8 mg of CsI (cesium iodide), and 5762.6 mg of PbI2 (lead iodide) were weighed and dissolved in a mixed solvent of 9 mL of DMF (N,N-dimethylformamide) and 1 mL of NMP (N-methylpyrrolidone). After stirring for 2 hours, the solution was used for preparation. Perovskite films were prepared by spin coating at 4000 rpm. The perovskite precursor solution was coated onto the first hole transport layer and spin-coated. Then, anisole was used as an antisolvent and gently dropped onto the rotating substrate. After spin coating, the resulting perovskite wet film was immediately placed on a hot plate at 120 degrees Celsius and annealed for 15 minutes to obtain a FA film with a thickness of 500 nm. 0.9 Cs 0.1 PbI3 perovskite thin films.

[0254] (4) Upper passivation layer: 5 nm LiF (lithium fluoride) was prepared by thermal evaporation to obtain the upper passivation layer.

[0255] (5) Electron transport layer preparation: A C60 thin film with a thickness of 25 nm was prepared on the upper passivation layer by thermal evaporation.

[0256] (6) Buffer layer: Tin oxide film is deposited using RPD (reactive plasma deposition) process. A small amount of oxygen is introduced during deposition to obtain a buffer layer with a thickness of 20 nm. No high temperature treatment is performed during or after deposition and the next step is carried out directly.

[0257] (7) Preparation of the second electrode layer: After removing part of the perovskite film layer of the first electrode layer, a 100 nm thick Cu metal electrode is prepared by thermal evaporation. At this point, the battery preparation is complete.

[0258] Example 2

[0259] Similar to Example 1, the difference is:

[0260] The preparation of the first hole transport layer in step (2) of Example 1 is adjusted as follows: the first hole transport layer is prepared on the second hole transport layer by dissolving M4P (0.3 mg / mL) and PEI (polyethyleneimine) (0.3 mg / mL) in DMSO (dimethyl sulfoxide) solvent and preparing it by spin coating at 4000 rpm without annealing post-treatment to obtain a first hole transport layer with a thickness of 7 nm.

[0261] Example 3

[0262] Similar to Example 1, the difference is:

[0263] The preparation of the first hole transport layer in step (2) of Example 1 was adjusted to: the mass ratio of M4P and polyacrylic acid was 1:1.

[0264] Example 4

[0265] Similar to Example 1, the difference is:

[0266] The preparation of the first hole transport layer in step (2) of Example 1 is adjusted as follows: the first hole transport layer is prepared on the second hole transport layer by dissolving PTAA with a concentration of 0.3 mg / mL and polyacrylic acid with a concentration of 0.3 mg / mL in DMSO (dimethyl sulfoxide) solvent and preparing it by spin coating at a speed of 4000 rpm without annealing post-treatment, to obtain a first hole transport layer with a thickness of 7 nm.

[0267] Example 5

[0268] Similar to Example 1, the difference is:

[0269] The thickness of the first hole transport layer in step (2) of Example 1 is changed to 1 nm.

[0270] Example 6

[0271] Similar to Example 1, the difference is:

[0272] The thickness of the first hole transport layer in step (2) of Example 1 is changed to 30nm.

[0273] Example 7

[0274] Similar to Example 1, the difference is:

[0275] The preparation of the first hole transport layer in step (2) of Example 1 was adjusted to: the mass ratio of M4P to polyacrylic acid was 1:5.

[0276] Example 8

[0277] Similar to Example 1, the difference is:

[0278] The preparation of the first hole transport layer in step (2) of Example 1 was adjusted to: the mass ratio of M4P to polyacrylic acid was 5:1.

[0279] Example 9

[0280] Similar to Example 1, the difference is:

[0281] No second hole transport layer is prepared.

[0282] The first hole transport layer is prepared directly on the first electrode layer, and the preparation method of the first hole transport layer is the same as that in Example 1.

[0283] Example 10

[0284] Similar to Example 1, the difference lies in that: M4P and polyethylene glycol with a weight-average molecular weight of 300,000 were dissolved in DMSO (dimethyl sulfoxide) solvent to obtain a mixed solution with an M4P concentration of 0.3 mg / mL and a polyethylene glycol concentration of 0.15 mg / mL. This solution was prepared by spin coating at 4000 rpm without annealing post-treatment, resulting in a first hole transport layer with a thickness of 7 nm. The mass ratio of M4P to polyethylene glycol was 2:1.

[0285] Comparative Example 1

[0286] Similar to Example 1, the difference is:

[0287] The preparation of the first hole transport layer in step (2) of Example 1 is adjusted as follows: the first hole transport layer is prepared on the second hole transport layer. M4P is dissolved in DMSO to obtain an M4P precursor solution with a concentration of 0.3 mg / mL. The first hole transport layer film is prepared by spin coating at a speed of 4000 rpm. No annealing post-treatment is required to obtain a first hole transport layer with a thickness of 7 nm.

[0288] The solar cells obtained in Examples 1-9 and Comparative Example 1 were subjected to battery performance tests, and Tables 1-1 and 1-2 were obtained.

[0289] The testing method is as follows:

[0290] 1. IV measurement method:

[0291] The IV characteristics of the device under test can be obtained by changing the bias voltage point and simultaneously measuring the current.

[0292] a) Place the test fixture containing the sample cell on the sample holder, so that it is in the measurement plane, and ensure that the sample cell is located at the center of the solar simulator's emitted light spot (or the photovoltaic cell normal is parallel to the center line of the solar simulator's emitted light beam).

[0293] b) A solar simulator, conforming to the national standard IEC61215, was used for testing. Crystalline silicon solar cells were used to correct the light intensity to achieve a solar intensity of 1000 W / m². 2 Under irradiation conditions, a mask is installed on the sample battery to be tested, and the temperature of the sample battery is controlled by a temperature monitoring device so that the temperature of the sample battery is maintained at (30±5℃) during the measurement process.

[0294] c) The performance of the perovskite solar cell was evaluated using a Keithley 2400 digital source meter under AM 1.5G irradiance. The positive terminal of the digital source meter was connected to the anode of the perovskite solar cell (i.e., the front electrode), and the negative terminal was connected to the cathode of the perovskite solar cell (i.e., the back electrode). A voltage ranging from -0.1V to 1.2V was continuously applied in steps of 0.02V, with each voltage applied for 0.5s. The corresponding current value at each voltage was recorded to obtain the IV characteristic curve of the perovskite solar cell. The open-circuit voltage V was also recorded. OC Short-circuit current J SC .

[0295] Calculation formula: Fill factor FF = J m ×V m / V OC ×J SC Energy conversion efficiency PCE = V OC ×J SC ×FF / P in P in The incident light intensity is 10³ W / m. 2 .

[0296] 2. Methods for measuring volume resistivity:

[0297] The four-probe method involves contacting the material surface with four equally spaced probes. A known current is passed through the two outer probes, while the voltage drop is measured on the two inner probes. According to Ohm's law, the resistivity is calculated by measuring the current and voltage.

[0298] 3. Method for measuring weight-average molecular weight:

[0299] Weight-average molecular weight (Mw) was determined using static light scattering (SEC-MALS) as follows: First, the sample was dissolved and injected into a size exclusion chromatography (SEC) column to separate different components based on molecular size. The separated components then entered a multi-angle light scattering detector, where the intensity of the scattered light was measured by laser irradiation. Combined with concentration information obtained from a differential refractive index detector, the Zimm equation was used for calculation. The weight-average molecular weight (Mw) was obtained through dual extrapolation of concentration and angle.

[0300] 4. Test methods for service life

[0301] Accelerated aging tests are used to evaluate the lifespan of solar cells. This application focuses on photothermal accelerated aging. Specifically, perovskite solar cells are placed under conditions of 75°C and one day of sunlight, while the output power of the cells is continuously monitored using maximum power point tracking (MPPT) technology. The time it takes for the cell's output power to decay to 80% of its maximum power is recorded as the cell's lifespan. The unit is hours.

[0302] Table 1-1 Performance test results of solar cells in each embodiment and comparative example

[0303]

[0304] Table 1-2 Performance test results of solar cells in each embodiment and comparative example

[0305]

[0306] As can be seen from the relevant data in Tables 1-1 and 1-2, the solar cells of Examples 1-9 all use insulating additives in the first hole transport layer. The open-circuit voltage, short-circuit current, fill factor, energy conversion efficiency, and lifetime of Examples 1-9 are all higher than those of Comparative Example 1. This indicates that after using insulating additives in the first hole transport layer in this application, the insulating additives can improve the solution viscosity and film-forming properties of the first hole transport layer, thereby increasing the coverage of the first hole transport layer on the covered film layer (such as the first electrode or the first light absorption layer), reducing the problem of electron and hole recombination caused by direct contact between the first light absorption layer and the solar cell electrode. Furthermore, the surface portion of the first hole transport layer near the first light absorption layer is made of a first polymer material that can transport holes, and the other part is made of an insulating second polymer material. This reduces the area of ​​the electrical contact interface between the first light absorption layer and the first hole transport layer, reducing the interface carrier recombination induced by interface defects, thereby improving the photoelectric conversion efficiency of the solar cell.

[0307] The above description is merely an embodiment of this application and does not limit the patent scope of this application. Any equivalent structural or procedural transformations made using the content of this application's specification and drawings, or direct or indirect applications in other related technical fields, are similarly included within the patent protection scope of this application.

Claims

1. A solar cell, wherein, The solar cell includes at least a first electrode, a first hole transport layer, a first light absorption layer, and a second electrode stacked together. The first light absorption layer and the first hole transport layer are disposed between the first electrode and the second electrode. The first hole transport layer is disposed between the first electrode and the first light absorption layer. The first hole transport layer includes a first hole transport material and an insulating additive. The first hole transport material includes a first polymer material, and the insulating additive includes a second polymer material.

2. The solar cell as claimed in claim 1, wherein, The volume resistivity of the second polymer material is in the range of 1×10⁻⁶. 10 Ω m~1×10 18 Ω m.

3. The solar cell as described in claim 1 or 2, wherein, The weight-average molecular weight of the second polymer material is greater than or equal to 20 kDa and less than or equal to 4 million Da.

4. The solar cell according to any one of claims 1 to 3, wherein, The polydispersity index (PDI) of the second polymer material is less than or equal to 5.

5. The solar cell according to any one of claims 1 to 4, wherein, The hydrophilic-lipophilic balance value of the second polymer material ranges from 9 to 35.

6. The solar cell according to any one of claims 1 to 5, wherein, The molecular structure of the second polymer material includes one or more of the following groups: organic acid group, hydroxyl group, amino group, carboxyl group, sulfonic acid group, phosphate group, ether group, amide group, and sulfoxide group.

7. The solar cell according to any one of claims 1 to 6, wherein, The second polymer material includes one or more of synthetic polymers, starch, protein, and cellulose; the synthetic polymer includes copolymers formed from one or more of polyacrylic acid, polystyrene sulfonic acid, polyacrylamide, polyvinyl alcohol, polyethylene glycol, poly(N-vinylpyrrolidone), poly(2-hydroxypropyl methacrylamide), polyethyleneimine, and poly(2-(methacryloyloxy)ethylphosphorylcholine).

8. The solar cell according to any one of claims 1 to 7, wherein, The weight-average molecular weight of the first hole transport material is 500~50000.

9. The solar cell according to any one of claims 1 to 8, wherein, The molecular structure of the first polymer material includes one or more of the following: aniline, carbazole, acridine, thiophenazine, phenoxazine, benzothiazolium, and thiophene.

10. The solar cell according to any one of claims 1 to 9, wherein, The first hole transport material comprises a polymer of N4,N4′-bis(naphthyl-1-yl)-N4,N4′-bis(4-vinylphenyl)biphenyl-4,4′-diamine, poly[bis(4-phenyl)(2,4,6-trimethylphenyl)amine], poly3-hexylthiophene, poly(3,4-ethylenedioxythiophene):polystyrene sulfonic acid, or one or more of the repeating units shown in formula (I): Formula (I), In formula (I), M includes substituted or unsubstituted aniline, substituted or unsubstituted carbazolyl, substituted or unsubstituted acridine, substituted or unsubstituted thiophenazinyl or substituted or unsubstituted phenoxazinyl; R is a single bond or a bridging group; Y includes H or one or more oxygen-containing groups.

11. The solar cell of claim 10, wherein, Equation (I) satisfies one or more of the following conditions: (1) The repeating unit shown in formula (I) includes one or more of the repeating units shown in formulas (I-1) to (I-6): Equation (I-1), Equation (I-2), Equation (I-3), Equation (I-4), Equation (I-5), Equation (I-6); where, R1 to R 12 Each and every one is independently selected from one or more of the following: hydrogen atom, halogen atom, nitrogen-containing group, hydroxyl group, substituted or unsubstituted C1-C5 alkyl group, substituted or unsubstituted C1-C5 alkoxy group, substituted or unsubstituted C1-C5 amide group, substituted or unsubstituted C1-C5 ester group, substituted or unsubstituted C1-C5 carboxyl group, substituted or unsubstituted C6-C30 aryl group, or substituted or unsubstituted C5-C30 heterocyclic aryl group; "Curve" " represents the connection key with adjacent repeating units; (2) The bridging group includes one or more of the following: oxygen atom, sulfur atom, substituted or unsubstituted alkylene group, substituted or unsubstituted alkenyl group, substituted or unsubstituted heteroalkylene group, substituted or unsubstituted aromatic group or substituted or unsubstituted heterocyclic group; In cases where the bridging group includes a substituted or unsubstituted alkylene group, a substituted or unsubstituted alkenyl group, or a substituted or unsubstituted heteroalkylene group, and the above group is substituted by a substituent group, the substituent group includes one or more of a halogen group, an amine group, an alkylthionyl group, an oxygen-containing substituent group, an aromatic group, or an aromatic heterocyclic group, and the number of carbon atoms is 1 to 10 when the substituent group includes a carbon atom. In cases where the bridging group includes a substituted or unsubstituted aromatic group or a substituted or unsubstituted heterocyclic group, and the above group is substituted by a substituent group, the substituent group includes one or more of halogen groups, amine groups, alkyl thio groups, oxygen-containing substituent groups or C1 to C5 alkyl groups. (3) The oxygen-containing group includes one or more of the following: carboxylic acid group, phosphite group, phosphate group, sulfonic acid group, silicate group, siloxane group, borate group, carboxylic acid ester group, phosphate ester group, sulfonate group, silicate group, borate group, carboxylate group, phosphite group, phosphate group, borate group or silicate group.

12. The solar cell of claim 11, wherein, The first hole transport material includes one or more of polyphosphate carbazole, polycarboxylic acid carbazole, and poly[bis(4-phenyl)(2,4,6-trimethylphenyl)amine].

13. The solar cell of claim 12, wherein, The repeating unit of the polyphosphate carbazole class or the polycarboxylic acid carbazole class is shown in formula (I-3), wherein Y in the polyphosphate carbazole class is selected from one or more of phosphate groups, phosphate ester groups, and phosphate groups; Y in the polycarboxylic acid carbazole class is selected from one or more of carboxylic acid groups, carboxylic acid ester groups, and carboxylic acid groups.

14. The solar cell according to any one of claims 1 to 13, wherein, The first polymer material comprises one or more of poly[4-(3,6-dimethyl-9H-carbazole-9-yl)butyl]phosphonic acid, poly[2-(3,6-dimethoxy-9H-carbazole-9-yl)ethyl]phosphonic acid, poly[2-(3,6-dimethyl-9H-carbazole-9-yl)ethyl]phosphonic acid, poly[2-(9H-carbazole-9-yl)ethyl]phosphonic acid, poly[2-(3,6-dibromo-9H-carbazole-9-yl)ethyl]phosphonic acid, poly[4-(3,6-dimethyl-9H-carbazole-9-yl)butyl]phosphonic acid, or poly[bis(4-phenyl)(2,4,6-trimethylphenyl)amine]; and / or, the second polymer material comprises one or both of polyacrylic acid or polyethyleneimine.

15. The solar cell according to any one of claims 1 to 14, wherein, The first hole transport material forms a hole transport region, and the insulating additive forms an insulating region. The hole transport region and the insulating region exhibit a microscopic phase separation structure.

16. The solar cell according to any one of claims 1 to 15, wherein, In the first hole transport layer, the mass ratio of the first hole transport material to the insulating additive is 1:5-5:

1.

17. The solar cell according to any one of claims 1 to 16, wherein, The thickness of the first hole transport layer is 1nm~30nm.

18. The solar cell according to any one of claims 1 to 17, wherein, The first light-absorbing layer comprises a first perovskite material, the general formula of which is ABX3 or A2CDX6. The A ions comprise inorganic, organic, or mixed organic-inorganic cations; the B ions comprise inorganic cations; the C ions comprise inorganic, organic, or mixed organic-inorganic cations; the D ions comprise inorganic cations; and the X ions comprise inorganic, organic, or mixed organic-inorganic anions.

19. The solar cell of claim 18, wherein, The first perovskite material satisfies one or more of the following conditions: (1) A ions include FA + MA + Gu + Cs + 、Rb + DMA + One or more of them; (2) B ions include Pb 2+ Sn 2+ Ge² + Mn² + One or more of them; (3) C ions include Ag + Cu + Au + FA + Gu + One or more of them; (4) D ions include Bi 3+ Sb 3+ And In 3+ One or more of them; (5) X ions include Cl - ,Br - I - SCN - CNO - OCN - OSCN - SH - OH - CN - SeCN - COO - One or more of them.

20. The solar cell according to any one of claims 1 to 19, wherein, The solar cell further includes a second hole transport layer, which is located on the side of the first hole transport layer away from the first light absorption layer.

21. The solar cell according to any one of claims 1 to 20, wherein, The second hole transport layer comprises nickel oxide.

22. The solar cell according to any one of claims 1 to 21, wherein, The solar cell is an inverted solar cell.

23. A tandem solar cell, comprising a solar cell as described in any one of claims 1 to 22, an intermediate layer and a second light-absorbing layer, wherein the intermediate layer is disposed on the side of the first light-absorbing layer near the second electrode, the second light-absorbing layer is disposed between the intermediate layer and the second electrode, and the second light-absorbing layer and the first light-absorbing layer have different band gaps.

24. The tandem solar cell as described in claim 23, wherein, The intermediate layer is an interconnect layer; or, the intermediate layer includes a third electrode, an insulating layer and a fourth electrode stacked together, the third electrode being disposed between the first light-absorbing layer and the insulating layer, and the fourth electrode being disposed between the insulating layer and the second light-absorbing layer.

25. A photovoltaic device, wherein, This includes the solar cell as described in any one of claims 1 to 22 or the tandem solar cell as described in claim 23 or 24.

26. An electrical appliance, wherein, This includes the solar cell as described in any one of claims 1 to 23, the tandem solar cell as described in claim 23 or 24, or the photovoltaic device as described in claim 25.

27. A power generation device, wherein, This includes the solar cell as described in any one of claims 1 to 23, the tandem solar cell as described in claim 23 or 24, or the photovoltaic device as described in claim 25.

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