Solar cell and preparation method thereof, photovoltaic module, power consumption and power generation device

Abstract

The application provides a solar cell, a preparation method thereof, a photovoltaic module, and a power generation and utilization device. The solar cell comprises a first electrode layer, a hole transport layer, a perovskite light absorption layer, and a second electrode layer. The perovskite light absorption layer is located between the first electrode layer and the second electrode layer. The hole transport layer is located between the first electrode layer and the perovskite light absorption layer. The hole transport layer comprises a thiophene compound and a self-assembled monomolecular compound mixed with each other. The thiophene compound comprises at least one of a compound (1) and an oxygen-containing group salt compound of the compound (1). The compound (1) comprises a thiophene parent ring Ar1 and an oxygen-containing group R1 connected to the thiophene parent ring. The thiophene parent ring Ar1 comprises at least one thiophene group. In this way, the photoelectric performance and stability of the solar cell can be improved.

Description

Technical Field

[0001] This application relates to the field of battery technology, and in particular to a solar cell and its preparation method, a photovoltaic module, and an electricity consumption and power generation device. Background Technology

[0002] Solar cells are a new type of photovoltaic device that directly converts solar radiation energy into electrical energy using the photovoltaic effect. Taking perovskite solar cells as an example, they use perovskite material as the light-absorbing layer and have advantages such as low cost, high performance in low-light conditions, and wide applicability. They are an excellent choice for next-generation mass-produced photovoltaic cells, can alleviate the energy crisis, and are one of the key development directions for new energy sources. However, current solar cells suffer from relatively low photoelectric performance in practical applications. Therefore, traditional technologies need improvement. Summary of the Invention

[0003] To achieve the above objectives, this application provides a solar cell and its preparation method, a photovoltaic module, and an electricity consumption and power generation device.

[0004] In a first aspect, this application provides a solar cell comprising a first electrode layer, a hole transport layer, a perovskite light-absorbing layer, and a second electrode layer, wherein the perovskite light-absorbing layer is located between the first electrode layer and the second electrode layer, and the hole transport layer is located between the first electrode layer and the perovskite light-absorbing layer. The hole transport layer comprises a mixture of thiophene compounds and self-assembled monomolecule compounds. The thiophene compounds comprise at least one of compound (1) and an oxygen-containing salt of compound (1). The compound (1) comprises a thiophene parent ring Ar1 and an oxygen-containing group R1 connected to the thiophene parent ring. The thiophene parent ring Ar1 comprises at least one thiophene group.

[0005] The aforementioned solar cell of this application comprises a hole transport layer consisting of a mixture of thiophene compounds and self-assembled monomolecule compounds. Both compounds exhibit excellent hole transport performance. Furthermore, the oxygen-containing group R1 of the thiophene compound acts as an interface linker, thereby forming a hole transport layer together with the self-assembled monomolecule compound. This improves the uniformity of the hole transport layer and reduces problems such as leakage current and non-radiative recombination. In addition, the sulfur-containing thiophene group and the oxygen-containing group R1 in the thiophene compound passivate the perovskite light-absorbing layer, thereby reducing defects such as pinhole traps in the perovskite light-absorbing layer, optimizing the film quality of the perovskite light-absorbing layer, and thus improving the photoelectric performance and stability of the solar cell.

[0006] In some embodiments of this application, the thiophene parent ring Ar1 is a thiophene group or a thiophene-containing fused ring group.

[0007] In some embodiments of this application, the thiophene-containing fused ring group includes a plurality of fused ring groups formed of thiophene or at least one thiophene group and at least one six-membered aryl fused ring group;

[0008] Optionally, the six-membered aryl group includes one or more of a benzene ring and a six-membered heteroaromatic ring;

[0009] Alternatively, the fused ring group formed by at least one thiophene group and at least one six-membered aryl group includes one or more of benzothiophene, dibenzothiophene, and benzothiophene-benzothiophene.

[0010] In some embodiments of this application, the oxygen-containing group R1 includes one or more of an oxyacid group and a hydroxyl group;

[0011] Optionally, the oxyacid group includes one or more of the following: phosphonic acid group, phosphonic acid group, sulfonic acid group, sulfinic acid group, carboxylic acid group, boric acid group, and silicate group.

[0012] In some embodiments of this application, the structure of compound (1) is as follows:

[0013]

[0014] Equation (1),

[0015] Where m is an integer from 1 to 4.

[0016] R1 is directly connected to Ar1. The thiophene compounds formed by direct connection have a denser electron cloud and better stability. In addition, their energy levels can better match the perovskite layer.

[0017] In some embodiments of this application, the compound (1) has the structure shown in any of the formulas (1-1) to (1-10):

[0018] .

[0019] In some embodiments of this application, the compound (1) has the structure shown in any of the formulas (1-1a) to (1-10a):

[0020] .

[0021] In this thiophene compound containing two oxygen-containing groups R1, and with each oxygen-containing group R1 attached to a thiophene-containing fused-ring group, the two ends of the thiophene-containing fused-ring group each have an oxygen-containing group R1 attached to them. This not only provides less steric hindrance but also facilitates the thiophene compound's role in connecting with the two interfaces of the hole transport layer.

[0022] In some embodiments of this application, the compound (1) has a structure as shown in any of the formulas (1-11a) to (1-101a):

[0023] .

[0024] The presence of the oxygen-containing group R1 at the aforementioned positions not only provides less steric hindrance, which is beneficial for thiophene compounds to exert their interfacial connection with the hole transport layer, but also influences the HOMO and effective face-to-face stacking of the compound. The aforementioned positions exhibit more matched energy levels, better hole mobility, and stability.

[0025] In some embodiments of this application, the hole transport layer comprises one or more thiophene compounds represented by formulas (11) to (15):

[0026]

[0027]

[0028] .

[0029] In some embodiments of this application, the self-assembled monomolecular compound includes a head group Ar2, an anchoring group R2, and a linking group L connecting the head group Ar2 and the anchoring group R2;

[0030] The self-assembled monomolecule compound has one or more of the following characteristics:

[0031] (1) The head group Ar2 includes substituted or unsubstituted C6~C30 aryl, substituted or unsubstituted C3~C30 heteroaryl or substituted or unsubstituted C6~C30 aromatic amino groups;

[0032] (2) The linking group L includes a single bond, a substituted or unsubstituted C1~C10 alkylene group, a substituted or unsubstituted C2~C10 alkenyl group, a substituted or unsubstituted C5~C30 aryl group, or a substituted or unsubstituted heterocyclic aryl group;

[0033] (3) The anchoring group R2 includes one or more of the following: an oxyacid group and its salt, and a hydroxyl group;

[0034] Optionally, the oxyacid group includes one or more of the following: phosphonic acid group, phosphonic acid group, sulfonic acid group, sulfinic acid group, carboxylic acid group, boric acid group, and silicate group.

[0035] In some embodiments of this application, one or more of the following features are present:

[0036] (1) In the head group Ar2, the C6~C30 aryl group includes substituted or unsubstituted phenyl, substituted or unsubstituted naphthyl, substituted or unsubstituted anthraquinone, substituted or unsubstituted phenanthyl, substituted or unsubstituted alkyl or substituted or unsubstituted pyrene;

[0037] (2) In the head group Ar2, the C3~C30 heteroaryl groups include substituted or unsubstituted carbazole group, substituted or unsubstituted dibenzocarbazole group, substituted or unsubstituted dibenzopyridinyl group or substituted or unsubstituted naphthalimide group;

[0038] (3) In the head group Ar2, the C6~C30 aromatic amino groups include substituted or unsubstituted triphenylamine groups;

[0039] (4) The anchoring group R2 includes one or more of the following: phosphonic acid group, phosphonic acid group, sulfonic acid group, sulfinic acid group, carboxylic acid group, boric acid group and silicate group.

[0040] In some embodiments of this application, the self-assembled monomolecular compound comprises a structure having the structure shown in formula (2) below:

[0041] Equation (2),

[0042] Where n is an integer from 1 to 10; R S1 The functional groups include one or more of H, C1-C30 alkyl, C1-C30 alkoxy, heterocyclic groups containing 3-20 cyclic atoms, aryl groups containing 5-20 cyclic atoms, heteroaryl groups containing 5-20 cyclic atoms, and halogens. Properly controlling the n value can reduce steric hindrance and improve the photoelectric conversion efficiency and stability of the battery.

[0043] In some embodiments of this application, the self-assembled monomolecular compound includes one or more of MeO-2PACz, Me-2PACz, MeO-4PACz, or Me-4PACz.

[0044] In some embodiments of this application, in the hole transport layer, the mass content of the self-assembled monomolecular compound is greater than or equal to the mass content of the thiophene compound.

[0045] In some embodiments of this application, the mass ratio of the self-assembled monomolecular compound to the thiophene compound in the hole transport layer is (1~10):1.

[0046] A second aspect of this application provides a method for preparing a solar cell, characterized by comprising the following steps:

[0047] A first electrode layer, a hole transport layer, a perovskite light-absorbing layer, and a second electrode layer are formed in a stacked configuration.

[0048] The hole transport layer comprises a mixture of thiophene compounds and self-assembled monomolecules. The thiophene compounds include at least one of compound (1) and an oxygen-containing salt of compound (1). Compound (1) comprises a thiophene parent ring Ar1 and an oxygen-containing group R1 connected to the thiophene parent ring. The thiophene parent ring Ar1 comprises at least one thiophene group.

[0049] In some embodiments of this application, forming the hole transport layer includes the following steps:

[0050] The thiophene compound and the self-assembled unimolecular compound are mixed in a solvent to prepare a mixed solution;

[0051] The mixed solution is applied to form a film, which is then annealed to form the hole transport layer.

[0052] In some embodiments of this application, the solar cell is any of the solar cells described above.

[0053] In a third aspect, this application provides a hole transport layer comprising a mixture of thiophene compounds and self-assembled monomolecules, wherein the thiophene compounds include at least one of compound (1) and an oxygen-containing salt of compound (1), wherein compound (1) comprises a thiophene parent ring Ar1 and an oxygen-containing group R1 connected to the thiophene parent ring, and the thiophene parent ring Ar1 comprises at least one thiophene group.

[0054] In some embodiments of this application, the hole transport layer is any of the hole transport layers described above.

[0055] In a fourth aspect, this application provides a photovoltaic module, including the solar cell provided in the first aspect of this application or the solar cell prepared by the preparation method provided in the second aspect of this application.

[0056] In a fifth aspect of this application, an electrical device is provided, including a solar cell provided in the first aspect of this application, a solar cell prepared by the preparation method provided in the second aspect of this application, or a photovoltaic module provided in the fourth aspect of this application.

[0057] In a sixth aspect of this application, a power generation device is provided, including a solar cell provided in the first aspect of this application, a solar cell prepared by the preparation method provided in the second aspect of this application, or a photovoltaic module provided in the fourth aspect of this application.

[0058] The photovoltaic modules, electrical devices, and power generation devices of this application include the solar cells provided in the first aspect of this application and the solar cells prepared by the preparation method provided in the second aspect of this application, and therefore have at least the same advantages as the solar cells described above.

[0059] Details of one or more embodiments of this application are set forth in the following drawings and description. Other features, objects, and advantages of this application will become apparent from the specification, drawings, and claims. Attached Figure Description

[0060] To better describe and illustrate the embodiments or examples provided in this application, reference may be made to one or more accompanying drawings. Additional details or examples used to describe the drawings should not be considered as limiting the scope of any of the disclosed applications, the currently described embodiments or examples, or the best mode of conduct of these applications as currently understood. Furthermore, the same reference numerals denote the same parts throughout the drawings. In the drawings:

[0061] Figure 1 This is a schematic diagram of a solar cell according to one embodiment of this application.

[0062] Figure 2 This is a surface morphology diagram of the perovskite light-absorbing layer prepared in Comparative Example 1 of this application.

[0063] Figure 3 This is a surface morphology diagram of the perovskite light-absorbing layer obtained in Example 1 of this application.

[0064] Figure 4 This is a surface morphology diagram of the perovskite light-absorbing layer obtained in Example 2 of this application.

[0065] Explanation of reference numerals in the attached figures:

[0066] 1. Solar cell; 11. Substrate; 12. First electrode layer; 13. Hole transport layer; 14. Perovskite light absorption layer; 15. Electron transport layer; 16. Second electrode layer. Detailed Implementation

[0067] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. 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.

[0068] The "range" disclosed in this application can be defined in the form of a lower limit and an upper limit. A given range is defined by selecting a lower limit and an upper limit, which define the boundaries of a particular range. Ranges defined in this way can include or exclude endpoints; any endpoint can be independently included or excluded, and they can be combined arbitrarily, meaning any lower limit can be combined with any upper limit to form a range. For example, if ranges of 60-120 and 80-110 are listed for a specific parameter, it is expected that ranges of 60-110 and 80-120 are also included. Furthermore, if minimum range values ​​1 and 2 are listed, and maximum range values ​​3, 4, and 5 are also listed, then the following ranges are all expected: 1-3, 1-4, 1-5, 2-3, 2-4, and 2-5. In this application, unless otherwise stated, the numerical range "ab" represents a shortened representation of any combination of real numbers between a and b, where a and b are real numbers. For example, the numerical range "0-5" indicates that all real numbers between "0-5" have been listed in this document; "0-5" is simply a shortened representation of these numerical combinations. Furthermore, stating that a parameter is an integer ≥2 is equivalent to disclosing that the parameter is, for example, an integer 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, etc. For instance, stating that a parameter is an integer selected from "2-10" is equivalent to listing the integers 2, 3, 4, 5, 6, 7, 8, 9, and 10.

[0069] In this application, the terms "multiple" or "various" are used unless otherwise specified, referring to a quantity greater than or equal to 2. For example, "one or more" means one or more types.

[0070] Unless otherwise specified, all embodiments and optional embodiments of this application can be combined to form new technical solutions.

[0071] 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 or implementation 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. The term "implementation" as used herein has a similar understanding.

[0072] Those skilled in the art will understand that the order in which the steps are written in the methods of various embodiments or examples does not imply a strict execution order and does not constitute any limitation on the implementation process. The detailed execution order of each step should be determined by its function and possible internal logic. Unless otherwise specified, all steps of this application may be performed sequentially or randomly, preferably sequentially. For example, if the method includes steps (a) and (b), it means that the method may include steps (a) and (b) performed sequentially, or it may include steps (b) and (a) performed sequentially. For example, if the method may also include step (c), it means that step (c) can be added to the method in any order. For example, the method may include steps (a), (b), and (c), or it may include steps (a), (c), and (b), or it may include steps (c), (a), and (b), etc.

[0073] In this application, unless otherwise specified, A (e.g., B) means that B is a non-limiting example of A, and it is understood that A is not limited to B.

[0074] In this application, "optionally," "optionally," and "optional" mean that something is optional, that is, it means that it is selected from either "with" or "without." If there are multiple "optional" entries in a technical solution, unless otherwise specified and there are no contradictions or mutual constraints, each "optional" entry shall be independent.

[0075] In this application, the term "alkyl" refers to a monovalent residue formed by the loss of a hydrogen atom from a saturated hydrocarbon containing a primary (normal) carbon atom, or a secondary carbon atom, or a tertiary carbon atom, or a quaternary carbon atom, or a combination thereof. Phrases containing this term, such as "C1-C6 alkyl," refer to alkyl groups containing 1 to 6 carbon atoms, and each occurrence can independently be C1 alkyl, C2 alkyl, C3 alkyl, C4 alkyl, C5 alkyl, or C6 alkyl. Suitable examples include, but are not limited to: methyl (Me, -CH3), ethyl (Et, -CH2CH3), 1-propyl (n-Pr, n-propyl, -CH2CH2CH3), 2-propyl (i-Pr, i-propyl, -CH(CH3)2), 1-butyl (n-Bu, n-butyl, -CH2CH2CH2CH3), 2-methyl-1-propyl (i-Bu, i-butyl, -CH2CH(CH3)2), 2-butyl (s-Bu, s-butyl, -CH(CH3)CH 2CH3), 2-methyl-2-propyl (t-Bu, t-butyl, -C(CH3)3), 1-pentyl (n-pentyl, -CH2CH2CH2CH2CH3), 2-pentyl (-CH(CH3)CH2CH2CH3), 3-pentyl (-CH(CH2CH3)2), 2-methyl-2-butyl (-C(CH3)2CH2CH3), 3-methyl-2-butyl (-CH(CH3)CH(CH3)2), 3-methyl-1-butyl (-CH2CH2CH(C H3)2), 2-methyl-1-butyl (-CH2CH(CH3)CH2CH3), 1-hexyl (-CH2CH2CH2CH2CH2CH3), 2-hexyl (-CH(CH3)CH2CH2CH2CH3), 3-hexyl (-CH(CH2CH3)(CH2CH2CH3)), 2-methyl-2-pentyl (-C(CH3)2CH2CH2CH3), 3-methyl-2-pentyl (-CH(CH3)CH(CH3)CH2CH3), 4- Methyl-2-pentyl (-CH(CH3)CH2CH(CH3)2), 3-methyl-3-pentyl (-C(CH3)(CH2CH3)2), 2-methyl-3-pentyl (-CH(CH2CH3)CH(CH3)2), 2,3-dimethyl-2-butyl (-C(CH3)2CH(CH3)2), 3,3-dimethyl-2-butyl (-CH(CH3)C(CH3)3). Understandably, "alkylene" refers to a subunit derived from "alkyl" by removing one hydrogen atom.

[0076] In this application, "aryl" refers to an aromatic hydrocarbon group derived from an aromatic ring compound by removing one hydrogen atom. It can be a monocyclic aryl, a fused-ring aryl, or a polycyclic aryl. For polycyclic rings, at least one is an aromatic ring system. For example, "C6-C30 aryl" refers to an aryl group containing 6 to 30 carbon atoms, and each occurrence can be independently C6, C7, C8, C9, C10, C15, C20, C25, or C30 aryl. Suitable examples include, but are not limited to, benzene, biphenyl, naphthalene, anthracene, phenanthrene, dinaphthalene, triphenylene, and their derivatives.

[0077] In this application, "arylamino group" refers to a group obtained by substituting an amino group onto an "aryl" group. Without limitation, one, two, or three "aryl" groups can be linked by one amino group. Suitable examples include, but are not limited to, triphenylamino group.

[0078] In this application, "heteroaryl" refers to an aryl group in which at least one carbon atom is replaced by a non-carbon atom, which can be an N atom, an O atom, an S atom, etc. For example, "C3~C30 heteroaryl" refers to a heteroaryl group containing 3 to 30 carbon atoms, and each occurrence can be independently C3 heteroaryl, C4 heteroaryl, C5 heteroaryl, C6 heteroaryl, C7 heteroaryl, C8 heteroaryl, C9 heteroaryl, C10 heteroaryl, C15 heteroaryl, C20 heteroaryl, C25 heteroaryl, and C30 heteroaryl. Suitable examples include, but are not limited to: furanyl, benzofuranyl, thiophenyl, benzothiophenyl, pyrroleyl, pyrazolyl, triazolyl, imidazoyl, oxazolyl, oxadiazolyl, thiazoyl, tetrazolyl, indolyl, carbazoyl, pyrroloimidazoyl, pyrrolopyrroleyl, thiophenolopyrroleyl, thiophenolothiophenyl, furanolopyrroleyl, furanolofuranyl, thiophenolofuranyl, benzoisooxazolyl, benzoisothiazoyl, benzoimidazoyl, pyridinyl, pyrazinyl, pyrimidinyl, triazinyl, quinolinyl, isoquinolinyl, o-diazanaphthyl, quinoxalinyl, phenanthridine, primidinyl, quinazolinyl, and quinazolinoneyl.

[0079] In this application, when no linking site is specified in the group, it means that any linkable site in the group is selected as the linking site.

[0080] In this application, the single bonds connecting the substituents extend through the corresponding ring, indicating that the substituent can be connected to any optional position on the ring.

[0081] In this application, when the same substituent, such as R, appears multiple times, each R can be independently selected from different groups.

[0082] In this application, "substituted or unsubstituted" means that the defined group may or may not be substituted. When the defined group is substituted, it should be understood that it may be substituted by a group acceptable in the art, including but not limited to: C1-C30 alkyl, C1-C30 alkoxy, heterocyclic group containing 3-20 cyclic atoms, aryl group containing 5-20 cyclic atoms, heteroaryl group containing 5-20 cyclic atoms, and one or more combinations of halogens. Further, substituents include but are not limited to: C1-C10 alkyl, C1-C10 alkoxy, heterocyclic group containing 3-15 cyclic atoms, aryl group containing 5-15 cyclic atoms, heteroaryl group containing 5-15 cyclic atoms, and one or more combinations of halogens.

[0083] Solar cells, also known as photovoltaic cells, are devices that directly convert light energy into electrical energy through the photoelectric effect or photochemical effect. Perovskite solar cells are solar cells that utilize perovskite material as the light-absorbing material. The photoelectric conversion principle of perovskite solar cells is as follows: Incident light (e.g., sunlight) enters the device and reaches the perovskite light-absorbing layer, where it is absorbed. Under the excitation of the incident light, the perovskite light-absorbing layer generates electron-hole pairs. Under the action of an electric field, the holes and electrons separate, with electrons transferring to one electrode and holes transferring to the other. Subsequently, a circuit is formed through an external circuit, which can be used to drive a load.

[0084] Compared with other solar cells, solar cells employing perovskite light-absorbing layers have higher theoretical photoelectric conversion efficiency. For perovskite light-absorbing layer solar cells, self-assembled monolayers (SAMs) are typically placed on the lower surface of the perovskite layer as hole transport layers to passivate the lower surface and extract and transport holes. However, in practical applications, their photoelectric performance remains relatively low. This study found that this is because the poor uniformity of the self-assembled monolayers leads to problems such as leakage current and non-radiative recombination, thus hindering the improvement of the photoelectric performance and stability of the solar cell.

[0085] Based on this, one embodiment of this application provides a solar cell, including a first electrode layer, a hole transport layer, a light-absorbing layer, and a second electrode layer. The light-absorbing layer is located between the first electrode layer and the second electrode layer, and the hole transport layer is located between the first electrode layer and the light-absorbing layer. The hole transport layer includes a mixture of thiophene compounds and self-assembled monomolecule compounds. The thiophene compounds include at least one of compound (1) and an oxygen-containing salt of compound (1). The compound (1) includes a thiophene parent ring Ar1 and an oxygen-containing group R1 connected to the thiophene parent ring. The thiophene parent ring Ar1 includes at least one thiophene group.

[0086] Understandably, the self-assembled monomolecular compound includes a head group Ar2, an anchoring group R2, and a linking group L connecting the head group Ar2 and the anchoring group R2. The self-assembled monomolecular compound can be anchored on the substrate through the anchoring group R2, thereby exhibiting good self-assembly film-forming properties.

[0087] Understandably, the oxygen-containing salt-forming compound of compound (1) refers to the salt-forming compound formed by compound (1) with a cation through its oxygen-containing group R1, wherein the cation includes, but is not limited to, metal cations and organic cations. For example, the metal cation can be one or more of sodium ions and potassium ions, and the organic cation can be ammonium ions.

[0088] The aforementioned solar cell of this application comprises a hole transport layer consisting of a mixture of thiophene compounds and self-assembled monomolecule compounds. Both compounds exhibit excellent hole transport performance. Furthermore, the oxygen-containing group R1 in the thiophene compound can act as an interface linker, thereby forming a hole transport layer together with the self-assembled monomolecule compound. This improves the uniformity of the hole transport layer and reduces problems such as leakage current and non-radiative recombination. In addition, the sulfur-containing thiophene group and the oxygen-containing group R1 in the thiophene compound can passivate the perovskite light-absorbing layer, thereby reducing defects such as pinhole traps in the perovskite light-absorbing layer, optimizing the film quality of the perovskite light-absorbing layer, and thus improving the photoelectric performance and stability of the solar cell.

[0089] In some embodiments, the perovskite light-absorbing layer is formed on the hole transport layer. Because the uniformity of the hole transport layer is improved, the film uniformity of the perovskite light-absorbing layer formed on the hole transport layer is also improved, which is beneficial for forming a more uniform perovskite light-absorbing layer, thereby improving the photoelectric performance and stability of the solar cell.

[0090] In some embodiments, the thiophene parent ring Ar1 is a thiophene group or a thiophene-containing fused ring group. A thiophene-containing fused ring group refers to a fused ring containing a thiophene group.

[0091] Further, the thiophene-containing fused-ring group comprises a plurality of thiophene-formed fused-ring groups or a fused-ring group formed by at least one thiophene group and at least one six-membered aryl group. The six-membered aryl group includes, but is not limited to, one or more of a benzene ring and a six-membered heteroaromatic ring, wherein the six-membered heteroaromatic ring contains one or more heteroatoms, which may be N or S, for example, 1 to 3 heteroatoms, such as a pyridyl group. As an example, the six-membered aryl group comprises one or more of substituted or unsubstituted phenyl groups and substituted or unsubstituted pyridine groups.

[0092] The number of thiophenes in the fused ring groups formed by multiple thiophenes can be any integer from 2 to 10. Furthermore, the fused ring groups formed by multiple thiophenes include 2 to 4 thiophene fused rings.

[0093] Wherein, at least one thiophene group and at least one six-membered aryl group form a fused ring group, wherein the number of thiophene groups can also be any integer from 2 to 4, and the number of six-membered aryl groups can also be any integer from 2 to 4.

[0094] Furthermore, the fused ring group formed by at least one thiophene group and at least one six-membered aryl group includes one or more of benzothiophene, dibenzothiophene, benzothiophene-benzothiophene.

[0095] In some embodiments, the oxygen-containing group R1 includes one or more of an oxyacid group and a hydroxyl group; optionally, the oxyacid group includes one or more of a phosphonic acid group -PO(OH)2, a phosphonic acid group -POR3(OH), a sulfonic acid group -SO3H, a sulfinic acid group -SO2H, a carboxylic acid group -COOH, a boric acid group, and a silicate group.

[0096] Understandably, the oxygen-containing salt of compound (1) can be the salt of compound (1) with an oxyacid group.

[0097] Furthermore, the oxygen-containing group R1 includes an oxyacid group. Further, the oxygen-containing group R1 includes one or more of a phosphonic acid group, a hypophosphonic acid group, and a carboxylic acid group, which is more conducive to the bonding between the thiophene compound and the first electrode layer. Optionally, the oxygen-containing group R1 includes a carboxylic acid group -COOH, which can effectively enhance the interaction with the perovskite light-absorbing layer, resulting in better photoelectric performance and stability.

[0098] Furthermore, the silica group can be -Si(R3)2OH or -SiR3(OH)2.

[0099] R3 in the phosphonic acid group and silicic acid group includes, but is not limited to: C1~C30 alkyl, heterocyclic group containing 3-20 cyclic atoms, aryl group containing 5-20 cyclic atoms, heteroaryl group containing 5-20 cyclic atoms, and one or more combinations of halogens.

[0100] Furthermore, the number of oxygen-containing groups R1 in the thiophene compound can be one or more, for example, 1 to 10, more specifically 2 to 10. Optionally, the number of oxygen-containing groups R1 in the thiophene compound can be multiple, for example, at least two. The two oxygen-containing groups R1 are respectively connected to two interfaces of the hole transport layer, for example, one is connected to the first electrode layer, and the other is connected to the perovskite light-absorbing layer and plays a passivation role. In this way, while improving the uniformity of the hole transport layer, the perovskite light-absorbing layer can also be passivated, effectively improving the photoelectric performance and stability of the solar cell.

[0101] Furthermore, when multiple oxygen-containing groups R1 are attached to a thiophene-containing fused-ring group, the multiple oxygen-containing groups R1 are attached to the rings at the ends of the thiophene-containing fused-ring group. Furthermore, when multiple oxygen-containing groups R1 are attached to a thiophene-containing fused-ring group, at least one oxygen-containing group R1 is attached to each of the rings at both ends of the thiophene-containing fused-ring group. This not only provides less steric hindrance but also facilitates the thiophene compound's interfacial connection with the hole transport layer.

[0102] In some embodiments, R1 is directly connected to Ar1. The thiophene compound formed by direct connection has a denser electron cloud, better stability, and its energy level can better match the perovskite layer.

[0103] In some embodiments, the structure of compound (1) is as follows:

[0104]

[0105] Equation (1),

[0106] Where m is an integer from 1 to 4. Ar1 and R1 are defined as described above, representing the thiophene parent ring and the oxygen-containing group attached to the thiophene parent ring, respectively. The number of R1 is m, which can be 1, 2, 3, or 4, for example, 2 to 4.

[0107] Furthermore, compound (1) has the structure shown in any of the formulas (1-1) to (1-10):

[0108] .

[0109] Furthermore, compound (1) has any of the structures shown in formulas (1-1a) to (1-10a) as follows:

[0110] .

[0111] In this thiophene compound containing two oxygen-containing groups R1, and with each oxygen-containing group R1 attached to a thiophene-containing fused-ring group, the two ends of the thiophene-containing fused-ring group each have an oxygen-containing group R1 attached to them. This not only provides less steric hindrance but also facilitates the thiophene compound's role in connecting with the two interfaces of the hole transport layer.

[0112] Furthermore, the thiophene compound has any of the structures shown in formulas (1-11a) to (1-101a):

[0113] .

[0114] Furthermore, the presence of the oxygen-containing group R1 at the aforementioned positions not only provides less steric hindrance, which is beneficial for thiophene compounds to exert their interfacial connection with the hole transport layer, but also influences the HOMO and effective face-to-face stacking of the compound. At the aforementioned positions, the compounds exhibit more matched energy levels, better hole mobility, and stability.

[0115] Understandably, the hole transport layer may contain one or more thiophene compounds as shown in the above structure.

[0116] As an example, the hole transport layer includes one or more of the thiophene compounds shown in formulas (11) to (15).

[0117]

[0118]

[0119] .

[0120] Among them, the Chinese name of the thiophene compound shown in formula (11) is thiopheno[3,2-b]thiopheno[2,2-d]thiophene dicarboxylic acid, and the Chinese name of the thiophene compound shown in formula (12) is benzene 3,7-dibenzothiophene dicarboxylic acid.

[0121] Optionally, the hole transport layer includes one or more thiophene compounds represented by formulas (11) to (12). The distribution position of S atoms in the compound affects the HOMO and effective face-to-face packing of the compound. The thiophene compounds represented by formulas (11) to (12) exhibit more matched energy levels, better hole mobility and stability.

[0122] Understandably, in a self-assembled monomolecular compound (SAM molecule), the anchoring group R2 serves to fix the self-assembled monomolecular compound to the surface of a substrate (such as the first electrode layer). The anchoring group R2 includes one or more of an oxyacid group and its salts, and a hydroxyl group; further, the oxyacid group includes one or more of a phosphonic acid group, a phosphonium hypophosphonic acid group, a sulfonic acid group, a sulfinic acid group, a carboxylic acid group, a boric acid group, and a silicate group. Without limitation, the anchoring group R2 includes one or more of a phosphonic acid group -PO(OH)2, a phosphonium hypophosphonic acid group -POR3(OH), a sulfonic acid group -SO3H, a sulfinic acid group -SO2H, a carboxylic acid group -COOH, a boric acid group, and a silicate group and their salts.

[0123] Understandably, the cations in salts containing oxyacid groups include, but are not limited to, metal cations and organic cations. For example, metal cations can be one or more of sodium ions and potassium ions, and organic cations can be ammonium ions.

[0124] Furthermore, R2 includes one or more of phosphonic acid groups, hypophosphonic acid groups, and carboxylic acid groups, which is more conducive to the bonding between the self-assembled monomolecular compound and the first electrode layer.

[0125] Understandably, the head group Ar2 is a functional group in the self-assembled single-molecule compound (SAM molecule). Specifically, the head group Ar2 in the self-assembled single-molecule compound (SAM molecule) includes substituted or unsubstituted C6-C30 aryl, substituted or unsubstituted C3-C30 heteroaryl, or substituted or unsubstituted C6-C30 aromatic amino groups. Without limitation, the C6-C30 aryl groups include substituted or unsubstituted phenyl, substituted or unsubstituted naphthyl, substituted or unsubstituted anthracene, substituted or unsubstituted phenanthryl, substituted or unsubstituted phenyl, or substituted or unsubstituted pyrene; the C3-C30 heteroaryl groups may include substituted or unsubstituted carbazole, substituted or unsubstituted dibenzocarbazole, substituted or unsubstituted dibenzopyridyl, or substituted or unsubstituted naphthalimide; and the C6-C30 aromatic amino groups include substituted or unsubstituted triphenylamino groups.

[0126] In some embodiments, the head group Ar2 comprises a substituted or unsubstituted C3-C30 heteroaryl group. The heteroatom in the heteroaryl group comprises one or more of N, O, and S, for example, at least N. Further, the linking group L can be linked to the anchoring group R2 via a heteroatom in the heteroaryl group.

[0127] Understandably, the linking group L is the linking group in the self-assembled monomolecular compound (SAM molecule), which mainly plays the role of spacer and support, connecting the anchoring group (R2) and the head group (Ar2) like a "bridge". Its length and structure affect the arrangement, density and overall performance of the self-assembled monomolecular compound.

[0128] In some embodiments, L includes a single bond, a substituted or unsubstituted C1-C10 alkylene group, a substituted or unsubstituted C2-C10 alkenyl group, a substituted or unsubstituted C5-C30 aryl group, or a substituted or unsubstituted heterocyclic aryl group. It is understood that when L is a single bond, it means that R2 and Ar2 are directly linked by a single bond.

[0129] Furthermore, in the presence of substitution, the C1-C10 alkylene substituents include any one of halogen groups, alkoxy groups, oxyacid groups, C6-C15 aromatic groups, and heteroaromatic groups with 5-15 cyclic atoms. By controlling the number of carbon atoms in L and its substituents, the steric hindrance of the self-assembled monomolecular compound can be reduced while its hydrophobicity can be improved, thereby further enhancing the photoelectric conversion efficiency and stability of the solar cell.

[0130] In some embodiments, L includes substituted or unsubstituted C1-C10 alkylene groups, and further includes C1-C5 alkylene groups.

[0131] In some embodiments, the self-assembled monomolecular compound comprises a structure having the structure shown in formula (2) below:

[0132] Equation (2),

[0133] Where n is an integer from 1 to 10; R S1 The group is a substituent, including one or more of the following: C1-C30 alkyl, C1-C30 alkoxy, heterocyclic group containing 3-20 cyclic atoms, aryl group containing 5-20 cyclic atoms, heteroaryl group containing 5-20 cyclic atoms, and halogen. Further, R S1 The functional groups include one or more of H, C1-C10 alkyl, C1-C10 alkoxy, heterocyclic groups containing 3-15 cyclic atoms, aryl groups containing 5-15 cyclic atoms, heteroaryl groups containing 5-15 cyclic atoms, and halogens. Properly controlling the n value can reduce steric hindrance and improve the photoelectric conversion efficiency and stability of the battery.

[0134] Furthermore, n is an integer from 1 to 5. Furthermore, R S1 The groups include one or more of C1-C10 alkyl and C1-C10 alkoxy groups.

[0135] As a non-limiting example, the self-assembled single-molecule compound includes one or more of MeO-2PACz, Me-2PACz, MeO-4PACz, or Me-4PACz.

[0136] MeO-2PACz's Chinese name is (2-(3,6-dimethoxy-9H-carbazole-9-yl)ethyl)phosphonic acid, and its structural formula is as follows:

[0137] .

[0138] Me-2PACz's Chinese name is 2-(3,6-dimethyl-9H-carbazole-9-yl)ethylphosphonic acid, and its structural formula is as follows:

[0139] .

[0140] MeO-4PACz's Chinese name is [4-(3,6-dimethoxy-9H-carbazole-9-yl)butyl]phosphonic acid, and its structural formula is as follows:

[0141] .

[0142] Me-4PACz's Chinese name is [4-(3,6-dimethyl-9H-carbazole-9-yl)butylphosphonic acid], and its structural formula is as follows:

[0143] .

[0144] In some embodiments, the mass content of self-assembled monomolecular compounds in the hole transport layer is greater than or equal to the mass content of thiophene compounds. This is because, compared to thiophene compounds, self-assembled monomolecular compounds have superior self-assembly and hole transport properties. Therefore, their application in solar cells can achieve higher open-circuit voltage, higher short-circuit current, and higher photoelectric conversion efficiency. Hence, the hole transport layer is dominated by self-assembled monomolecular compounds, with thiophene compounds playing a secondary role.

[0145] The qualitative and mass content of self-assembled monomolecular compounds and thiophene compounds in the hole transport layer can be obtained by detecting one or more of the following methods: nuclear magnetic resonance spectroscopy, infrared spectroscopy, and ultraviolet spectroscopy.

[0146] Further, the mass ratio of the self-assembled monomolecular compound to the thiophene compound is (1~10):1, optionally (2~5):1. As an example, the mass ratio of the self-assembled monomolecular compound to the thiophene compound is 1:1, 2:1, 3:1, 4:1, 5:1, 6:1, 7:1, 8:1, 9:1, 10:1, or any two of the above values ​​as endpoints. Controlling the mass ratio of the self-assembled monomolecular compound to the thiophene compound in the hole transport layer within the above range not only fully utilizes the excellent self-assembly and hole transport properties of the self-assembled monomolecular compound, but also allows the thiophene compound to work synergistically to improve the uniformity of the hole transport layer, thereby further enhancing the photoelectric performance and stability of the solar cell.

[0147] Understandably, the hole transport layer is a monolayer with a thickness on the nanometer scale. In some embodiments, the thickness of the hole transport layer is 0.01 nm to 5 nm. For example, it can be 0.01 nm, 0.05 nm, 0.08 nm, 0.1 nm, 0.5 nm, 0.8 nm, 1 nm, 2 nm, 3 nm, 4 nm, 5 nm, or any two of the above values ​​as endpoints.

[0148] Additionally, in some implementations, such as Figure 1 As shown, the solar cell 1 includes a first electrode layer 12, a hole transport layer 13, a perovskite light-absorbing layer 14, an electron transport layer 15, and a second electrode layer 16 stacked together. The hole transport layer 13 includes a mixture of the aforementioned thiophene compounds and self-assembled monomolecule compounds.

[0149] Without limitation, the hole transport layer 13 can be directly used as the hole transport layer of the perovskite solar cell, or other hole transport layers can be additionally provided between the first electrode layer 12 and the perovskite light-absorbing layer 14. Figure 1 (Not shown in the image). A hole transport layer, capable of extracting and transporting hole carriers, and blocking the passage of free electrons. Without limitation, other hole transport layers may include, but are 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), nickel oxide (NiO2). x Materials such as poly(3,4-ethylenedioxythiophene), polystyrene sulfonate (PEDOT:PSS), and WO3 can transport holes and block electrons.

[0150] In some embodiments, at least one of the first electrode layer and the second electrode layer is a transparent electrode for light incident. For example... Figure 1 As shown, in one example, the solar cell 1 also includes a substrate 11. A first electrode layer 12 is disposed on the substrate 11; furthermore, both the first electrode layer 12 and the substrate 11 are made of transparent material, and accordingly, the solar cell is a reverse pin cell. Understandably, in other examples, a second electrode layer 16 may also be disposed on the substrate, and accordingly, the solar cell is a conventional cell.

[0151] The transparent electrode can be a transparent conductive metal oxide electrode. Without limitation, the material of the transparent electrode can be, for example, one or more of the following: FTO (fluorine-doped tin oxide), ITO (tin-doped indium oxide), AZO (aluminum-doped zinc oxide), BZO (boron-doped zinc oxide), IZO (indium zinc oxide), IWO (tungsten-doped indium oxide), lanthanide-doped indium oxide, antimony-doped tin oxide, etc. It is understood that the transparent electrode can use glass as a substrate, or it can use a transparent flexible substrate. Specifically, the material of the transparent flexible substrate can be, for example, an organic polymer material, which can be a mixture of one or more of the following materials in different proportions: polyvinyl alcohol (PVA), polyester (PET), polyimide (PI), polyethylene naphthalate (PEN), and polydimethylsiloxane (PDMS).

[0152] In some embodiments, the second electrode layer comprises a conductive material. Further, the conductive material can be an organic conductive material, an inorganic conductive material, or a combination thereof. Non-limiting examples of inorganic conductive materials include metallic conductive materials. Further, metallic conductive materials can include any one of gold (Au), silver (Ag), copper (Cu), aluminum (Al), nickel (Ni), chromium (Cr), bismuth (Bi), platinum (Pt), magnesium (Mg), or any suitable mixture of the aforementioned elements. The conductive material can include a conductive oxide. Further, the conductive material can be a conductive oxide; non-limiting examples of conductive oxides can include one or more of FTO, ITO, IWO, AZO, etc.

[0153] In some embodiments, the crystal structure of the perovskite light-absorbing layer is ABX3 or A2CDX6. Here, A ions are monovalent cations, B ions are divalent metal cations, C ions are monovalent metal cations, D ions are trivalent metal cations, and X ions are monovalent anions.

[0154] Optionally, A ion is a monovalent cation with a large radius, including one or more organic cations and metal cations. More preferably, the organic cation includes organic amine ions, formamidinyl (HC(NH2)2) ions, etc. + FA + One or more of the following: ) and imidazole groups; more preferably, the metal cation includes lithium ions (Li ions) + Sodium ions (Na) + ), potassium ions (K) + ), rubidium ions (Rb + ), cesium ions (Cs) + One or more of the following. Further, the organic amine ion includes methylamine (CH3NH3). + MA + ), dimethyl diammonium ion (MDA) 2+ ), phenylethylammonium ion (PEA) + ), oleyl ammonium ions (OA) + ( ), one or more of ethylamino, propylamino, butylamino, pentamino, and hexamino.

[0155] Optionally, the B ion includes Pb. 2+ (lead ions), Sn 2+ (Tin ion), Be 2+ (beryllium ion), Mg 2+ (Magnesium ions), Ca 2+ (calcium ions), Sr 2+ (Strontium ion), Ba 2+ (Barium ions), Zn 2+ (Zinc ions), Ge 2+ (Germanium ions), Fe2+ (ferrous ion), Mn 2+ Co 2+ (Divalent cobalt ions), Cu 2+ (Divalent copper ions) and Ni 2+ One or more of (divalent nickel ions); more preferably, B ions include Pb. 2+ (Lead ions) and Sn 2+ One or two of (tin ions).

[0156] Optionally, the C ions include Cs + (cesium ion), Ag + (Silver ions), K + (Potassium ions) and Rb + One or more of (rubidium ions).

[0157] Optionally, the D ion includes Bi. 3+ (bismuth ion), Ni 3+ (trivalent nickel ions), Fe 3+ (Fe3+) and Cu 3+ One or more of (trivalent copper ions);

[0158] Optionally, the X ion includes one or more halogens or halogen-like ions, specifically including fluoride ions (F... - ), chloride ions (Cl) - ), bromide ions (Br) - ), iodide ions (I - ), cyanate ions (CN) - ), thiocyanate ions (SCN) - One or more of the following; optionally, X ions include Cl... - ,Br - and I - One or more of them. Further, X includes I. - ,Br - One or two of them. X can be I. - ,Br - Or combinations thereof. In some embodiments, X is I. - .

[0159] It is understandable that the perovskite material in the aforementioned perovskite light-absorbing layer can be selected from Cs. x1 FA 1-x1 PbX3, Cs x1 MA 1-x1 PbX3, Cs m FA n MA 1-m-n PbX3, CsPbX3, MAPbX3, FAPbX3, CsFAPbSnX3, Csx1 FA 1-x1 Pb x2 Sn 1-x2 X3, Cs m FA n MA 1-m- n Pb x2 Sn 1-x2 X3, Cs Pb x2 Sn 1-x2 X3, MAPb x2 Sn 1-x2 X3 and FAPb x2 Sn 1-x2 One or more of X3, where 0 < x1 < 1, 0 < x2 < 1, 0 < m < 1, and 0 < n < 1.

[0160] As examples, perovskite materials include CH8I3N2Pb (FAPbI3) and Cs. 0.05 (FA 0.83 MA 0.17 ) 0.95 Pb(I 0.83 Br 0.17 )3, CsPbBr3, CsPbI3, Cs 0.1 FA 0.9 PbI3 and MA 0.1 FA 0.9 One or more of PbI3.

[0161] In some embodiments, the electron transport layer functions to transport electrons generated by the excitation of the perovskite light-absorbing layer to an adjacent electrode and to prevent hole transport. The electron transport layer may include an electron transport material, which may include one or more of doped or undoped tin oxide, doped or undoped titanium oxide, doped or undoped zinc oxide, or doped or undoped organic molecular materials. The doping element may include one or more of Mg, Zn, Ag, Li, Rb, Ta, and Nb, for example, by doping with chlorides of the above elements. Specifically, the electron transport material may include [6,6]-phenylC 61 Methyl butyrate (PC) 61 BM), [6,6]-phenyl C 71 Methyl butyrate PC 71 BM, Fullerene C 60 Fullerene C 70 One or more of the following: tin dioxide (SnO2), zinc oxide (ZnO), etc.

[0162] Understandably, other film layers can be provided between the film layers of the aforementioned solar cell as needed. For example, optionally, a hole-blocking layer may be provided between the electrode layer and the electron transport layer of the aforementioned solar cell. The material of the hole-blocking layer may include, but is not limited to, BCP (2,9-dimethyl-4,7-diphenyl-1,10-phenanthroline). Alternatively, an electron-blocking layer may be provided between the electrode layer and the hole transport layer of the aforementioned solar cell.

[0163] In some embodiments, perovskite solar cells include single-junction cells and tandem cells. Tandem cells include double-junction cells, triple-junction cells, quadruple-junction cells, etc., which contain perovskite solar cells. Examples include perovskite-perovskite tandem cells and perovskite-crystalline silicon tandem cells.

[0164] Another embodiment of this application provides a method for fabricating a solar cell, which can be used to fabricate any of the solar cells described above. The method includes the following steps:

[0165] A first electrode layer, a hole transport layer, a light-absorbing layer, and a second electrode layer are formed in a stacked manner; wherein, the hole transport layer comprises the above-mentioned thiophene compounds and the above-mentioned self-assembled monomolecule compounds mixed together.

[0166] In some embodiments, forming the hole transport layer includes the following steps:

[0167] The thiophene compound and the self-assembled unimolecular compound are mixed in a solvent to prepare a mixed solution;

[0168] The mixed solution is applied to form a film, which is then annealed to form the hole transport layer.

[0169] The film formation method using solution self-assembly is simple, efficient, and cost-effective. The methods for applying the mixed solution to form the film include, but are not limited to, any one of spin coating, spraying, blade coating, and slot coating.

[0170] In some embodiments, the annealing conditions include a temperature of 90°C to 120°C and a time of 5 min to 30 min. Specifically, the temperature includes, but is not limited to, 90°C, 92°C, 950°C, 100°C, 103°C, 105°C, 107°C, 110°C, 103°C, 105°C, 107°C, 120°C, or any two of the foregoing; the time includes, but is not limited to, 5 min, 10 min, 15 min, 20 min, 25 min, 30 min, or any two of the foregoing.

[0171] In some embodiments, the solvent includes one or more of methanol, ethanol, dimethylformamide (DMF), and dimethyl sulfoxide (DMSO). The mass of the thiophene compound and the self-assembled unimolecular compound is as described above, and the concentration in the mixed solution, based on their total mass concentration, can be from 0.1 mg / mL to 5 mg / mL. Examples include 0.1 mg / mL, 0.5 mg / mL, 0.8 mg / mL, 1 mg / mL, 2 mg / mL, 3 mg / mL, 4 mg / mL, and 5 mg / mL, or any two of the above values ​​as endpoints.

[0172] In some examples, the material of the perovskite light-absorbing layer includes a perovskite-type metal halide with the chemical formula ABX3. The preparation method of the perovskite light-absorbing layer includes the following steps: mixing material A, BX2 and solvent to obtain a perovskite precursor solution; then coating the perovskite precursor solution onto the corresponding substrate and annealing to obtain the perovskite light-absorbing layer.

[0173] The aforementioned first electrode layer, hole transport layer, electron transport layer, and second electrode layer can be prepared using methods commonly used in the art, including but not limited to solution methods and solid deposition methods. Solution methods include any one of spin coating, spraying, blade coating, and slot coating. Solid deposition methods include any one of vacuum evaporation, sputtering deposition, plasma deposition, ion deposition, and atomic layer deposition (ALD).

[0174] In some embodiments, the step of forming the hole transport layer is performed on the first electrode layer. Correspondingly, a perovskite light-absorbing layer is formed on the hole transport layer. Because the uniformity of the hole transport layer is improved, the film uniformity of the perovskite light-absorbing layer formed on the hole transport layer is also improved, which is beneficial for forming a more uniform perovskite light-absorbing layer, thereby improving the photoelectric performance and stability of the solar cell.

[0175] One embodiment of this application provides the application of the above-described thiophene compounds and the above-described self-assembled monomolecular compounds in the preparation of hole transport layers.

[0176] Another embodiment of this application provides a hole transport layer comprising a mixture of the aforementioned thiophene compounds and the aforementioned self-assembled monomolecule compounds. Furthermore, this hole transport layer possesses the technical features and effects described above, which will not be repeated here.

[0177] Other embodiments of this application provide a photovoltaic module, including the solar cell as described above.

[0178] The aforementioned solar cells have high light conversion efficiency and good stability, which can improve the efficiency of photovoltaic modules.

[0179] The aforementioned photovoltaic module includes one or more of the aforementioned solar cells, which can be selected according to specific application scenarios; further, the aforementioned photovoltaic module includes multiple of the aforementioned solar cells, which are connected in series or parallel to form a solar cell. Further, the aforementioned photovoltaic module may also include tandem cells. Tandem cells include, but are not limited to, crystalline silicon / perovskite tandem cells, all-perovskite tandem cells, and thin-film / perovskite tandem cells such as copper indium gallium selenide (CIGS).

[0180] In some embodiments, the photovoltaic module further includes a photovoltaic glass layer, an adhesive layer, and a backsheet.

[0181] The solar cell has an adhesive layer on each of its two surfaces. A backsheet is provided on the surface of one adhesive layer away from the solar cell, and a photovoltaic glass layer is provided on the surface of the other adhesive layer away from the solar cell.

[0182] The photovoltaic glass layer and backsheet are used to protect the solar cells, and they have the functions of sealing, insulation and waterproofing; the adhesive layer plays the role of bonding the photovoltaic glass layer to the solar cells and bonding the backsheet to the solar cells.

[0183] Optionally, the photovoltaic glass layer is made of tempered glass, the backsheet is made of TPT (polyvinyl fluoride) or TPE (thermoplastic elastomer), and the adhesive layer is made of EVA (polyethylene-polyvinyl acetate copolymer).

[0184] Furthermore, the aforementioned photovoltaic modules also include junction boxes and outer frames.

[0185] Junction boxes are used to protect the entire photovoltaic module's power generation system. They are essentially a current transfer station. When a cell short-circuits, the junction box will automatically disconnect the short-circuited cell string.

[0186] The outer frame serves to support and protect the entire photovoltaic module. The frame can be made of aluminum alloy, which has excellent strength and corrosion resistance.

[0187] Furthermore, silicone is used to bond and seal the connections between the frame and other parts of the photovoltaic module. The photovoltaic module can convert solar energy into electrical energy, which can then be stored in batteries or used to power loads.

[0188] In some embodiments, the photovoltaic module is a solar panel.

[0189] According to one embodiment of this application, a photovoltaic system is also provided, including the photovoltaic module described above.

[0190] The photovoltaic system utilizes the photovoltaic effect of the solar cells in the aforementioned photovoltaic modules to directly convert solar radiation energy into electrical energy with high efficiency; furthermore, the aforementioned photovoltaic system is a photovoltaic power generation system.

[0191] Photovoltaic modules are the core component of a photovoltaic power generation system. The aforementioned photovoltaic system includes one or more photovoltaic modules, which can be selected according to specific application scenarios. Furthermore, when the aforementioned photovoltaic system includes multiple photovoltaic modules, the multiple photovoltaic modules form a photovoltaic array.

[0192] The aforementioned photovoltaic system can be a stand-alone photovoltaic power generation system or a grid-connected photovoltaic power generation system.

[0193] An independent photovoltaic (PV) power generation system includes a PV array, battery bank, charge controller, power electronic converter (inverter), and load. Its working principle is that solar radiation energy is first converted into electrical energy by the PV array, then converted by the power electronic converter to supply power to the load. Simultaneously, excess electrical energy is stored as chemical energy in an energy storage device after passing through the charge controller. Thus, when sunlight is insufficient, the energy stored in the battery can be converted into 220V AC, 50Hz electrical energy through the power electronic inverter, filter, and power frequency transformer to supply AC loads.

[0194] A grid-connected photovoltaic (PV) power generation system includes a photovoltaic array, a high-frequency DC / DC boost circuit, a power electronic converter (inverter), and system monitoring. Its working principle is that solar radiation energy is converted by the photovoltaic array, then converted into high-voltage DC by a high-frequency DC converter, and finally inverted by the power electronic inverter to output a sinusoidal alternating current to the grid that is in phase with the grid voltage.

[0195] The two photovoltaic power generation systems mentioned above each have their own characteristics and can be selected according to the specific application scenario.

[0196] Other embodiments of this application provide an electrical device, including a solar cell as described above or a photovoltaic module as described above.

[0197] Other embodiments of this application provide a power generation device, including a solar cell as described above or a photovoltaic module as described above.

[0198] In some embodiments, the perovskite solar cell described above can be a power generation device that functions as an electrical device. The type of power generation device may include, but is not limited to, integrated power generation. The location of the power generation device may include, but is not limited to, the roof of a vehicle, the back panel, etc.

[0199] Furthermore, the aforementioned electrical devices may include mobile devices, such as electric vehicles, electric trains, ships and satellites, power generation systems, etc., but are not limited to these.

[0200] As another implementation method, the power supply device can be a wearable device, such as a watch.

[0201] To make the technical problems, technical solutions, and beneficial effects solved by this application clearer, the application will be further described in detail below with reference to embodiments and accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. 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 in this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0202] Where specific techniques or conditions are not specified in the examples, they shall be performed in accordance with the techniques or conditions described in the literature in this field or in accordance with the product instructions. Reagents or instruments whose manufacturers are not specified are all commercially available conventional products.

[0203] I. Device Fabrication

[0204] Example 1

[0205] A method for fabricating a solar cell device is as follows:

[0206] 1) Fabrication of FTO conductive glass (including the first electrode layer with substrate): Dimensions: 2.0 × 2.0 cm 2 The FTO glass was subjected to laser etching to remove 0.35 cm of FTO from each end, exposing the glass substrate. The substrate was then ultrasonically cleaned sequentially with a 2% Triton X-100 deionized water solution, anhydrous ethanol solution, deionized water solution, and anhydrous ethanol solution. After cleaning and drying, the substrate was irradiated in a UV ozone generator for 30 minutes.

[0207] 2) Preparation of hole transport layer: A methanol solution of self-assembled monomolecular compound (Me-4PACz) and thieno[3,2-b]thieno[2,2-d]thienodicarboxylic acid (i.e., the thiophene compound shown in formula (11)) mixed at a mass ratio of 3:1 (wherein the total mass concentration of both is 0.5 mg / mL) was spin-coated onto an ITO substrate. After spin-coating at 5000 rpm for 30 s, the mixture was annealed at 100 °C for 15 min to obtain a monomolecular hole transport layer.

[0208] 3) Preparation of the perovskite light-absorbing layer: 8.5 mg MACl, 12 mg CsI, 130 mg FAI, 13 mg MAI, and 400 mg PbI2 were dissolved in 800 μL DMF and 200 μL DMSO and stirred for 30 minutes to obtain a perovskite precursor solution. Under a nitrogen atmosphere, the perovskite precursor solution was dropwise added onto a substrate containing a hole transport layer. The film was spin-coated at 1000 rpm for 10 seconds, then at 5000 rpm for 30 seconds, with 200 μL of chlorobenzene injected as an antisolvent during the spin-coating process. The resulting film was annealed at 150 °C for 10 minutes to obtain a perovskite film with a thickness of 600 nm. The perovskite material composition in the perovskite film was FA. 0.85 MA 0.1 Cs 0.05 PbI3.

[0209] 4) Preparation of the electron transport layer: Place the intermediate product obtained in step 3) into a vapor deposition apparatus and wait for the vapor deposition vacuum degree to reach 5*10 -4 A C60 layer with a thickness of 25 nm was deposited at a rate of 0.1 A / s below Pa, and then a SnO2 layer with a thickness of 20 nm was deposited on the C60 layer using ALD.

[0210] 5) Preparation of the metal counter electrode (second electrode layer): Place the thin film with the electron transport layer obtained in step 4) into a vapor deposition apparatus, and wait for the vapor deposition vacuum degree to reach 5*10 -4 A 100 nm thick Cu metal electrode is deposited at a rate of 0.2 A / s below Pa.

[0211] Example 2

[0212] Example 2 is basically the same as Example 1, except that the hole transport layer is prepared differently. Specifically, the type of thiophene compound used in Example 2 is different, and it is replaced by an equal mass of benzene 3,7-dibenzothiophene dicarboxylic acid (i.e., the thiophene compound shown in formula (12)).

[0213] Examples 3-9

[0214] It is basically the same as Example 2, with the differences shown in Table 1.

[0215] Comparative Example 1

[0216] It is basically the same as Example 1, except that the hole transport layer is prepared differently in 2). Specifically, the thiophene compound was omitted from the hole transport layer of Comparative Example 1 and replaced with an equal mass of self-assembled single-molecule compound (Me-4PACz).

[0217] Comparative Example 2

[0218] It is basically the same as Comparative Example 1, except that the hole transport layer is prepared differently in 2). Specifically, the thiophene compound was omitted from the hole transport layer of Comparative Example 2, and an equal mass of self-assembled single-molecule compound (MeO-2PACz) was used instead.

[0219] Comparative Example 3

[0220] It is basically the same as Example 1, except that the hole transport layer is prepared differently in 2). Specifically, the self-assembled monomolecular compound (Me-4PACz) was omitted from the hole transport layer in Comparative Example 3, and it was replaced by an equal mass of thieno[3,2-b]thieno[2,2-d]thienodicarboxylic acid.

[0221] Comparative Example 4

[0222] It is basically the same as Example 2, except that the preparation of the hole transport layer is different in 2). Specifically, the self-assembled monomolecular compound (Me-4PACz) was omitted in the hole transport layer of Comparative Example 4, and it was replaced by an equal mass of phenyl 3,7-dibenzothiophene dicarboxylic acid.

[0223] II. Scanning Electron Microscopy Testing

[0224] The surface of the perovskite light-absorbing layer in step 3) of Comparative Example 1 and Examples 1-2 was subjected to scanning electron microscopy (SEM) analysis. The obtained SEM images are shown below. Figure 2 , Figure 3 and Figure 4 As shown.

[0225] From this, we can see that, compared to Figure 2 , Figure 3 and Figure 4 The perovskite crystal particles in the perovskite light-absorbing layer shown are more uniform, indicating that the hole transport layer of Examples 1-2 can reduce defects such as pinhole traps in the perovskite light-absorbing layer compared to Comparative Example 1, thus optimizing the film quality of the perovskite light-absorbing layer.

[0226] III. Photoelectric Performance Testing

[0227] The photoelectric conversion efficiency (PCE) of the perovskite solar cells was tested at room temperature (25°C):

[0228] Using an AAA-grade solar simulator under standard test conditions: incident light power 100mW / cm² 2 The photoelectric performance parameters of the tested battery were measured using a spectral energy of AM1.5G, and the P values ​​were obtained. out P in V mpp J mpp V oc J sc Then, calculate the PCE based on the following formula:

[0229] PCE=P out / P in ;

[0230] =V oc ×J sc ×[(V mpp ×J mpp ) / (V oc ×J sc )] / P in ;

[0231] =V oc ×J sc ×FF / P in ;

[0232] Among them, P in P out V mpp J mpp V oc J sc FF represent: incident light power, operating output power of the battery under test, voltage at the maximum power point of the battery under test, current at the maximum power point of the battery under test, open circuit voltage, short circuit current, and fill factor, respectively.

[0233] The following table shows some parameters and performance results of the solar cells in each embodiment and comparative example. In the table, the mass ratio K represents the mass ratio of the self-assembled monomolecular compound and the thiophene compound in the hole transport layer.

[0234] Table 1

[0235]

[0236] As can be seen from the comparison of the examples and comparative examples in the table above, comparative examples 1 and 2 use a single self-assembled monomolecular compound, resulting in lower photoelectric conversion efficiency; comparative examples 3 and 4 use a single thiophene compound, and their photoelectric conversion efficiency is even lower than that of comparative example 1. The embodiments of this application, by using a mixture of self-assembled monomolecular compounds and thiophene compounds in the hole transport layer, can effectively improve the photoelectric conversion efficiency of solar cells.

[0237] As can be seen from Examples 2-5, the mass ratio of self-assembled monomolecular compounds and thiophene compounds in the hole transport layer of this application is (1-10):1, and the resulting solar cells all have good photoelectric conversion efficiency; further controlling the mass ratio within (2-5):1 results in even better photoelectric conversion efficiency.

[0238] As can be seen from Examples 1-2 and 6-9, the solar cells made of self-assembled monomolecular compounds and thiophene compounds shown in Formulas (11) to (15) in the hole transport layer of this application all have good photoelectric conversion efficiency; furthermore, the thiophene compounds shown in Formulas (11) to (12) have even better photoelectric conversion efficiency.

[0239] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0240] The embodiments described above are merely illustrative of several implementation methods of this application, and while the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the invention patent. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of this application, and these all fall within the protection scope of this application. Therefore, the protection scope of this patent application should be determined by the appended claims, and the specification and drawings can be used to interpret the scope of the claims.

Claims

1. A solar cell, characterized in that, The device includes a first electrode layer, a hole transport layer, a perovskite light-absorbing layer, and a second electrode layer. The perovskite light-absorbing layer is located between the first electrode layer and the second electrode layer. The hole transport layer is located between the first electrode layer and the perovskite light-absorbing layer. The hole transport layer includes a mixture of thiophene compounds and self-assembled monomolecule compounds. The thiophene compounds include at least one of compound (1) and an oxygen-containing salt of compound (1). Compound (1) includes a thiophene parent ring Ar1 and an oxygen-containing group R1 connected to the thiophene parent ring. The thiophene parent ring Ar1 includes at least one thiophene group.

2. The solar cell as described in claim 1, characterized in that, The thiophene parent ring Ar1 is a thiophene group or a thiophene-containing fused ring group.

3. The solar cell as described in claim 2, characterized in that, The thiophene-containing fused-ring group includes a plurality of fused-ring groups formed by thiophene or at least one thiophene group and at least one six-membered aryl group; Optionally, the six-membered aryl group includes one or more of a benzene ring and a six-membered heteroaromatic ring; Alternatively, the fused ring group formed by at least one thiophene group and at least one six-membered aryl group includes one or more of benzothiophene, dibenzothiophene, and benzothiophene-benzothiophene.

4. The solar cell according to any one of claims 1 to 3, characterized in that, The oxygen-containing group R1 includes one or more of an oxyacid group and a hydroxyl group; Optionally, the oxyacid group includes one or more of the following: phosphonic acid group, phosphonic acid group, sulfonic acid group, sulfinic acid group, carboxylic acid group, boric acid group, and silicate group.

5. The solar cell according to any one of claims 1 to 4, characterized in that, The compound (1) has the structure shown in formula (1): Equation (1), Where m is an integer from 1 to 4.

6. The solar cell according to any one of claims 1 to 5, characterized in that, The compound (1) has the structure shown in any of the following formulas (1-1) to (1-10): 。 7. The solar cell as claimed in claim 6, characterized in that, The compound (1) has the structure shown in any of the following formulas (1-1a) to (1-10a): 。 8. The solar cell as claimed in claim 7, characterized in that, The compound (1) has any of the structures shown in formulas (1-11a) to (1-101a): 。 9. The solar cell according to claim 1, characterized in that, The hole transport layer comprises one or more of the thiophene compounds shown in formulas (11) to (15): 。 10. The solar cell according to any one of claims 1 to 9, characterized in that, The self-assembled monomolecule compound includes a head group Ar2, an anchoring group R2, and a linking group L connecting the head group Ar2 and the anchoring group R2; The self-assembled monomolecule compound has one or more of the following characteristics: (1) The head group Ar2 includes substituted or unsubstituted C6~C30 aryl, substituted or unsubstituted C3~C30 heteroaryl or substituted or unsubstituted C6~C30 aromatic amino groups; (2) The linking group L includes a single bond, a substituted or unsubstituted C1~C10 alkylene group, a substituted or unsubstituted C2~C10 alkenyl group, a substituted or unsubstituted C5~C30 aryl group, or a substituted or unsubstituted heterocyclic aryl group; (3) The anchoring group R2 includes one or more of the following: an oxyacid group and its salt, and a hydroxyl group; Optionally, the oxyacid group includes one or more of the following: phosphonic acid group, phosphonic acid group, sulfonic acid group, sulfinic acid group, carboxylic acid group, boric acid group, and silicate group.

11. The solar cell as claimed in claim 10, characterized in that, It has one or more of the following characteristics: (1) In the head group Ar2, the C6~C30 aryl group includes substituted or unsubstituted phenyl, substituted or unsubstituted naphthyl, substituted or unsubstituted anthraquinone, substituted or unsubstituted phenanthyl, substituted or unsubstituted alkyl or substituted or unsubstituted pyrene; (2) In the head group Ar2, the C3~C30 heteroaryl groups include substituted or unsubstituted carbazole group, substituted or unsubstituted dibenzocarbazole group, substituted or unsubstituted dibenzopyridinyl group or substituted or unsubstituted naphthalimide group; (3) In the head group Ar2, the C6~C30 aromatic amino groups include substituted or unsubstituted triphenylamine groups; (4) The anchoring group R2 includes one or more of the following: phosphonic acid group, phosphonic acid group, sulfonic acid group, sulfinic acid group, carboxylic acid group, boric acid group and silicate group.

12. The solar cell according to any one of claims 1 to 11, characterized in that, The self-assembled monomolecular compound includes the structure shown in formula (2): Equation (2), Where n is an integer from 1 to 10; R S1 The groups include one or more of H, C1-C30 alkyl, C1-C30 alkoxy, heterocyclic groups containing 3-20 cyclic atoms, aryl groups containing 5-20 cyclic atoms, heteroaryl groups containing 5-20 cyclic atoms, and halogens.

13. The solar cell according to any one of claims 1 to 12, characterized in that, The self-assembled monomolecular compound includes one or more of MeO-2PACz, Me-2PACz, MeO-4PACz, or Me-4PACz.

14. The solar cell according to any one of claims 1 to 13, characterized in that, In the hole transport layer, the mass content of the self-assembled monomolecular compound is greater than or equal to the mass content of the thiophene compound.

15. The solar cell as claimed in claim 14, characterized in that, In the hole transport layer, the mass ratio of the self-assembled monomolecular compound to the thiophene compound is (1~10):

1.

16. A method for preparing a solar cell, characterized in that, Includes the following steps: A first electrode layer, a hole transport layer, a perovskite light-absorbing layer, and a second electrode layer are formed in a stacked configuration. The hole transport layer comprises a mixture of thiophene compounds and self-assembled monomolecules. The thiophene compounds include at least one of compound (1) and an oxygen-containing salt of compound (1). Compound (1) comprises a thiophene parent ring Ar1 and an oxygen-containing group R1 connected to the thiophene parent ring. The thiophene parent ring Ar1 comprises at least one thiophene group.

17. The preparation method according to claim 16, characterized in that, Forming the hole transport layer includes the following steps: The thiophene compound and the self-assembled unimolecular compound are mixed in a solvent to prepare a mixed solution; The mixed solution is applied to form a film, which is then annealed to form the hole transport layer.

18. The preparation method according to claim 16, characterized in that, The solar cell is the solar cell as described in any one of claims 2 to 15.

19. A hole transport layer, characterized in that, The hole transport layer comprises a mixture of thiophene compounds and self-assembled monomolecule compounds. The thiophene compounds include at least one of compound (1) and an oxygen-containing salt of compound (1). Compound (1) includes a thiophene parent ring Ar1 and an oxygen-containing group R1 connected to the thiophene parent ring. The thiophene parent ring Ar1 includes at least one thiophene group.

20. The hole transport layer as described in claim 19, characterized in that, The hole transport layer is the hole transport layer as described in any one of claims 2 to 15.

21. A photovoltaic module, characterized in that, This includes the solar cell according to any one of claims 1 to 15 or the solar cell prepared by the preparation method according to any one of claims 16 to 18.

22. An electrical appliance, characterized in that, This includes the solar cell according to any one of claims 1 to 15, the solar cell prepared by the preparation method according to any one of claims 16 to 18, or the photovoltaic module according to claim 21.

23. A power generation device, characterized in that, This includes the solar cell according to any one of claims 1 to 15, the solar cell prepared by the preparation method according to any one of claims 16 to 18, or the photovoltaic module according to claim 21.

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