Hole transport layer, solar cell, photovoltaic module, photovoltaic system

Abstract

This application relates to a hole transport layer, a solar cell, a photovoltaic module, and a photovoltaic system. The hole transport layer includes: a hole transport polymer; and a coordination polymer, which is intertwined with the hole transport polymer to form a self-assembled mixed-phase structure. The hole transport layer provided in this application, on the one hand, allows the structural units of the coordination polymer to capture metal ions at the interface of the perovskite layer, improving the surface wettability of the perovskite solution in the hole transport layer and enhancing the crystallinity of the perovskite film, thereby improving the photoelectric conversion efficiency of the solar cell; on the other hand, the self-assembled mixed-phase structure formed by the intertwining of the coordination polymer and the hole transport polymer achieves lattice contact with the perovskite layer at the hole transport layer / perovskite layer interface, reducing the direct contact area between the hole transport layer and the perovskite layer, thereby reducing non-radiative recombination losses of charge carriers caused by contact and improving the device performance of the solar cell.

Description

Technical Field

[0001] This application relates to the field of photovoltaic cell technology, and in particular to a hole transport layer, a solar cell, a photovoltaic module, and a photovoltaic system. Background Technology

[0002] Perovskite solar cells have attracted widespread attention due to their numerous advantages, including long carrier diffusion lengths, high absorption coefficients, tunable band gaps, compatibility with various fabrication methods, and simple fabrication processes. The hole transport layer, as a crucial component, extracts holes generated in the perovskite layer and transports them to the electrodes. Therefore, the energy levels of the hole transport material need to match the energy levels of both the perovskite layer and the electrodes to efficiently extract and transport holes while simultaneously blocking electrons to suppress recombination. In inverted (pin-type) perovskite solar cells, the hole transport layer also serves as the growth substrate for the perovskite thin film, significantly influencing its quality. The contact and energy level matching at the hole transport layer / perovskite interface largely determine the performance of the perovskite solar cell.

[0003] Hole transport polymer materials are expected to achieve better device performance due to their ability to achieve good energy level matching with perovskites. However, the hole transport layer formed by the hole transport polymer material has poor wettability to the perovskite precursor solution, resulting in the following problems: (1) It affects the crystallization and surface morphology of the perovskite film, leading to poor device repeatability; (2) Poor electrical contact between the hole transport layer and the perovskite layer will trigger additional nonradiative recombination of charge carriers, thereby limiting the performance of the device; (3) For pin-type perovskite solar cells, when using the one-step method to form a large area of ​​perovskite film, the wet perovskite film cannot extend on its surface, the bonding force between the perovskite film and the substrate is poor, and the roughness of the upper and lower surfaces of the perovskite film is large, resulting in a low perovskite film process yield. Summary of the Invention

[0004] Based on this, it is necessary to provide a hole transport layer, a solar cell, a photovoltaic module, and a photovoltaic system that improves the surface wettability of the perovskite solution in the hole transport layer, thereby improving the crystallinity of the perovskite film, improving the electrical contact between the hole transport layer and the perovskite layer, and thus improving the photoelectric conversion efficiency of the solar cell; in inverted solar cells, it improves the surface ductility of the perovskite film, thereby improving the process yield of the perovskite film.

[0005] A first aspect of this application provides a hole transport layer comprising: a hole transport polymer; and a coordination polymer intertwined with the hole transport polymer to form a self-assembled mixed-phase structure, wherein the coordination polymer has at least one of the structural units shown in formulas (I) to (VIII):

[0006] Equation (I), Formula (II)

[0007] Formula (Ⅲ), Formula (Ⅳ)

[0008] Formula (V) Formula (VI),

[0009] Formula (VII) Formula (VIII).

[0010] In some embodiments, the coordination polymer is an ionic polymer.

[0011] In some embodiments, the coordination polymer has phosphate or ammonium ions.

[0012] In some implementations, the mass ratio of hole transport polymer to coordination polymer is (9:1) to (3:7).

[0013] In some embodiments, the coordination polymer is selected from one or more of polyhexamethylene guanidine phosphate, polyaminopropyl biguanide, polyvinylpyridine, polylactic acid, polyaspartic acid, polyurea, polythiourea, and ammonium polyphosphate.

[0014] A second aspect of this application provides a solar cell comprising a hole transport layer and a perovskite layer as described in the first aspect, wherein the perovskite layer is disposed on the hole transport layer.

[0015] In some implementations, the self-assembled mixed-phase structure forms a lattice contact structure at the interface between the hole transport layer and the perovskite layer.

[0016] In some embodiments, the solar cell is an inverted solar cell, and the solar cell also includes a substrate, on which a hole transport layer is disposed.

[0017] A third aspect of this application provides a photovoltaic module, which includes the hole transport layer provided in the first aspect or the solar cell provided in the second aspect.

[0018] The fourth aspect of this application provides a photovoltaic system comprising the photovoltaic modules provided in the third aspect above.

[0019] Compared with traditional technologies, this application has at least the following beneficial effects:

[0020] The hole transport layer provided in this application utilizes a coordination polymer with multiple structural units capable of chelating metal cations. On one hand, the structural units of the coordination polymer trap metal ions (such as lead and tin ions) within the perovskite layer at the interface near the perovskite layer, improving the surface wettability of the perovskite solution in the hole transport layer and thus enhancing the uniformity of perovskite film formation. Simultaneously, due to the coordination effect, the defect state density at the perovskite interface is reduced, thereby improving the photoelectric conversion efficiency of the solar cell. On the other hand, the self-assembled mixed-phase structure formed by the intertwining of the coordination polymer and the hole transport polymer achieves a lattice contact structure with the perovskite layer at the interface between the hole transport layer and the perovskite layer, reducing the direct contact area between the hole transport layer and the perovskite layer. This reduces non-radiative recombination losses of charge carriers caused by contact and improves the device performance of the solar cell.

[0021] Furthermore, for inverted solar cells, when using a one-step large-area perovskite film deposition method, the improved surface wettability of the perovskite solution in the hole transport layer facilitates the surface extension of the perovskite film on the hole transport layer, thereby improving the process yield of the perovskite film. Attached Figure Description

[0022] Figure 1 This is a schematic diagram of the structure of a solar cell in one embodiment of this application.

[0023] 1. Solar cells;

[0024] 10. Base;

[0025] 20. Hole transport layer; 21. Hole transport polymer; 22. Coordination polymer;

[0026] 30. Perovskite layer;

[0027] 40. Electron transport layer;

[0028] 50. Electrode layer. Detailed Implementation

[0029] Reference will now be made to detailed embodiments of this application, one or more of which are described below. Each example is provided for explanation and not for limitation of this application. In fact, it will be apparent to those skilled in the art that various modifications and variations can be made to this application without departing from its scope or spirit. For example, features described or illustrated as part of one embodiment may be used in another embodiment to produce further embodiments.

[0030] Therefore, this application is intended to cover such modifications and variations falling within the scope of the appended claims and their equivalents. Other objects, features, and aspects of this application are disclosed in or will be apparent from the following detailed description. It will be understood by those skilled in the art that this discussion is merely a description of exemplary embodiments and is not intended to limit the broader aspects of this application.

[0031] In this application, the technical features described in an open-ended manner include both closed technical solutions consisting of the listed features and open technical solutions that include the listed features.

[0032] In this application, numerical ranges are referred to as continuous unless otherwise specified, and include the minimum and maximum values ​​of the range, as well as every value between the minimum and maximum values. Furthermore, when the range refers to integers, it includes every integer between the minimum and maximum values ​​of the range. Additionally, when multiple ranges are provided to describe a feature or characteristic, the ranges may be merged. In other words, unless otherwise specified, all ranges disclosed herein should be understood to include any and all subranges to which they are incorporated.

[0033] Unless otherwise specified, all embodiments and optional embodiments of this application can be combined to form new technical solutions.

[0034] Unless otherwise specified, all technical features and optional technical features of this application may be combined to form new technical solutions.

[0035] Unless otherwise specified, all steps of this application may be performed sequentially or randomly, preferably sequentially. For example, the method includes steps (a) and (b), indicating that the method may include steps (a) and (b) performed sequentially, or it may include steps (b) and (a) performed sequentially. For example, the mention that the method may also include step (c) indicates that step (c) may 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.

[0036] Unless otherwise specified, the terms "comprising" and "including" as used in this application can be open-ended or closed-ended. For example, "comprising" and "including" can mean that other components not listed may also be included, or that only the listed components may be included.

[0037] Unless otherwise specified, the term "or" is inclusive in this application. For example, the phrase "A or B" means "A, B, or both A and B". More specifically, the condition "A or B" is satisfied by any of the following conditions: A is true (or exists) and B is false (or does not exist); A is false (or does not exist) and B is true (or exists); or both A and B are true (or exist).

[0038] Terminology Explanation:

[0039] Unless otherwise stated or in case of contradiction, the terms or phrases used herein shall have the following meanings:

[0040] "Alkylene" refers to a hydrocarbon group derived from an alkyl group by removing one hydrogen atom, forming a group with two monovalent groups at its center. This can be a saturated branched alkyl group or a saturated straight-chain alkyl group. Suitable examples include, but are not limited to: methylene (-CH2-), 1,1-ethyl (-CH(CH3)-), 1,2-ethyl (-CH2CH2-), 1,1-propyl (-CH(CH2CH3)-), 1,2-propyl (-CH2CH(CH3)-), 1,3-propyl (-CH2CH2CH2-), and 1,4-butyl (-CH2CH2CH2CH2-).

[0041] "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 compounds, at least one must be an aromatic ring system. Suitable examples include, but are not limited to: benzene, biphenyl, naphthalene, anthracene, phenanthrene, dinaphthalene, triphenylene and their derivatives.

[0042] "Amino" refers to a derivative of ammonia, possessing the structural characteristic of the formula -N(X)2, where each "X" is independently H, a substituted or unsubstituted alkyl group, a substituted or unsubstituted cycloalkyl group, a substituted or unsubstituted heterocyclic group, etc. Non-limiting types of amino groups include -NH2, -N(alkyl)2, -NH(alkyl), -N(cycloalkyl)2, -NH(cycloalkyl), -N(heterocyclic)2, -NH(heterocyclic), -N(aryl)2, -NH(aryl), -N(alkyl)(aryl), -N(alkyl)(heterocyclic), -N(cycloalkyl)(heterocyclic), -N(aryl)(heteroaryl), -N(alkyl)(heteroaryl), etc.

[0043] "Alkyl" refers to a saturated hydrocarbon containing a primary (positive) carbon atom, or a secondary carbon atom, or a tertiary carbon atom, or a quaternary carbon atom, or a combination thereof. 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(C H3)CH2CH3), 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(CH3)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 and octyl (-(CH2)7CH3).

[0044] "Alkoxy" refers to a group having an -O-alkyl group, i.e., an alkyl group as defined above that is attached to the parent nucleus via an oxygen atom. Suitable examples include, but are not limited to: methoxy (-O-CH3 or -OMe), ethoxy (-O-CH2CH3 or -OEt), and tert-butoxy (-OC(CH3)3 or -OtBu).

[0045] "Cycloalkyl" refers to a non-aromatic hydrocarbon containing a ring of carbon atoms, and can be monocycloalkyl, spirocycloalkyl, or bridged cycloalkyl. Suitable examples include, but are not limited to, cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, and cycloheptyl. Additionally, "cycloalkyl" may contain one or more double bonds; representative examples of cycloalkyl compounds containing double bonds include cyclopentenyl, cyclohexenyl, cyclohexadienyl, and cyclobutadienyl.

[0046] "Heterocyclic group" refers to a cycloalkyl group in which at least one carbon atom is replaced by a non-carbon atom. The non-carbon atom can be a nitrogen atom, an oxygen atom, a sulfur atom, etc., and can be a saturated ring or a partially unsaturated ring. Suitable examples include, but are not limited to: dihydropyridyl, tetrahydropyridyl (piperidinyl), tetrahydrothiophenyl, sulfur-oxidized tetrahydrothiophenyl, tetrahydrofuranyl, tetrahydroquinolinyl, tetrahydroisoquinolinyl, and dihydroindolyl.

[0047] "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, O atom, S atom, etc. Suitable examples include, but are not limited to: furan, benzofuran, thiophene, benzothiophene, pyrrole, pyrazole, triazole, imidazole, oxazole, oxadiazole, thiazole, tetrazolium, indole, carbazole, pyrroloimidazol, pyrrolopyrrole, thiophenolopyrrole, thiophenolothiophene, furanolopyrrole, furanolofuran, thiophenolofuran, benzoisoxazole, benzoisothiazolium, benzimidazole, pyridine, pyrazine, pyridazine, pyrimidine, triazine, quinoline, isoquinoline, o-diazonyl, quinoxaline, phenanthridine, primidine, quinazoline, and quinazolineone.

[0048] "Carbonyl" refers to -(CO)-.

[0049] "Aldehyde group" refers to -CHO.

[0050] "Carboxyl group" refers to -CO2H.

[0051] "Nitro" refers to -NO2.

[0052] like Figure 1 As shown, a first aspect of this application provides a hole transport layer 20, which includes a hole transport polymer 21 and a coordination polymer 22. The coordination polymer 22 and the hole transport polymer 21 are intertwined to form a self-assembled mixed-phase structure, and the coordination polymer 22 has at least one of the structural units shown in formulas (I) to (VIII):

[0053] Equation (I), Formula (II)

[0054] Formula (Ⅲ), Formula (Ⅳ)

[0055] Formula (V) Formula (VI),

[0056] Formula (VII) Formula (VIII).

[0057] The hole transport layer 20 provided in this application has multiple structural units in the coordination polymer 22 capable of coordinating with metal cations. On the one hand, the structural units of the coordination polymer 22 capture metal ions (such as lead ions and tin ions) in the perovskite layer 30 near the interface of the perovskite layer 30, improving the surface wettability of the perovskite solution in the hole transport layer 20, thereby improving the uniformity of perovskite film formation. At the same time, due to the coordination effect, the defect state density at the perovskite interface is reduced, thereby improving the photoelectric conversion efficiency of the solar cell 1. On the other hand, the self-assembled mixed-phase structure formed by the intertwining of the coordination polymer 22 and the hole transport polymer 21 achieves a lattice contact structure with the perovskite layer 30 at the interface of the hole transport layer 20 and the perovskite layer 30, reducing the direct contact area between the hole transport layer 20 and the perovskite layer 30, thereby reducing the non-radiative recombination loss of charge carriers caused by contact and improving the device performance of the solar cell 1.

[0058] Furthermore, for the inverted solar cell 1, when a large-area perovskite film is formed using a one-step method, the surface wettability of the perovskite solution on the hole transport layer 20 is improved, which is beneficial for the surface extension of the perovskite film on the hole transport layer 20, thereby improving the process yield of the perovskite film.

[0059] Understandably, some atoms or groups of atoms in the structural units of coordination polymer 22 can act as ligands, donating lone pairs of electrons to form coordinate bonds with metal cations via Lewis acid / base relationships. Coordination polymer 22 possesses multiple ligands capable of coordination, thus having the ability to act as bridges between multiple metal centers. The ligands can be monodentate ligands capable of forming a single coordinate bond with a metal cation, or polydentate ligands capable of forming multiple coordinate bonds with a metal cation. When coordination polymer 22 includes polydentate ligands, it can connect multiple metal centers together to form an infinite array, while simultaneously forming multiple bonds that bind multiple identical metals (i.e., chelation).

[0060] In some embodiments, the coordination polymer 22 is an ionic polymer. When the coordination polymer 22 is an ionic polymer, it can fill the defect vacancies in the perovskite layer 30, enhance the defect passivation effect, thereby further reducing the defect state density at the perovskite interface and improving the photoelectric conversion efficiency of the solar cell 1.

[0061] In this article, "ionic polymer" refers to a polymer chain segment with covalently linked ionic groups, and to ensure charge balance, the sites of the ionic groups have corresponding ions with opposite charges.

[0062] Furthermore, coordination polymer 22 has phosphate or ammonium ions.

[0063] In some embodiments, the mass ratio of hole transport polymer 21 to coordination polymer 22 is (9:1) to (3:7), including but not limited to 9:1, 8:2, 7:3, 6:4, 5:5, 4:6, and 3:7. Within the above mass ratio range, hole transport polymer 21 and coordination polymer 22 can intertwine to form a self-assembled mixed-phase structure, thereby forming a lattice contact structure at the interface between hole transport layer 20 and perovskite layer 30. This improves the wettability of the perovskite solution at the interface of hole transport layer 20 while reducing non-radiative recombination of charge carriers, ensuring the hole transport performance of hole transport layer 20, and improving the device performance of solar cell 1. Further, the mass ratio of hole transport polymer 21 to coordination polymer 22 is 7:3.

[0064] In some embodiments, the coordination polymer 22 is selected from one or more of polyhexamethylene guanidine phosphate (PHMG), polyaminopropyl biguanide (PHMB), polyvinylpyridine (PVP), polylactic acid (PLA), polyaspartic acid (PASP), polyurea, polythiourea, and ammonium polyphosphate (APP).

[0065] In some embodiments, the general structural formula of polyurea is shown in formula (IX):

[0066]

[0067] In formula (IX), R1 and R2 may be the same or different from each other, and each is independently selected from substituted or unsubstituted alkylene or phenyl groups; the substituents include one or more of amino, carbonyl, aldehyde, carboxyl and nitro groups; and n is an integer from 1 to 2000.

[0068] In some embodiments, the general structural formula of polythiourea is shown in formula (X):

[0069]

[0070] In formula (X), R1 and R2 may be the same or different from each other, and each is independently selected from alkylene or alkoxy; where m takes the value of an integer from 10 to 500,000.

[0071] In some embodiments, the hole transport polymer 21 is selected from one or more of poly[bis(4-phenyl)(2,4,6-trimethylphenyl)amine] (PTAA), poly[bis(4-phenyl)(4-butylphenyl)amine] (polyTPD), poly(3-hexylthiophene-2,5-diyl) (P3HT), and poly[3-(4-carboxybutylthiophene-2,5-diyl) (P3CT).

[0072] The hole transport layer 20 can be prepared using conventional methods in the art, including but not limited to sol-gel method, spin coating method, spraying method, blade coating method and slot coating method.

[0073] In some embodiments, the hole transport layer 20 is prepared by the following method: dissolving the hole transport polymer 21 and coordination polymer 22 in an organic solvent to prepare a hole transport layer solution; then coating the hole transport layer solution onto a substrate and annealing it to obtain the hole transport layer 20. The concentrations of the hole transport polymer 21 and coordination polymer 22 in the hole transport layer solution are 0.1 mg / mL to 10 mg / mL; the organic solvent is chloroform, chlorobenzene, toluene, methanol, ethanol, or a mixture thereof.

[0074] The second aspect of this application provides a solar cell 1, which includes a hole transport layer 20 and a perovskite layer 30 provided in the first aspect above, wherein the perovskite layer 30 is disposed on the hole transport layer 21.

[0075] In some embodiments, the perovskite layer 30 has the chemical formula ABX3 or A2CDX6, where A is an inorganic, organic, or mixed organic / inorganic cation, and can be at least one of MA, FA, and Cs; B is an inorganic, organic, or mixed organic / inorganic cation, and can be at least one of Pb and Sn; and C is an inorganic, organic, or mixed organic / inorganic cation, commonly Ag. + D is an inorganic, organic, or mixed organic-inorganic cation, which can be a bismuth cation (Bi). 3+ Antimony cation Sb 3+ and indium cations In 3+ At least one of the following: X is an inorganic, organic, or organic / inorganic mixed anion, and can be at least one of Br or I. The perovskite layer band gap is 1.20 eV to 2.30 eV.

[0076] The perovskite layer 30 can be prepared using conventional techniques in the art, or it can be prepared using the following method: Weigh the perovskite precursor material, such as lead iodide (PbI2), formamidine iodide (FAI), cesium iodide (CsI), methyl bromide (MABr), lead bromide (PbBr2), etc., dissolve it in a solvent (e.g., dimethylformamide (DMF), dimethyl sulfoxide (DMSO), etc.), stir evenly, filter, and take the supernatant; cover the prepared electron transport layer or hole transport layer with the supernatant, which can be coated by spin coating using a spin coater, wherein the rotation speed can be 500 rpm to 5000 rpm, the spin coating time can be 5 to 50 seconds, and after spin coating, annealing is performed, the annealing temperature can be 80℃ to 150℃, and the annealing time can be 0 min to 60 min, and the perovskite layer 30 is obtained after annealing.

[0077] The thickness of the perovskite layer 30 can be any thickness used in the art. Optionally, the thickness of the perovskite layer 30 is 200 nm to 1000 nm.

[0078] In some embodiments, the self-assembled mixed-phase structure forms a lattice contact structure at the interface between the hole transport layer 20 and the perovskite layer 30.

[0079] In some of these implementations, such as Figure 1 As shown, the solar cell 1 is a reverse solar cell 1, and the solar cell 1 also includes a substrate 10, with a hole transport layer 20 disposed on the substrate 10.

[0080] Generally, a reverse solar cell 1 includes, in sequence, a substrate 10, a hole transport layer 20, a perovskite layer 30, an electron transport layer 40, and an electrode layer 50; that is, incident light passes through the substrate 10, the hole transport layer, the perovskite layer 30, the electron transport layer 40, and the electrode layer 50 in sequence.

[0081] In some embodiments, the substrate 10 is selected from crystalline silicon cells, conductive glass, and flexible conductive films.

[0082] In some embodiments, the crystalline silicon solar cell includes one of the following: passivated emitter and back contact cell (PERC cell), tunnel oxide passivated contact cell (TOPCon cell), crystalline silicon heterojunction solar cell (HJT cell), and back contact cell (IBC cell).

[0083] In some embodiments, the conductive glass has a certain degree of transparency. The conductive glass typically consists of a glass substrate and a conductive oxide thin film (TCO) layer. Commonly used TCOs include, but are not limited to, the following materials: fluorine-doped tin oxide (FTO), indium tin oxide (ITO), aluminum-doped zinc oxide (AZO), boron-doped zinc oxide (BZO), and indium zinc oxide (IZO). The conductive glass is generally any conductive glass used in the art. Conductive glass is commercially available. The conductive glass needs to be cleaned before use, for example, by ultrasonic cleaning with a cleaning agent, deionized water, or ethanol.

[0084] In some embodiments, the flexible conductive film includes one of indium tin oxide (ITO) film, fluorine-doped tin oxide (FTO) film, aluminum-doped zinc oxide (AZO) film, boron-doped zinc oxide (BZO) film, and indium zinc oxide (IZO) film.

[0085] In some embodiments, the material of the electron transport layer 40 includes [6,6]-phenylC 61 Methyl butyrate (PC61BM), [6,6]-phenyl C 71 Methyl butyrate (PC71BM), Fullerene C 60 (C 60 ), fullerene C 70 (C 70 One or more of the following: tin dioxide (SnO2), zinc oxide (ZnO), titanium dioxide (TiO2), and derivatives of the above substances, as well as materials obtained by doping or passivation.

[0086] The electron transport layer 40 can be prepared using conventional methods in the art, or it can be prepared using the following method: The electron transport layer material is dissolved in an organic solvent (e.g., chlorobenzene, dichlorobenzene, toluene, xylene) to prepare a solution with a concentration range of 5 mg / mL to 50 mg / mL. Then, it is coated onto the surface of a conductive glass or perovskite layer. The coating method can be spin-coating using a spin coater, with a rotation speed of 500 rpm to 5000 rpm and a spin-coating time of 5 to 50 seconds. After spin-coating, annealing is performed at a temperature of 80°C to 150°C for 5 to 60 minutes, resulting in the electron transport layer 40.

[0087] The thickness of the electron transport layer 40 can be any thickness used in the art. Optionally, the thickness of the electron transport layer 40 is 10 nm to 100 nm.

[0088] The electrode layer 50 can be any electrode used in the art. Optionally, the electrode layer 50 is made of an organic, inorganic, or mixed organic-inorganic conductive material, including but not limited to the following materials: Ag, Cu, C, Au, and Al. The electrode layer 50 can be prepared by vapor deposition.

[0089] The thickness of the electrode layer 50 can be any thickness used in the art. Optionally, the thickness of the electrode layer 50 is 10 nm to 200 nm.

[0090] A third aspect of this application provides a photovoltaic module, which includes the hole transport layer provided in the first aspect or the solar cell 1 provided in the second aspect.

[0091] For example, the photovoltaic module may include multiple solar cells 1 connected in series and / or in parallel. These multiple solar cells 1 may be arranged at intervals or stacked together in a shingled configuration.

[0092] The fourth aspect of this application provides a photovoltaic system comprising the photovoltaic modules provided in the third aspect above.

[0093] In some embodiments of this application, the application of the photovoltaic system is not particularly limited. Those skilled in the art can flexibly choose according to actual needs. For example, it can be applied to photovoltaic power plants, such as ground-mounted power plants, rooftop power plants, and water-based power plants, as well as to equipment or devices that utilize solar energy to generate electricity, such as user solar power supplies, solar streetlights, solar cars, and solar buildings. Of course, it is understood that the application scenarios of the photovoltaic system are not limited to these; that is, the photovoltaic system can be applied in all fields that require solar energy to generate electricity. Taking a photovoltaic power generation system network as an example, the photovoltaic system may include a photovoltaic array, a combiner box, and an inverter. The photovoltaic array may be an array combination of multiple photovoltaic modules. For example, multiple photovoltaic modules can form multiple photovoltaic arrays. The photovoltaic array is connected to the combiner box, which can collect the current generated by the photovoltaic array. The collected current flows through the inverter and is converted into AC power required by the mains power grid before being connected to the mains power grid to realize solar power supply.

[0094] The present application will be further described below with reference to specific embodiments and comparative examples.

[0095] 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.

[0096] Example 1

[0097] Hole transport polymers:

[0098] Poly[bis(4-phenyl)(2,4,6-trimethylphenyl)amine] (PTAA), PTAA weight average molecular weight M w It is 20000 g / mol.

[0099] Coordination polymers:

[0100] Polyhexamethylene guanidine phosphate (PHMG).

[0101] Solar cells:

[0102] The solar cell is a reverse solar cell.

[0103] 1) Weigh 1.4 mg of hole transport polymer and 0.6 mg of coordination polymer and dissolve them in 1 mL of chlorobenzene to obtain a hole transport layer solution. Then spin-coat the hole transport layer solution (60 μL) onto FTO conductive glass at a speed of 3000 rpm / s, anneal at 100 °C for 5 minutes, and cool to room temperature to form a hole transport layer with a thickness of 7 nm.

[0104] The mass ratio of hole transport polymer to coordination polymer is 7:3.

[0105] 2) A perovskite layer, an electron transport layer, and an electrode layer are sequentially fabricated on the hole transport layer to obtain a solar cell. The perovskite layer includes a FA (Feature Element). 0.95 Cs 0.05 PbI3 material, electron transport layer includes C 60 The material, the electrode layer includes Ag metal.

[0106] Example 2

[0107] Hole transport polymers:

[0108] Poly[bis(4-phenyl)(2,4,6-trimethylphenyl)amine] (PTAA), PTAA weight average molecular weight M w It is 20000 g / mol.

[0109] Coordination polymers:

[0110] Polyurethane-propyl biguanide (PHMB).

[0111] Solar cells:

[0112] The solar cell is a reverse solar cell.

[0113] 1) Weigh 1.4 mg of hole transport polymer and 0.6 mg of coordination polymer and dissolve them in 1 mL of chlorobenzene to obtain a hole transport layer solution. Then spin-coat the hole transport layer solution (60 μL) onto FTO conductive glass at a speed of 3000 rpm / s, anneal at 100 °C for 5 minutes, and cool to room temperature to form a hole transport layer with a thickness of 7 nm.

[0114] The mass ratio of hole transport polymer to coordination polymer is 7:3.

[0115] 2) A perovskite layer, an electron transport layer, and an electrode layer are sequentially fabricated on the hole transport layer to obtain a solar cell. The perovskite layer includes a FA (Feature Element). 0.95 Cs 0.05 PbI3 material, electron transport layer includes C 60 The material, the electrode layer includes Ag metal.

[0116] Example 3

[0117] Hole transport polymers:

[0118] Poly[bis(4-phenyl)(2,4,6-trimethylphenyl)amine] (PTAA), PTAA weight average molecular weight M w It is 20000 g / mol.

[0119] Coordination polymers:

[0120] Polyvinylpyridine (PVP). The weight-average molecular weight (Mw) of PVP is 300,000 g / mol.

[0121] Solar cells:

[0122] The solar cell is a reverse solar cell.

[0123] 1) Weigh 1.4 mg of hole transport polymer and 0.6 mg of coordination polymer and dissolve them in 1 mL of chlorobenzene to obtain a hole transport layer solution. Then spin-coat the hole transport layer solution (60 μL) onto FTO conductive glass at a speed of 3000 rpm / s, anneal at 100 °C for 5 minutes, and cool to room temperature to form a hole transport layer with a thickness of 7 nm.

[0124] The mass ratio of hole transport polymer to coordination polymer is 7:3.

[0125] 2) A perovskite layer, an electron transport layer, and an electrode layer are sequentially fabricated on the hole transport layer to obtain a solar cell. The perovskite layer includes a FA (Feature Element). 0.95 Cs 0.05 PbI3 material, electron transport layer includes C 60 The material, the electrode layer includes Ag metal.

[0126] Example 4

[0127] Hole transport polymers:

[0128] Poly[bis(4-phenyl)(2,4,6-trimethylphenyl)amine] (PTAA), PTAA weight average molecular weight M w It is 20000 g / mol.

[0129] Coordination polymers:

[0130] Polylactic acid (PLA). The weight-average molecular weight (Mw) of PLA is 100,000 g / mol.

[0131] Solar cells:

[0132] The solar cell is a reverse solar cell.

[0133] 1) Weigh 1.4 mg of hole transport polymer and 0.6 mg of coordination polymer and dissolve them in 1 mL of chlorobenzene to obtain a hole transport layer solution. Then spin-coat the hole transport layer solution (60 μL) onto FTO conductive glass at a speed of 3000 rpm / s, anneal at 100 °C for 5 minutes, and cool to room temperature to form a hole transport layer with a thickness of 7 nm.

[0134] The mass ratio of hole transport polymer to coordination polymer is 7:3.

[0135] 2) A perovskite layer, an electron transport layer, and an electrode layer are sequentially fabricated on the hole transport layer to obtain a solar cell. The perovskite layer includes a FA (Feature Element). 0.95 Cs 0.05 PbI3 material, electron transport layer includes C 60 The material, the electrode layer includes Ag metal.

[0136] Example 5

[0137] Hole transport polymers:

[0138] Poly[bis(4-phenyl)(2,4,6-trimethylphenyl)amine] (PTAA), PTAA weight average molecular weight M w It is 20000 g / mol.

[0139] Coordination polymers:

[0140] Polyaspartic acid (PASP).

[0141] Solar cells:

[0142] The solar cell is a reverse solar cell.

[0143] 1) Weigh 1.4 mg of hole transport polymer and 0.6 mg of coordination polymer and dissolve them in 1 mL of chlorobenzene to obtain a hole transport layer solution. Then spin-coat the hole transport layer solution (60 μL) onto FTO conductive glass at a speed of 3000 rpm / s, anneal at 100 °C for 5 minutes, and cool to room temperature to form a hole transport layer with a thickness of 7 nm.

[0144] The mass ratio of hole transport polymer to coordination polymer is 7:3.

[0145] 2) A perovskite layer, an electron transport layer, and an electrode layer are sequentially fabricated on the hole transport layer to obtain a solar cell. The perovskite layer includes a FA (Feature Element). 0.95 Cs 0.05 PbI3 material, electron transport layer includes C 60 The material, the electrode layer includes Ag metal.

[0146] Example 6

[0147] Hole transport polymers:

[0148] Poly[bis(4-phenyl)(2,4,6-trimethylphenyl)amine] (PTAA), PTAA weight average molecular weight M w It is 20000 g / mol.

[0149] Coordination polymers:

[0150] Polyurea molecules with the following structural formula:

[0151]

[0152] That is, in equation (IX), R1=R2=-CH2-, where n1=n / 2=100000.

[0153] Solar cells:

[0154] 1) Weigh 1.4 mg of hole transport polymer and 0.6 mg of coordination polymer and dissolve them in 1 mL of chlorobenzene to obtain a hole transport layer solution. Then spin-coat the hole transport layer solution (60 μL) onto FTO conductive glass at a speed of 3000 rpm / s, anneal at 100 °C for 5 minutes, and cool to room temperature to form a hole transport layer with a thickness of 7 nm.

[0155] The mass ratio of hole transport polymer to coordination polymer is 7:3.

[0156] 2) A perovskite layer, an electron transport layer, and an electrode layer are sequentially fabricated on the hole transport layer to obtain a solar cell. The perovskite layer includes a FA (Feature Element). 0.95 Cs 0.05 PbI3 material, electron transport layer includes C60 The material, the electrode layer includes Ag metal.

[0157] Example 7

[0158] Hole transport polymers:

[0159] Poly[bis(4-phenyl)(2,4,6-trimethylphenyl)amine] (PTAA), PTAA weight average molecular weight M w It is 20000 g / mol.

[0160] Coordination polymers:

[0161] Polythiourea molecules with the following structural formula:

[0162]

[0163] That is, in equation (X), R3=R4=-CH2CH2OCH2CH2-, where m1=m / 2=20000.

[0164] Solar cells:

[0165] 1) Weigh 1.4 mg of hole transport polymer and 0.6 mg of coordination polymer and dissolve them in 1 mL of chlorobenzene to obtain a hole transport layer solution. Then spin-coat the hole transport layer solution (60 μL) onto FTO conductive glass at a speed of 3000 rpm / s, anneal at 100 °C for 5 minutes, and cool to room temperature to form a hole transport layer with a thickness of 60 nm.

[0166] The mass ratio of hole transport polymer to coordination polymer is 7:3.

[0167] 2) A perovskite layer, an electron transport layer, and an electrode layer are sequentially fabricated on the hole transport layer to obtain a solar cell. The perovskite layer includes a FA (Feature Element). 0.95 Cs 0.05 PbI3 material, electron transport layer includes C 60 The material, the electrode layer includes Ag metal.

[0168] Example 8

[0169] Hole transport polymers:

[0170] Poly[bis(4-phenyl)(2,4,6-trimethylphenyl)amine] (PTAA), PTAA weight average molecular weight M w It is 20000 g / mol.

[0171] Coordination polymers:

[0172] Ammonium polyphosphate (APP).

[0173] Solar cells:

[0174] The solar cell is a reverse solar cell.

[0175] 1) Weigh 1.4 mg of hole transport polymer and 0.6 mg of coordination polymer and dissolve them in 20 mL of chlorobenzene to obtain a hole transport layer solution. Then spin-coat the hole transport layer solution (60 μL) onto FTO conductive glass at 3000 rpm / s, anneal at 100 °C for 5 minutes, and cool to room temperature to form a hole transport layer with a thickness of 7 nm.

[0176] The mass ratio of hole transport polymer to coordination polymer is 7:3.

[0177] 2) A perovskite layer, an electron transport layer, and an electrode layer are sequentially fabricated on the hole transport layer to obtain a solar cell. The perovskite layer includes a FA (Feature Element). 0.95 Cs 0.05 PbI3 material, electron transport layer includes C 60 The material, the electrode layer includes Ag metal.

[0178] Example 9

[0179] The hole transport polymer, coordination polymer, and solar cell preparation methods in this embodiment are basically the same as in Example 1, except that:

[0180] In step 1), the mass ratio of hole transport polymer to coordination polymer is 9:1.

[0181] Example 10

[0182] The hole transport polymer, coordination polymer, and solar cell preparation methods in this embodiment are basically the same as in Example 1, except that:

[0183] In step 1), the mass ratio of hole transport polymer to coordination polymer is 3:7.

[0184] Comparative Example 1

[0185] Hole transport polymers:

[0186] Poly[bis(4-phenyl)(2,4,6-trimethylphenyl)amine] (PTAA), PTAA weight average molecular weight M w It is 20000 g / mol.

[0187] Solar cells:

[0188] The solar cell is a reverse solar cell.

[0189] 1) Weigh 2 mg of hole transport polymer and dissolve it in 1 mL of chlorobenzene to obtain a hole transport layer solution. Then spin-coat the hole transport layer solution (60 μL) onto FTO conductive glass at a speed of 3000 rpm / s, anneal at 100 °C for 5 minutes, and cool to room temperature to form a hole transport layer with a thickness of 7 nm.

[0190] 2) A perovskite layer, an electron transport layer, and an electrode layer are sequentially fabricated on the hole transport layer to obtain a solar cell. The perovskite layer includes a FA (Feature Element). 0.95 Cs 0.05 PbI3 material, electron transport layer includes C 60 The material, the electrode layer includes Ag metal.

[0191] Performance testing:

[0192] (1) Contact angle test

[0193] The contact angle of the hole transport layers prepared in the above embodiments and comparative examples was tested using a perovskite solution. The test results are shown in Table 1.

[0194] (2) Photoelectric performance testing

[0195] The solar cells fabricated in the above embodiments and comparative examples were placed in a solar simulator (manufacturer: Wavelabs). Under the illumination of a certain solar intensity, a bias voltage (Vp, bias voltage range of -0.1 to 1.2V) was applied to the device using a test source meter, and the output current of the device was tested to obtain the bias voltage-current density curve.

[0196] Open-circuit voltage (Voc): The terminal voltage of the solar cell when no load is connected, i.e., when the current density in the bias-current density curve is 0 mA·cm. -2 The bias voltage value at that time.

[0197] Short-circuit current density (Jsc): The output current per unit area of ​​the solar cell when it is short-circuited, i.e., the current density when the bias voltage is 0V in the bias voltage-current density curve.

[0198] Fill factor (FF): FF = max(Vp × Jsc),

[0199] Where Vp is the bias voltage and Jsc is the short-circuit current density.

[0200] Photovoltaic cell efficiency (PCE): PCE = Voc × Jsc × FF.

[0201] The test results for the above performance are shown in Table 1.

[0202] Table 1

[0203]

[0204] As shown in Table 1, comparing Examples 1-10 and Comparative Example 1, it can be seen that the hole transport layer provided in this application improves the surface wettability of the perovskite solution in the hole transport layer, improves the crystallinity of the perovskite film, reduces non-radiative recombination of carriers caused by contact, and further improves the photovoltaic cell efficiency of perovskite solar cells.

[0205] 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.

[0206] The embodiments described above are merely illustrative of several implementation methods of this application, and while the descriptions are specific and detailed, they should not be construed as limiting the scope of this patent application. It should be noted that those skilled in the art can make various modifications and improvements without departing from the technical concept of this application, and these modifications and improvements all fall within the protection scope of this application. Therefore, the protection scope of this application should be determined by the appended claims.

Claims

1. A hole transport layer, characterized in that, include: Hole transport polymers; A coordination polymer, intertwined with the hole-transporting polymer to form a self-assembled mixed-phase structure, wherein the coordination polymer has at least one of the structural units shown in formulas (I) to (VIII): Equation (I), Formula (II) Formula (Ⅲ), Formula (Ⅳ) Formula (V) Formula (VI), Formula (VII) Formula (VIII).

2. The hole transport layer according to claim 1, characterized in that, The coordination polymer is an ionic polymer.

3. The hole transport layer according to claim 2, characterized in that, The coordination polymer has phosphate ions or ammonium ions.

4. The hole transport layer according to any one of claims 1 to 3, characterized in that, The mass ratio of the hole transport polymer to the coordination polymer is (9:1) to (3:7).

5. The hole transport layer according to any one of claims 1 to 3, characterized in that, The coordination polymer is selected from one or more of polyhexamethylene guanidine phosphate, polyaminopropyl biguanide, polyvinylpyridine, polylactic acid, polyaspartic acid, polyurea, polythiourea, and ammonium polyphosphate.

6. A solar cell, characterized in that, It includes the hole transport layer and the perovskite layer as described in any one of claims 1 to 5, wherein the perovskite layer is disposed on the hole transport layer.

7. The solar cell according to claim 6, characterized in that, The self-assembled mixed-phase structure forms a lattice contact structure at the interface between the hole transport layer and the perovskite layer.

8. The solar cell according to claim 6, characterized in that, The solar cell is an inverted solar cell, and the solar cell also includes a substrate, with the hole transport layer disposed on the substrate.

9. A photovoltaic module, characterized in that, It includes the hole transport layer as described in any one of claims 1 to 5, or the solar cell as described in any one of claims 6 to 8.

10. A photovoltaic system, characterized in that, Includes the photovoltaic module as described in claim 9.

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