Hole transport layer and preparation method thereof, perovskite solar cell and photovoltaic module

Abstract

The embodiment of the invention relates to the technical field of solar cells, in particular to a hole transport layer and a preparation method thereof, a perovskite solar cell and a photovoltaic module. The hole transport layer comprises a self-assembled monomolecular layer and a modification material, wherein the modification material is anchored on a substrate which is not covered by the self-assembled monomolecular layer; the modification material comprises a compound shown in a formula (I). According to the embodiment of the invention, the modification material in the hole transport layer can realize accurate chemical repair and good passivation of an interface.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of solar cells, in particular to a hole transport layer and a preparation method thereof, a perovskite solar cell and a photovoltaic module. BACKGROUND

[0002] Perovskite solar cells, especially the tandem cells composed of perovskite and crystalline silicon, have become the research frontier due to their excellent potential of photoelectric conversion efficiency. In such cells, the hole transport layer is crucial for achieving efficient charge extraction and transport. In recent years, self-assembled monolayer (SAM) materials, such as 2PACz, Me-4PACz, etc., have been widely studied and used as hole transport layers for high-performance perovskite solar cells due to their advantages of low material consumption, low parasitic absorption, and adjustable energy level.

[0003] However, the skilled person in the art has found in practice that the SAM-based hole transport layer still has technical defects to be solved, especially in large-area and large-scale preparation, which seriously restricts its further application in high-efficiency and high-stability solar cells. Specifically, the existing technology at least has the following problems: during the self-assembly process of SAM materials on the substrate (such as transparent conductive oxide indium zinc oxide (IZO)), influenced by intermolecular forces, solvent evaporation, and self-assembly kinetics, etc., the molecular aggregation phenomenon is easy to occur. This leads to the existence of uncovered micro regions in the formed SAM layer, resulting in insufficient coverage. These "vacancies" make the perovskite precursor solution or the final film formation directly contact with the active IZO surface, not only becoming the center of interface non-radiative recombination, significantly increasing the carrier recombination loss, but also possibly catalyzing the decomposition of perovskite material, degrading the long-term stability of the device. Due to the significant difference in surface energy and chemical properties between the IZO region not covered by SAM and the SAM molecules themselves, the perovskite light absorption layer deposited thereon faces non-uniform nucleation and growth. This inconsistent crystallization environment induces more grain boundaries, pinholes, and other defects in the perovskite, thereby reducing the film quality of the perovskite light absorption layer and affecting the diffusion and collection of photo-generated carriers. The SAM molecules and the exposed IZO surface have different surface dipole moments and work functions, resulting in uneven potential distribution at the interface of the hole transport layer. This inconsistency in potential distorts the energy level alignment at the interface, hinders the efficient and uniform extraction of holes, and causes serious interface recombination, ultimately leading to a decrease in open-circuit voltage and fill factor, limiting the further improvement of photoelectric conversion efficiency. Therefore, how to effectively solve the problem of uneven coverage during the self-assembly process of SAM materials and optimize the interface properties between the SAM and the perovskite light absorption layer has become a key challenge in the development of high-efficiency and stable perovskite solar cells in the field.

[0004] It should be noted that the above content is not necessarily prior art, nor is it used to limit the patent protection scope of the present application. SUMMARY

[0005] Embodiments of the present application provide a hole transport layer and a preparation method thereof, a perovskite solar cell and a photovoltaic module, to solve or alleviate one or more technical problems raised above.

[0006] The first aspect of embodiments of the present application provides a hole transport layer, comprising a self-assembled monolayer and a modification material, wherein the modification material is anchored on a substrate not covered by the self-assembled monolayer. The modification material comprises a compound represented by Formula (I):

[0007] wherein R1-R5 are independently selected from hydrogen, substituted or unsubstituted alkyl with carbon chain length of 1-6, alkoxy, halogen, nitro, substituted or unsubstituted amino, cyano or hydroxyl; M is selected from H, metal cation, substituted or unsubstituted alkyl with carbon chain length of 1-6 or -S(=O)2-Ar'; Ar' is substituted or unsubstituted phenyl.

[0008] The first aspect of embodiments of the present application can achieve precise chemical repair and good passivation of the interface by using the modification material.

[0009] The second aspect of the present application provides a preparation method of a hole transport layer, comprising the following operations: Preparation of a self-assembled monolayer on a substrate; Providing a modification solution comprising a modification material, and using the modification solution to prepare a film on the self-assembled monolayer, so that the modification material is anchored on the substrate not covered by the self-assembled monolayer; Cleaning treatment is performed to clean the modification material not anchored on the substrate; Annealing treatment is performed to obtain a hole transport layer; wherein the modification material comprises a compound represented by Formula (1):

[0010] wherein R1-R5 are independently selected from hydrogen, substituted or unsubstituted alkyl with carbon chain length of 1-6, alkoxy, halogen, nitro, amino, cyano or hydroxyl; M is selected from H, metal cation, substituted or unsubstituted alkyl with carbon chain length of 1-6 or -S(=O)2-Ar'; Ar' is substituted or unsubstituted phenyl.

[0011] The preparation method of the embodiments of the present application can realize precise interface chemical repair by using a modification material. The method only needs to add a simple modification solution treatment step on the basis of a standard self-assembled monolayer (SAM) process, and is highly compatible with the existing perovskite device preparation process.

[0012] The third aspect of the embodiments of the present application provides a perovskite solar cell, comprising a substrate, a hole transport layer of the first aspect or a hole transport layer prepared by the preparation method of the second aspect, a perovskite light absorption layer, and an electron transport layer, which are sequentially stacked.

[0013] Thanks to the precise repair and synergistic passivation of the interface by the modification material, the open-circuit voltage (Voc) and the fill factor (FF) of the perovskite solar cell are simultaneously improved, thereby realizing higher photoelectric conversion efficiency.

[0014] The fourth aspect of the embodiments of the present application provides a photovoltaic module, comprising the perovskite solar cell of the third aspect of the present application.

[0015] By integrating the high-performance perovskite solar cell provided in the third aspect, the following advantages are achieved: based on the significant improvement of the conversion efficiency of the perovskite solar cell itself, the photovoltaic module can realize higher power output per unit area; thanks to the fundamental optimization of the interface structure of the perovskite solar cell, the module exhibits a lower efficiency decay rate under long-term operating conditions, and the service life is significantly prolonged. BRIEF DESCRIPTION OF DRAWINGS

[0016] In the drawings, like reference numerals designate like elements throughout the various drawings. The drawings are not necessarily to scale, the emphasis instead being placed upon illustrating principles of the application. It should be understood that the drawings are merely depictions of some embodiments of the application and should not be construed as limiting the scope of the application.

[0017] Figure 1 FIG. 1 is a structural schematic diagram of a stacked cell provided by the embodiments of the present application.

[0018] BRIEF DESCRIPTION OF DRAWINGS 1-1-back gate line; 1-2-back film layer of the bottom cell of the crystalline silicon; 1-3-crystalline silicon wafer; 1-4-front film layer of the bottom cell of the crystalline silicon; 1-5-intermediate connecting layer; 1-6-hole transport layer; 1-7-perovskite light absorption layer; 1-8-electron transport layer; 1-9-front transparent conductive layer; 1-10-front anti-reflection film; 1-11-front gate line. DETAILED DESCRIPTION

[0019] Embodiments of the present application are described in detail below with reference to examples illustrated in the accompanying drawings. In the drawings, the size and relative sizes of layers, regions, elements, and the like can be exaggerated for clarity. Like reference numerals can represent like elements throughout the drawings. The embodiments described below are examples of the present application and are not intended to limit the present application. It should be noted that the embodiments in the present application and the features in the embodiments can be combined with each other without conflict if not explicitly stated otherwise.

[0020] It should be understood that when an element or layer is referred to as being "on", "adjacent", "connected to", or "coupled to" another element or layer, it can be directly on, adjacent, connected or coupled to the other element or layer, or one intervening element or layer can be present. In contrast, when an element is referred to as being "directly on", "directly adjacent", "directly connected to", or "directly coupled to" another element or layer, then there are no intervening elements or layers present. It will be understood that, although the terms first, second, third, etc. can be used herein to describe various elements, components, regions, layers and / or sections, these elements, components, regions, layers and / or sections should not be limited by these terms. These terms are only used to distinguish one element, component, region, layer or section from another element, component, region, layer or section. Thus, a first element, component, region, layer or section discussed below could be termed a second element, component, region, layer or section without departing from the teachings of the present application. Similarly, a second element, component, region, layer or section discussed below could be termed a first element, component, region, layer or section without departing from the teachings of the present application.

[0021] In the present application, unless specifically stated and limited otherwise, the terms "mount", "connect", "connection", "contact", "engaging" and the like, should be interpreted broadly, for example, can be fixed connection, can be detachable connection, or integral; can be mechanical connection, can be electrical connection; can be direct connection, can be indirect connection through an intermediate medium, can be internal connection of two elements or interaction relationship between two elements, unless otherwise explicitly limited. For those skilled in the art, the specific meaning of the above terms in the present application can be understood according to the specific circumstances.

[0022] It should be noted that the terms "first", "second", and the like in the description and in the claims of the present application and the above drawings merely mean to distinguish similar objects, and do not necessarily imply a specific order or sequence. It should be understood that the terms thus used can be interchanged under appropriate circumstances, so that the embodiments of the present application described herein can be implemented in other than the order illustrated or described herein. In addition, the terms "comprise" and "have" and any variations thereof are intended to cover non-exclusive inclusion, for example, a process, method, system, product, or apparatus that comprises a list of steps or units does not have to be limited to those steps or units clearly listed, but can include other steps or units not clearly listed or inherent to such processes, methods, products, or apparatuses.

[0023] In the present application, when referring to a numerical interval (i.e., a numerical range), the distribution of the optional numbers in the numerical interval is considered to be continuous and includes both numerical end points (i.e., the minimum value and the maximum value) of the numerical interval and each number between the two numerical end points, unless otherwise specified. When a numerical interval refers only to integers within the numerical interval, including both end point integers of the numerical range and each integer between the two end point integers, it is equivalent to directly listing each integer, unless otherwise specified. When multiple numerical ranges are provided to describe a feature or a characteristic, the numerical ranges can be combined. In other words, unless otherwise specified, the numerical ranges disclosed in the present application should be understood to include any and all sub-ranges encompassed therein. The "numbers" in the numerical interval can be any quantitative value, such as a number, a percentage, a ratio, etc. The "numerical interval" is intended to broadly include quantitative intervals such as percentage intervals, ratio intervals, value intervals, etc.

[0024] In the following, exemplary embodiments according to the present application will be described in more detail with reference to the accompanying drawings. It should be noted that these exemplary embodiments can be implemented in various different ways, and should not be construed as being limited only to the embodiments set forth herein.

[0025] The first aspect of the embodiments of the present application provides a hole transport layer.

[0026] In some embodiments, the hole transport layer comprises a self-assembled monolayer and a modifying material, the modifying material being anchored on a substrate not covered by the self-assembled monolayer; The modifying material comprises a compound shown in formula (I):

[0027] wherein R1-R5 are independently selected from hydrogen (H), substituted or unsubstituted alkyl with carbon chain length of 1-6, alkoxy, halogen (F, Cl, Br, I), nitro (-NO2), substituted or unsubstituted amino, cyano (-CN), or hydroxyl (-OH); M is selected from H, a metal cation, a substituted or unsubstituted alkyl group having a carbon chain length of 1-6, or -S(=0)2-Ar'; Ar' is a substituted or unsubstituted phenyl group.

[0028] The first aspect of the embodiments of the present application can realize accurate chemical repair and good passivation of the interface. The -S(=0)2-O-M functional group of the compound of formula (I) in the modification material has very high reactivity and can chemically react with active sites (such as hydroxyl groups and oxygen vacancies) on the surface of the substrate (such as IZO) that are not covered by the SAM layer to form a firm chemical anchor (such as a sulfonate bond). This process realizes "accurate chemical repair" of the uncovered sites caused by the aggregation of SAM molecules, thereby completely blocking the direct contact between the perovskite precursor or film and the active substrate surface in a physical and chemical manner, fundamentally reducing the interface charge recombination center, and significantly reducing the non-radiative recombination loss. At the same time, an ideal perovskite nucleation interface is constructed, guiding high-quality crystallization. The rigid benzene ring structure in the modification material cooperates with the underlying SAM molecules to form a rigid, flat, and hydrophobic composite interface. This interface not only effectively reduces the nucleation barrier of perovskite and induces lateral growth of the crystal grains, but also provides a wider operating window for the crystallization process due to its hydrophobicity and can inhibit the erosion of moisture in the environment. Ultimately, a high-quality perovskite polycrystalline film with larger and denser crystal grains and fewer pinholes is formed, laying the foundation for obtaining high photoelectric performance. At the same time, the inherent dipole moment of the sulfonate group cooperates with the dipole moment of the SAM molecule to effectively balance the interface potential difference caused by uneven SAM coverage, making the energy level alignment more optimized. This promotes efficient and uniform extraction and transport of holes at the interface, while inhibiting the backflow of electrons to the hole transport side, thereby helping to simultaneously improve the open-circuit voltage and fill factor of the device.

[0029] It should be noted that the substrate of the present application can be a transparent conductive oxide layer (TCO).

[0030] In some embodiments, in the hole transport layer, R1-R5 in the modification material molecule are each independently selected from hydrogen (H), methyl, tert-butyl, methoxy, fluorine (F), chlorine (Cl), bromine (Br), iodine (I), nitro (-NO2), amino (-NH2), cyano (-CN), hydroxyl (-OH), trifluoromethyl (-CF3), -NHCl, -NHCH3, -CF3, or -C(CH3)3.

[0031] In some embodiments, in the hole transport layer, M in the modification material molecule is selected from H, Na + , K + , Zn 2+ , Fe 3+ , methyl, ethyl, isopropyl, butyl, cyanomethyl, or p-toluenesulfonyl. Thus, M is K +or Na + M is Zn 2+ or Fe 3+ I - defects. Toluene sulfonic acid can act as a strong Lewis base to passivate uncoordinated cation defects (e.g. Pb 2+ ).

[0032] It is noted that when the present application refers to (Ar'-SO3)-M comprising a metal cation, formula (I) represents the basic building block of the modifying material. When X is a divalent or trivalent metal cation (e.g. Zn 2+ , Fe 3+ ), one metal cation will be associated with two or three building blocks of the general formula, forming a neutral molecule as indicated by (Ar'-SO3)2Zn or (Ar'-SO3)3Fe.

[0033] Exemplary, the modifying material can be at least one of p-toluenesulfonic acid, p-toluenesulfonic anhydride, sodium p-toluenesulfonate, iron p-toluenesulfonate, zinc p-toluenesulfonate, o-toluenesulfonic acid, m-toluenesulfonic acid, aminobenzenesulfonic acid, xylene sulfonic acid, potassium xylene sulfonate, p-chlorobenzenesulfonic acid, o-iodobenzenesulfonic acid, p-hydroxybenzenesulfonic acid, butyl p-nitrobenzenesulfonate, isopropyl benzenesulfonate, propyl benzenesulfonate, ethyl o-toluenesulfonate, ethyl benzenesulfonate, ethyl m-nitrobenzenesulfonate, ethyl p-fluorobenzenesulfonate, ethyl p-toluenesulfonate, ethyl 4-amino-3-chloro-5-toluenesulfonate, ethyl 4-amino-3-methylbenzenesulfonate, ethyl 4-chlorobenzenesulfonate, ethyl 2-nitrobenzenesulfonate, ethyl 2-bromobenzenesulfonate, ethyl 2,4-dimethylbenzenesulfonate, ethyl 4-(trifluoromethyl)benzenesulfonate, ethyl 4-tert-butylbenzenesulfonate, ethyl 3-nitrobenzenesulfonate, methyl p-fluorobenzenesulfonate, methyl p-toluenesulfonate, methyl 3-aminobenzenesulfonate, methyl 2,4,6-trimethylbenzenesulfonate, methyl 4-chlorobenzenesulfonate, methyl p-aminobenzenesulfonate, methyl p-nitrobenzenesulfonate, methyl 2,4-dimethylbenzenesulfonate, 2-cyanophenyl 2-cyanobenzenesulfonate (CAS: 1171919-29-1), cyanomethyl benzenesulfonate (CAS: 10531-13-2), 4-bromobenzenesulfonic acid.

[0034] In some embodiments, in the hole transport layer, the self-assembled monolayer comprises a self-assembled monolayer (SAM) material, and the self-assembled monolayer material comprises a phosphonic acid group (-PO(OH)2). Thus, the SAM molecules can be anchored by the phosphonic acid group to form a rigid two-dimensional ordered monolayer with a specific molecular orientation on the substrate. This provides the interface with preliminary structural stability and flatness. The modification material can "precisely fill" and "rigidly enhance". The modification material can fill the SAM vacancies while further enhancing the rigidity of the entire interface by the rigid structure of the benzene ring of the modification material. This "rigid-flexible" composite structure ("flexible" refers to the molecular level thickness that can self-adaptively fill, and "rigid" refers to the molecular skeleton) provides an unprecedented ideal template for perovskite crystallization.

[0035] Optionally, the self-assembled monolayer (SAM) material comprises [2 (9H Carbazole 9 yl)ethyl]phosphonic acid (2PACz), [2 (3,6 Diphenyl 9H Carbazole 9 yl)ethyl]phosphonic acid (Me-2PACz), (2-(3,6-dimethoxy-9H-carbazol-9-yl)ethyl)phosphonic acid (MeO-2PACz), 2-(3,6-dibromo-9H-carbazol-9-yl)ethyl]phosphonic acid (Br-2PACz), 2-(3,6-dichloro-9H-carbazol-9-yl)ethyl]phosphonic acid (Cl-2PACz), 2-(3,6-difluoro-9H-carbazol-9-yl)ethyl]phosphonic acid (F-2PACz), [4-(9H-carbazol-9-yl)ethyl]phosphonic acid (4PACz), [4 (3,6 Dimethyl 9H Carbazole 9 yl)butyl]phosphonic acid (Me-4PACz), [4 (3,6 Dimethoxy 9H Carbazole 9 [4-(3,6-dibromo-9H-carbazol-9-yl)butyl]phosphonic acid (Br-4PACz), (4-(3,6-dichloro-9H-carbazol-9-yl)butyl)phosphonic acid (Cl-4PACz), (4-(3,6-difluoro-9H-carbazol-9-yl)butyl)phosphonic acid (F-4PACz), [4 (7H dibenzocarbazole 7 [4-(3,6-dibromo-9H-carbazol-9-yl)butyl]phosphonic acid (4PADCB), [4 (2,7 dibromo 9,9 dimethylacridine 10(9 hydrogen) [2-(3,7-dibromo-10H-phenothiazin-10-yl)ethyl]phosphonic acid (Br-2EPT), 4-phenylbutyric acid sodium salt (4-PBA), (2-(4-(bis(4-methoxyphenyl)amino)phenyl)-1-cyanoethenyl)phosphonic acid (MPA-CPA).

[0036] The second aspect of the present application provides a preparation method of a hole transport layer, comprising the following steps S1 to S4: S1, preparing a self-assembled monolayer on a substrate; Optionally, the film can be prepared into a wet film by one of spin coating, blade coating, slot coating or inkjet printing, and then annealed at a temperature of 80-120°C for 5-20 min.

[0037] Optionally, the concentration of the self-assembled monomolecular material in the self-assembled monomolecular solution can be 0.1-3 mg / mL. Thus, it is convenient to form a continuous film. For example, the concentration of the self-assembled monomolecular material can be 0.1 mg / mL, 0.5 mg / mL, 1 mg / mL, 1.5 mg / mL, 2 mg / mL, 2.5 mg / mL, 3 mg / mL, etc.

[0038] Optionally, the solvent of the self-assembled monomolecular solution comprises at least one of methanol, ethanol, isopropanol and n-propanol.

[0039] S2, providing a modification solution comprising a modification material, and preparing a film on the self-assembled monolayer by using the modification solution, so that the modification material is anchored on the substrate not covered by the self-assembled monolayer.

[0040] The modification material comprises a compound represented by formula (1):

[0041] wherein R1-R5 are independently selected from hydrogen, substituted or unsubstituted alkyl group with carbon chain length of 1-6, alkoxy group, halogen, nitro group, substituted or unsubstituted amino group, cyano group or hydroxyl group; M is selected from H, metal cation, substituted or unsubstituted alkyl group with carbon chain length of 1-6 or -S(=O)2-Ar'; Ar' is substituted or unsubstituted phenyl group.

[0042] Due to the self-assembled monolayer is difficult to completely cover the substrate because of the self-assembled monomolecular material itself agglomeration, so that the self-assembled monolayer exists some windows to expose the substrate. After the modified solution is made into a wet film, the modified material in the modified solution will cover the self-assembled monolayer and the substrate not covered by the self-assembled monolayer. Since the TCO on the substrate has a hydroxyl group, the modified material on the substrate can chemically react with the hydroxyl group on the TCO to form a bond, thereby anchoring the modified material on the substrate not covered by the self-assembled monolayer; and the modified material covering the SAM layer is physically attached.

[0043] Optionally, the concentration of the modified material can be 0.1 mg / mL-4 mg / mL. For example, the concentration of the modified material can be 0.1 mg / mL, 1 mg / mL, 2 mg / mL, 3 mg / mL, 3.5 mg / mL, or 4 mg / mL.

[0044] Optionally, the solvent in the modified solution includes at least one of methanol, ethanol, isopropanol, n-propanol, N,N-dimethylformamide (DMF), and dimethyl sulfoxide (DMSO).

[0045] Further, when the modified material is p-toluenesulfonic anhydride, chloroform, dichloromethane, and the like can also be used as solvents to prepare the modified solution.

[0046] S3, then a cleaning process is performed to clean the modified material not anchored on the substrate; thereby, the modified material attached to the SAM layer is removed.

[0047] In some embodiments, the cleaning process includes: adding a cleaning liquid on the self-assembled monolayer so that the cleaning liquid mixes with the modified material to form a mixture; and removing part of the mixture to take away the unanchored modified material. The anchoring between the modified material and the substrate mainly relies on chemical bonding, so after the cleaning liquid is added, the modified material anchored on the substrate is difficult to be washed away by the cleaning liquid. The adsorption between the modified material and the self-assembled monolayer mainly relies on van der Waals force, so after the cleaning liquid is added, the modified material dissolves into the cleaning liquid to form a mixture, and removing the mixture can take away the unanchored modified material, while the anchored modified material is retained due to its stronger binding force with the substrate.

[0048] Optionally, the cleaning solution comprises an alcohol solvent.

[0049] It can be understood that the cleaning solution is selected from a solvent that can dissolve the modification material, and therefore the solvent used for preparing the modification solution can be used. In consideration of cost, an alcohol solvent is preferably selected as the cleaning solution.

[0050] Further, the alcohol solvent can be a low alcohol having a low molecular weight and being easy to volatilize. For example, the alcohol can be methanol, ethanol, isopropanol, n-propanol, etc., and ethanol is further preferred.

[0051] Optionally, the cleaning solution can be added by using a spin coating method, and the removal of the mixture is completed. After the cleaning solution is added, the cleaning solution can form a mixture with the modification material, and the rotation rate can be controlled to brush off part of the mixture.

[0052] Further, when the cleaning solution is added by using the spin coating method and the removal of the mixture is completed, the rotation rate is 4000 rpm to 8000 rpm. Thus, the modification material can be completely removed. For example, the rotation rate can be 4000 rpm, 5000 rpm, 6000 rpm, 7000 rpm, 8000 rpm, etc.

[0053] Optionally, the rotation time is 10 s to 25 s. Thus, the modification material can be completely removed. For example, the rotation time can be 10 s, 15 s, 20 s, 25 s, etc.

[0054] S4, then annealing treatment is performed to obtain a hole transport layer. Thus, the annealing treatment can drive the modification material anchored on the substrate to be arranged more regularly, and can also repair the damage to the SAM layer caused by the cleaning solution.

[0055] Optionally, the annealing temperature is 50 to 150°C. For example, the annealing temperature can be 50°C, 100°C, 120°C, 150°C, etc.

[0056] Optionally, the annealing time is 3 min to 20 min. For example, the annealing time can be 3 min, 5 min, 10 min, 15 min, 20 min, etc.

[0057] The preparation method of the second aspect of the embodiments of the present application can realize precise interface chemical repair: by wet deposition of the modification material on the pre-formed SAM layer, the modification molecules can be precisely anchored on the substrate area exposed due to SAM aggregation. This "after repair" strategy realizes selective deposition at the molecular level, forming a complete and defect-free composite hole transport layer, effectively blocking the direct contact of perovskite with the substrate. A multiple synergistic passivation mechanism is established: the modification material forms a firm chemical bond with the substrate through the sulfonate group, while its benzene ring structure provides an ideal nucleation interface for perovskite crystallization. This dual-function synergistic effect of interface anchoring-crystal guiding significantly reduces the interface defect density and non-radiative recombination loss. Excellent process compatibility and stability are obtained: this method only needs to add one simple solution treatment step based on the standard SAM process, which is highly compatible with the existing perovskite device preparation process. At the same time, by removing the unanchored molecules through subsequent cleaning procedures, the cleanliness and stability of the interface are ensured, providing a reliable guarantee for the preparation of high-performance and high-reproducibility perovskite solar cells.

[0058] The third aspect of the embodiments of the present application provides a perovskite solar cell, comprising a substrate, a hole transport layer, a perovskite light absorption layer, and an electron transport layer which are sequentially stacked; wherein the hole transport layer is the hole transport layer of the first aspect, or the hole transport layer is prepared by the preparation method of the hole transport layer of the second aspect.

[0059] Thanks to the precise repair and synergistic passivation of the modification material on the interface, the open-circuit voltage (Voc) and the fill factor (FF) of the cell are simultaneously improved, thereby realizing higher photoelectric conversion efficiency. The complete hole transport layer can effectively block the direct contact of perovskite with the substrate surface, inhibit the interface-induced decomposition of perovskite, and significantly improve the working life and long-term stability of the cell. The cell structure is also compatible with the existing low-temperature solution process.

[0060] In some embodiments, the material of the perovskite light absorption layer has a structural formula of ABX3; wherein the A-site cation is usually a monovalent cation, including at least one of a monovalent metal cation and a monovalent organic cation, wherein the monovalent metal cation is selected from one or more of cesium ion (Cs + ), rubidium ion (Rb + ), lithium ion (Li + ), sodium ion (Na + ), potassium ion (K + ), thallium ion (Tl + ), and the monovalent organic cation is selected from ammonium ion (NH4 + ), methylamine ion (CH3NH3 + ), ethylamine ion (CH3CH2NH3 + ), dimethylamine ion ((CH3)2NH2+ trimethylammonium ion [(CH3)3NH + + formamidinium ion (FA) (HC(NH2)2 + methylformamidinium ion (CH3C(NH2)2 + acetamidinium ion (H3C2(NH2)2 + guanidinium ion [C(NH2)3] + The B-site cation is typically a divalent metal cation selected from one or more of a lead ion (Pb 2+ 2+ 2+ The X-site anion includes one or more of a halide anion, a thiocyanate ion (SCN - - - The halide anion includes at least one of a bromide ion (Br - - -

[0061] Thus, after the perovskite light-absorbing layer is prepared on the hole transport layer, the sulfonate groups of the modifying material, as strong Lewis bases, can preferentially and actively bind to these uncoordinated divalent cations, such as Pb 2+ forming a firm O-Pb coordination bond, directly neutralizing such cationic defects. Meanwhile, the large π-conjugated electron cloud on the benzene ring of the modifying material can further enhance the adsorption and stability of the lead defects through π-Pb 2+ interaction. This synergistic effect of the sulfonate and benzene ring π system constitutes a double passivation mechanism for the interfacial lead defects, greatly reducing the interface state density.

[0062] Further, the perovskite light-absorbing layer has a thickness of 100-1000 nm.

[0063] Optionally, the perovskite solar cell is a single-junction cell or a tandem cell.

[0064] ​​​​​​​​Further, when the perovskite solar cell is a single-junction cell, the substrate comprises a substrate and a transparent conductive layer disposed on the substrate, and the hole transport layer is disposed on the transparent conductive layer, wherein the material of the transparent conductive layer comprises at least one of ITO (indium tin oxide), IZO (indium zinc oxide), IWO (indium tungsten oxide), FTO (fluorine-doped tin oxide), ICO (indium cadmium oxide), AZO (aluminum-doped zinc oxide), ATO (antimony-doped tin oxide), and GZO (gallium-doped zinc oxide).

[0065] Further, the substrate comprises a rigid substrate or a flexible substrate, the material of the rigid substrate comprises, but is not limited to, soda-lime glass and borosilicate glass, and the thickness is 0.5-5 mm, so that the prepared perovskite solar cell is a rigid single-junction cell. The material of the flexible substrate comprises, but is not limited to, polyimide (PI), polyester (PET), polyethylene naphthalate (PEN), or metal foil, so that the prepared perovskite solar cell is a flexible single-junction cell.

[0066] Further, when the perovskite solar cell is a tandem cell, the substrate is a bottom cell structure. The bottom cell of the tandem cell can be a crystalline silicon solar cell, a CIGS thin-film solar cell, a cadmium telluride thin-film solar cell, a III-V thin-film solar cell, or a perovskite solar cell.

[0067] As a specific example, the tandem cell can be a perovskite / crystalline silicon tandem cell, as shown in FIG. 1. Figure 1 As shown in FIG. 1, the perovskite / crystalline silicon tandem cell comprises, from bottom to top, a back grid 1-1, a crystalline silicon bottom cell back film layer 1-2, a crystalline silicon wafer 1-3, a crystalline silicon bottom cell front film layer 1-4, an intermediate connection layer 1-5, a hole transport layer 1-6, a perovskite light absorption layer 1-7, an electron transport layer 1-8, a front transparent conductive layer 1-9, a front anti-reflection film 1-10, and a front grid 1-11, which are sequentially stacked.

[0068] Optionally, the back grid 1-1 can be a silver grid, which can be prepared by screen printing.

[0069] Optionally, the material of the crystalline silicon bottom cell back film layer 1-2 comprises at least one of ITO (indium tin oxide), IZO (indium zinc oxide), IWO (indium tungsten oxide), FTO (fluorine-doped tin oxide), ICO (indium cadmium oxide), AZO (aluminum-doped zinc oxide), ATO (antimony-doped tin oxide), and GZO (gallium-doped zinc oxide). The crystalline silicon bottom cell back film layer 1-2 is prepared by magnetron sputtering deposition, and the thickness can be 80 nm. The back of the crystalline silicon bottom cell back film layer 1-2 is sequentially stacked with a first intrinsic amorphous silicon layer and a p-type amorphous silicon layer.

[0070] Further, the thickness of the p-type amorphous silicon layer can be 10 nm, and the p-type amorphous silicon layer can be prepared by plasma enhanced chemical vapor deposition (PECVD).

[0071] Further, the thickness of the first intrinsic amorphous silicon layer can be 10 nm, and the first intrinsic amorphous silicon layer can be prepared by PECVD.

[0072] Optionally, the crystalline silicon wafer 1-3 can be an n-type silicon wafer or a p-type silicon wafer, and preferably an n-type silicon wafer, and the thickness of the crystalline silicon wafer 1-3 can be 150 microns to 250 microns.

[0073] Optionally, the crystalline silicon bottom cell front surface film layer 1-4 comprises a second intrinsic amorphous silicon layer and an n-type amorphous silicon layer which are sequentially stacked.

[0074] Further, the thickness of the second intrinsic amorphous silicon layer can be 10 nm, and the second intrinsic amorphous silicon layer can be prepared by PECVD.

[0075] Further, the thickness of the n-type amorphous silicon layer can be 10 nm, and the n-type amorphous silicon layer can be prepared by PECVD.

[0076] Optionally, the intermediate connecting layer 1-5 can be prepared by magnetron sputtering deposition, and the thickness of the intermediate connecting layer 1-5 can be about 5-20 nm. The material of the intermediate connecting layer 1-5 comprises at least one of indium tin oxide (ITO), indium zinc oxide (IZO), tungsten-doped indium oxide (IWO), fluorine-doped tin oxide (FTO), indium cadmium oxide (ICO), aluminum-doped zinc oxide (AZO), antimony-doped tin oxide (ATO), and gallium-doped zinc oxide (GZO).

[0077] Optionally, the hole transport layer 1-6 can be prepared by spin coating or slot coating.

[0078] As a specific example, the hole transport layer 1-6 can be prepared by the steps S1-S4 described above. Specifically, a self-assembled monolayer (SAM) material is mixed with a solvent to obtain a self-assembled monolayer solution, and the self-assembled monolayer solution is wetly formed on the intermediate connecting layer 1-5 to obtain a self-assembled monolayer; a solution containing a modification material is spin-coated on the self-assembled monolayer so that the modification material is anchored on the intermediate connecting layer 1-5 which is not covered by the self-assembled monolayer, and then a cleaning solution is added on the self-assembled monolayer to clean the modification material which is not anchored on the intermediate connecting layer 1-5; finally, annealing is performed at 50-150°C for 3-20 min to obtain the hole transport layer 1-6.

[0079] Optionally, the solvent in the self-assembled monolayer solution comprises at least one of methanol, ethanol, isopropanol, and n-propanol. Optionally, the concentration of the modification material in the modification solution containing the modification material is 0.1 mg / mL to 4 mg / mL, and the solvent in the modification solution includes at least one of methanol, ethanol, isopropanol, n-propanol, N,N-dimethylformamide (DMF), and dimethyl sulfoxide (DMSO). The cleaning solution is selected from a solution that can dissolve the modification material, such as an alcohol solution of methanol, ethanol, isopropanol, n-propanol, etc.

[0080] Optionally, a self-assembled monolayer (SAM) material generally has a specific molecular structure, and the SAM molecule generally consists of an anchor group, a linking group, and a terminal group. The anchor group generally contains a polar atom (such as oxygen, nitrogen, sulfur) or an active functional group, and can form a chemical bond (such as a covalent bond, a coordination bond) or a strong hydrogen bond with the hydroxyl group (-OH) or metal atom on the TCO surface. Common types of anchor groups include carboxyl groups (-COOH), phosphonic acid groups (-PO (OH)2), hydroxyl groups (-OH), and thiol groups (-SH). The binding strength of the anchor group directly determines the stability (such as water resistance and heat resistance) of the SAM; if the binding is too weak, the SAM is easily detached, resulting in degradation of the device performance.

[0081] The terminal group is generally in contact with the perovskite light absorption layer, and its main function is to regulate the interface energy level matching, wettability, and charge extraction efficiency of the SAM and the perovskite light absorption layer. Common types of terminal groups include amino groups (-NH2), cyano groups (-CN), alkyl groups (-CH3), and conjugated groups, wherein common types of conjugated structures include benzene rings and thiophenes.

[0082] The linking group is a "skeleton" that connects the anchor group and the terminal group in the SAM molecule, and is generally composed of a carbon chain, which is commonly a C6-C 18 alkyl chain. The length of the linking group determines the spatial distance between the anchor group (TCO side) and the terminal group (perovskite side). The length and chemical properties of the linking group also affect the order, conductivity, and steric hindrance of the SAM.

[0083] Optionally, the SAM material includes: [2 (9H carbazole 9 (9H (3,6 diphenyl 9H carbazole 9 [3,6-dimethoxy-9H-carbazole-9-yl)ethyl]phosphonic acid (Me-2PACz), [3,6-dibromo-9H-carbazole-9-yl)ethyl]phosphonic acid (MeO-2PACz), [3,6-dibromo-9H-carbazole-9-yl)ethyl]phosphonic acid (Br-2PACz), [3,6-dichloro-9H-carbazole-9-yl)ethyl]phosphonic acid (Cl-2PACz), [3,6-difluoro-9H-carbazole-9-yl)ethyl]phosphonic acid (F-2PACz), [4-(9H-carbazole-9-yl)ethyl]phosphonic acid (4PACz), [4 (3,6 dimethyl 9H carbazole 9 [4-butylphosphonic acid (Me-4PACz), [4-butylphosphonic acid (Me-4PACz)] (3,6 Dimethoxy 9H carbazole 9 [4-(3,6-dibromo-9H-carbazole-9-yl)butyl]phosphonic acid (MeO-4PACz), [4-(3,6-dibromo-9H-carbazole-9-yl)butyl]phosphonic acid (Br-4PACz), (4-(3,6-dichloro-9H-carbazole-9-yl)butyl)phosphonic acid (Cl-4PACz), (4-(3,6-difluoro-9H-carbazole-9-yl)butyl)phosphonic acid (F-4PACz), [4 (7H dibenzocarbazole 7 [4-butylphosphonic acid (4PADCB)] (2,7 dibromo 9,9 dimethylacridine 10(9 hydrogens) [2Br-4DMAcPA](2-(4-(4-methoxyphenyl)amino)phenyl)-1-cyanovinyl)phosphonic acid (MPA-CPA), [2-(3,7-dibromo-10H-phenthiazin-10-yl)ethyl]phosphonic acid (Br-2EPT), poly[bis(4-phenyl)(2,4,6-trimethylphenyl)amine](PTAA), 4,4'-cyclohexylbis[N,N-di(4-methylphenyl)aniline](TAPC).

[0084] Optionally, the composition of perovskite light-absorbing layers 1-7 can be Cs. x MA y FA 1-x-y Pb(I zBr 1-z )3, wherein 0≤x≤1, 0≤y≤1, and x+y≤1, 0.7≤z≤1.

[0085] Optionally, the preparation method of the perovskite light absorption layer 1-7 can be: co-evaporating cesium halide and lead halide first, then spin-coating cations on the evaporated layer, and annealing to obtain the perovskite light absorption layer. Further, the preparation method of the perovskite light absorption layer 1-7 can be: using a thermal evaporation method to co-evaporate and deposit a lead iodide (PbI2) and cesium bromide (CsBr) skeleton layer; spin-coating a cation solution with a concentration of 0.1 mol / L to 0.9 mol / L on the skeleton layer. The spin-coating speed of the solution is 2000 rpm to 5000 rpm. Then, annealing at 120 to 180℃ for 5 to 30 min to form the perovskite light absorption layer.

[0086] Further, the deposition rate of PbI2 is 0.1 nm / s to 0.5 nm / s, and the deposition rate of CsBr is 0.01 nm / s to 0.1 nm / s.

[0087] Further, the cation solution includes one or more of formamidinium iodide, formamidinium bromide, methylamine bromide, methylamine iodide, formamidinium chloride, and methylamine chloride.

[0088] Optionally, the material of the electron transport layer 1-8 is tin oxide and fullerene (C 60 ), which can be prepared by atomic layer deposition (ALD) and vacuum thermal evaporation, and the thickness is 10 to 50 nm.

[0089] Optionally, the front transparent conductive layer 1-9 can be one of ITO, IZO, IWO, FTO, ICO, AZO, ATO, and GZO, which can be prepared by magnetron sputtering, and the thickness is 30 to 80 nm.

[0090] Optionally, the front anti-reflection film 1-10 can be LiF or MgF2, and the thickness can be 80 nm to 150 nm.

[0091] Optionally, the front grid line 1-11 can be a silver grid, which can be prepared by screen printing or vacuum thermal evaporation.

[0092] Further, when the perovskite solar cell is a flexible battery, the substrate includes a flexible substrate and a transparent conductive film arranged on the flexible substrate, and the hole transport layer is arranged on the transparent conductive film, wherein the material of the flexible substrate includes polyimide, polyester, polyethylene naphthalate, or a metal foil; and the material of the transparent conductive film includes one of ITO, IZO, IWO, FTO, ICO, AZO, ATO, and GZO.

[0093] The fourth aspect of the embodiments of the present application provides a photovoltaic module comprising the perovskite solar cell of the third aspect of the present application. By integrating the high-performance perovskite solar cell described above, the following advantages are achieved: based on the significant improvement of the conversion efficiency of the cell itself, the photovoltaic module can achieve higher power output per unit area; thanks to the fundamental optimization of the cell interface structure, the module exhibits a lower efficiency decay rate under long-term operating conditions, and the service life is significantly extended.

[0094] The structure or preparation method of the perovskite / crystalline silicon tandem solar cell provided by the embodiments of the present application and the related comparative examples will be tested for performance.

[0095] Example 1 The structure of the perovskite / crystalline silicon tandem solar cell is shown in Figure 1 The preparation method of the perovskite / crystalline silicon tandem solar cell comprises the following steps: Step 1, providing a crystalline silicon bottom cell, which is reserved after being treated with ultraviolet ozone for 15 minutes The crystalline silicon bottom cell comprises an N-type monocrystalline silicon substrate with a thickness of 100 μm, a P-type amorphous silicon film (P face) with a thickness of 10 nm, an indium tin oxide (ITO) transparent conductive layer with a thickness of 20 nm and a back silver electrode with a thickness of 5 μm, which are sequentially deposited on the back surface (backlight surface) of the N-type monocrystalline silicon substrate, and an N-type amorphous silicon film (N face) with a thickness of 10 nm, an indium tin oxide (ITO) composite layer with a thickness of 20 nm, which are sequentially deposited on the light surface of the N-type monocrystalline silicon substrate.

[0096] Step 2, preparation of the hole transport layer The self-assembled monolayer (SAM) material 2PACz is dissolved in anhydrous ethanol and stirred at room temperature in a nitrogen atmosphere glove box until completely dissolved to prepare a SAM solution with a concentration of 0.8 mg / mL. The SAM solution is spin-coated on the indium tin oxide (ITO) composite layer on the front surface (N face) of the crystalline silicon bottom cell at a spin speed of 2000 rpm, and then annealed at 100°C for 8 minutes to form a self-assembled monolayer. A sodium p-toluenesulfonate solution is spin-coated on the self-assembled monolayer, the solution has a concentration of 0.1 mg / mL and a mixed solvent of anhydrous ethanol and DMSO in a volume ratio of 4:1, and the spin speed is 3000 rpm. Then, anhydrous ethanol is added and rotated at 5000 rpm for 10 seconds to remove the sodium p-toluenesulfonate that is not anchored on the ITO composite layer; then annealed at 100°C for 5 minutes to obtain the hole transport layer.

[0097] Step 3, preparation of the perovskite light absorption layer On the hole transport layer, lead iodide (PbI2) and cesium bromide (CsBr) were co-deposited by thermal evaporation method to construct a skeleton layer, wherein the deposition rate of PbI2 was 0.1 nm / s, and the deposition rate of CsBr was 0.01 nm / s. Subsequently, a mixed cation solution with a concentration of 0.6 mol / L was spin-coated on the skeleton layer, the solution containing formamidinium iodide, formamidinium bromide, methylamine bromide and methylamine chloride, and the spin-coating speed was 2500 rpm. Finally, the crystal was formed by annealing at 140°C for 30 minutes to form a high-quality Cs 0.24 MA 0.02 FA 0.74 Pb(I 0.76 Br 0.24 )3 perovskite light absorption layer.

[0098] Step 4, preparation of the electron transport layer On the perovskite light absorption layer, a 20 nm thick fullerene (C 60 ) layer was prepared by thermal evaporation method, and then a 20 nm thick tin oxide layer was prepared on it by atomic layer deposition technology, together constituting the electron transport layer.

[0099] Step 5, preparation of the transparent conductive layer On the electron transport layer, a 60 nm thick indium zinc oxide transparent conductive layer was prepared by magnetron sputtering method.

[0100] Step 6, preparation of the electrode On the indium zinc oxide transparent conductive layer, a 500 nm thick silver grid line was prepared by thermal evaporation process as the front electrode.

[0101]

Example 2

[0102]

Example 3

[0103]

Example 4

[0104]

Example 5

[0105] [Example 6] The other steps of Example 5 are the same as those of Example 1, except that the kind and concentration of the modifying material in Step 2 are different, specifically: the modifying material is isopropyl benzene sulfonate, and the concentration is 2.5 mg / mL.

[0106] [Example 7] The other steps of Example 5 are the same as those of Example 1, except that the kind and concentration of the modifying material in Step 2 are different, specifically: the modifying material is isopropyl benzene sulfonate, and the concentration is 2.5 mg / mL. On the self-assembled monolayer, a layer of sodium p-toluenesulfonate solution is spin-coated, the concentration of the solution is 0.1 mg / mL, the solvent is a mixed solvent of anhydrous ethanol and DMSO in a volume ratio of 4:1, and the spin-coating speed is 3000 rpm. Then, anhydrous ethanol is spin-coated at 5000 rpm for 10 s to remove the modifying molecules that are not firmly anchored on the ITO composite layer.

[0107] [Example 8] The other steps of Comparative Example 8 are the same as those of Example 1, except that the operation of using anhydrous ethanol in combination with 5000 rpm rotation for 10 s in Step 2 is not performed to remove the unanchored modifying molecules.

[0108] [Comparative Example 1] The other steps of Comparative Example 1 are the same as those of Example 1, except that no modifying material is introduced when the hole transport layer is prepared in Step 2, specifically: Step 1, provide a crystalline silicon bottom cell, which is treated with ultraviolet ozone for 15 min and then reserved The crystalline silicon bottom cell includes an N-type monocrystalline silicon substrate with a thickness of 100 μm, a P-type amorphous silicon film (P face) with a thickness of 10 nm, an indium tin oxide (ITO) transparent conductive layer with a thickness of 20 nm, and a back silver electrode with a thickness of 5 μm, which are sequentially deposited on the back surface (backlight surface) of the N-type monocrystalline silicon substrate; and an N-type amorphous silicon film (N face) with a thickness of 10 nm, an indium tin oxide (ITO) composite layer with a thickness of 20 nm, which are sequentially deposited on the light surface of the N-type monocrystalline silicon substrate.

[0109] Step 2, preparation of the hole transport layer The self-assembled monolayer (SAM) material 2PACz was dissolved in anhydrous ethanol and stirred at room temperature in a nitrogen atmosphere glove box until completely dissolved to prepare a SAM solution with a concentration of 0.8 mg / mL. The SAM solution was spin-coated on the indium tin oxide (ITO) composite layer on the front surface (N surface) of the crystalline silicon bottom cell at a spin-coating speed of 2000 rpm, followed by annealing at 100°C for 8 minutes to form a self-assembled monolayer as a hole transport layer.

[0110] Step 3, preparation of a perovskite light absorption layer On the hole transport layer, lead iodide (PbI2) and cesium bromide (CsBr) were sequentially co-deposited by thermal evaporation to construct a framework layer, wherein the deposition rate of PbI2 was 0.1 nm / s and the deposition rate of CsBr was 0.01 nm / s. Subsequently, a mixed cation solution with a concentration of 0.6 mol / L was spin-coated on the framework layer, the solution containing formamidinium iodide, formamidinium bromide, methylamine bromide, and methylamine chloride, and the spin-coating speed was 2500 rpm. Finally, annealing was performed at 140°C for 30 minutes to crystallize and form a high-quality Cs 0.24 MA 0.02 FA 0.74 Pb(I 0.76 Br 0.24 )3 perovskite light absorption layer.

[0111] Step 4, preparation of an electron transport layer On the perovskite light absorption layer, a 20 nm thick fullerene (C 60 ) layer was prepared by thermal evaporation, and then a 20 nm thick tin oxide layer was prepared on it using atomic layer deposition technology, together constituting an electron transport layer.

[0112] Step 5, preparation of a transparent conductive layer On the electron transport layer, a 60 nm thick indium zinc oxide transparent conductive layer was prepared by magnetron sputtering.

[0113] Step 6, preparation of an electrode On the indium zinc oxide transparent conductive layer, a 500 nm thick silver grid line was prepared as a front electrode by thermal evaporation process.

[0114] IV tests were performed on Examples 1-8 and Comparative Example 1, and the results are shown in Table 1. The following provides an explanation of the terms of the present application.

[0115] As used herein, the fill factor (FF) is the ratio of the actual maximum obtainable power (Pm or Vmp x Jmp) to the theoretical (non-actually obtainable) power (Jsc x Voc). Thus, FF can be determined by the equation: FF = (Vmp x Jmp) / (Jsc x Voc), where Jmp and Vmp represent the current density and voltage at the maximum power point (Pm), which is obtained by changing the resistance in the circuit until J x V is maximized; Jsc and Voc represent the short-circuit current and open-circuit voltage, respectively. The fill factor is a key parameter for evaluating solar cells. Commercial solar cells usually have a fill factor of about 60% or more.

[0116] As used herein, the open-circuit voltage (Voc) is the potential difference between the anode and cathode of the device under the condition of no connected external load.

[0117] As used herein, the short-circuit current density (Isc) is the maximum current density flowing through the photovoltaic cell or module output when short-circuited (voltage V = 0) under the STC condition.

[0118] As used herein, the power conversion efficiency (PCE) of a solar cell refers to the percentage of power converted from absorbed light to electrical energy. The power conversion efficiency (PCE) of a solar cell can be calculated by dividing the maximum power point (Pm) by the incident light radiation intensity (E: W / m 2 ) and the surface area (Ac: m 2 ) of the solar cell under standard test conditions (STC). STC usually refers to a spectrum with a temperature of 25°C, a radiation intensity of 1000 W / m 2 , and an air mass of 1.5 (AM1.5).

[0119] Table 1:

[0120] As can be seen from Table 1, coating the modification material on the SAM layer can effectively achieve precise repair and synergistic passivation of the hole transport layer / perovskite interface. Thanks to this interface optimization, the battery performance of Examples 1-8 is better than that of Comparative Example 1, specifically, the open-circuit voltage and fill factor are significantly improved, thereby obtaining a higher photoelectric conversion efficiency. As can be seen from Comparative Example 1 and Example 7, annealing after coating the modification material can further improve the battery efficiency. As can be seen from Comparative Example 1 and Example 8, washing the modification material attached to the SAM layer after coating the modification material can further improve the battery efficiency.

[0121] Comparing the comparative example 1 and the comparative example 2, it can be seen that after the SAM layer is prepared, coating the modification material can effectively improve the battery efficiency cleaning. The embodiments of the present application can also provide a photovoltaic module (not shown), which comprises the perovskite solar cell as described above. The perovskite solar cell can be connected in series and / or parallel with one or more other solar cells in a preset manner. Among them, a plurality of cells can form a cell string, and adjacent cells can be connected together by string welding.

[0122] It should also be noted that the "one embodiment", "another embodiment", "embodiment" and the like mentioned in the present application refer to the specific features, structures or characteristics described in conjunction with the embodiment, which are included in at least one embodiment described in the general description of the present application. The same expression appearing in several places in the specification does not necessarily refer to the same embodiment. Further, when a specific feature, structure or characteristic is described in conjunction with any embodiment, it is claimed that the implementation of such feature, structure or characteristic in conjunction with other embodiments also falls within the scope of the present application.

[0123] In the above embodiments, the description of each embodiment has its own emphasis, and the parts not described in detail in a certain embodiment can be referred to the relevant description of other embodiments.

[0124] It should also be noted that the above is only the preferred embodiment of the present application, and does not limit the patent protection scope of the present application, and any equivalent structure or equivalent process transformation using the content of the present application specification and drawings, or directly or indirectly used in other related technical fields, are also included in the patent protection scope of the present application.

Claims

1. A hole transport layer, characterized in that, It includes a self-assembled monolayer and a modifying material, wherein the modifying material is anchored on a substrate not covered by the self-assembled monolayer; The modifying material includes the compound shown in formula (1): R1 to R5 are each independently selected from hydrogen, substituted or unsubstituted alkyl, alkoxy, halogen, nitro, substituted or unsubstituted amino, cyano or hydroxyl groups with a carbon chain length of 1 to 6. M is selected from H, metal cations, substituted or unsubstituted alkyl groups with a carbon chain length of 1 to 6, or -S(=O)2-Ar'; Ar' is a substituted or unsubstituted phenyl group.

2. The hole transport layer according to claim 1, characterized in that, R1 to R5 are each independently selected from hydrogen, methyl, tert-butyl, methoxy, fluorine, chlorine, bromine, iodine, nitro, amino, cyano, hydroxyl, trifluoromethyl, -NHCl, -NHCH3, -CF3 or -C(CH3)3; M is selected from H and Na. + K + Zn 2+ Fe 3+ Methyl, ethyl, isopropyl, butyl, cyanomethyl, or p-toluenesulfonyl.

3. The hole transport layer according to claim 1, characterized in that, The modifying materials include p-toluenesulfonic acid, p-toluenesulfonic anhydride, sodium p-toluenesulfonate, iron p-toluenesulfonate, zinc p-toluenesulfonate, o-toluenesulfonic acid, m-toluenesulfonic acid, aminobenzenesulfonic acid, xylenesulfonic acid, potassium xylenesulfonate, p-chlorobenzenesulfonic acid, o-iodobenzenesulfonic acid, p-hydroxybenzenesulfonic acid, butyl p-nitrobenzenesulfonate, isopropyl benzenesulfonate, propyl benzenesulfonate, ethyl o-toluenesulfonate, ethyl benzenesulfonate, ethyl m-nitrobenzenesulfonate, ethyl p-fluorobenzenesulfonate, ethyl p-toluenesulfonate, ethyl 4-amino-3-chloro-5-toluenesulfonate, ethyl 4-amino-3-methylbenzenesulfonate, and 4-chlorobenzenesulfonate. Ethyl benzene sulfonate, ethyl 2-nitrobenzenesulfonate, ethyl 2-bromobenzenesulfonate, ethyl 2,4-dimethylbenzenesulfonate, ethyl 4-(trifluoromethyl)benzenesulfonate, ethyl 4-tert-butylbenzenesulfonate, ethyl 3-nitrobenzenesulfonate, methyl p-fluorobenzenesulfonate, methyl p-toluenesulfonate, methyl 3-aminobenzenesulfonate, methyl 2,4,6-trimethylbenzenesulfonate, methyl 4-chlorobenzenesulfonate, methyl p-aminobenzenesulfonate, methyl p-nitrobenzenesulfonate, methyl 2,4-dimethylbenzenesulfonate, methyl 2,4,6-trichlorophenyl-2-cyanobenzenesulfonate, cyanomethylbenzenesulfonate, and 4-bromobenzenesulfonic acid.

4. A method for preparing a hole transport layer, characterized in that, include: Prepare self-assembled monolayers on a substrate; A modification solution comprising a modification material is provided, and a film is formed on a self-assembled monolayer using the modification solution, so that the modification material is anchored on a substrate not covered by the self-assembled monolayer; A cleaning process is performed to remove the decorative material that is not anchored to the substrate; Annealing is performed to obtain the hole transport layer; The modifying material includes the compound shown in formula (1): R1 to R5 are each independently selected from hydrogen, substituted or unsubstituted alkyl, alkoxy, halogen, nitro, substituted or unsubstituted amino, cyano or hydroxyl groups with a carbon chain length of 1 to 6. M is selected from H, metal cations, substituted or unsubstituted alkyl groups with a carbon chain length of 1 to 6, or -S(=O)2-Ar'; Ar' is a substituted or unsubstituted phenyl group.

5. The method for preparing the hole transport layer as described in claim 4, characterized in that, The concentration of the modified material is 0.1 mg / mL to 4 mg / mL.

6. The method for preparing the hole transport layer as described in claim 5, characterized in that, The cleaning process includes: The cleaning solution and the modification material are mixed to form a mixture, and a portion of the mixture is removed to remove the unanchored modification material. The cleaning solution includes alcohol solvents.

7. The method for preparing a hole transport layer as described in claim 4, characterized in that, The annealing temperature is 50℃~150℃; and / or, The annealing process takes 3 to 20 minutes.

8. The method for preparing a hole transport layer as described in claim 4, characterized in that, The preparation of a self-assembled monolayer on a substrate includes: Provides self-assembled monomolecular solutions; The concentration of the self-assembled monomolecular material in the self-assembled monomolecular solution is 0.1 mg / mL to 3 mg / mL. The self-assembled monomolecule solution was used to form a wet film on the substrate, and then annealed at a temperature of 80°C to 120°C for 5 min to 20 min.

9. A perovskite solar cell, characterized in that, It includes a substrate, a hole transport layer, a perovskite light absorption layer, and an electron transport layer that are stacked sequentially. Wherein, the hole transport layer is the hole transport layer according to any one of claims 1 to 3; Alternatively, the hole transport layer is a hole transport layer prepared by the method described in any one of claims 4 to 8.

10. A photovoltaic module comprising the perovskite solar cell of claim 9.

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