Connecting layer, composite layer, solar cell and laminated cell

Abstract

The embodiment of the invention provides a connecting layer, a composite layer, a solar cell and a laminated cell. The connecting layer comprises a first transparent conductive layer and a hole transport layer which are stacked; and the hole transport layer is an alloy film containing Ga, Al, In, Sn, O and N elements. Component regulation and control are carried out on the hole transport layer, P-type doping is realized by utilizing a co-doping strategy, the hole concentration of a traditional tin oxide material layer is improved, long wavelength absorption is not remarkably increased, and in addition, multi-component doping can also avoid that a single component is easy to separate out and split phases.

Description

Technical Field

[0001] This application relates to the field of solar cell technology, and specifically to a connecting layer, a composite layer, a solar cell, and a tandem cell. Background Technology

[0002] With the improvement of my country's energy structure, more and more new energy sources are replacing traditional thermal power generation. Among them, solar energy is a renewable energy source. Solar power generation is simple to install, requires little site space, and is suitable for various occasions and needs. Therefore, it is widely used in various fields.

[0003] Perovskite solar cells (PSCs) represent a new generation of photovoltaic technology, attracting significant research attention due to their high photoelectric conversion efficiency and low-cost solution processing. With the evolution of photovoltaic technology, the need to overcome the Schockley-Queisser limit to achieve even higher photoelectric conversion efficiency has spurred the rapid development of tandem solar cells.

[0004] In perovskite and tandem solar cells, the hole transport layer is the core functional component of the composite junction, and its performance directly determines the device's efficiency and long-term stability. Currently, commonly used hole transport layer schemes are mainly divided into two categories, but both have significant limitations.

[0005] The first approach uses inorganic metal oxides, such as nickel oxide, tin oxide, and their ternary alloys. These nanocrystals are typically prepared using liquid-phase or solid-phase methods, followed by p-type doping to adjust conductivity and band structure. However, nanocrystals prepared by this method are prone to aggregation, leading to uneven liquid-phase reactions and difficulty in obtaining uniformly ion-doped p-type nanocrystal films. This results in poor quality control and reproducibility of the hole transport layer, hindering large-scale production. More importantly, traditional metal oxides, such as nickel oxide, undergo interfacial deprotonation reactions with the overlying perovskite active layer, severely impacting the long-term stability of perovskite solar cells.

[0006] The second approach addresses the low efficiency of the aforementioned inorganic materials by introducing organic self-assembled monolayer (SAM) materials. For example, naphthodithiophene compounds, aminosiloxanes, or molecules containing phosphate or carboxylic acid groups are used to modify the inorganic hole transport layer (such as nickel oxide). While these SAM materials can improve interfacial energy level matching to some extent, the inherent tendency of nanoparticles to aggregate makes it difficult for their surfaces to be fully and uniformly modified by SAM molecules. Furthermore, the bonding force between organic small molecules and inorganic materials is typically weak. Under the stress conditions of light, heat, water, and oxygen during actual solar cell operation, the SAM layer is prone to aging, detachment, or failure, leading to rapid performance degradation of the device.

[0007] Given the problems with existing technologies, it is essential to develop a new type of solar cell.

[0008] It should be noted that the above content is not necessarily prior art, nor is it intended to limit the scope of patent protection of this application. Summary of the Invention

[0009] This application provides a connecting layer, a composite layer, a solar cell, and a stacked cell to solve or alleviate one or more of the technical problems mentioned above.

[0010] A first aspect of this application provides a connection layer, the connection layer comprising a first transparent conductive layer and a hole transport layer stacked together; The hole transport layer is an alloy thin film containing Ga, Al, In, Sn, O, and N elements.

[0011] Optionally, the hole transport layer is a P-type alloy thin film containing Ga, Al, In, Sn, O and N elements; Optionally, the thickness of the hole transport layer is 7-20 nm; Optionally, the thickness of the first transparent conductive layer is 20-100 nm.

[0012] Optionally, a transition metal oxide layer is further disposed between the first transparent conductive layer and the hole transport layer; Optionally, the thickness of the transition metal oxide layer is 5-15 nm; Optionally, the material of the transition metal oxide layer includes any one or a combination of at least two of nickel oxide, titanium oxide, molybdenum trioxide, tungsten trioxide, or copper oxide.

[0013] A second aspect of this application provides a method for preparing a connecting layer, the method comprising: forming a hole transport layer on one side surface of a first transparent conductive layer by magnetron sputtering; In the magnetron sputtering method, a multi-component oxide is used as the target material, an inert gas is used as the sputtering gas, and a nitrogen-containing gas is used as the reaction gas.

[0014] Optionally, the multi-component oxide comprises 1-3 wt% Ga2O3, 5-10 wt% SnO2, 0.5-1.5 wt% Al2O3, and 85-95 wt% In2O3.

[0015] Optionally, the magnetron sputtering method has a sputtering power of 500-1000 W and a gas pressure of 10 W. -5 -5×10 -4 Pa.

[0016] Optionally, the preparation method further includes: before forming the hole transport layer, a transition metal oxide layer is pre-formed in the first transparent layer; Optionally, the transition metal oxide layer may be formed by any one of solution method, physical vapor deposition, atomic layer deposition or inkjet printing.

[0017] A third aspect of this application provides a composite layer, the composite layer comprising the aforementioned connecting layer and a perovskite absorber layer; Optionally, the perovskite absorber layer is disposed on the surface of the hole transport layer away from the first transparent conductive layer; Optionally, the thickness of the perovskite absorber layer is 600-1200 nm.

[0018] Optionally, a SAM layer is further disposed between the hole transport layer and the perovskite absorber layer; Optionally, the thickness of the SAM layer is 1-10 nm; Optionally, the SAM layer is made of SAM material, or a combination of SAM material and passivation material; Optionally, the molar ratio of the SAM material to the passivation material is 1:(0.1-1).

[0019] A fourth aspect of this application provides a perovskite solar cell, the perovskite solar cell comprising a composite layer, an electron transport layer and an electrode layer stacked together; The composite layer is the composite layer described in the third aspect; In the composite layer, the surface of the perovskite absorber layer away from the hole transport layer is connected to the electron transport layer.

[0020] A fifth aspect of this application provides a stacked battery, the stacked battery comprising a base battery, a composite layer, an electron transport layer, a second transparent conductive layer, and an electrode layer; The composite layer is the composite layer described above; In the composite layer, the first transparent conductive layer is connected to the bottom battery, and the perovskite absorption layer is connected to the electron transport layer.

[0021] A sixth aspect of this application provides a photovoltaic module, which includes the solar cell described in the fourth aspect, or the tandem cell described in the fifth aspect.

[0022] The embodiments of this application employing the above-described technical solution may have the following advantages: This application improves the hole concentration of traditional tin oxide material layers by controlling the composition of the hole transport layer and using a co-doping strategy to achieve P-type doping without significantly increasing long-wavelength absorption. In addition, multi-component doping can also avoid the easy precipitation and phase separation of single components. Attached Figure Description

[0023] In the accompanying drawings, unless otherwise specified, the same reference numerals throughout the various drawings denote the same or similar parts or elements. These drawings are not necessarily drawn to scale. It should be understood that these drawings depict only some embodiments disclosed in this application and should not be construed as limiting the scope of this application.

[0024] Figure 1 This is a schematic diagram of the structure of the solar cell in a specific embodiment of this application; Figure 2 This is a schematic diagram of the structure of the stacked battery in a specific embodiment of this application; Figure 3 This is a cross-sectional scanning electron microscope image of the composite layer after the formation of the perovskite absorber layer in Example 7 of this application; Figure 4 This is a cross-sectional scanning electron microscope image of the composite layer after the formation of the perovskite absorber layer in Comparative Example 4 of this application; Explanation of reference numerals in the attached figures: 0. Bottom cell; 1. First transparent conductive layer; 2. Hole transport layer; 3. Perovskite absorber layer; 4. Electron transport layer; 5. Electrode layer; 6. Second transparent conductive layer. Detailed Implementation

[0025] The embodiments of this application are described in detail below, examples of which are illustrated in the accompanying drawings. In the drawings, for clarity, the dimensions of layers, regions, and elements, as well as their relative dimensions, may be exaggerated. Throughout, the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain this application, and should not be construed as limiting this application. It should be noted that, unless otherwise specified, the embodiments and features in the embodiments of this application can be combined with each other.

[0026] It should be understood that when an element or layer is referred to as "on," "adjacent to," "connected to," or "coupled to" other elements or layers, it may be directly on, adjacent to, connected to, or coupled to other elements or layers, or there may be intervening elements or layers. Conversely, when an element is referred to as "directly on," "directly adjacent to," "directly connected to," or "directly coupled to" other elements or layers, there are no intervening elements or layers. It should be understood that although the terms first, second, third, etc., may be used to describe various elements, components, areas, layers, and / or portions, these elements, components, areas, layers, and / or portions should not be limited by these terms. These terms are only used to distinguish one element, component, area, layer, or portion from another element, component, area, layer, or portion. Therefore, without departing from the teachings of this application, the first element, component, area, layer, or portion discussed below may be referred to as a second element, component, area, layer, or portion. And the discussion of a second element, component, area, layer, or portion does not imply that the first element, component, area, layer, or portion necessarily exists in this application.

[0027] In this application, unless otherwise expressly specified and limited, the terms "installation," "connection," "joining," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components, unless otherwise expressly limited. Those skilled in the art can understand the specific meaning of the above terms in this application according to the specific circumstances.

[0028] It should be noted that the terms "first," "second," etc., in the specification, claims, and accompanying drawings of this application are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that such terms can be used interchangeably where appropriate so that the embodiments of this application described herein can be implemented, for example, in orders other than those illustrated or described herein. Furthermore, the terms "comprising" and "having," and any variations thereof, are intended to cover a non-exclusive inclusion; for example, a process, method, system, product, or apparatus that comprises a series of steps or units is not necessarily limited to those steps or units explicitly listed, but may include other steps or units not explicitly listed or inherent to such processes, methods, products, or apparatus.

[0029] In this application, when numerical intervals (i.e., numerical ranges) are involved, unless otherwise specified, the distribution of selectable numerical values ​​within the numerical interval is considered continuous, and includes the two endpoints of the numerical interval (i.e., the minimum and maximum values), as well as every numerical value between these two endpoints. Unless otherwise specified, when a numerical interval refers only to integers within that numerical interval, it includes the two endpoint integers of the numerical range, as well as every integer between the two endpoints, which is equivalent to directly listing every integer. When multiple numerical ranges are provided to describe features or characteristics, these numerical ranges can be merged. In other words, unless otherwise specified, the numerical ranges disclosed in this application should be understood to include any and all subranges included therein. The "numerical value" in the numerical interval can be any quantitative value, such as a number, percentage, ratio, etc. The term "numerical interval" can be broadly included to include percentage intervals, ratio intervals, proportion intervals, etc.

[0030] This application provides a technical solution for a connecting layer, a composite layer, a solar cell, and a tandem cell. Details are provided below.

[0031] Exemplary embodiments according to this application will now be described in more detail with reference to the accompanying drawings. It should be understood that these exemplary embodiments may be implemented in many different forms and should not be construed as being limited to the embodiments set forth herein.

[0032] This application provides a connection layer, which includes a first transparent conductive layer and a hole transport layer stacked together. The hole transport layer is an alloy thin film containing Ga, Al, In, Sn, O, and N elements.

[0033] This application improves the hole concentration of traditional tin oxide material layers by controlling the composition of the hole transport layer and using a co-doping strategy to achieve P-type doping without significantly increasing long-wavelength absorption. In addition, multi-component doping can also avoid the easy precipitation and phase separation of single components.

[0034] It should be noted that the hole transport layer in this application is a P-type multi-element alloy thin film, which will be referred to as a P-type GaAlInSnON multi-element alloy thin film for the convenience of subsequent description.

[0035] In some embodiments, the thickness of the hole transport layer is 7-20 nm (exemplary thicknesses include 7 nm, 10 nm, 12 nm, 15 nm, 18 nm, 20 nm, etc.). The thickness of the first transparent conductive layer is 20-100 nm (exemplary thicknesses include 20 nm, 30 nm, 40 nm, 50 nm, 60 nm, 70 nm, 80 nm, 90 nm, 100 nm, etc.).

[0036] In some embodiments, the material of the first transparent conductive layer includes, but is not limited to, ITO, IZO, IWO, FTO, ICO, and AZO, and the preparation method includes, but is not limited to, magnetron sputtering (PVD) and reactive plasma deposition (RPD). In this application, by setting the thickness of the hole transport layer, it is possible to minimize the absorption of incident light and the transport path of charge carriers while ensuring sufficient hole transport capacity, thereby reducing the series resistance.

[0037] In this application, by limiting the thickness of the first transparent conductive layer, conductivity and light transmittance can be balanced.

[0038] In some embodiments, a transition metal oxide layer is further disposed between the first transparent conductive layer and the hole transport layer; The thickness of the transition metal oxide layer is 5-15 nm (exemplary thicknesses include 5 nm, 8 nm, 10 nm, 12 nm, 15 nm, etc.). The material of the transition metal oxide layer includes any one or a combination of at least two of nickel oxide, titanium oxide, molybdenum trioxide, tungsten trioxide, or copper oxide.

[0039] In this application, by setting a transition metal oxide layer and controlling its thickness within the aforementioned range, an efficient hole transport channel and optimized energy level can be formed with the upper P-type GaAlInSnON multi-element alloy thin film; at the same time, it can prevent metal ions in the first transparent conductive layer from migrating upward, thereby significantly enhancing the thermal stability and operating life of the device.

[0040] This application provides a method for preparing a connecting layer, the method comprising: forming a hole transport layer on one side surface of a first transparent conductive layer by magnetron sputtering; In the magnetron sputtering method, a multi-component oxide is used as the target material, an inert gas is used as the sputtering gas, and a nitrogen-containing gas is used as the reaction gas.

[0041] In some embodiments, the multi-component oxide comprises 1-3 wt% (exemplary, 1 wt%, 1.5 wt%, 2 wt%, 2.5 wt%, 3 wt%, etc.) of Ga2O3, 5-10 wt% (exemplary, 5 wt%, 6 wt%, 7 wt%, 8 wt%, 9 wt%, 10 wt%, etc.) of SnO2, 0.5-1.5 wt% (exemplary, 0.5 wt%, 0.8 wt%, 1 wt%, 1.2 wt%, 1.5 wt%, etc.) of Al2O3, and 85-95 wt% (exemplary, 85 wt%, 88 wt%, 90 wt%, 92 wt%, 95 wt%, etc.) of In2O3.

[0042] In some descriptions, the inert gas is argon.

[0043] In some embodiments, the nitrogen-containing gas is nitric oxide (NO).

[0044] In some embodiments, the magnetron sputtering method uses a sputtering power of 500-1000 W (exemplary sputtering powers include 500 W, 600 W, 700 W, 800 W, 900 W, 1000 W, etc.) and an air pressure of 10. -5 ~5×10 -4 Pa (for example, air pressure is 10) -5 Pa, 3×10 -5 Pa, 5×10 -5 Pa, 7×10 -5 Pa, 10 -4 Pa, 3×10 -4 Pa, 5×10 -4 Pa, etc.

[0045] In this application, a hole transport layer is prepared by magnetron sputtering. Based on a specific target material and reactive gas configuration, multi-component co-doping of Ga, Al, In, Sn, O, and N is achieved, thereby realizing P-type conductivity. This not only avoids the problems associated with traditional NiO but also... x The deprotonation side reaction between the material and the perovskite interface improves the chemical stability of the interface. At the same time, its dense thin film structure can effectively block the migration of underlying metal ions, laying the core material foundation for the preparation of high-efficiency and stable perovskite batteries and tandem batteries.

[0046] The hole transport layer formed by this method has advantages such as good density, good uniformity, no pinholes, and strong adhesion to the first transparent conductive layer. It also achieves room temperature preparation of the hole transport layer, which is convenient for large-scale industrial production and application.

[0047] This application provides a composite layer, which includes the above-described connecting layer and perovskite absorber layer; The perovskite absorber layer is disposed on the surface of the hole transport layer on the side away from the first transparent conductive layer. The thickness of the perovskite absorber layer is 600-1200 nm (exemplary thicknesses include 600 nm, 700 nm, 800 nm, 900 nm, 1000 nm, 1100 nm, 1200 nm, etc.).

[0048] In this application, by setting a hole transport layer on the surface of the connecting layer and limiting the thickness of the hole transport layer, it is possible to fully absorb sunlight and generate sufficient photogenerated carriers, while avoiding the problem of excessively long carrier transport distance and increased recombination due to excessive thickness, thereby achieving an optimal balance between light absorption and charge collection.

[0049] In this application, the perovskite absorber layer is made of a perovskite structure material with the general ABX3 structure formula.

[0050] Wherein: the A-site cation is usually a monovalent cation, including at least one of a monovalent metal cation and a monovalent organic cation; The monovalent metal cation is selected from cesium ions (Cs). + ), rubidium ions (Rb + Lithium ion (Li) + Sodium ions (Na) + ), potassium ions (K) + ), thallium ions (Tl) + Any one or at least two of the following; Monovalent organic cations are selected from ammonium ions (NH4+) + ), Methylamine ion (MA) (CH3NH3) + ), ethylammonium ion (CH3CH2NH3) + ), dimethylamine ion ((CH3)2NH2) + ), trimethylammonium ion ((CH3)3NH + ), tetramethylammonium ion ((CH3)4N + ), formamidinium ion (FA) (HC(NH2)2) + ), Methylformamidinium ion (CH3C(NH2)2 + Acetamidinium ion (H3C2(NH2)2) + ), guanidine ion (C(NH2)3) + Any one or at least two of the following.

[0051] The B-site cation is usually a divalent metal cation, selected from lead ions (Pb). 2+ ), tin ions (Sn)2+ or germanium ions (Ge 2 + Any combination of one or at least two of the following.

[0052] The X-position anion is a halide anion, including bromide ions (Br). - ), iodide ions (I - ), chloride ions (Cl) - ), thiocyanate ions (SCN) - ), tetrafluoroborate ion (BF4) - ) or hexafluoroborate ion (BF6) - Any one or at least two of the following.

[0053] As a preferred technical solution of this application, the perovskite structural material is selected from FAPbI3, MAPbI3, CsPbI3 or Cs x FA 1-x Pb(Br y I 1-y Any one or at least two of the following 3, wherein 0.1 <x<0.3,0.15<y<0.4。

[0054] In some embodiments, the perovskite structure includes a first precursor compound and a second precursor compound. The first precursor compound has the chemical formula AX and includes any one or a combination of at least two of FAI (formamidine iodide), FABr (formamidine bromide), MAI (methylammonium iodide), MABr (methylammonium bromide), CsI (cesium iodide), and CsBr (cesium bromide). The second precursor compound has the chemical formula BX2 and includes any one or a combination of at least two of PbI2 (lead iodide), PbBr2 (lead bromide), SnI2 (stannous iodide), and SnBr2 (stannous bromide).

[0055] Understandably, the molar ratio of the first precursor compound to the second precursor compound is usually 1:1, so as to control the molar ratio of A ions, B ions, and X ions to be 1:1:3. In this way, after annealing, a perovskite structure with the general formula ABX3 can be obtained to form a perovskite absorption layer.

[0056] In some embodiments, the preparation process of the perovskite absorber layer includes: first forming a perovskite precursor layer, and then annealing and crystallizing it.

[0057] In some embodiments, the method of forming the perovskite precursor layer includes coating or vapor deposition.

[0058] The coating process includes slot coating, blade coating, or spin coating.

[0059] When using the coating method, the perovskite structural material is mixed with a solvent to form a precursor solution, and the coating is performed using the precursor solution.

[0060] In the precursor solution, the molar concentration of the perovskite structure material is 1-2 mol / L (exemplary molar concentrations are 1 mol / L, 1.2 mol / L, 1.5 mol / L, 1.8 mol / L, 2 mol / L, etc.).

[0061] The solvent in the precursor solution includes any one or a combination of at least two of N,N-dimethylformamide (DMF), N,N-dimethylacetamide (DMAc), N-methylpyrrolidone (NMP) or dimethyl sulfoxide (DMSO), preferably a combination of DMF and NMP, a combination of DMF and DMI, or a combination of DMF and DMSO.

[0062] When the solvent is a combination of DMF and NMP, the volume ratio of DMF to NMP is 4:1; When the solvent is a combination of DMF and DMI, the volume ratio of DMF to DMI is 9:1; When the solvent is a combination of DMF and DMSO, the volume ratio of DMF to DMSO is 4:1.

[0063] In some embodiments, the annealing crystallization temperature is 90-150°C (exemplary temperatures are 90°C, 100°C, 110°C, 120°C, 130°C, 140°C, 150°C, etc.), and the time is 5-30 min (exemplary times are 5 min, 10 min, 15 min, 20 min, 25 min, 30 min, etc.).

[0064] When using the vapor deposition method, lead iodide (PbI2) and cesium bromide (CsBr) framework layers are co-deposited by thermal evaporation. Next, a monovalent cation solution is spin-coated onto the framework layer, followed by annealing to form a perovskite absorber layer.

[0065] In some embodiments, the deposition rate of lead iodide is 0.1-0.5 nm / s (exemplary deposition rates are 0.1 nm / s, 0.2 nm / s, 0.3 nm / s, 0.4 nm / s, 0.5 nm / s, etc.), and the deposition rate of cesium bromide is 0.01-0.1 nm / s (exemplary deposition rates are 0.01 nm / s, 0.03 nm / s, 0.05 nm / s, 0.08 nm / s, 0.1 nm / s, etc.).

[0066] In some embodiments, the concentration of the monovalent cation solution is 0.1-0.9 mol / L (exemplary concentrations are 0.1 mol / L, 0.3 mol / L, 0.5 mol / L, 0.7 mol / L, 0.9 mol / L, etc.).

[0067] In some embodiments, the spin coating rate is 2000-5000 rpm (exemplary rates include 2000 rpm, 3000 rpm, 4000 rpm, 5000 rpm, etc.).

[0068] In some embodiments, the annealing temperature is 120-180°C (exemplary temperatures are 120°C, 130°C, 140°C, 150°C, 160°C, 170°C, 160°C, etc.) and the time is 5-30 min (exemplary times are 5 min, 10 min, 15 min, 20 min, 25 min, 30 min, etc.).

[0069] In some embodiments, a SAM layer is further disposed between the hole transport layer and the perovskite absorber layer; In some embodiments, the thickness of the SAM layer is 1-10 nm (exemplary thicknesses include 1 nm, 2 nm, 3 nm, 5 nm, 7 nm, 10 nm, etc.). The SAM layer is made of SAM material, or a combination of SAM material and passivation material; The molar ratio of the SAM material to the passivation material is 1:(0.1-1) (exemplary molar ratios include 1:0.1, 1:0.3, 1:0.5, 1:0.8, 1:1, etc.).

[0070] In this application, by setting a SAM layer between the hole transport layer and the perovskite absorption layer, it is possible to achieve precise control of the interface energy level and effective passivation of interface defects at the bottom of the perovskite without introducing almost any additional light absorption and series resistance, thereby synergistically improving the open-circuit voltage, fill factor and stability of the device.

[0071] When the SAM layer is a combination of SAM material and passivation material, it can further achieve precise control of interface energy levels and effective passivation of interface defects at the bottom of the perovskite, thereby synergistically improving the open-circuit voltage, fill factor and stability of the device.

[0072] In some embodiments, the organic small molecule material is a SAM (self-assembled monolayer) material. SAM molecules can form a monolayer on the substrate surface through self-assembly, thereby playing a role in regulating interface properties, promoting charge transport, and reducing non-radiative recombination.

[0073] In some embodiments, SAM materials typically possess a specific molecular structure. SAM molecules generally consist of anchoring groups, linking groups, and terminal groups. Anchoring groups typically contain polar atoms (such as oxygen, nitrogen, and sulfur) or active functional groups, capable of forming chemical bonds (such as covalent bonds, coordinate bonds) or strong hydrogen bonds with hydroxyl groups (-OH) or metal atoms on the TCO surface. Common types of anchoring groups include carboxyl groups (-COOH), phosphonic acid groups (-PO(OH)2), hydroxyl groups (-OH), or thiol groups (-SH). The bonding strength of the anchoring groups directly determines the stability of the SAM (such as water resistance and heat resistance); if the bonding is too weak, the SAM is prone to detachment, leading to device performance degradation.

[0074] Terminal groups typically contact the perovskite absorber layer, and their main function is to regulate the interfacial energy level matching, wettability, and charge extraction efficiency between SAM and the perovskite absorber layer. Common types of terminal groups are amino (-NH2), cyano (-CN), alkyl (-CH3), or conjugated groups, among which the common types of conjugated structures are benzene rings or thiophenes.

[0075] Linking groups are the "backbone" of SAM molecules, connecting the anchoring group and the terminal group. They are typically composed of carbon chains, commonly C6-C18 alkyl chains. The length of the linking group determines the spatial distance between the anchoring group (TCO side) and the terminal group (perovskite side). The length and chemical properties of the linking group also affect the orderliness, conductivity, and steric hindrance of the SAM.

[0076] In some embodiments, the SAM material includes: [2] (9H carbazole 9 [2-ethyl]phosphonic acid (2PACz), ... (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) or 4,4'-cyclohexylbis[N,N-di(4-methylphenyl)aniline](TAPC) (any one or a combination of at least two of these.

[0077] In some embodiments, the fabrication process of the SAM layer is as follows: The SAM material is mixed with a solvent and stirred at room temperature in a glove box under a nitrogen atmosphere until completely dissolved to obtain a SAM solution. The concentration of SAM material in the hole transport layer solution is 0.1-3 mg / mL (exemplary concentrations are 0.1 mg / mL, 0.5 mg / mL, 1 mg / mL, 1.5 mg / mL, 2 mg / mL, 2.5 mg / mL, and 3 mg / mL). In a glove box under a nitrogen atmosphere, the SAM solution is coated to obtain a wet film; then it is placed on a hot plate at 80-120°C (exemplary temperatures are 80°C, 90°C, 100°C, 110°C, and 120°C) for annealing for 5-20 minutes (exemplary times are 5 minutes, 10 minutes, 15 minutes, and 20 minutes) to form a SAM layer.

[0078] In some alternative implementations, the SAM solution can also be inkjet printed. The process parameters for inkjet printing are as follows: Nozzle diameter: within the range of 10-50 μm (exemplary diameters of 10 μm, 20 μm, 30 μm, 40 μm, and 50 μm), determining the droplet volume to be 1-100 pL (exemplary volumes of 1 pL, 10 pL, 30 pL, 50 pL, 80 pL, and 100 pL); Driving voltage: typically 20-100 V (exemplary voltages of 20 V, 40 V, 60 V, 80 V, and 100 V), used to control droplet speed and morphological stability; Substrate temperature: generally controlled at 40-80℃ (exemplary temperatures of 40℃, 50℃, 60℃, 70℃, and 80℃), used to regulate solvent evaporation rate and crystallization quality; Printing resolution: up to 300-1200 dpi (exemplary resolutions of 300 dpi, 600 dpi, 900 dpi, and 1200 dpi). (dpi), affecting pattern accuracy and film uniformity; Annealing: hot plate heat treatment of the film at 100℃. SAM solution is processed on the substrate to form a SAM layer with a thickness ranging from 10-100nm.

[0079] In some embodiments, the passivating material includes any one or a combination of at least two of methylamine iodine (MAI), formamidin iodine (FAI), phenethylamine iodine (PEAI), butylamine iodine (BAI), hexamethylenetetramine (HABr), and choline iodine (ChI).

[0080] In some embodiments, the passivation material needs to have interaction with interface defects (such as uncoordinated Pb). 2+ The ability to interact with halide ions (vacancies) without affecting charge transport can be achieved. Specific materials can also be halide salts of metals such as cesium, zinc, and lithium, for example, CsX (X = Cl, Br, I), ZnI2, LiY (Y = Cl, Br), etc. + It can fill vacancies and defects on the perovskite surface, X - With Pb 2+ Coordination forms stable Pb-X bonds, reducing interface trap density. Zn 2+ Pb on the perovskite surface 2+ Ion exchange occurs, forming a Zn-Pb-I interface layer, while I... - Passivation Pb 2+ Defects, reducing charge recombination. Li + Adjustable ETL surface energy level, Y - Pb at the perovskite interface 2+ Coordination, and Li + Its small radius can fill the lattice gaps and improve interface contact.

[0081] The passivation layer material can also be an organic small molecule passivation material, such as 4-tert-butylpyridine (tBP), pyridine-3-boronic acid (PBA), and other pyridines and their derivatives. The nitrogen atom of the pyridine ring is related to Pb. 2+ Coordination forms stable coordination bonds, suppressing defect states; boric acid groups can react with hydroxyl groups on the TiO2 surface, enhancing interfacial bonding. Other examples include amine compounds such as n-butylamine (n-BA), phenylethylamine (PEA), and methylamine (MA), where the amine group (-NH2) reacts with Pb on the perovskite surface. 2+ Coordination occurs, forming Pb-N bonds and passivating uncoordinated Pb. 2+ Long-chain amines (such as PEA) can also form a hydrophobic layer at the interface, inhibiting water penetration. Other examples include halogen-containing organic molecules such as 1-chloro-3-iodobenzene (CIB) and trifluoroacetic acid (TFA). Further examples include graphene oxide (GO), fluorinated graphene (FG), and other graphene and its derivatives. In GO, the oxygen-containing groups (such as hydroxyl and carboxyl groups) combine with the hydroxyl groups on the TiO2 surface, while the π-π conjugated structure of graphene interacts with the perovskite interface, reducing defects; the fluorine atoms in FG can react with Pb. 2+ Coordination.

[0082] In some embodiments, the passivation layer is made of nitrogen-containing heterocyclic compounds such as 2-phenylbenzimidazole (PBI), imidazole, and benzothiazole. This type of passivation material interacts with lead ions (Pb) on the perovskite surface through the lone pair electrons of the nitrogen atom. 2+ Coordination fills uncoordinated Pb sites. 2+ Defects, reducing the density of interface trap states.

[0083] In some embodiments, the passivation layer can also be a carboxylic acid compound such as acetic acid, benzoic acid, or stearic acid; the carboxylic acid group (-COO) in such passivation materials - Pb on the perovskite surface 2+ Coordination bonds are formed, and the alkyl chain can improve the hydrophobicity of the interface and inhibit water penetration.

[0084] In some embodiments, the passivation layer can also be made of amine compounds such as polyethyleneimine (PEI), hexylamine, and methylamine (MA); the amine groups (-NH2) in such passivation materials interact with the iodine vacancies (V2) on the perovskite surface. i The amine molecules combine to neutralize the interfacial charge, and the dipole moment of the amine molecules can adjust the energy level matching of the HTL. Passivation materials are mainly used to reduce interfacial defects, suppress charge recombination, and improve device stability.

[0085] Understandably, the goal of setting a passivation layer is to reduce interfacial nonradiative recombination (lower open-circuit voltage loss), suppress ion migration / interfacial reactions (improve stability), and optimize carrier extraction efficiency (increase fill factor FF). The passivation layer covers different chemical sites on the surface of the perovskite absorber layer, forming complete protection.

[0086] In some embodiments, the passivation layer can be processed by solution spin coating, slot coating, or vapor deposition.

[0087] In some embodiments, the method for preparing the passivation layer includes: mixing a passivation material with isopropanol to obtain a passivation solution, wherein the concentration of the passivation material in the passivation solution is 0.3-1 mg / mL; coating the passivation solution onto the surface of the perovskite absorber layer; and annealing at 80-120°C for 5-30 min to obtain the passivation layer.

[0088] This application provides a solar cell, which includes a composite layer, an electron transport layer, a second transparent conductive layer, and an electrode layer stacked together; the composite layer is the composite layer described above; the surface of the perovskite absorber layer away from the hole transport layer in the composite layer is connected to the electron transport layer.

[0089] As a preferred technical solution in this application, such as Figure 1 As shown, the solar cell comprises, from bottom to top, a first transparent electrode layer 1, a hole transport layer 2, a perovskite absorber layer 3, an electron transport layer 4, and an electrode layer 5.

[0090] In some embodiments, the material of the electron transport layer includes any one of inorganic metal oxide materials, organic materials, inorganic silicon materials, or inorganic salt materials.

[0091] Among them, inorganic metal oxide materials include any one or a combination of at least two of SnO2, TiO2, ZnO, ZrO2, ZnO, MgO, zinc gallium oxide, zinc indium oxide, fluorine-doped tin oxide, or indium tin oxide.

[0092] Inorganic metal oxide material preparation processes include sol-gel methods, atomic layer deposition (ALD), chemical vapor deposition (CVD, including plasma-enhanced chemical vapor deposition (PECVD), metal-organic chemical vapor deposition (MOCVD), physical vapor deposition (PVD, including magnetron sputtering, thermal evaporation, pulsed laser deposition (PLD), spray pyrolysis, solution spin coating, electrochemical deposition, and chemical bath deposition. Atomic layer deposition (ALD) is preferred.

[0093] The specific process for preparing the electron transport layer of inorganic metal oxide materials by atomic layer deposition (ALD) includes: alternately introducing a metal precursor and an oxygen source under a gas pressure of 0.05-1.5 Torr (exemplary, 0.05 Torr, 0.1 Torr, 0.5 Torr, 1.0 Torr, 1.5 Torr). The flow rate of the metal precursor introduced in each cycle is 10-100 sccm (exemplary, 10 sccm, 30 sccm, 50 sccm, 80 sccm, 100 sccm), and the pulse time of the metal precursor introduced in each cycle is 100-300 ms (exemplary, 100 ms, 150 ms, 200 ms, 250 ms, 300 ms). The oxygen flow rate in each cycle is 10-100 sccm (exemplary, 10 sccm, 30 sccm, 50 sccm, 80 sccm, 100 sccm), and the pulse duration of the oxygen flow rate in each cycle is 100-300 ms (exemplary, 100 ms, 150 ms, 200 ms, 250 ms, 300 ms).

[0094] The electron transport layer thickness of inorganic metal oxide materials prepared by atomic layer deposition (ALD) is 20-200 nm (exemplary values: 20 nm, 50 nm, 80 nm, 100 nm, 150 nm, 200 nm). The growth rate of the inorganic metal oxide is typically between 0.03-0.2 nm / cycle (exemplary values: 0.03 nm / cycle, 0.05 nm / cycle, 0.1 nm / cycle, 0.15 nm / cycle, 0.2 nm / cycle), and the required number of cycles depends on the type of metal precursor, the type of oxygen source, and the process temperature. It is important to note that in the alternating introduction of the metal precursor and oxygen source, the first introduction is of the metal precursor.

[0095] Organic materials include C 60 Fullerene C 70 The combination of any one or at least two of the following: methyl (6,6)-phenyl-C61-butyrate (PCBM) or 4-(1',5'-dihydro-1'-methyl-2'H-(5,6)fullerene-C60-In-(1,9-c)pyrrole-2'-yl)benzamine chloride (CPMAC).

[0096] Organic material preparation processes include vacuum evaporation, spin coating, inkjet printing, doctor blade coating, slot coating, dip coating, spray coating, drop coating, and roll-to-roll printing. Vacuum evaporation is preferred, with an evaporation rate of 0.05-0.1 nm / s (exemplary evaporation rates are 0.05 nm / s, 0.06 nm / s, 0.07 nm / s, 0.08 nm / s, 0.09 nm / s, and 0.1 nm / s).

[0097] Inorganic silicon materials include any one or a combination of at least two of n-type monocrystalline silicon, n-type polycrystalline silicon, or n-type amorphous silicon.

[0098] The main processes for preparing inorganic silicon materials include low-pressure chemical vapor deposition (LPCVD), plasma-enhanced chemical vapor deposition (PECVD), atomic layer deposition (ALD), magnetron sputtering, thermal diffusion (such as phosphorus diffusion), ion implantation, sol-gel method, and electron beam evaporation.

[0099] Inorganic salt materials include BaSnO3 and TiSnO x or SnZnO x Any one or at least two of them.

[0100] The main processes for preparing inorganic salt materials include sol-gel method, atomic layer deposition (ALD), chemical vapor deposition (CVD, including plasma-enhanced chemical vapor deposition PECVD), physical vapor deposition (PVD, including magnetron sputtering, pulsed laser deposition (PLD), electron beam evaporation), spray pyrolysis, solution spin coating, electrochemical deposition, chemical bath deposition, and magnetron sputtering-annealing combined method.

[0101] As a preferred technical solution of this application, the material of the electron transport layer includes C60, fullerene derivative (6,6)-phenyl-C61-butyrate methyl ester (PCBM), a combination of C60 and PCBM, a combination of PCBM and ZnO, a combination of ZnO and MgO, a combination of C60, PCBM and ZnO, a combination of PCBM, ZnO and MgO, and a combination of C60, PCBM, ZnO and MgO.

[0102] In some embodiments, the thickness of the electron transport layer is 3-50 nm (exemplary thicknesses include 3 nm, 10 nm, 20 nm, 30 nm, 40 nm, 50 nm, etc.).

[0103] In some embodiments, the method for preparing the electron transport layer includes wet coating, sol-gel method, chemical vapor deposition, physical vapor deposition or plasma deposition.

[0104] In some embodiments, the material of the second transparent conductive layer includes, but is not limited to, ITO, IZO, IWO, FTO, ICO, and AZO, and the preparation method includes, but is not limited to, magnetron sputtering (PVD) and reactive plasma deposition (RPD), with a thickness of 10-100 nm (exemplary thicknesses of 10 nm, 30 nm, 50 nm, 80 nm, and 100 nm).

[0105] In some embodiments, the electrode layer is made of any one or a combination of at least two of copper (Cu), aluminum (Al), silver (Ag), nickel (Ni), cobalt (Co), gold (Au), molybdenum (Mo), or chromium (Cr), preferably a combination of Ag, copper, Cu, and Al, a combination of Ag and Ni, a combination of Co and Au, a combination of Mo and Cr, or a combination of Cu, Al, Ag, Ni, Co, Au, Mo, and Cr.

[0106] In some embodiments, the electrode layer is prepared by methods including but not limited to vapor deposition, screen printing, electroplating, laser technology, PVD (Physical Vapor Deposition), and inkjet printing, and the electrode thickness is 0.1-20 μm.

[0107] In this application, the second transparent conductive layer is a thin film that is both conductive and transparent to light. It is used to collect charge carriers laterally and transport them to the metal electrode layer. It can also reduce the reflection of incident light on the battery surface and increase the absorption of light by the battery.

[0108] In some embodiments, the electrode layer is prepared by methods including vapor deposition, screen printing, electroplating, laser technology, physical vapor deposition (PVD), or inkjet printing.

[0109] In some embodiments, the thickness of the electrode layer is 10-120 μm (exemplary thicknesses include 10 μm, 30 μm, 50 μm, 70 μm, 100 μm, 120 μm, etc.).

[0110] In this application, the electrode layer is used for efficient current collection and extraction of charge carriers transported by the transparent conductive layer. The second transparent conductive layer and the electrode layer together constitute the efficient current collection and extraction system of the solar cell.

[0111] This application embodiment also provides a stacked battery, the stacked battery including a bottom cell, a composite layer, an electron transport layer, a second transparent conductive layer and an electrode layer; the composite layer is the composite layer described above; in the composite layer, the first transparent conductive layer is connected to the bottom cell, and the perovskite absorber layer is connected to the electron transport layer.

[0112] In some embodiments, the bottom cell may be a crystalline silicon bottom cell, a CIGS thin-film bottom cell, a cadmium telluride thin-film bottom cell, a III V thin-film bottom cell, or a perovskite bottom cell.

[0113] In some embodiments, the crystalline silicon bottom cell includes an N-type monocrystalline silicon substrate, a P-type amorphous silicon thin film (P-side) deposited on the front side of the N-type monocrystalline silicon substrate and a silver electrode, and an N-type amorphous silicon thin film (N-side) deposited on the back side of the N-type monocrystalline silicon substrate. It should be noted that the N-type amorphous silicon thin film (N-side) is connected to the first transparent electrode layer in the composite layer.

[0114] The N-type monocrystalline silicon substrate has a thickness of 90-220 μm and is mainly used to absorb light and generate charge carriers; the P-type amorphous silicon has a thickness of 5-30 nm and is mainly used as an emitter to form a PN heterojunction; the silver electrode has a thickness of 2-30 μm and is mainly used to collect current and conduct it; the N-type amorphous silicon thin film has a thickness of 5-30 nm and is mainly used to form a back surface field to promote electron collection.

[0115] In some embodiments, the substrate may also be polyimide (PI), polyester (PET), polyethylene naphthalate (PEN), or metal foil, thus preparing a flexible solar cell.

[0116] As a preferred technical solution in this application, such as Figure 2 As shown, the stacked solar cell, from bottom to top, includes a crystalline silicon base cell 0, a first transparent conductive layer 1, a hole transport layer 2, a perovskite absorption layer 3, an electron transport layer 4, a second transparent conductive layer 6, and an electrode layer 5.

[0117]

Example 1

[0118] This embodiment provides a method for preparing a connecting layer, including: S101. Cleaning the ITO transparent conductive substrate: 1×1cm 2 The ITO transparent conductive substrate was ultrasonically cleaned in ethanol, detergent, ultrapure water, isopropanol and ethanol in sequence, and the cleaned ITO glass substrate was dried with nitrogen. The volume of solvent used for ultrasonic cleaning was 500 mL, and the ultrasonic cleaning time was 15 minutes each time. The ITO transparent conductive substrate includes a glass substrate and an indium tin oxide transparent conductive layer formed on the surface of the glass substrate. S102. Preparation of the hole transport layer: A magnetron sputtering process was employed, using pure Ga2O3, SnO2, Al2O3, and In2O3 as targets (Ga2O3 with a mass percentage of 2 wt%, SnO2 with a mass percentage of 7 wt%, Al2O3 with a mass percentage of 1 wt%, and In2O3 with a mass percentage of 90 wt%). Argon was used as the sputtering gas, and nitric oxide was used as the reactant gas. The sputtering power was 700 W, and the gas pressure was 10 W. -4 Pa, a 7 nm thick P-type GaAlInSnON thin film was prepared on the first transparent conductive layer to form a hole transport layer.

[0119] This embodiment provides a composite layer, including a connecting layer and a perovskite absorption layer stacked together. The perovskite absorption layer is disposed on the surface of the hole transport layer away from the first transparent conductive layer. The connecting layer is the connecting layer prepared above. The thickness of the perovskite absorption layer is 500 nm.

[0120] This embodiment provides a method for preparing a composite layer, including: S103. Preparation of the perovskite absorber layer: In a glove box under a nitrogen atmosphere, the perovskite precursor material is dissolved in N,N In a mixed solvent of dimethylformamide (DMF) and dimethyl sulfoxide (DMSO) (volume ratio 4:1), the solution was stirred at room temperature until completely dissolved to obtain a perovskite precursor solution. In a glove box under nitrogen atmosphere, the perovskite precursor solution was spin-coated onto the bonding layer at 2500 rpm and 5500 rpm for 25 s and 12 s, respectively. At 25 s, 300 μL of antisolvent was slowly added dropwise, and then the mixture was heated and annealed at 100°C for 30 min to form the perovskite absorber layer. In this application, the solar cell utilizes a composite layer with excellent hole extraction capability and interfacial stability, enabling it to simultaneously achieve high conversion efficiency and excellent long-term operational stability. Its performance is far superior to that using traditional hole transport layers (such as pure SAM layers or NiO). x ) battery.

[0121] This embodiment also provides a solar cell, including a composite layer, an electron transport layer and an electrode layer stacked together; wherein the composite layer is the composite layer prepared as described above.

[0122] This embodiment also provides a method for preparing a solar cell, including: S104. Preparation of electron transport layer: The surface of the perovskite absorber layer of the composite layer is transferred to a vacuum coating instrument, and a 10 nm thick C60 layer is deposited on the perovskite absorber layer as an electron transport layer. S105. Electrode layer preparation: The composite layer with the electron transport layer is transferred to a vacuum coating instrument, and a silver electrode is deposited to obtain a single-junction perovskite solar cell.

[0123] In this application, the composite layer is used in the tandem solar cell, which can efficiently realize the recombination and transport of charge carriers generated by the top and bottom cells, while its wide-spectrum high transmittance ensures that enough photons are absorbed by the bottom cell. Ultimately, this structure enables the tandem solar cell to break through the Shockley-Quiseer efficiency limit of single-junction cells, achieving a conversion efficiency far exceeding that of monocrystalline silicon cells, while also possessing the reliability to withstand harsh outdoor environments.

[0124]

Example 2

[0125]

Example 3

[0126] The preparation of the SAM layer includes: Before preparing the perovskite absorber layer, the SAM material 4PADCB was mixed with anhydrous ethanol and stirred at room temperature in a glove box under nitrogen atmosphere until completely dissolved to obtain a SAM solution. The concentration of 4PADCB in the SAM solution was 1 mg / mL. The SAM solution was coated onto a GaAlInSnON film and then placed on a hot stage at 100°C for annealing for 10 min to form a SAM layer with a thickness of 10 nm. Other operations were the same as in Example 1.

[0127]

Example 4

[0128]

Example 5

[0129] This embodiment provides a method for preparing a connecting layer, including: S101. Cleaning the ITO transparent conductive substrate: 1×1cm 2 The ITO transparent conductive substrate was ultrasonically cleaned in ethanol, detergent, ultrapure water, isopropanol and ethanol in sequence, and the cleaned ITO glass substrate was dried with nitrogen. The volume of solvent used for ultrasonic cleaning was 500 mL, and the ultrasonic cleaning time was 15 minutes each time. The ITO transparent conductive substrate includes a glass substrate and an indium tin oxide transparent conductive layer formed on the surface of the glass substrate. S102. Preparation of the hole transport layer: A magnetron sputtering process was employed, using pure Ga2O3, SnO2, Al2O3, and In2O3 as targets (where Ga2O3 has a mass percentage of 3 wt%, SnO2 has a mass percentage of 5 wt%, Al2O3 has a mass percentage of 1.5 wt%, and In2O3 has a mass percentage of 90.5 wt%). Argon was used as the sputtering gas, and nitric oxide was used as the reactant gas. The sputtering power was 1000 W, and the gas pressure was 5 × 10⁻⁶ W / m². -4 Pa, a 20 nm thick P-type GaAlInSnON thin film was prepared on the first transparent conductive layer to form a hole transport layer.

[0130] In this embodiment, the structure and preparation method of the composite layer and the solar cell are the same as in Example 1.

[0131]

Example 6

[0132] This embodiment provides a method for preparing a connecting layer, including: S101. Cleaning the ITO transparent conductive substrate: 1×1cm 2 The ITO transparent conductive substrate was ultrasonically cleaned in ethanol, detergent, ultrapure water, isopropanol and ethanol in sequence, and the cleaned ITO glass substrate was dried with nitrogen. The volume of solvent used for ultrasonic cleaning was 500 mL, and the ultrasonic cleaning time was 15 minutes each time. The ITO transparent conductive substrate includes a glass substrate and an indium tin oxide transparent conductive layer formed on the surface of the glass substrate. S102. Preparation of the hole transport layer: A magnetron sputtering process was employed, using pure Ga2O3, SnO2, Al2O3, and In2O3 as targets (where Ga2O3 has a mass percentage of 1 wt%, SnO2 has a mass percentage of 10 wt%, Al2O3 has a mass percentage of 0.5 wt%, and In2O3 has a mass percentage of 88.5 wt%), argon as the sputtering gas, and nitric oxide as the reactant gas. The sputtering power was 500 W, and the gas pressure was 10 W. -5 Pa, a 10 nm thick P-type GaAlInSnON thin film is prepared on the first transparent conductive layer to form a hole transport layer.

[0133] In this embodiment, the structure and preparation method of the composite layer and the solar cell are the same as in Example 1.

[0134] Comparative Example 1 The difference from Example 1 is that the hole transport layer uses SAM material 4PADCB.

[0135] The fabrication of the hole transport layer includes: SAM material 4PADCB was mixed with anhydrous ethanol and stirred at room temperature in a glove box under nitrogen atmosphere until completely dissolved to obtain a hole transport layer solution with a 4PADCB concentration of 1 mg / mL. In a glove box under nitrogen atmosphere, the hole transport layer solution was spin-coated onto the transparent conductive layer of an ITO glass substrate at a spin-coating speed of 3000 rpm / s for 30 s. Then, it was heated and annealed on a hot stage at 100℃ for 10 min to form a 7 nm thick SAM layer as the hole transport layer.

[0136] Comparative Example 2 The difference from Example 1 is that pure Ga2O3, SnO2, and In2O3 are used as targets (wherein the sputtering amounts of Ga2O3, SnO2, and In2O3 are consistent with those in Example 1), argon is used as the sputtering gas, and nitric oxide is used as the reaction gas to prepare a 7 nm thick P-type GaInSnON thin film on the first transparent conductive layer to form a hole transport layer.

[0137] Comparative Example 3 The difference from Example 1 is that pure Ga2O3 and In2O3 are used as targets (wherein the sputtering amounts of Ga2O3 and In2O3 are the same as in Example 1), argon is used as the sputtering gas, and nitric oxide is used as the reaction gas to prepare a 7 nm thick P-type GaInON thin film on the first transparent conductive layer to form a hole transport layer.

[0138] The short-circuit current, open-circuit voltage, fill factor, and light conversion efficiency of the solar cells obtained in Examples 1-6 and Comparative Examples 1-3 were tested, and the results are shown in Table 1. Table 1 Performance test results of perovskite solar cells obtained in Examples 1-6 and Comparative Examples 1-3

[0139] As can be seen from the comparison of Example 1 and Comparative Examples 1-3, by co-doping the hole transport layer with the four substances specified in this application to achieve P-type doping, sufficient hole transport capacity is ensured while minimizing the absorption of incident light and the transport path of charge carriers, reducing the series resistance, thereby improving the light conversion efficiency of the solar cell.

[0140] A comparison of Examples 1 and 2 shows that by setting a transition metal oxide layer between the hole transport layer and the first transparent conductive layer, an efficient hole transport channel and an optimized energy level can be formed with the hole transport layer above; at the same time, it can prevent metal ions in the first transparent conductive layer from migrating upward, thereby enhancing the light conversion efficiency of the device.

[0141] A comparison of Examples 1 and 3-4 shows that by setting a SAM layer between the hole transport layer and the perovskite absorber layer, the light conversion efficiency of the solar cell can be significantly increased. The efficiency is higher than that of pure SAM when passivation material is added to the SAM.

[0142] The single-junction cells obtained in Examples 1-6 and Comparative Examples 1-3 were subjected to a high-temperature and high-humidity aging test (85°C, 85%RH) for 1000 hours. The percentage point decrease in cell efficiency after aging is shown in Table 2 below. This indicates that the single-junction cell using the scheme of this application has the strongest tolerance to high-temperature and high-humidity environments.

[0143] Table 2

[0144] As shown in Table 2, after aging for 1000 hours in Examples 1 to 6, the battery efficiency decreased by less than 5%, while after aging for 1000 hours in Comparative Example 1, the battery efficiency decreased by more than 20%, and its rate of decrease was more than 4 times that of Examples 1 to 6. This indicates that the solar cell obtained by adopting the scheme of this application is more stable and has a longer lifespan.

[0145]

Example 7

[0146] This embodiment provides a method for preparing a connecting layer, including: S201. Provide a crystalline silicon base cell: The crystalline silicon base cell includes an N-type monocrystalline silicon substrate, a P-type amorphous silicon thin film (P-side) deposited on the front side of the N-type monocrystalline silicon substrate and a silver electrode, an N-type amorphous silicon thin film (N-side) deposited on the back side of the N-type monocrystalline silicon substrate, and a transparent conductive layer (TCO) deposited on the N-type amorphous silicon thin film (N-side). Ethanol is spin-coated onto the transparent conductive layer (TCO) of the crystalline silicon base cell at 3000 rpm for 30 seconds in a spin coater, repeated twice, followed by heat treatment at 200℃ for 10 minutes to complete cleaning. S202. Preparation of hole transport layer: Using magnetron sputtering, pure Ga2O3, SnO2, Al2O3, In2O3, etc. are used as targets and nitrogen-containing gas is used as the reaction gas to prepare a 7 nm thick P-type GaAlInSnON thin film on a transparent conductive layer as a hole transport layer.

[0147] This embodiment provides a composite layer, including a connecting layer and a perovskite absorption layer stacked together. The perovskite absorption layer is disposed on the surface of the hole transport layer away from the first transparent conductive layer. The connecting layer is the connecting layer prepared above. The thickness of the perovskite absorption layer is 500 nm.

[0148] This embodiment provides a method for preparing a composite layer, including: S103. Preparation of perovskite absorber layer: PbI2 and MAI are placed in independent evaporation sources, and the deposition sequence is controlled by a baffle. PbI2 is evaporated first on the hole transport layer, followed by MAI. Then, the layer is heated and annealed at 150 °C for 30 min to allow PbI2 to react with FAI to form a perovskite phase, resulting in a perovskite absorber layer with the chemical formula MAPbI3 (methylamine lead iodide).

[0149] This embodiment also provides a tandem solar cell, including a bottom cell, a composite layer, an electron transport layer, a second transparent conductive layer, and an electrode layer stacked together; wherein the composite layer is the composite layer prepared as described above.

[0150] This embodiment also provides a method for fabricating a tandem solar cell, including: S204. Preparation of electron transport layer: The crystalline silicon bottom cell with the perovskite absorber layer is transferred to a vacuum coating instrument. A 15 nm thick C60 layer is deposited on the perovskite absorber layer. Then, an atomic layer deposition process is used to prepare a 10 nm thick tin dioxide (SnO2) layer on the C60 layer. C60 and SnO2 constitute the electron transport layer.

[0151] S205. Preparation of transparent conductive layer: At room temperature, an indium zinc oxide (IZO) transparent conductive layer is deposited on the surface of the electron transport layer by radio frequency magnetron sputtering. The sputtering power is controlled at 300 W, the cavity pressure at 0.6 Pa, the argon gas flow rate at 20 s ccm, the 5% argon-oxygen mixed gas flow rate at 5 sccm, and the sputtering time is 210 s.

[0152] S206. Electrode layer preparation: Silver paste is coated onto the indium zinc oxide (IZO) transparent conductive layer using screen printing to form a patterned silver paste layer. Annealing is then performed to form a silver electrode layer, resulting in a perovskite / crystalline silicon tandem solar cell.

[0153]

Example 8

[0154]

Example 9

[0155] The preparation of the SAM layer includes: Before preparing the perovskite absorber layer, the SAM material 4PADCB was mixed with anhydrous ethanol and stirred at room temperature in a glove box under nitrogen atmosphere until completely dissolved to obtain a SAM solution. The concentration of 4PADCB in the SAM solution was 0.5 mg / mL. The SAM solution was coated onto a GaAlInSnON film and then placed on a hot stage at 100°C for annealing for 10 min to form a SAM layer with a thickness of 10 nm. Other operations were the same as in Example 7.

[0156]

Example 10

[0157]

Example 11

[0158] This embodiment provides a method for preparing a connecting layer, including: S201. Provide a crystalline silicon base cell: The crystalline silicon base cell includes an N-type monocrystalline silicon substrate, a P-type amorphous silicon thin film (P-side) deposited on the front side of the N-type monocrystalline silicon substrate and a silver electrode, an N-type amorphous silicon thin film (N-side) deposited on the back side of the N-type monocrystalline silicon substrate, and a transparent conductive layer (TCO) deposited on the N-type amorphous silicon thin film (N-side). Ethanol is spin-coated onto the transparent conductive layer (TCO) of the crystalline silicon base cell at 3000 rpm for 30 seconds in a spin coater, repeated twice, followed by heat treatment at 200℃ for 10 minutes to complete cleaning. S202. Preparation of the hole transport layer: A magnetron sputtering process was employed, using pure Ga2O3, SnO2, Al2O3, and In2O3 as targets (Ga2O3 3 wt%, SnO2 5 wt%, Al2O3 1.5 wt%, and In2O3 90.5 wt%), argon as the sputtering gas, and nitric oxide as the reactant gas. The sputtering power was 1000 W, and the gas pressure was 5 × 10⁻⁶ W / m². -4 Pa, a 20 nm thick P-type GaAlInSnON thin film was prepared on the first transparent conductive layer to form a hole transport layer.

[0159] The structure and preparation method of the composite layer and solar cell in this embodiment are the same as those in Example 7.

[0160]

Example 12

[0161] This embodiment provides a method for preparing a connecting layer, including: S201. Provide a crystalline silicon base cell: The crystalline silicon base cell includes an N-type monocrystalline silicon substrate, a P-type amorphous silicon thin film (P-side) deposited on the front side of the N-type monocrystalline silicon substrate and a silver electrode, an N-type amorphous silicon thin film (N-side) deposited on the back side of the N-type monocrystalline silicon substrate, and a transparent conductive layer (TCO) deposited on the N-type amorphous silicon thin film (N-side). Ethanol is spin-coated onto the transparent conductive layer (TCO) of the crystalline silicon base cell at 3000 rpm for 30 seconds in a spin coater, repeated twice, followed by heat treatment at 200℃ for 10 minutes to complete cleaning. S202. Preparation of the hole transport layer: The hole transport layer was prepared using magnetron sputtering with pure Ga2O3, SnO2, Al2O3, and In2O3 as targets (Ga2O3 1 wt%, SnO2 10 wt%, Al2O3 0.5 wt%, and In2O3 88.5 wt%). Argon was used as the sputtering gas, and nitric oxide was used as the reactant gas. The sputtering power was 500 W, and the gas pressure was 10 W. -5 Pa was used to prepare a 10 nm thick P-type GaAlInSnON thin film on the bottom cell to form a hole transport layer.

[0162] In this embodiment, the structure and preparation method of the composite layer and the stacked battery are the same as in Example 7.

[0163] Comparative Example 4 The difference from Example 7 is that the hole transport layer uses SAM material 4PADCB.

[0164] The fabrication of the hole transport layer includes: The SAM material 4PADCB was mixed with anhydrous ethanol and stirred at room temperature in a glove box under nitrogen atmosphere until completely dissolved to obtain a hole transport layer solution with a 4PADCB concentration of 1 mg / mL. In a glove box under nitrogen atmosphere, the hole transport layer solution was spin-coated onto a bottom cell with a first transparent conductive layer at a spin-coating speed of 3000 rpm / s for 30 s. Then, it was placed on a hot plate at 100°C and heated and annealed for 10 min to form a 7 nm thick SAM layer as the hole transport layer.

[0165] Figure 3 This is a cross-sectional scanning electron microscope (SEM) image of the composite layer after the formation of the perovskite absorber layer in Example 7. Figure 4 This is a cross-sectional scanning electron microscope image of the composite layer after the formation of the perovskite absorber layer in Comparative Example 4. Figure 3 and Figure 4 In the middle, through Figure 3 and Figure 4 The comparison shows that the material of the hole transport layer in Example 7 has changed compared to that in Comparative Example 4, resulting in a significantly higher crystallinity of the perovskite absorber layer in Example 7 compared to that in Comparative Example 4.

[0166] Comparative Example 5 The difference from Example 7 is that pure Ga2O3, SnO2, and In2O3 are used as targets (wherein the sputtering amounts of Ga2O3, SnO2, and In2O3 are consistent with those in Example 7), argon is used as the sputtering gas, and nitric oxide is used as the reaction gas to prepare a 7 nm thick P-type GaInSnON thin film on the first transparent conductive layer to form a hole transport layer.

[0167] Comparative Example 6 The difference from Example 7 is that pure Ga2O3 and In2O3 are used as targets (wherein the sputtering amounts of Ga2O3 and In2O3 are the same as in Example 7), argon is used as the sputtering gas, and nitric oxide is used as the reaction gas to prepare a 7 nm thick P-type GaInON thin film on the first transparent conductive layer to form a hole transport layer.

[0168] The short-circuit current, open-circuit voltage, fill factor, and light conversion efficiency of the solar cells obtained in Examples 7-12 and Comparative Examples 4-6 were tested, and the results are shown in Table 3. Table 3 Performance test results of the tandem cells obtained in Examples 7-12 and Comparative Examples 4-6

[0169] As can be seen from the comparison between Example 7 and Comparative Examples 4-6, by co-doping the hole transport layer with the four substances specified in this application to achieve P-type doping, sufficient hole transport capacity is ensured while minimizing the absorption of incident light and the transport path of charge carriers, reducing the series resistance, thereby improving the light conversion efficiency of the tandem solar cell.

[0170] A comparison of Examples 7 and 8 shows that by setting a transition metal oxide layer between the hole transport layer and the first transparent conductive layer, an efficient hole transport channel and an optimized energy level can be formed with the hole transport layer above; at the same time, it can prevent metal ions in the first transparent conductive layer from migrating upward, thereby enhancing the light conversion efficiency of the device.

[0171] A comparison of Examples 7 and 9-10 shows that the SAM layer disposed between the hole transport layer and the perovskite absorber layer can significantly increase the light conversion efficiency of the solar cell.

[0172] This application embodiment can also provide a photovoltaic module (not shown), which includes the solar cells or tandem cells as described above. The solar cells can be connected in series and / or in parallel with one or more other solar cells in a predetermined manner. Multiple cells can form a cell string, and adjacent cells can be connected together by string welding.

[0173] This application provides a photovoltaic system including the photovoltaic modules described in any of the above embodiments. The advantages of the aforementioned photovoltaic modules are also present in this photovoltaic system, and will not be repeated here. The application fields of the aforementioned photovoltaic system are wide, not limited to photovoltaic power plants, such as ground-mounted power plants, rooftop power plants, and floating power plants, but also including various devices and apparatuses that utilize solar energy for power generation, 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 for power generation. 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 achieve solar power supply.

[0174] It should be noted that the terms "center," "longitudinal," "lateral," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "clockwise," "counterclockwise," "axial," "radial," and "circumferential," etc., are used only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation on this application. The directional terms "inner" and "outer" refer to the inside or outside relative to the outline of the component itself. For example, if a device in the drawings is inverted, a device described as "above" or "on top of" other devices or structures will subsequently be positioned as "below" or "under" other devices or structures. Thus, the exemplary term "above" can include both "above" and "below." The device may also be positioned in other different ways (rotated 90 degrees or in other orientations), and the spatial relative descriptions used herein are interpreted accordingly.

[0175] It should also be noted that the terms "one embodiment," "another embodiment," and "embodiment" used in this application refer to specific features, structures, or characteristics described in connection with that embodiment, which are included in at least one embodiment described in the general description of this application. The appearance of the same expression in multiple places in the specification does not necessarily refer to the same embodiment. Furthermore, when a specific feature, structure, or characteristic is described in connection with any embodiment, the intention is to suggest that implementing such a feature, structure, or characteristic in conjunction with other embodiments also falls within the scope of this application.

[0176] In the above embodiments, the descriptions of each embodiment have different focuses. For parts not described in detail in a certain embodiment, please refer to the relevant descriptions in other embodiments.

[0177] It should also be noted that the above are merely preferred embodiments of this application and do not limit the scope of patent protection of this application. Any equivalent structural or procedural changes made using the content of this application’s specification and drawings, or direct or indirect applications in other related technical fields, are similarly included within the scope of patent protection of this application.

Claims

1. A tie layer characterized in that, The connecting layer comprises a first transparent conductive layer and a hole transport layer arranged in a stack. The hole transport layer is an alloy thin film comprising Ga, Al, In, Sn, O and N elements.

2. The tie layer of claim 1, wherein, The hole transport layer is a P-type alloy thin film comprising Ga, Al, In, Sn, O and N elements. The thickness of the hole transport layer is 7-20 nm. The thickness of the first transparent conductive layer is 20-100 nm.

3. The tie layer of claim 1, wherein, A transition metal oxide layer is further arranged between the first transparent conductive layer and the hole transport layer. The thickness of the transition metal oxide layer is 5-15 nm. The material of the transition metal oxide layer comprises any one or a combination of at least two of nickel oxide, titanium oxide, molybdenum trioxide, tungsten trioxide or copper oxide.

4. A method for producing a tie layer, characterized by The preparation method comprises forming the hole transport layer on one side surface of the first transparent conductive layer by a magnetron sputtering method. In the magnetron sputtering method, a multi-component oxide is used as a target material, an inert gas is used as a sputtering gas, and a nitrogen-containing gas is used as a reaction gas. The multi-component oxide comprises Ga2O3 with a mass percentage of 1-3 wt%, SnO2 with a mass percentage of 5-10 wt%, Al2O3 with a mass percentage of 0.5-1.5 wt%, and In2O3 with a mass percentage of 85-95 wt%. The sputtering power of the magnetron sputtering method is 500-1000 W, the gas pressure is 10 -5 -5x10 -4 Pa.

5. The preparation method according to claim 4, characterized in that, The preparation method further comprises forming a transition metal oxide layer in advance before the first transparent layer forms the hole transport layer. The transition metal oxide layer is formed by any one of a solution method, a physical vapor deposition method, an atomic layer deposition method or an inkjet printing method.

6. A composite layer, characterized by The composite layer comprises the connecting layer of any one of claims 1-3 and a perovskite absorption layer. The perovskite absorption layer is arranged on a surface of the hole transport layer away from the first transparent conductive layer. The thickness of the perovskite absorption layer is 600-1200 nm.

7. The composite layer of claim 6, wherein, A SAM layer is further arranged between the hole transport layer and the perovskite absorption layer. The thickness of the SAM layer is 1-10 nm. The material of the SAM layer is a SAM material or a combination of a SAM material and a passivation material. The passivation material comprises any one or a combination of at least two of a nitrogen-containing heterocyclic compound, a carboxylic acid compound or an amine compound. The molar ratio of the SAM material to the passivation material is 1:(0.1-1).

8. A perovskite cell characterized by, The perovskite solar cell comprises a composite layer, an electron transport layer and an electrode layer arranged in a stack. The composite layer is the composite layer of claim 6 or 7. The surface of the perovskite absorption layer away from the hole transport layer in the composite layer is connected to the electron transport layer.

9. A stacked battery characterized by comprising: The stacked solar cell comprises a bottom solar cell, a composite layer, an electron transport layer, a second transparent conductive layer and an electrode layer. The composite layer is the composite layer of claim 6 or 7. The first transparent conductive layer in the composite layer is connected to the bottom solar cell, and the perovskite absorption layer is connected to the electron transport layer.

10. A photovoltaic module, characterized by, The photovoltaic module comprises the solar cell of claim 8 or the stacked solar cell of claim 9.

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