Functional layer, perovskite solar cell and preparation method thereof

Abstract

The application provides a functional layer, a perovskite solar cell and a preparation method thereof. The functional layer is arranged between a substrate and a hole transport layer. The functional layer comprises a first functional layer and a second functional layer. The first functional layer is a first transparent conductive oxide. The second functional layer is a second transparent conductive oxide. The second functional layer is deposited on the surface of the first functional layer by an atomic layer deposition process and can be in contact with the hole transport layer. The application sets the functional layer with a double-layer transparent conductive oxide structure. The second functional layer is deposited on the surface of the first functional layer by an atomic layer deposition process. The charge extraction efficiency is improved. The surface of the second functional layer is hydroxylated. The hole transport layer is stably adsorbed on the surface of the second functional layer.

Description

Technical Field

[0001] This application belongs to the field of battery technology, specifically, this application relates to a functional layer, a perovskite solar cell and a method for preparing the same. Background Technology

[0002] In the field of perovskite solar cells, a hole transport layer, a perovskite layer, and an electron transport layer are sequentially arranged on a substrate to achieve photoelectric conversion.

[0003] In related technologies, hole transport layers are used to collect and transport photogenerated holes. However, the hole transport layer has poor adhesion to the substrate, which makes it easy for the hole transport layer to fall off the substrate. This not only affects the effective transport of internal charges in perovskite solar cells and reduces photoelectric conversion efficiency, but also significantly shortens the lifespan of perovskite solar cells and increases the cost of use.

[0004] Therefore, improving the adhesion of the hole transport layer to the substrate has become a key issue that needs to be addressed to enhance the performance of perovskite solar cells. Summary of the Invention

[0005] One objective of this application is to provide a new technical solution for a functional layer, a perovskite solar cell, and a method for fabricating the same.

[0006] According to a first aspect of the embodiments of this application, a functional layer for a perovskite solar cell is provided, the functional layer being disposed between a substrate and a hole transport layer, comprising:

[0007] The first functional layer is a first transparent conductive oxide;

[0008] The second functional layer is a second transparent conductive oxide. The second functional layer is deposited on the surface of the first functional layer using an atomic layer deposition process and can contact the hole transport layer.

[0009] Optionally, the first transparent conductive oxide and the second transparent conductive oxide are made of the same material.

[0010] Optionally, the first functional layer is formed on one side surface of the substrate using a physical vapor deposition process;

[0011] The thickness of the first functional layer is 300nm-800nm.

[0012] Optionally, the thickness of the second functional layer is 5nm-10nm.

[0013] Optionally, the second transparent conductive oxide is indium tin oxide, fluorine-doped tin oxide, or indium zinc oxide.

[0014] Optionally, the second transparent conductive oxide is indium tin oxide, which is deposited on the surface of the first functional layer using an atomic layer deposition process;

[0015] The atomic layer deposition process has a reaction temperature of 100℃-250℃ and a reaction pressure of 0.2mbar-10mbar.

[0016] Optionally, the second transparent conductive oxide is fluorine-doped tin oxide, which is deposited on the surface of the first functional layer using an atomic layer deposition process;

[0017] The atomic layer deposition process has a reaction temperature of 150℃-400℃ and a reaction pressure of 0.2mbar-10mbar.

[0018] According to a second aspect of the embodiments of this application, a perovskite solar cell is provided, comprising:

[0019] Base;

[0020] The substrate comprises a hole transport layer, a perovskite layer, an electron transport layer, and the functional layer described in the first aspect, wherein the functional layer, the hole transport layer, the perovskite layer, and the electron transport layer are sequentially disposed on one side surface of the substrate.

[0021] Optionally, the first functional layer is formed on one side surface of the substrate using a physical vapor deposition process, and the second functional layer is deposited on the surface of the first functional layer using an atomic layer deposition process and is in contact with the hole transport layer.

[0022] Optionally, the hole transport layer is a self-assembled monomolecular film attached to the surface of the second transparent conductive oxide, and the self-assembled monomolecular film is one or more combinations of nPACz and G-nPACz;

[0023] Where G is an organic unit, R is a functional group, and n is an integer between 2 and 4, the molecular formula of nPACz is as follows:

[0024] .

[0025] Optionally, the thickness of the hole transport layer is 5nm-10nm;

[0026] The self-assembled monolayer includes one or more combinations of MeO-2PACz, 2PACz, 4PACz, Me-4PACz, MeO-4PACz, and Poly-2PACz.

[0027] Optionally, the oxygen source in the atomic layer deposition process includes at least one of deionized water, hydrogen peroxide, oxygen, and ozone.

[0028] Optionally, it also includes:

[0029] An electrode layer is disposed on the side of the electron transport layer away from the perovskite layer;

[0030] The thickness of the electrode layer is 10nm-200nm.

[0031] Optionally, the thickness of the perovskite layer is 300nm-600nm, and the thickness of the electron transport layer is 10nm-50nm.

[0032] Optionally, the perovskite solar cell is an inverted perovskite solar cell.

[0033] According to a third aspect of the embodiments of this application, a method for fabricating a perovskite solar cell is provided, comprising:

[0034] The first functional layer is formed on one side surface of the substrate using a physical vapor deposition process;

[0035] A second functional layer is deposited on the surface of the first functional layer using an atomic layer deposition process;

[0036] A hole transport layer, a perovskite layer, and an electron transport layer are sequentially disposed on the surface of the second functional layer.

[0037] Optionally, the first transparent conductive oxide of the first functional layer and the second transparent conductive oxide of the second functional layer are made of the same material.

[0038] Optionally, the second functional layer is indium tin oxide, and the preparation method includes:

[0039] Indium tin oxide is deposited on the surface of the first functional layer away from the substrate using an atomic layer deposition process, and then a hole transport layer is deposited on the side of the indium tin oxide away from the first functional layer.

[0040] The atomic layer deposition process has a reaction temperature of 100℃-250℃ and a reaction pressure of 0.2mbar-10mbar.

[0041] The indium source precursor is trimethylindium or cyclopentadienylindium, the tin source precursor is tetra(dimethylamino)tin or tin tetrachloride, and the oxygen source is at least one of deionized water, hydrogen peroxide, oxygen and ozone.

[0042] Optionally, the second functional layer is fluorine-doped tin oxide, and the preparation method includes:

[0043] A fluorine-doped tin oxide is deposited on the surface of the first functional layer away from the substrate using an atomic layer deposition process, and then a hole transport layer is deposited on the side of the fluorine-doped tin oxide away from the first functional layer.

[0044] The atomic layer deposition process has a reaction temperature of 150℃-400℃ and a reaction pressure of 0.2mbar-10mbar.

[0045] The tin source precursor is tetra(dimethylamino)tin or tin tetrachloride, the fluorine source precursor is hydrogen fluoride, trifluoromethane or ammonium fluoride, and the oxygen source is at least one of deionized water, hydrogen peroxide, oxygen and ozone.

[0046] Optionally, the second functional layer is indium zinc oxide, and the preparation method includes:

[0047] Indium zinc oxide is deposited on the surface of the first functional layer away from the substrate using atomic layer deposition (ALD) technology, and then a hole transport layer is deposited on the side of the indium zinc oxide away from the first functional layer.

[0048] The atomic layer deposition process has a reaction temperature of 100℃-250℃ and a reaction pressure of 0.2mbar-10mbar.

[0049] The indium source precursor is trimethylindium or cyclopentadienylindium, the zinc source precursor is diethylzinc, and the oxygen source is at least one of deionized water, hydrogen peroxide, oxygen, and ozone.

[0050] Optionally, forming a hole transport layer on the surface of the second functional layer includes:

[0051] After dissolving the hole transport layer, spin-coat it onto the surface of the second functional layer away from the first functional layer.

[0052] The hole transport layer is a self-assembled monolayer, which is one or more combinations of nPACz and G-nPACz.

[0053] Wherein, G is one or more combinations of Me, MeO, and Poly, R is a functional group, n is an integer between 2 and 4, and the molecular formula of nPACz is as follows:

[0054] .

[0055] One technical advantage of this application is:

[0056] This application provides a functional layer for perovskite solar cells. This functional layer is disposed between a substrate and a hole transport layer. The functional layer includes a first functional layer and a second functional layer. The first functional layer is a first transparent conductive oxide, and the second functional layer is a second transparent conductive oxide. The second functional layer is deposited on the surface of the first functional layer using atomic layer deposition (ALD) and is capable of contacting the hole transport layer. By setting a functional layer with a double-layer transparent conductive oxide structure and depositing the second functional layer on the surface of the first functional layer using ALD, this application improves charge extraction efficiency, promotes surface hydroxylation of the second functional layer, and achieves stable adsorption of the hole transport layer on the surface of the second functional layer. Perovskite solar cells are fabricated using this functional layer, thereby achieving high efficiency and stable performance in perovskite solar cells.

[0057] Other features and advantages of this application will become clear from the following detailed description of exemplary embodiments with reference to the accompanying drawings. Attached Figure Description

[0058] The accompanying drawings, which are incorporated in and form part of this specification, illustrate embodiments of the present application and, together with their description, serve to explain the principles of the present application.

[0059] Figure 1 This is a schematic diagram of the structure of a perovskite solar cell provided in one embodiment of this application;

[0060] Figure 2 This is a schematic diagram of hole transport layer adsorption in existing perovskite solar cells.

[0061] Figure 3 This is a schematic diagram of the adsorption of hole transport layer and functional layer in a perovskite solar cell according to an embodiment of this application;

[0062] Figure 4 A comparative test characterization diagram of a perovskite solar cell provided in one embodiment of this application;

[0063] Figure 5 A comparative graph showing the test characterization of another perovskite solar cell provided in one embodiment of this application.

[0064] Wherein: 1. Substrate; 2. Hole transport layer; 3. Perovskite layer; 4. Electron transport layer; 5. Electrode layer; 6. Functional layer; 61. First functional layer; 62. Second functional layer. Detailed Implementation

[0065] Various exemplary embodiments of the present application will now be described in detail with reference to the accompanying drawings. It should be noted that, unless otherwise specifically stated, the relative arrangement, numerical expressions, and values ​​of the components and steps set forth in these embodiments do not limit the scope of the present application.

[0066] The embodiments of this application will now be described in detail, examples of which are illustrated in the accompanying drawings. 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. All other embodiments obtained by those skilled in the art based on the embodiments of this application without inventive effort are within the scope of protection of this application.

[0067] The terms "first" and "second" in the specification and claims of this application may explicitly or implicitly include one or more of the features. In the description of this application, unless otherwise stated, "multiple" means two or more. Furthermore, "and / or" in the specification and claims indicates at least one of the connected objects, and the character " / " generally indicates that the preceding and following objects are in an "or" relationship.

[0068] In the description of this application, it should be understood 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", "circumferential", etc., indicating the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, are 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 of this application.

[0069] In the description of this application, it should be noted that, unless otherwise expressly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; 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; and they can refer to the internal connection between two components. Those skilled in the art can understand the specific meaning of the above terms in this application based on the specific circumstances.

[0070] It should be noted that similar labels and letters in the following figures indicate similar items; therefore, once an item is defined in one figure, it does not need to be discussed further in subsequent figures.

[0071] In related technologies, hole transport layers are used to collect and transport photogenerated holes. However, the hole transport layer has poor adhesion to the substrate, which makes it easy for the hole transport layer to fall off the substrate. This not only affects the effective transport of internal charges in perovskite solar cells and reduces photoelectric conversion efficiency, but also significantly shortens the lifespan of perovskite solar cells and increases the cost of use.

[0072] Atomic layer deposition (ALD) is a method for depositing ultrathin, uniform, and pinhole-free dense layers using surface-controlled vapor phase precursors. ALD has a low reaction temperature and does not damage the substrate.

[0073] Reference Figures 1 to 3 This application provides a functional layer 6 for a perovskite solar cell. The functional layer 6 is disposed between a substrate and a hole transport layer. The functional layer 6 includes:

[0074] The first functional layer 61 is a first transparent conductive oxide;

[0075] The second functional layer 62 is a second transparent conductive oxide. The second functional layer 62 is deposited on the surface of the first functional layer 61 using an atomic layer deposition process and can contact the hole transport layer.

[0076] In the above embodiments, the functional layer 6 is disposed between the substrate and the hole transport layer of the perovskite solar cell, which can play the role of bridging between the substrate and the hole transport layer, improve the connection between the hole transport layer and the substrate, and enhance the photoelectric conversion performance of the perovskite solar cell.

[0077] See Figure 1 The functional layer 6 includes a first functional layer 61 and a second functional layer 62 stacked together. The first functional layer 61 is composed of a first transparent conductive oxide, which has good conductivity and light transmittance. This ensures that light can pass smoothly through to the perovskite layer for photoelectric conversion, while also providing a conductive path for charge transport, thus improving the overall electrical performance of the battery. Meanwhile, the second functional layer 62 is composed of a second transparent conductive oxide, which further guarantees the electrical and optical performance of the perovskite solar cell.

[0078] In the above embodiments, the second functional layer 62 is formed by atomic layer deposition (ALD). ALD allows for precise atomic-level thickness control, resulting in a uniform and dense second transparent conductive oxide film, ensuring the performance stability and consistency of the second functional layer 62. Furthermore, the second functional layer 62 directly interacts with the hole transport layer, improving the adhesion between the second functional layer 62 and the hole transport layer.

[0079] In this embodiment, an atomic layer deposition process is used to deposit the second functional layer 62 on the surface of the first functional layer 61, which promotes the surface hydroxylation of the second functional layer 62. The hydroxylated surface has better chemical activity and can interact with the chemical groups in the hole transport layer, thereby achieving stable adsorption of the hole transport layer 2 on the surface of the second functional layer 62. This ensures good interfacial contact between the hole transport layer 2 and the functional layer 6, which is beneficial to the effective transport of holes. In turn, it ensures the effective transport of charges inside the perovskite solar cell, improves the photoelectric conversion efficiency, extends the battery's lifespan, and ensures high efficiency and stable performance.

[0080] Furthermore, the hydroxyl groups formed by atomic layer deposition on the surface of the second functional layer 62 in this application can also form hydrogen bonds with the perovskite precursor, promoting the optimization of perovskite crystal orientation and thus improving the light absorption performance of perovskite solar cell devices.

[0081] In some embodiments, the first transparent conductive oxide and the second transparent conductive oxide are made of the same material.

[0082] In the above embodiments, since the first transparent conductive oxide and the second transparent conductive oxide are made of the same material, they have good compatibility and can effectively reduce the interfacial contact resistance between the first functional layer 61 and the second functional layer 62, so that the charge can be transferred more smoothly in the functional layer 6, thereby improving the charge extraction efficiency.

[0083] In some embodiments, the first functional layer 61 is formed on one side surface of the substrate using a physical vapor deposition process.

[0084] In the above embodiments, the first functional layer 61 is formed by physical vapor deposition. Physical vapor deposition can quickly deposit the first functional layer 61, so that the first transparent conductive oxide can be efficiently and uniformly covered on the light-emitting side of the substrate 1, which can provide a channel for charge transmission and reduce the charge transmission resistance between the substrate 1 and the functional layer 6.

[0085] In addition, the surface of the first functional layer 61 formed by physical vapor deposition may have micro-defects such as pinholes. Atomic layer deposition can fill these micro-defects when depositing the second transparent conductive oxide on the surface of the first functional layer 61, making the surface of the functional layer 6 smoother and denser, and improving the structural integrity of the functional layer 6.

[0086] In some embodiments, the thickness of the first functional layer 61 is 300nm-800nm, such as 350nm, 400nm, 450nm, 500nm, 550nm, 600nm or 650nm, which can ensure the conductivity of the first functional layer 61 and provide an effective channel for the transfer of charge between the substrate 1 and the functional layer 6.

[0087] In one embodiment, when the first functional layer 61 is indium tin oxide (ITO), the ITO thickness is 300 nm-500 nm. This ensures high conductivity while increasing the transmittance of the first functional layer 61 to visible light, reducing light absorption loss, and facilitating sufficient light absorption by the perovskite layer, thereby improving the photoelectric conversion efficiency of the battery. Furthermore, within the ITO thickness range of 300 nm-500 nm, physical vapor deposition can produce a uniform and dense ITO thin film structure, reducing internal defects and stress, and improving the stability and reliability of the ITO thin film.

[0088] In one embodiment, when the first functional layer 61 is fluorine-doped tin oxide, the thickness of the fluorine-doped tin oxide is 350nm-500nm, which can better regulate the propagation path of light in the battery, enhance the anti-reflection effect, reduce the reflection loss of light at the interface, improve the absorption rate of light in the perovskite layer, and thus improve the photoelectric conversion performance of the battery.

[0089] In one embodiment, when the first functional layer 61 is indium zinc oxide, the thickness of the indium zinc oxide is 300nm-500nm, which ensures high conductivity while achieving high light transmittance, which is beneficial for the battery to absorb light and transfer charge.

[0090] In some embodiments, the thickness of the second functional layer 62 is 5nm-10nm, for example, the thickness of the second functional layer 62 is 6nm, 7nm, 8nm or 9nm.

[0091] In this embodiment, based on the physical vapor deposition of the first functional layer 61, an atomic layer deposition technique is used to deposit a second functional layer 62, which increases the proportion of hydroxyl groups on the surface of the second functional layer 62 and enhances the adsorption of the self-assembled monolayer on the surface of the second functional layer 62.

[0092] See Figure 1 The second functional layer 62 is located between the first functional layer 61 and the hole transport layer 2, which makes the second functional layer 62 form a good energy level match with the first functional layer 61 and the hole transport layer 2. This reduces the interface barrier for hole transport from the perovskite layer 3 to the first functional layer 61, thereby improving the hole injection and transport efficiency, reducing charge recombination loss, and thus improving the photoelectric conversion efficiency of the perovskite solar cell.

[0093] When the second functional layer 62 provided in this application embodiment is in the thickness range of 5nm-10nm, atomic layer deposition can obtain a uniform and dense thin film structure of the second functional layer 62, which is beneficial to the uniform adsorption and reaction of atoms on the surface of the substrate 1, reduces defects and pores inside the film, and improves the quality and stability of the second functional layer 62.

[0094] In some embodiments, the second transparent conductive oxide is indium tin oxide, fluorine-doped tin oxide, or indium zinc oxide.

[0095] In the above embodiments, when the second functional layer 62 is indium tin oxide (ITO), ITO exhibits excellent conductivity, enabling effective collection and transport of holes. In perovskite solar cells, ITO can rapidly transport holes generated in the perovskite layer 3 to the first functional layer 61, reducing hole accumulation at the interface, lowering the probability of charge recombination, thereby increasing the short-circuit current and fill factor of the cell, and improving photoelectric conversion efficiency. Furthermore, ITO has high transmittance to visible light, facilitating light transmission through the second functional layer 62 to the perovskite layer, allowing the perovskite layer to fully absorb photons and generate electron-hole pairs, thus improving the cell's light utilization rate.

[0096] When the second functional layer 62 is fluorine-doped tin oxide (FTO), it exhibits high chemical stability. In perovskite solar cells, FTO can resist the corrosive effects of chemicals that may be released during the fabrication and use of the perovskite material, ensuring long-term stable operation of the cell. Furthermore, FTO possesses high thermal stability, enabling it to withstand the high-temperature environments that the cell may encounter during fabrication and use. For example, during the annealing process of the perovskite layer, the performance of FTO does not change due to high temperatures, ensuring that the cell's structure and performance remain unaffected.

[0097] When the second functional layer 62 is indium zinc oxide (IZO), IZO has a high carrier mobility, allowing holes to move rapidly within the IZO film, which is beneficial for improving hole transport efficiency. In perovskite solar cells, high carrier mobility can reduce hole loss during transport and improve the cell's photoelectric conversion efficiency.

[0098] In some embodiments, the second transparent conductive oxide is indium tin oxide, which is deposited on the surface of the first functional layer 61 using an atomic layer deposition process.

[0099] The atomic layer deposition process involves a reaction temperature of 100℃-250℃ and a reaction pressure of 0.2mbar-10mbar.

[0100] In this embodiment, surface hydroxyl groups are fixed to the surface of indium tin oxide in the form of covalent bonds through a chemical reaction in the atomic layer deposition process, thereby providing stable adsorption sites for self-assembled monolayers, improving the density of the self-assembled monolayer film, and ensuring the uniformity of charge transport and the stability of battery performance.

[0101] Under reaction temperatures of 100℃-250℃ and reaction pressures of 0.2mbar-10mbar, the precursor molecules used in the atomic layer deposition reaction have sufficient activity to effectively undergo chemical reactions on the surface of the first functional layer 61 to form a stable indium tin oxide film. At the same time, the transport and reaction processes of the precursor molecules can be precisely controlled, thereby achieving control over the deposition rate of the indium tin oxide film.

[0102] In one embodiment, the method for depositing indium tin oxide (ITO) via atomic layer deposition includes alternately and sequentially exposing a substrate (a substrate on which a first functional layer of ITO material is deposited) to a vapor indium precursor, a vapor tin precursor, and one or more oxygen reactants. The specific deposition process steps are as follows:

[0103] Step 1: Place the substrate (with -OH on its surface, as shown in the Surface-OH diagram below) in the ALD reaction chamber, controlling the chamber temperature at 100-250℃ and the pressure at 0.2-10 mbar. First, introduce an indium source precursor into the reaction chamber. The indium source precursor can be trimethylindium (TMI, In(CH3)3) or cyclopentadienylindium (InCp, C5H5In). After the indium source pulse ends, purge the reaction chamber with an inert gas (nitrogen or argon) to remove unreacted tin tetrachloride and reaction byproducts (such as hydrogen chloride). Taking InCp as an example, the reaction process in Step 1 is as follows:

[0104] Surface-OH+InCp→Surface-O-InCp+CpH↑

[0105] Step Two: Introduce an oxygen source precursor (deionized water, oxygen, or ozone) into the reaction chamber. After the oxygen source pulse ends, purge the reaction chamber with an inert gas (nitrogen or argon) to complete one indium oxide (InOx) sub-cycle deposition. The reaction process in Step Two is as follows:

[0106] Surface-O-InCp+H2O→Surface-O-In-OH+CpH↑

[0107] 2Surface-O-In-OH→In2O3+H2O↑

[0108] Step 3: Introduce a tin source precursor, such as tetra(dimethylamino)tin (TDMASn) or tin tetrachloride (SnCl4), into the reaction chamber. The tin source adsorbs on the surface of the indium oxide substrate and reacts with the indium oxide, incorporating tin into the indium oxide lattice to form an indium tin oxide film. Then, an inert gas (nitrogen or argon) is introduced into the reaction chamber for purging. Taking TDMASn as an example, the reaction process in step 3 is as follows:

[0109] TDMASn +Surface - In2O3→Surface - In2O3- TDMASn+HN (CH3)2(g)

[0110] Repeat steps one through three above to obtain an indium tin oxide layer with a target thickness of 10 nm by performing the deposition according to the set number of cycles.

[0111] In some embodiments, the second transparent conductive oxide is fluorine-doped tin oxide, which is deposited on the surface of the first functional layer 61 using an atomic layer deposition process.

[0112] The atomic layer deposition process involves a reaction temperature of 150℃-400℃ and a reaction pressure of 0.2mbar-10mbar.

[0113] In this embodiment, surface hydroxyl groups are covalently fixed on the surface of fluorine-doped tin oxide through a chemical reaction in the atomic layer deposition process, thereby providing stable adsorption sites for self-assembled monolayers, improving the density of the self-assembled monolayer film, and ensuring the uniformity of charge transport and the stability of battery performance.

[0114] Under reaction temperatures ranging from 150℃ to 400℃ and reaction pressures ranging from 0.2 mbar to 10 mbar, atomic layer deposition can effectively form a stable fluorine-doped tin oxide film on the surface of the first functional layer 61. This facilitates the crystallization of the fluorine-doped tin oxide film, improves its conductivity and optical properties, reduces defects and impurities within the film, and thus enhances the photoelectric conversion efficiency and stability of the battery.

[0115] In one embodiment, the method for depositing fluorine-doped tin oxide by atomic layer deposition includes alternately and sequentially exposing a substrate (a substrate on which a first functional layer of fluorine-doped tin oxide material is deposited) to a vapor-phase tin precursor, a fluorine source precursor, and one or more oxygen reactants. The specific deposition process steps are as follows:

[0116] Step 1: Place the substrate (the substrate surface has Sn-OH) * The sample is placed in an ALD reaction chamber, with the temperature controlled at 150-400℃ and the pressure at 0.2-10 mbar. First, a tin source precursor, such as tin tetrachloride (SnCl4), is introduced into the reaction chamber. After the tin source pulse ends, an inert gas (nitrogen or argon) is introduced into the reaction chamber for purging, removing unreacted tin tetrachloride and reaction byproducts (such as hydrogen chloride) from the reaction chamber. The reaction process in step one is as follows:

[0117] Sn-OH * +SnCl4→Sn-O-SnCl3 * +HCl↑

[0118] Step Two: Introduce an oxygen source precursor (deionized water, oxygen, or ozone) into the reaction chamber. After the oxygen source pulse ends, purge the reaction chamber with an inert gas (nitrogen or argon) to complete the deposition of one tin oxide (SnOx) sub-cycle. Taking H2O as the oxygen source precursor as an example, the reaction process in Step Two is as follows:

[0119] Sn-Cl * +H₂O→Sn-OH * +HCl↑

[0120] Step 3: Introduce a fluorine precursor, such as hydrogen fluoride (HF), trifluoromethane (CHF3), or ammonium fluoride (NH4F), into the reaction chamber. The fluorine precursor reacts with the already formed tin oxide on the tin oxide substrate surface, causing fluorine atoms to be doped into the tin dioxide lattice to form a fluorine-doped tin oxide film. Then, an inert gas (nitrogen or argon) is introduced into the reaction chamber for purging. Taking HF as an example, the reaction process in step 3 is as follows:

[0121] Sn-OH * +HF→Sn-F * +H2O↑

[0122] Repeat steps one through three above to obtain a fluorine-doped tin oxide layer with a target thickness of 10 nm by depositing according to the set number of cycles.

[0123] In this embodiment, after depositing a first transparent conductive oxide by physical vapor deposition (PVD), a second transparent conductive oxide of the same material is deposited using atomic layer deposition (ALD) technology. This improves the density and uniformity of the second functional layer and allows surface hydroxyl groups to be fixed on the surface of the functional layer in the form of covalent bonds, providing stable adsorption sites for the adsorption of the hole transport layer, thereby ensuring the photoelectric conversion stability of the perovskite solar cell.

[0124] Reference Figure 1 This application provides a perovskite solar cell, which includes:

[0125] Base 1;

[0126] Hole transport layer 2, perovskite layer 3, electron transport layer 4 and the aforementioned functional layer 6 are stacked on one side surface of substrate 1.

[0127] In the above embodiments, the substrate 1 has a light-incident side and a light-emitting side; the substrate 1 can be a conductive glass substrate, and the light-incident side of the substrate 1 can be a surface on the substrate 1 such as... Figure 1As shown in the lower surface, the light-emitting side of substrate 1 can be such as the surface on substrate 1. Figure 1 The upper surface shown has an incident light side on the substrate 1 that can receive external light, transmit light through the substrate 1 and transmit the light from the emitting light side to the perovskite layer 3, so as to achieve an effective conversion of light energy into electrical energy.

[0128] In the perovskite solar cells of this application embodiment, the perovskite solar cell can be an inverted perovskite solar cell or a conventional perovskite solar cell. See also Figure 1 The perovskite solar cell is an inverted perovskite solar cell, with a functional layer 6, a hole transport layer 2, a perovskite layer 3, and an electron transport layer 4, which are sequentially disposed on one side surface of the substrate 1.

[0129] See Figure 1 Hole transport layer 2, perovskite layer 3, and electron transport layer 4 are sequentially disposed on the light-emitting side of substrate 1. After being excited by light, perovskite layer 3 generates electron-hole pairs. Hole transport layer 2 transports the holes generated by light excitation in perovskite layer 3, while electron transport layer 4 transports the electrons. The hole transport layer 2, perovskite layer 3, and electron transport layer 4 work together to achieve effective separation and transport of electrons and holes, ensuring the stability of the current generated by the perovskite solar cell. Functional layer 6 is disposed between substrate 1 and hole transport layer 2, serving to pre-treat substrate 1 and optimize the charge transport environment.

[0130] In some embodiments, the first functional layer 61 is a first transparent conductive oxide formed on the light-emitting side of the substrate 1 by physical vapor deposition, and the second functional layer 62 is a second transparent conductive oxide deposited on the surface of the first functional layer 61 by atomic layer deposition. The second functional layer 62 is in contact with the hole transport layer 2, and the first transparent conductive oxide and the second transparent conductive oxide are made of the same material.

[0131] In the above embodiments, this application uses atomic layer deposition to deposit the second functional layer 62 on the surface of the first functional layer 61, which promotes the surface hydroxylation of the second functional layer 62. The hydroxylated surface has better chemical activity and can interact with the chemical groups in the hole transport layer, thereby achieving stable adsorption of the hole transport layer 2 on the surface of the second functional layer 62. This ensures good interfacial contact between the hole transport layer 2 and the functional layer 6, which is beneficial to the effective transport of holes. In turn, it ensures the effective transport of charges inside the perovskite solar cell, improves the photoelectric conversion efficiency, and extends the battery's lifespan.

[0132] In some embodiments, the hole transport layer 2 is a self-assembled monomolecular film attached to the surface of the second transparent conductive oxide, and the self-assembled monomolecular film is one or more combinations of nPACz and G-nPACz;

[0133] Wherein, G is an organic unit, R is a group, and R can specifically include one or more combinations of alkyl, alkoxy, aromatic hydrocarbon, phosphoric acid, methylthio group, triphenylamine, pyrene nucleus, halogen atom, spirodifluorene, and phenylthiazide, and n is an integer between 2 and 4. The molecular formula of nPACz is as follows:

[0134] .

[0135] In the above embodiments, G may include one or more combinations of Me (methyl), MeO (methoxy), and Poly (polymer), where PA in nPACz represents a phosphate group, Cz represents a carbazole group, and n represents the carbon chain length, as shown in the above molecular formula. Self-assembled monomolecular films (SAMs) possess low transmission resistance, low parasitic absorption loss, high hole mobility, and excellent energy level alignment in batteries. The self-assembled monomolecular film can be anchored to hydroxyl groups (-OH) adsorbed on the surface of a transparent conductive oxide via phosphate groups.

[0136] In this embodiment, atomic layer deposition (ALD) is used to deposit a second functional layer 62 of the same material on the first functional layer 61, forming a sandwich structure of the first functional layer 61, the second functional layer 62, and the self-assembled monolayer. The oxygen source in ALD includes deionized water, which promotes hydroxylation on the surface of the second functional layer 62. This allows the surface of the self-assembled monolayer to be continuously exposed to a water molecule environment, which is beneficial for improving the wettability of the self-assembled monolayer and achieving stable adsorption of the self-assembled monolayer on the surface of the functional layer 6, thereby improving the lifespan of the perovskite solar cell.

[0137] In addition, atomic layer deposition technology can precisely control the oxygen vacancies and doping concentration in the second functional layer 62 to optimize the energy level arrangement of the first functional layer 61 and the self-assembled monolayer.

[0138] It is worth noting that although the self-assembled monolayer itself has good photothermal stability, the self-assembled monolayer adsorbed on the transparent conductive oxide film is easily desorbed by the polar solvent in the perovskite precursor solvent, which leads to a decrease in the photoelectric conversion performance and stability of the battery.

[0139] See Figure 3 The self-assembled monolayer is anchored on the second functional layer 62. The self-assembled monolayer includes anchoring groups, linking groups, and terminal groups from bottom to top. The anchoring groups (e.g., phosphonic acids or carboxylic acids) form chemical bonds such as hydrogen bonds, covalent bonds, or coordination bonds with hydroxyl groups (-OH) bonded to the surface of the second functional layer 62 through their functional groups, thereby realizing the self-assembly process of the self-assembled monolayer.

[0140] In related technologies, the hydroxyl groups on transparent conductive oxides (PVD TCOs) obtained by physical vapor deposition are usually weakly bonded by physical adsorption or hydrogen bonding. Rinsing with polar solvents can cause the bonded hydroxyl groups to desorb, resulting in a decrease in the anchoring stability of self-assembled monolayers. Figure 2 As shown. In this embodiment, an atomic layer deposition process is used to deposit a second functional layer 62 on the surface of the first functional layer 61, so that the second functional layer 62 completely covers the covalent hydroxyl groups, thereby strengthening the adsorption sites of the self-assembled monolayer and enhancing the anchoring stability of the self-assembled monolayer. The enhanced anchoring effect enables the self-assembled monolayer to resist the washing of polar solvents and reduces non-radiative recombination caused by pinholes or pore defects, such as... Figure 3 As shown.

[0141] In one specific embodiment, the self-assembled monolayer is dissolved in ethanol and spin-coated onto the second functional layer 62 at 3000 rpm for 30 seconds, and then annealed at 100°C for 10 minutes to obtain the hole transport layer 2 of the self-assembled monolayer structure.

[0142] The thickness of hole transport layer 2 is 5nm-10nm;

[0143] Self-assembled monolayers include one or more combinations of MeO-2PACz, 2PACz, 4PACz, Me-4PACz, MeO-4PACz, and Poly-2PACz; wherein PACz is a carbazole phosphate group.

[0144] In the above embodiments, when the thickness of the hole transport layer 2 is in the range of 5nm-10nm, such as 6nm, 8nm, or 9nm, the hole transport layer 2 can provide a suitable transport path length for holes. However, an excessively thin hole transport layer (e.g., less than 5nm) cannot form a complete and continuous molecular layer, resulting in discontinuous hole transport channels, increasing resistance to hole transport, causing recombination during transport, and reducing hole transport efficiency. Conversely, an excessively thick hole transport layer (e.g., greater than 10nm) increases the probability of hole scattering and recombination during transport, and also increases the series resistance of the battery, hindering effective charge collection and thus reducing the battery's photoelectric conversion efficiency.

[0145] In the above embodiments, the self-assembled monolayer may include MeO-2PACz (methoxy-2PACz, full name [2-(3,6-dimethoxy-9H-carbazole-9-yl)ethyl]phosphonic acid). The functional groups in the MeO-2PACz molecule can form good interactions with the adjacent second transparent conductive oxide and perovskite layer, which is beneficial to hole injection and transport, so as to form an ordered molecular arrangement at the interface, reduce the interface resistance, and improve the hole transport efficiency.

[0146] Self-assembled monolayers can include 2PACz (terpyridine diphosphonic acid, full name [2-(9H-carbazole-9-yl)ethyl]phosphonic acid). 2PACz has a simple molecular structure but has a high hole mobility, which can quickly transport holes from the perovskite layer to the electrode, reducing the accumulation and recombination of holes during the transport process, thereby improving the short-circuit current and fill factor of the battery.

[0147] Self-assembled monolayers can include 4PACz (terphenyl diphosphonic acid, full name [4-(9H-carbazole-9-yl)ethyl]phosphonic acid). The molecular structure of 4PACz has more conjugated systems, which helps to enhance the intramolecular electron delocalization effect and improve the hole transport capability. At the same time, the molecular size and shape of 4PACz may be more suitable for forming a closely packed molecular layer in hole transport layer 2, optimizing the hole transport channels.

[0148] Self-assembled monolayers may include Me-4PACz (methyl-4PACz, full name [4-(3,6-dimethyl-9H-carbazole-9-yl)butyl]phosphonic acid). By introducing methyl groups, Me-4PACz can change the electronic properties and steric hindrance of the molecule, thereby adjusting the energy level structure of hole transport layer 2. This makes the energy levels of hole transport layer 2 more matched with those of the perovskite layer and the electrode, which is beneficial for the smooth transport of holes and the effective separation of charges.

[0149] Self-assembled monolayers may include MeO-4PACz (methoxy-4PACz is officially called [4-(3,6-dimethoxy-9H-carbazole-9-yl)ethyl]phosphonic acid). MeO-4PACz can enhance the solubility and dispersibility of molecules in hole transport layer 2, which helps to form a uniform and dense molecular layer, improves the quality and stability of hole transport layer 2, and thus enhances hole transport performance.

[0150] Self-assembled monolayers can include Poly-2PACz (polymer-2PACz, full name poly[2-(9H-carbazole-9-yl)ethyl]phosphonic acid). Poly-2PACz has longer molecular chains and a larger molecular weight, which can form a three-dimensional network structure of hole transport layer 2, increasing the number of hole transport paths and channels, and improving hole transport efficiency. Simultaneously, the polymer structure can also enhance the mechanical strength and stability of hole transport layer 2.

[0151] Furthermore, the embodiments of this application can combine the above-mentioned materials to form a hole transport layer, and the combination of multiple self-assembled monolayers can achieve complementary advantages. For example, combining molecules with high hole mobility with molecules with good interfacial interactions and energy level matching can simultaneously improve hole transport efficiency and charge separation efficiency. By adjusting the proportion of different molecules, the performance of the hole transport layer 2 can be further optimized to meet the requirements of different battery structures and performance.

[0152] In some embodiments, the oxygen source in the atomic layer deposition process includes at least one of deionized water, hydrogen peroxide, oxygen, and ozone.

[0153] In the above embodiments, when the oxygen source in the atomic layer deposition process includes deionized water, the deionized water can decompose during the atomic layer deposition process to provide oxygen atoms, which participate in the oxidation reaction to form the target thin film. For example, when depositing a metal oxide thin film, the oxygen in the deionized water reacts with the metal precursor to generate metal oxide, thereby constructing the desired thin film structure.

[0154] When hydrogen peroxide is included as the oxygen source in atomic layer deposition (ALD) processes, its strong oxidizing properties provide more active oxygen atoms, promoting the reaction. This is particularly true for recalcitrant metal precursors; using hydrogen peroxide as the oxygen source allows for more effective oxidation, resulting in high-quality metal oxide films.

[0155] When oxygen is included as the oxygen source in atomic layer deposition (ALD) processes, it provides sufficient oxygen atoms to ensure the continuous progress of the reaction and improve production efficiency. However, when ozone is included as the oxygen source, its stronger oxidizing properties compared to oxygen and hydrogen peroxide enable rapid oxidation of metal precursors at lower temperatures. This reduces high-temperature damage to the substrate and thin film, improving film performance and quality.

[0156] In some embodiments, see Figure 1 Perovskite solar cells also include:

[0157] Electrode layer 5 is disposed on the side of electron transport layer 4 away from perovskite layer 3;

[0158] The thickness of electrode layer 5 is 10nm-200nm.

[0159] In the above embodiments, in the perovskite solar cell, the electron transport layer 4 is used to collect and transport electrons generated by the perovskite layer 3, and the electrode layer 5 is disposed on the side of the electron transport layer 4 away from the perovskite layer 3, providing an efficient collection and export channel for electrons. Electrons can be smoothly transported from the electron transport layer 4 to the electrode layer 5, and then current is output through external circuitry, completing charge collection in the photoelectric conversion process and achieving efficient output of electrical energy.

[0160] When the thickness of electrode layer 5 is 10nm-200nm, such as 20nm, 50nm, 80nm, 120nm, 150nm or 180nm, electrode layer 5 can form a uniform and continuous conductive film, providing an effective transmission path for electrons, enabling efficient collection and transmission of electrons, reducing electron loss during transmission, and improving photoelectric conversion efficiency.

[0161] In one embodiment, the electrode layer 5 is a copper metal electrode with a thickness of 100 nm. The copper metal electrode is deposited on the side of the electron transport layer 4 away from the perovskite layer 3 under vacuum conditions. Copper atoms can be deposited on the surface of the electron transport layer 4 in a pure state, avoiding the influence of impurities in the air on the electrode layer 5, and preparing a high-quality, uniform copper metal thin film electrode.

[0162] In some embodiments, the thickness of the perovskite layer 3 is 300nm-600nm, such as 350nm, 400nm, 450nm, 500nm or 550nm, and the thickness of the electron transport layer 4 is 10nm-50nm, such as 20nm, 30nm or 40nm.

[0163] In some embodiments, a thickness of 300nm-600nm ensures that the perovskite layer 3 fully absorbs photons from sunlight. This, in turn, excites the generation of a large number of electron-hole pairs, providing sufficient photogenerated carriers for the battery and improving the battery's short-circuit current and photoelectric conversion efficiency.

[0164] In one specific embodiment, the perovskite layer deposition step includes: dissolving the weighed perovskite precursor material in a mixed solvent of DMF and DMSO (DMF:DMSO = 4:1), and obtaining a black perovskite layer by a one-step spin coating process under annealing conditions at 100°C for 40 minutes.

[0165] In some embodiments, an electron transport layer 4 with a thickness of 10nm-50nm can ensure the number of active sites in the electron transport layer 4, which facilitates the collection and transport of electrons generated by the perovskite layer 3. Electrons can be transported from the perovskite layer to the electrode layer 5 quickly and efficiently, reducing energy loss and recombination probability during electron transport, thereby improving the short-circuit current and fill factor of the battery.

[0166] In one specific embodiment, the electron transport layer deposition step includes: thermally evaporating 20 nm C under vacuum conditions. 60 The thin film and the 5 nm BCP (Block Copolymer) thin film form a bilayer composite electron transport layer.

[0167] This application illustrates the functional layers used in perovskite solar cells through specific embodiments and comparative examples.

[0168] Example 1 is a perovskite solar cell formed by a functional layer including a first functional layer and a second functional layer of indium tin oxide material. Example 2 is a perovskite solar cell formed by a functional layer including only a first functional layer of indium tin oxide material. Example 3 is a perovskite solar cell formed by a functional layer including a first functional layer and a second functional layer of fluorine-doped tin oxide material. Example 4 is a perovskite solar cell formed by a functional layer including only a first functional layer of fluorine-doped tin oxide material.

[0169] Example 1

[0170] S1, Indium tin oxide material is deposited on one side surface of the substrate using physical vapor deposition process to form a first functional layer with a thickness of 300nm;

[0171] S2, the substrate with the first functional layer deposited is placed in the ALD reaction chamber, and the temperature of the reaction chamber is controlled at 100°C and the pressure at 0.2 mbar. First, a trimethylindium indium source precursor (temperature 40°C, injection duration 2 s, flow rate 500 sccm) is introduced into the reaction chamber. After the indium source pulse ends, nitrogen gas is introduced into the reaction chamber for purging.

[0172] In step S3, deionized water is first introduced into the reaction chamber as an oxygen source precursor (room temperature, injection duration 2 s, flow rate 500 sccm). After the deionized water oxygen source pulse ends, nitrogen gas is introduced into the reaction chamber for purging. Then, oxygen gas is introduced as an oxygen source precursor (room temperature, injection duration 3 s, flow rate 500 sccm). After the oxygen source pulse ends, nitrogen gas is introduced into the reaction chamber for purging, completing one indium oxide (InOx) sub-cycle deposition. This process is repeated 19 times to obtain an indium oxide thin film.

[0173] S4. Maintain the reaction temperature at 100℃ and the pressure at 0.2mbar. Introduce a tetrakis(dimethylamino)tin tin source precursor (temperature 70℃, injection time 1s, flow rate 500sccm) into the reaction chamber. The tin source is adsorbed on the surface of the indium oxide substrate and reacts with the indium oxide, causing tin to be incorporated into the indium oxide lattice to form an indium tin oxide film. Then, nitrogen gas is introduced into the reaction chamber for purging.

[0174] S5, deionized water is introduced into the reaction chamber as an oxygen source precursor (room temperature, injection duration 2s, flow rate 500sccm). After the oxygen source pulse ends, nitrogen gas is introduced into the reaction chamber for purging to complete the deposition of one tin oxide cycle.

[0175] Repeat steps S2 to S5 eight times to obtain a second functional layer with a thickness of 10 nm by depositing according to the set number of cycles.

[0176] Example 2

[0177] S1, using physical vapor deposition, fluorine-doped tin oxide material is deposited on one side surface of the substrate to form a first functional layer with a thickness of 300 nm;

[0178] S2, the substrate with the first functional layer deposited is placed in the ALD reaction chamber, and the temperature of the reaction chamber is controlled at 150°C and the pressure at 0.2 mbar. First, a tin source precursor of tin tetrachloride is introduced into the reaction chamber (temperature 70°C, injection time 0.5 s, flow rate 500 sccm). After the tin source pulse ends, nitrogen gas is introduced into the reaction chamber for purging.

[0179] In step S3, deionized water is introduced into the reaction chamber as an oxygen source precursor (room temperature, injection time 0.2 s, flow rate 500 sccm). After the oxygen source pulse ends, nitrogen gas is introduced into the reaction chamber for purging, completing one tin oxide (SnOx) sub-cycle deposition. This process is repeated for 20 sub-cycles to obtain a thin tin oxide film.

[0180] S4, a fluorine source precursor of hydrogen fluoride (room temperature, injection time 1s, flow rate 500sccm) is introduced into the reaction chamber. The fluorine source is adsorbed on the surface of the tin oxide substrate and reacts with the tin oxide, so that fluorine is incorporated into the tin oxide lattice to form a fluorine-doped tin oxide film. Then, nitrogen gas is introduced into the reaction chamber for purging to complete the deposition of one fluorine-doped tin oxide sub-cycle.

[0181] Repeat steps S2 to S4 above 20 times to obtain a second functional layer with a thickness of 10 nm by deposition according to the set number of cycles.

[0182] Example 3

[0183] The only difference from Example 1 is:

[0184] The thickness of the first functional layer is 800 nm, and the thickness of the second functional layer is 5 nm.

[0185] Example 4

[0186] The only difference from Example 1 is:

[0187] The thickness of the first functional layer is 500 nm, and the thickness of the second functional layer is 8 nm.

[0188] Comparative Example 1 (using indium tin oxide as the functional layer alone via physical vapor deposition)

[0189] S11 uses physical vapor deposition to deposit indium tin oxide on one side of the substrate to form a functional layer with a thickness of 300 nm.

[0190] Comparative Example 2 (using fluorine-doped tin oxide as the functional layer alone via physical vapor deposition)

[0191] S11 uses physical vapor deposition to deposit fluorine-doped tin oxide material onto one side of the substrate to form a functional layer with a thickness of 300 nm.

[0192] The parameter characterization for battery testing in Example 1 and Comparative Example 1 is shown in Table 1 and... Figure 4 In Example 1, the photoelectric conversion efficiency (reverse scan) of the battery can reach 19.02%, while the photoelectric conversion efficiency (reverse scan) of the battery in Comparative Example 1 is only 18.01%. This means that the normalized efficiency and stability of the battery in Example 1 are significantly improved compared to the battery in Comparative Example 1.

[0193] Among them, Jsc (short-circuit current density), Voc (open-circuit voltage), FF (fill factor), and PCE (photovoltaic conversion efficiency).

[0194] Battery parameters for Example 2 and Comparative Example 2 were characterized. See Table 1 and... Figure 5 In Example 2, the photoelectric conversion efficiency (reverse scan) of the battery can reach 18.51%, while the photoelectric conversion efficiency (reverse scan) of the battery in Comparative Example 2 is only 18.06%. This means that the normalized efficiency and stability of the battery in Example 2 are significantly improved compared to the battery in Comparative Example 2.

[0195] Table 1 Characterization parameters of the examples and comparative examples

[0196]

[0197] This application provides a method for fabricating a perovskite solar cell, the method comprising:

[0198] S101, a first functional layer is formed on one side surface of the substrate using a physical vapor deposition process;

[0199] Physical vapor deposition (PVD) can create a good physical and chemical bond between the first functional layer material and the substrate, enhance the adhesion between the first functional layer film and the substrate, prevent the first functional layer from easily detaching, maintain the integrity of the perovskite solar cell structure, and extend the lifespan of the cell.

[0200] S102, depositing a second functional layer on the surface of the first functional layer using an atomic layer deposition process;

[0201] Atomic layer deposition (ALD) technology enables precise control of atomic-level thickness, allowing for the deposition of nanoscale, highly uniform second functional layer films. This ensures good interfacial contact between battery layers, reduces interfacial defects and recombination centers, and improves charge transport efficiency. Furthermore, the second functional layer can modify and optimize the interface between the first functional layer and the hole transport layer, adjusting energy level matching and lowering the interfacial barrier. This facilitates the smooth injection of charge from the first functional layer to the hole transport layer, improving the battery's charge collection efficiency and enhancing its long-term stability and performance consistency.

[0202] S103, a hole transport layer, a perovskite layer and an electron transport layer are sequentially disposed on the surface of the second functional layer.

[0203] In the above embodiments, a hole transport layer, such as a self-assembled monolayer, is located on the surface of the second functional layer. This layer selectively transports holes and blocks electrons, efficiently collecting and transporting holes generated in the perovskite layer to the electrode, reducing the recombination probability of holes and electrons, and improving the short-circuit current and fill factor of the battery. The perovskite layer absorbs photons and generates electron-hole pairs, optimizing light absorption and carrier transport characteristics, and improving the photoelectric conversion efficiency of the battery. An electron transport layer is located on the surface of the perovskite layer. This layer selectively transports electrons and blocks holes, efficiently collecting and transporting electrons generated in the perovskite layer to the electrode, thus improving the photoelectric conversion performance of the battery.

[0204] In some embodiments, the first transparent conductive oxide and the second transparent conductive oxide are made of the same material.

[0205] When the first transparent conductive oxide and the second transparent conductive oxide are made of the same material, the similarity of material properties at the interface between the first transparent conductive oxide and the second transparent conductive oxide can reduce interface defects caused by factors such as lattice mismatch, which helps to reduce the probability of charge recombination and improve the fill factor and photoelectric conversion efficiency of the battery.

[0206] In some embodiments, the second functional layer is indium tin oxide, and the preparation method includes:

[0207] Indium tin oxide is deposited on the surface of the first functional layer away from the substrate using atomic layer deposition technology, and then a hole transport layer is deposited on the side of the indium tin oxide away from the first functional layer.

[0208] The atomic layer deposition process involves a reaction temperature of 100℃-250℃ and a reaction pressure of 0.2mbar-10mbar.

[0209] The indium source precursor is trimethylindium or cyclopentadienylindium, the tin source precursor is tetra(dimethylamino)tin or tin tetrachloride, and the oxygen source is at least one of deionized water, hydrogen peroxide, oxygen and ozone.

[0210] In the above embodiments, surface hydroxyl groups are fixed on the surface of indium tin oxide in the form of covalent bonds through chemical reactions in the atomic layer deposition process, thereby providing stable adsorption sites for self-assembled monolayers, improving the density of the self-assembled monolayer film, and ensuring the uniformity of charge transport and the stability of battery performance.

[0211] Under reaction temperatures of 100℃-250℃ and reaction pressures of 0.2mbar-10mbar, the precursor molecules used in atomic layer deposition (ALD) have sufficient activity to effectively undergo chemical reactions on the surface of the first functional layer, forming a stable indium tin oxide (ITO) thin film. At the same time, the transport and reaction processes of precursor molecules can be precisely controlled, thereby enabling control over the deposition rate of ITO thin films.

[0212] In some embodiments, the second functional layer is fluorine-doped tin oxide, and the preparation method includes:

[0213] A fluorine-doped tin oxide is deposited on the surface of the first functional layer on the side away from the substrate using atomic layer deposition technology, and then a hole transport layer is deposited on the side of the fluorine-doped tin oxide away from the first functional layer.

[0214] The atomic layer deposition process involves a reaction temperature of 150℃-400℃ and a reaction pressure of 0.2mbar-10mbar.

[0215] The tin source precursor is tetra(dimethylamino)tin or tin tetrachloride, the fluorine source precursor is hydrogen fluoride, trifluoromethane or ammonium fluoride, and the oxygen source is at least one of deionized water, hydrogen peroxide, oxygen and ozone.

[0216] In the above embodiments, surface hydroxyl groups are fixed on the fluorine-doped tin oxide surface in the form of covalent bonds through chemical reactions in the atomic layer deposition process, thereby providing stable adsorption sites for the self-assembled monolayer, improving the density of the self-assembled monolayer film, and ensuring the uniformity of charge transport and the stability of battery performance.

[0217] Under reaction temperatures ranging from 150℃ to 400℃ and reaction pressures ranging from 0.2 mbar to 10 mbar, atomic layer deposition (ALD) can effectively form stable fluorine-doped tin oxide films on the surface of the first functional layer. This facilitates the crystallization of the fluorine-doped tin oxide films, improves their conductivity and optical properties, reduces internal defects and impurities, and thus enhances the photoelectric conversion efficiency and stability of the battery.

[0218] In some embodiments, the second functional layer is indium zinc oxide, and the preparation method includes:

[0219] Indium zinc oxide is deposited on the surface of the first functional layer away from the substrate using atomic layer deposition technology, and then a hole transport layer is deposited on the side of the indium zinc oxide away from the first functional layer.

[0220] The atomic layer deposition process involves a reaction temperature of 100℃-250℃ and a reaction pressure of 0.2mbar-10mbar.

[0221] The indium source precursor is trimethylindium or cyclopentadienylindium, the zinc source precursor is diethylzinc, and the oxygen source is at least one of deionized water, hydrogen peroxide, oxygen, and ozone.

[0222] In the above embodiments, indium zinc oxide (IZO) exhibits high carrier mobility, enabling charge carriers (such as electrons or holes) to move rapidly, which is beneficial for achieving efficient charge transport. In optoelectronic devices, the functional layer made of indium zinc oxide can reduce recombination losses during charge transport, improve the current density and fill factor of the device, and thus enhance the overall performance of the device.

[0223] A temperature range of 100℃ to 250℃ and a pressure range of 0.2mbar to 10mbar facilitate the formation of high-quality indium zinc oxide thin films. Within this temperature and pressure range, the reacting atoms have sufficient energy to migrate and rearrange on the substrate surface, which is conducive to the formation of a dense and uniform thin film structure, thereby improving the electrical and optical properties of the film.

[0224] In some embodiments, providing a hole transport layer on the surface of the second functional layer includes:

[0225] The hole transport layer is dissolved and spin-coated onto the surface of the second functional layer away from the first functional layer;

[0226] Among them, the hole transport layer is a self-assembled monolayer, and the self-assembled monolayer is one or more combinations of nPACz and G-nPACz;

[0227] Wherein, G is one or more combinations of Me, MeO, and Poly; R is a functional group, which may specifically include one or more combinations of alkyl, alkoxy, aromatic hydrocarbon, phosphoric acid, methylthio group, triphenylamine, pyrene nucleus, halogen atom, spirodifluorene, and phenylthiazide; n is an integer between 2 and 4; and the molecular formula of nPACz is as follows:

[0228] .

[0229] In other words, self-assembled monolayers can include one or more combinations of MeO-2PACz, 2PACz, 4PACz, Me-4PACz, MeO-4PACz, and Poly-2PACz.

[0230] In the above embodiments, the self-assembled monolayer may include MeO-2PACz (methoxy-2PACz, full name [2-(3,6-dimethoxy-9H-carbazole-9-yl)ethyl]phosphonic acid). The functional groups in the MeO-2PACz molecule can form good interactions with the adjacent second transparent conductive oxide and perovskite layer, which is beneficial to hole injection and transport, so as to form an ordered molecular arrangement at the interface, reduce the interface resistance, and improve the hole transport efficiency.

[0231] Self-assembled monolayers can include 2PACz (terpyridine diphosphonic acid, full name [2-(9H-carbazole-9-yl)ethyl]phosphonic acid). 2PACz has a simple molecular structure but has a high hole mobility, which can quickly transport holes from the perovskite layer to the electrode, reducing the accumulation and recombination of holes during the transport process, thereby improving the short-circuit current and fill factor of the battery.

[0232] Self-assembled monolayers can include 4PACz (terphenyl diphosphonic acid, full name [4-(9H-carbazole-9-yl)ethyl]phosphonic acid). The molecular structure of 4PACz has more conjugated systems, which helps to enhance the intramolecular electron delocalization effect and improve the hole transport capability. At the same time, the molecular size and shape of 4PACz may be more suitable for forming a closely packed molecular layer in the hole transport layer, optimizing the hole transport channel.

[0233] Self-assembled monolayers can include Me-4PACz (methyl-4PACz, full name [4-(3,6-dimethyl-9H-carbazole-9-yl)butyl]phosphonic acid). By introducing methyl groups, Me-4PACz can change the electronic properties and steric hindrance of the molecule, thereby adjusting the energy level structure of the hole transport layer. This makes the energy levels of the hole transport layer more matched with those of the perovskite layer and the electrode, which is beneficial for the smooth transport of holes and the effective separation of charges.

[0234] Self-assembled monolayers may include MeO-4PACz (methoxy-4PACz is also known as [4-(3,6-dimethoxy-9H-carbazole-9-yl)ethyl]phosphonic acid). MeO-4PACz can enhance the solubility and dispersibility of molecules in the hole transport layer, which helps to form a uniform and dense molecular layer, improves the quality and stability of the hole transport layer, and thus enhances hole transport performance.

[0235] Self-assembled monolayers can include Poly-2PACz (polymer-2PACz, full name poly[2-(9H-carbazole-9-yl)ethyl]phosphonic acid). Poly-2PACz has longer molecular chains and a larger molecular weight, which can form a three-dimensional network structure of hole transport layer, increasing the number of hole transport paths and channels, and improving hole transport efficiency. At the same time, the polymer structure can also enhance the mechanical strength and stability of the hole transport layer.

[0236] Furthermore, the embodiments of this application can combine the above-mentioned materials to form a hole transport layer, and the combination of multiple self-assembled monolayers can achieve complementary advantages. For example, combining molecules with high hole mobility with molecules with good interfacial interactions and energy level matching can simultaneously improve hole transport efficiency and charge separation efficiency. By adjusting the proportion of different molecules, the performance of the hole transport layer can be further optimized to meet the requirements of different battery structures and performance.

[0237] While specific embodiments of this application have been described in detail by way of examples, those skilled in the art should understand that the above examples are for illustrative purposes only and are not intended to limit the scope of this application. Those skilled in the art should understand that modifications can be made to the above embodiments without departing from the scope and spirit of this application. The scope of this application is defined by the appended claims.

Claims

1. A functional layer for a perovskite solar cell, the functional layer being disposed between a substrate and a hole transport layer, characterized in that, include: The first functional layer (61) is a first transparent conductive oxide; The second functional layer (62) is a second transparent conductive oxide. The second functional layer (62) is deposited on the surface of the first functional layer (61) by atomic layer deposition and can contact the hole transport layer. The first transparent conductive oxide and the second transparent conductive oxide are made of the same material; The hole transport layer is a self-assembled monolayer.

2. The functional layer according to claim 1, characterized in that, The first functional layer (61) is formed on one side surface of the substrate using a physical vapor deposition process; The thickness of the first functional layer (61) is 300nm-800nm.

3. The functional layer according to claim 1, characterized in that, The thickness of the second functional layer (62) is 5nm-10nm.

4. The functional layer according to claim 1, characterized in that, The second transparent conductive oxide is indium tin oxide, fluorine-doped tin oxide, or indium zinc oxide.

5. The functional layer according to claim 4, characterized in that, The second transparent conductive oxide is indium tin oxide, which is deposited on the surface of the first functional layer (61) using an atomic layer deposition process; The atomic layer deposition process has a reaction temperature of 100℃-250℃ and a reaction pressure of 0.2mbar-10mbar.

6. The functional layer according to claim 4, characterized in that, The second transparent conductive oxide is fluorine-doped tin oxide, which is deposited on the surface of the first functional layer (61) using an atomic layer deposition process; The atomic layer deposition process has a reaction temperature of 150℃-400℃ and a reaction pressure of 0.2mbar-10mbar.

7. A perovskite solar cell, characterized in that, include: Base (1); Hole transport layer (2), perovskite layer (3), electron transport layer (4) and functional layer (6) as described in any one of claims 1-6, wherein the functional layer (6), the hole transport layer (2), the perovskite layer (3) and the electron transport layer (4) are stacked on one side surface of the substrate (1); The hole transport layer (2) is a self-assembled monolayer.

8. The perovskite solar cell according to claim 7, characterized in that, The first functional layer (61) is formed on one side surface of the substrate (1) using a physical vapor deposition process, and the second functional layer (62) is deposited on the surface of the first functional layer (61) using an atomic layer deposition process and is in contact with the hole transport layer (2).

9. The perovskite solar cell according to claim 7, characterized in that, The hole transport layer (2) is a self-assembled monomolecular film attached to the surface of the second transparent conductive oxide, and the self-assembled monomolecular film is one or more combinations of nPACz and G-nPACz; Where G is an organic unit, R is a functional group, and n is an integer between 2 and 4, the molecular formula of nPACz is as follows: 。 10. The perovskite solar cell according to claim 9, characterized in that, The hole transport layer (2) has a thickness of 5nm-10nm; The self-assembled monolayer includes one or more combinations of MeO-2PACz, 2PACz, 4PACz, Me-4PACz, MeO-4PACz, and Poly-2PACz.

11. The perovskite solar cell according to claim 8, characterized in that, The oxygen source in the atomic layer deposition process includes at least one of deionized water, hydrogen peroxide, oxygen, and ozone.

12. The perovskite solar cell according to claim 7, characterized in that, Also includes: Electrode layer (5), the electrode layer (5) is disposed on the side of the electron transport layer (4) away from the perovskite layer (3); The thickness of the electrode layer (5) is 10nm-200nm.

13. The perovskite solar cell according to claim 7, characterized in that, The thickness of the perovskite layer (3) is 300nm-600nm, and the thickness of the electron transport layer (4) is 10nm-50nm.

14. The perovskite solar cell according to claim 7, characterized in that, The perovskite solar cell is an inverted perovskite solar cell.

15. A method for fabricating a perovskite solar cell, characterized in that, include: The first functional layer is formed on one side surface of the substrate using a physical vapor deposition process; A second functional layer is deposited on the surface of the first functional layer using an atomic layer deposition process; A hole transport layer, a perovskite layer, and an electron transport layer are sequentially disposed on the surface of the second functional layer. The first transparent conductive oxide of the first functional layer and the second transparent conductive oxide of the second functional layer are made of the same material; The hole transport layer is a self-assembled monolayer.

16. The preparation method according to claim 15, characterized in that, The second functional layer is indium tin oxide, and the preparation method includes: Indium tin oxide is deposited on the surface of the first functional layer away from the substrate using an atomic layer deposition process, and then a hole transport layer is deposited on the side of the indium tin oxide away from the first functional layer. The atomic layer deposition process has a reaction temperature of 100℃-250℃ and a reaction pressure of 0.2mbar-10mbar. The indium source precursor is trimethylindium or cyclopentadienylindium, the tin source precursor is tetra(dimethylamino)tin or tin tetrachloride, and the oxygen source is at least one of deionized water, hydrogen peroxide, oxygen and ozone.

17. The preparation method according to claim 15, characterized in that, The second functional layer is fluorine-doped tin oxide, and the preparation method includes: A fluorine-doped tin oxide is deposited on the surface of the first functional layer away from the substrate using an atomic layer deposition process, and then a hole transport layer is deposited on the side of the fluorine-doped tin oxide away from the first functional layer. The atomic layer deposition process has a reaction temperature of 150℃-400℃ and a reaction pressure of 0.2mbar-10mbar. The tin source precursor is tetra(dimethylamino)tin or tin tetrachloride, the fluorine source precursor is hydrogen fluoride, trifluoromethane or ammonium fluoride, and the oxygen source is at least one of deionized water, hydrogen peroxide, oxygen and ozone.

18. The preparation method according to claim 15, characterized in that, The second functional layer is indium zinc oxide, and the preparation method includes: Indium zinc oxide is deposited on the surface of the first functional layer away from the substrate using atomic layer deposition (ALD) technology, and then a hole transport layer is deposited on the side of the indium zinc oxide away from the first functional layer. The atomic layer deposition process has a reaction temperature of 100℃-250℃ and a reaction pressure of 0.2mbar-10mbar. The indium source precursor is trimethylindium or cyclopentadienylindium, the zinc source precursor is diethylzinc, and the oxygen source is at least one of deionized water, hydrogen peroxide, oxygen, and ozone.

19. The preparation method according to claim 15, characterized in that, The hole transport layer is disposed on the surface of the second functional layer, including: After dissolving the hole transport layer, spin-coat it onto the surface of the second functional layer away from the first functional layer. The self-assembled monolayer is one or a combination of nPACz and G-nPACz; Wherein, G is one or more combinations of Me, MeO, and Poly, R is a functional group, n is an integer between 2 and 4, and the molecular formula of nPACz is as follows: 。

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