Storage method and application of electrode substrate

Abstract

The invention discloses a preservation method and application of an electrode substrate, and relates to the technical field of perovskite batteries, and the method comprises the steps: providing an electrode substrate which is a self-assembled monomolecular layer modified electrode substrate; the electrode substrate is placed in a sealed container to be stored, the relative humidity of the sealed container is 5%-25%, and the oxygen volume fraction is 10%-21%. According to the invention, the interface stability of the stored self-assembled monomolecular layer modified electrode substrate is improved.

Description

Methods for preserving and applying electrode substrates Technical Field

[0001] This application relates to the field of perovskite battery technology, and in particular to methods and applications for preserving electrode substrates. Background Technology

[0002] In recent years, perovskite solar cells (PSCs) have become a research hotspot in the photovoltaic field due to their high photoelectric conversion efficiency, low cost, and process compatibility. In the structure of perovskite solar cells, the interface quality between the transparent electrode substrate and the transport layer is crucial to cell performance. Recently, modifying the electrode substrate surface with self-assembled monolayers (SAMs) has effectively improved interface energy level matching, reduced defect state density, and enhanced carrier extraction efficiency. SAM layers can be formed into ultrathin modification layers on transparent electrode substrates using simple solution methods (spin coating, blade coating, slot coating, inkjet printing).

[0003] However, in the actual fabrication process of perovskite solar cells, SAM deposition and perovskite layer deposition are not continuous processes. There are storage and transfer steps involved in the fabrication process. The preservation of the electrode substrate coated with the SAM layer affects its interfacial chemistry and the performance of the subsequently fabricated cell. Existing methods include using a nitrogen glove box for storage, which avoids water and oxygen, but causes SAM molecular orientation to loosen over time, leading to decreased wettability. Another method is air storage, which is simple but results in SAM molecular degradation due to continuous moisture absorption and oxidation.

[0004] The above content is only used to help understand the technical solution of this application and does not represent an admission that the above content is prior art. Summary of the Invention

[0005] The main objective of this application is to provide a method and application for preserving electrode substrates, aiming to improve the interface stability of self-assembled monolayer modified electrode substrates after preservation.

[0006] To achieve the above objectives, this application proposes a method for preserving an electrode substrate, the method comprising: providing an electrode substrate, wherein the electrode substrate is a self-assembled monolayer modified electrode substrate; and storing the electrode substrate in a sealed container, wherein the relative humidity of the sealed container is 5% to 25% and the oxygen volume fraction is 10% to 21%.

[0007] In one feasible embodiment, the ratio of the head space volume of the sealed container to the effective area of ​​the electrode substrate is 0.2 mL·cm². -2 ~0.6 mL·cm -2 .

[0008] In one feasible embodiment, prior to the step of storing the electrode substrate in a sealed container, the method further includes: providing a sealed container; adjusting the relative humidity and oxygen volume fraction of the sealed container using a desiccant and an oxygen limiting agent; and placing the electrode substrate, after completing the self-assembled monolayer modification, into the sealed container according to the ratio of the headspace volume of the sealed container to the effective area of ​​the electrode substrate.

[0009] In one feasible embodiment, the sealed container includes an aluminum-plastic composite film bag or a glass container.

[0010] In one feasible embodiment, the water vapor transmission rate of the aluminum-plastic composite film bag is ≤0.05 g·m. -2 ·day -1 Oxygen permeability ≤1 cm 3 ·m -2 ·day -1 ·atm -1 .

[0011] In one feasible embodiment, the water vapor transmission rate of the glass container is ≤1×10⁻⁶. -4 g·m -2 ·day -1 Oxygen permeability ≤1 cm 3 ·m -2 ·day -1 ·atm -1 .

[0012] In one feasible embodiment, the desiccant comprises silica gel and / or molecular sieves; and / or, the oxygen limiting agent comprises at least one of iron-based oxygen limiting agents, sulfites, and inert gases.

[0013] In one feasible embodiment, the material of the self-assembled monolayer includes at least one of carbazole, triphenylamine, phosphate-anchored molecules, carboxylic acid-anchored molecules, and C60; and / or, the electrode substrate includes a fluorine-doped tin oxide substrate or a tin-doped indium oxide substrate.

[0014] In one feasible embodiment, the electrode substrate is stored for a maximum of 30 days.

[0015] This application also provides an application of the electrode substrate preservation method described above in the fabrication of perovskite solar cells.

[0016] One or more technical solutions proposed in this application have at least the following technical effects: a method for preserving a self-assembled monolayer modified electrode substrate, comprising: providing an electrode substrate, wherein the electrode substrate is a self-assembled monolayer modified electrode substrate; and preserving the electrode substrate in a sealed container, wherein the relative humidity of the sealed container is 5%~25% and the oxygen volume fraction is 10%~21%. In this application, by controlling the relative humidity and oxygen volume fraction of the environment in the sealed container, a stable adsorption layer forms on the surface of the self-assembled monolayer modified electrode substrate during preservation. This stable adsorption layer effectively achieves orientation locking and interface passivation. Orientation locking causes the molecules in the self-assembled monolayer to align in a specific direction, ensuring the consistency and stability of the electrode substrate's performance. Simultaneously, the sealed container prevents continuous water and oxygen exchange with the external environment, thereby improving the interface stability of the self-assembled monolayer modified electrode substrate after preservation. Attached Figure Description

[0017] The accompanying drawings, which are incorporated in and form part of this specification, illustrate embodiments consistent with this application and, together with the description, serve to explain the principles of this application.

[0018] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, for those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0019] Figure 1 is a flowchart illustrating the method for preserving an electrode substrate according to an embodiment of this application; Figure 2 is a structural diagram illustrating the method for preserving an electrode substrate according to an embodiment of this application.

[0020] Explanation of the reference numerals: 10, sealed container; 101, desiccant; 102, oxygen limiting agent; 20, electrode substrate; 30, head space.

[0021] The purpose, features, and advantages of this application will be further explained in conjunction with the embodiments and with reference to the accompanying drawings. Detailed Implementation

[0022] To make the objectives, technical solutions, and advantages of the embodiments of this application clearer, the technical solutions in the embodiments of this application will be clearly and completely described below. Where specific conditions are not specified in the embodiments, conventional conditions or conditions recommended by the manufacturer shall apply. Reagents or instruments whose manufacturers are not specified are all conventional products that can be purchased commercially.

[0023] The following detailed description, with appropriate reference to the accompanying drawings, discloses the method for preserving the electrode substrate and its application embodiments. However, unnecessary details may be omitted. For example, detailed descriptions of well-known matters and repetitive descriptions of essentially the same structures may be omitted. This is to avoid unnecessarily lengthy descriptions and to facilitate understanding by those skilled in the art. Furthermore, the accompanying drawings and the following description are provided for the purpose of enabling those skilled in the art to fully understand this application and are not intended to limit the subject matter of the claims.

[0024] The "range" disclosed in this application is defined by a lower limit and an upper limit. A given range is defined by selecting a lower limit and an upper limit, which define the boundaries of a particular range. Ranges defined in this way can include or exclude endpoints and can be arbitrarily combined; that is, any lower limit can be combined with any upper limit to form a range. For example, if ranges of 60~120 and 80~110 are listed for a specific parameter, it is also expected that ranges of 60~110 and 80~120 are also included. Furthermore, if minimum range values ​​of 1 and 2 are listed, and if maximum range values ​​of 3, 4, and 5 are listed, then the following ranges are all expected: 1~3, 1~4, 1~5, 2~3, 2~4, and 2~5. In this application, unless otherwise stated, the numerical range "a~b" represents a shortened representation of any combination of real numbers between a and b, where a and b are real numbers. For example, the numerical range "0~5" indicates that all real numbers between "0~5" have been listed in this article; "0~5" is simply a shortened representation of these numerical combinations. Furthermore, when a parameter is stated as an integer ≥2, it is equivalent to disclosing that the parameter is, for example, an integer such as 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, etc.

[0025] Unless otherwise specified, all embodiments and optional embodiments of this application can be combined to form new technical solutions.

[0026] Unless otherwise specified, all technical features and optional technical features of this application may be combined to form new technical solutions.

[0027] Unless otherwise specified, all steps in this application may be performed sequentially or randomly, preferably sequentially. For example, the method includes steps (a) and (b), indicating that the method may include steps (a) and (b) performed sequentially, or it may include steps (b) and (a) performed sequentially. For example, the mention that the method may also include step (c) indicates that step (c) may be added to the method in any order. For example, the method may include steps (a), (b), and (c), or it may include steps (a), (c), and (b), or it may include steps (c), (a), and (b), etc.

[0028] Unless otherwise specified, the terms "comprising" and "including" as used in this application can be open-ended or closed-ended. For example, "comprising" and "including" can mean that other components not listed may also be included, or that only the listed components may be included.

[0029] Unless otherwise specified, the term "or" is inclusive in this application. For example, the phrase "A or B" means "A, B, or both A and B". More specifically, the condition "A or B" is satisfied by any of the following conditions: A is true (or exists) and B is false (or does not exist); A is false (or does not exist) and B is true (or exists); or both A and B are true (or exist).

[0030] To make the above-mentioned objectives, features, and advantages of this application more apparent and understandable, the technical solution of this application is further described below in conjunction with the accompanying drawings and embodiments. However, this application is not limited to the listed embodiments, but should also include any other well-known modifications within the scope of the claims made in this application.

[0031] The term "an embodiment" or "embodiment" as used herein refers to a specific feature, structure, or characteristic that may be included in at least one implementation of this application. The phrase "in one embodiment" appearing in different places throughout this specification does not necessarily refer to the same embodiment, nor is it a single or selective embodiment that is mutually exclusive with other embodiments.

[0032] Existing methods for preserving self-assembled monolayer modified electrode substrates include: one is storage in a nitrogen glove box, which avoids water and oxygen, but causes the SAM molecular orientation to loosen over time, leading to decreased wettability; the other is air storage, which is simple but causes SAM molecular degradation due to continuous moisture absorption and oxidation.

[0033] The method for preserving a self-assembled monolayer modified electrode substrate provided in this application includes: providing an electrode substrate, wherein the electrode substrate is a self-assembled monolayer modified electrode substrate; and storing the electrode substrate in a sealed container, wherein the relative humidity of the sealed container is 5%~25% and the oxygen volume fraction is 10%~21%. This application embodiment controls the relative humidity and oxygen volume fraction of the environment in the sealed container, enabling the formation of a stable adsorption layer on the surface of the self-assembled monolayer modified electrode substrate during storage. This stable adsorption layer effectively achieves orientation locking and interface passivation. Orientation locking ensures that the molecules in the self-assembled monolayer are aligned in a specific direction, guaranteeing the consistency and stability of the electrode substrate's performance. Simultaneously, the sealed container prevents continuous water and oxygen exchange with the external environment, thereby improving the interface stability of the self-assembled monolayer modified electrode substrate after storage.

[0034] To better understand the technical solution of this application, a detailed description will be provided below in conjunction with the accompanying drawings and specific implementation methods.

[0035] Based on this, this application provides a method for preserving an electrode substrate, as shown in FIG1. ​​In this embodiment, the method includes: step S10, providing an electrode substrate, wherein the electrode substrate is a self-assembled monolayer modified electrode substrate; step S20, placing the electrode substrate in a sealed container for preservation, wherein the relative humidity of the sealed container is 5%~25% and the oxygen volume fraction is 10%~21%.

[0036] In one feasible embodiment, a sealed container is used to store the electrode substrate in order to isolate it from the external environment and prevent external dust, moisture, oxygen and other possible contaminants from damaging the electrode substrate and the self-assembled monolayer, thereby providing a relatively stable storage environment for the electrode substrate.

[0037] Optionally, the SAM layer can be formed on a transparent electrode substrate using a simple solution method to create an ultrathin modification layer. The SAM layer can improve the charge injection process by adjusting the work function of the transparent electrode substrate. The work function is the minimum energy required to move an electron from the interior to the exterior of a material. By selecting appropriate SAM molecules, the functional groups at their ends can alter the electron distribution on the electrode surface, thereby reducing the charge injection barrier. The SAM layer can also act as a physical and chemical barrier, protecting the transparent electrode substrate from external environmental factors and significantly improving the efficiency and stability of the device.

[0038] Optionally, the relative humidity of the sealed container can be 5%, 7%, 9%, 11%, 13%, 15%, 17%, 19%, 21%, 23%, 25%, etc.

[0039] Optionally, moisture may disrupt the structure of the self-assembled monolayer. At high relative humidity, water molecules may insert into the monolayer, altering intermolecular forces and disrupting its ordered structure, thus affecting its functional properties, such as electron transport performance. Excessive humidity may also cause oxidation, corrosion, and other chemical reactions in the electrode substrate, reducing its conductivity and stability. Conversely, excessively low relative humidity may lead to material brittleness. Therefore, controlling the relative humidity within the range of 5% to 25% can ensure that the self-assembled monolayer and electrode substrate are not affected by excessive moisture while avoiding problems caused by over-drying.

[0040] Optionally, the oxygen volume fraction of the sealed container can be 10%, 11%, 12%, 13%, 14%, 15%, 16%, 17%, 18%, 19%, 20%, 21%, etc.

[0041] Optionally, oxygen has oxidizing properties and may react chemically with certain components in the self-assembled monolayer, leading to changes in molecular structure and a decrease in performance. For example, some organic molecules with unsaturated bonds may be oxidized by oxygen, thus affecting the electron transport and interfacial properties of the monolayer. A small amount of oxygen may help maintain the equilibrium between the self-assembled monolayer and the electrode substrate. Completely removing oxygen could increase storage costs and operational complexity. Controlling the oxygen volume fraction within the range of 10%–20% can reduce oxidation reactions to some extent without excessively increasing storage complexity.

[0042] Optionally, SAM adsorbs a small amount of oxygen and water molecules in the initial stage, which can act as an interfacial passivation agent, stabilizing molecular orientation and improving interfacial stability. Specifically, SAM molecules contain functional groups such as hydroxyl and phosphate groups, which can form hydrogen bonds. Hydrogen bonds are a relatively weak intermolecular force that can be used to maintain the specific structure and arrangement of SAM molecules. Moderate relative humidity provides an appropriate amount of water molecules, which can participate in the formation of the hydrogen bond network, stabilizing the hydroxyl-phosphate hydrogen bonds. At the same time, an appropriate amount of oxygen may indirectly promote the stability of hydrogen bonds by weakly interacting with SAM molecules and changing the electron cloud distribution around the molecules. However, due to factors such as thermal motion, SAM molecules may undergo orientation changes, i.e., orientation relaxation. Orientation relaxation will destroy the ordered structure of SAM and affect its performance. Moderate relative humidity strengthens the intermolecular interactions by stabilizing the hydroxyl-phosphate hydrogen bonds, thereby restricting the free movement of molecules, inhibiting molecular orientation relaxation, and ensuring the ordered and stable arrangement of SAM molecules. Furthermore, an appropriate oxygen volume fraction will cause some molecules on the surface of the SAM layer to undergo an oxidation reaction, forming a partially oxidized intermediate layer. This intermediate layer is not completely oxidized, but is in a specific oxidation state, which can enhance the interaction between SAM molecules and the substrate, making the SAM molecules more firmly anchored to the substrate surface and maintaining the anchored configuration of the molecules.

[0043] In one feasible implementation, the ratio of the head space volume of the sealed container to the effective area of ​​the electrode substrate is preset to 0.2 mL·cm². -2 ~0.6 mL·cm -2 .

[0044] Optionally, the ratio of the head space volume of the sealed container to the effective area of ​​the electrode substrate can be 0.2 mL·cm². -2 0.3 mL·cm -2 0.4 mL·cm -2 0.5 mL·cm -2 0.6 mL·cm -2 .

[0045] Optionally, the head space volume refers to the remaining space volume within the sealed container after desiccant, oxygen limiting agent, and self-assembled monolayer modified electrode substrate are occupied. Referring to Figure 2, in the sealed container 10, desiccant 101 and oxygen limiting agent 102 are located at the bottom of the sealed container 10, and the self-assembled monolayer modified electrode substrate 20 is located above desiccant 101 and oxygen limiting agent 102. The space above the electrode substrate 20 is the head space 30.

[0046] When the headspace volume is too small, the ratio of the headspace volume of the sealed container to the effective area of ​​the self-assembled monolayer modified electrode substrate is too small. The total amount of water and oxygen molecules available for adsorption per unit area is limited, and adsorption on the SAM surface and inside the substrate will rapidly consume water and oxygen molecules in the gas phase. At the same time, the effects of desiccants and oxygen limiting agents will further reduce the partial pressure of moisture and oxygen in the chamber. As a result, the relative humidity and oxygen volume fraction in the chamber will drop to an excessively dry region below 5% relative humidity or less than 10% oxygen volume fraction in a short period of time. At this point, SAM molecules undergo significant orientation relaxation and surface energy decrease, disrupting the required moderately moist oxygen adsorption equilibrium and affecting the efficiency retention rate during the final formation period.

[0047] When the headspace volume is too large, the ratio of the headspace volume of the sealed container to the effective area of ​​the self-assembled monolayer modified electrode substrate becomes excessive. This significantly increases the total amount of gaseous water and oxygen per unit area, requiring more adsorption sites and a longer time to establish adsorption-desorption equilibrium on the SAM layer surface. Furthermore, even if the sealed container has low WVTR (Water Vapor Transmission Rate) and OTR (Oxygen Transmission Rate), small amounts of external water and oxygen will accumulate within the large cavity during long-term storage. This causes the relative humidity and oxygen volume fraction inside the sealed container to gradually increase, deviating from the range of 5%–25% relative humidity and 10%–21% oxygen volume fraction. At this point, multiple water / oxygen adsorption layers will form on the SAM surface, and chemical degradation may even occur, resulting in wettability and a significant decrease in device efficiency over time.

[0048] The ratio of the head space volume of the sealed container to the effective area of ​​the electrode substrate is within the aforementioned suitable range, and the number of gaseous water and oxygen molecules per unit area is in a suitable ratio to the number of adsorption sites on the SAM surface: on the one hand, there are a sufficient number of water and oxygen molecules in the sealed container to form a stable monomolecular adsorption layer and a small amount of intermediate oxidation state on the SAM surface, thereby locking molecular orientation and stabilizing the interface energy level; on the other hand, the relative humidity and oxygen volume fraction of the desiccant at the effective position in the sealed container with limited volume fluctuate slowly, but do not deviate from the range of 5%~25% relative humidity and 10%~21% oxygen volume fraction of the sealed container.

[0049] In one feasible embodiment, before the step of storing the electrode substrate in a sealed container, the method further includes: step A10, providing a sealed container; in one feasible embodiment, a container capable of achieving a sealing function is prepared, the sealed container being used to provide a relatively independent and stable storage space for the electrode substrate coated with a self-assembled monolayer, isolating the electrode substrate from the external environment, and preventing external factors such as dust, moisture, and oxygen from adversely affecting the electrode substrate and the self-assembled monolayer on its surface.

[0050] In one feasible implementation, the sealed container includes an aluminum-plastic composite film bag or a glass container.

[0051] Optionally, aluminum-plastic composite film bags are typically made of plastic film and aluminum foil, which have a certain degree of flexibility and lightness, making them easy to handle and seal. They can be cut and heat-sealed according to the size of the electrode substrate, and can better adapt to the preservation needs of electrode substrates of different shapes and sizes.

[0052] Alternatively, glass containers possess excellent chemical stability and airtightness, making them less prone to chemical reactions with substances in the storage environment, thus providing a relatively stable storage space for the electrode substrate. Furthermore, the high transparency of glass containers facilitates observation of the storage status of the electrode substrate inside the container.

[0053] In one feasible embodiment, the water vapor permeability of the aluminum-plastic composite film bag is ≤0.05 g·m. -2 ·day -1 Oxygen permeability ≤1 cm 3 ·m -2 ·day -1 ·atm -1 .

[0054] Water vapor transmission rate indicates the mass of water vapor that passes through a unit area of ​​a sealed container per unit time. A lower water vapor transmission rate can effectively prevent external water vapor from entering the sealed container, thus preventing water vapor from damaging the self-assembled monolayer and electrode substrate, such as causing problems like monolayer structure destruction.

[0055] Oxygen permeability refers to the volume of oxygen that passes through a closed container per unit area, unit time, and unit pressure difference. Low oxygen permeability reduces the amount of oxygen entering the container and reacting with the electrode substrate and self-assembled monolayer, thereby ensuring the stability of the electrode substrate's performance.

[0056] In one feasible embodiment, the water vapor transmission rate of the glass container is ≤1×10⁻⁶. -4 g·m -2 ·day -1 Oxygen permeability ≤1 cm 3 ·m-2 ·day -1 ·atm -1 .

[0057] Glass itself has good water vapor barrier properties, and strict water vapor transmission requirements can further ensure a dry environment inside the sealed container, minimizing the impact of water vapor on the electrode substrate.

[0058] Step A20 involves regulating the relative humidity and preset oxygen volume fraction of the sealed container using a desiccant and an oxygen limiting agent. In one feasible embodiment, a desiccant is used to regulate the relative humidity and oxygen volume fraction within the sealed container to achieve a suitable set range (relative humidity of 5%–25% and oxygen volume fraction of 10%–21%). Desiccants typically adsorb moisture, reducing the moisture content within the container and thus controlling the relative humidity. Simultaneously, an oxygen limiting agent may be used to regulate the oxygen volume fraction.

[0059] In one feasible implementation, the desiccant includes silica gel and / or molecular sieves.

[0060] Optionally, silica gel is a highly active adsorbent material, typically produced by reacting sodium silicate and sulfuric acid, followed by a series of post-treatment processes such as aging and acid soaking. It possesses an open, porous structure, a large specific surface area, and a strong adsorption capacity for water molecules. It can operate under varying temperature and humidity conditions, rapidly and effectively adsorbing moisture and reducing the relative humidity of sealed containers to a suitable range. Furthermore, silica gel desiccants are usually in granular form, making them easy to use and place in sealed containers. When storing electrode substrates, silica gel desiccants can effectively adsorb moisture within the container, maintaining a dry environment, making them suitable for most storage scenarios requiring humidity control.

[0061] Optionally, a molecular sieve is a crystalline aluminosilicate material with a uniform microporous structure and uniform pore size, which functions to sieve molecules. Molecular sieves exhibit extremely high adsorption selectivity for water molecules, selectively adsorbing them based on molecule size and shape. Molecular sieve desiccants possess high adsorption capacity and adsorption rate, maintaining good adsorption performance even in low humidity environments. Molecular sieves also exhibit high temperature resistance and good chemical stability, allowing for use under relatively harsh conditions. Furthermore, molecular sieve desiccants can be regenerated through heating and other methods, enabling reuse.

[0062] In one feasible implementation, the oxygen limiting agent includes at least one of iron-based oxygen limiting agents, sulfites, and inert gases.

[0063] The function of an oxygen limiting agent is to control the volume fraction of oxygen in a sealed container.

[0064] Optionally, iron-based oxygen limiting agents are usually iron powder, etc. Iron has strong reducing properties and can react with oxygen to consume it, thereby reducing the oxygen volume fraction.

[0065] Alternatively, sulfites such as sodium sulfite (Na2SO3) can be used. Sulfite ions have strong reducing properties and can react with oxygen to generate sulfate ions, thereby achieving the purpose of controlling the oxygen volume fraction in a closed container.

[0066] Alternatively, inert gases such as nitrogen (N2) and argon (Ar) are chemically inert and do not readily react with the electrode substrate. The oxygen volume fraction in the sealed container can be controlled by filling it with an inert gas, which replaces the original air (including oxygen) inside.

[0067] Step A30: According to the ratio of the head space volume of the sealed container to the effective area of ​​the electrode substrate, the electrode substrate that has completed self-assembly monolayer modification is placed into the sealed container.

[0068] In one feasible embodiment, the electrode substrate, which has been modified with a self-assembled monolayer, is placed into the sealed container according to the previously set ratio of the head space volume of the sealed container to the effective area of ​​the electrode substrate. The sealed container with the electrode substrate placed inside is then sealed to completely isolate the environment inside the container from the outside world, thereby initiating the preservation of the electrode substrate. Sealing prevents external environmental factors (such as dust, moisture, oxygen, etc.) from entering the container and disrupting the pre-controlled preservation environment, ensuring that the electrode substrate is preserved in a stable environment, maximizing its performance and stability, and extending its usable lifespan.

[0069] Alternatively, methods for self-assembly monolayer modification include spin coating, blade coating, slot coating, or inkjet printing.

[0070] In one feasible embodiment, the electrode substrate includes a fluorine-doped tin oxide substrate or a tin-doped indium oxide substrate.

[0071] The electrode substrate is the basic supporting part of the electrode, providing a surface for the self-assembled monolayer to adhere. The self-assembled monolayer is coated on the surface of the electrode substrate, and the two together constitute an electrode structure with specific functions. Its performance directly affects the performance of the entire device.

[0072] Optionally, FTO (Fluorine-doped Tin Oxide) is a transparent conductive oxide material formed by doping fluorine (F) atoms into the tin oxide (SnO2) crystal structure. The incorporation of fluorine atoms increases the carrier concentration of tin oxide, thereby enhancing its conductivity. It exhibits good conductivity, chemical stability, and thermal stability, while also possessing high transmittance in the visible light range. In perovskite solar cells, the FTO substrate is often used as a transparent conductive anode, providing a transport channel for photogenerated carriers while allowing light to pass through to the light-absorbing layer.

[0073] Optionally, ITO (Indium Tin Oxide) is a transparent conductive oxide material composed of indium oxide (In₂O₃) and a small amount of tin oxide (SnO₂). The doping of tin atoms can significantly improve the conductivity of indium oxide. It exhibits extremely low resistivity, high visible light transmittance, and good chemical stability. Furthermore, ITO films possess good surface smoothness and mechanical properties, making them easy to process and pattern.

[0074] Alternatively, both fluorine-doped tin oxide substrates and indium tin oxide substrates possess excellent electrical conductivity and optical transparency, meeting the electrical and optical performance requirements of self-assembled monolayer electrodes. Simultaneously, they exhibit high chemical stability, offering some resistance to external environmental influences and ensuring the stability and performance of the self-assembled monolayer. Therefore, these two substrates are suitable choices for preserving electrode substrates based on self-assembled monolayers.

[0075] In one feasible implementation, the material for self-assembling a monolayer includes at least one of carbazole, triphenylamine, phosphate-anchored molecules, carboxylic acid-anchored molecules, and C60.

[0076] Optionally, carbazole is a nitrogen-containing aromatic heterocyclic compound whose molecular structure consists of two benzene rings fused with a pyrrole ring. Carbazole compounds typically exhibit good hole transport properties and can serve as hole transport materials in self-assembled monolayers, thus contributing to improved charge transport efficiency in devices.

[0077] Optionally, the triphenylamine molecule consists of one nitrogen atom linked to three benzene rings, exhibiting a large conjugated system and a favorable planar structure. Triphenylamine compounds possess excellent hole transport capabilities and charge stability, making them suitable as hole transport layers or charge injection layers in self-assembled monolayers. Furthermore, triphenylamine compounds also possess good optical properties, making them useful for preparing self-assembled monolayers with specific optical characteristics.

[0078] Optionally, phosphate-anchored and carboxylic acid-anchored molecules typically contain phosphate groups (-PO3H2) or carboxylic acid groups (-COOH) as anchoring groups, along with organic segments with specific functions. Phosphate and carboxylic acid groups can form strong chemical bonds with metal atoms or oxides on solid surfaces, allowing the molecules to firmly adsorb onto the surface and form a self-assembled monolayer. By altering the structure and properties of the organic segments, the surface properties of the self-assembled monolayer, such as hydrophilicity / hydrophobicity and surface charge, can be controlled. In solar cells, phosphate-anchored and carboxylic acid-anchored molecules can be used to modify the electrode substrate surface, improving the interfacial contact between the electrode substrate and the active layer, and enhancing the photoelectric conversion efficiency of the cell.

[0079] Alternatively, C60 is a spherical molecule composed of 60 carbon atoms with a highly symmetrical structure. Also known as a fullerene, it has good electron accepting and transport properties and can be used as an electron transport material in self-assembled monolayers.

[0080] In one feasible implementation, the electrode substrate modified with a self-assembled monolayer can be stored for up to 30 days.

[0081] Optionally, appropriate relative humidity and oxygen volume fraction in a sealed container promote the stability of hydroxyl-phosphate hydrogen bonds on the SAM surface, inhibit molecular orientation relaxation, and prevent continuous oxidation during storage. Furthermore, when the relative humidity and oxygen volume fraction in the sealed container are within the aforementioned range, a stable monomolecular adsorbed water film and a partially oxidized intermediate layer form on the SAM layer surface, which helps maintain molecular anchoring configuration and energy level stability, similar to traditional methods that require storage in a dry atmosphere. However, the self-assembled molecular layer modified electrode substrate of this application embodiment maintains performance close to the initial sample after 30 days of storage and maintains a high effective retention rate of battery device efficiency.

[0082] This embodiment provides a method for preserving a self-assembled monolayer modified electrode substrate, comprising: placing the electrode substrate coated with the self-assembled monolayer in a sealed container for preservation, wherein the relative humidity of the sealed container is 5%~25% and the oxygen volume fraction is 10%~21%. This embodiment, by controlling the relative humidity and oxygen volume fraction of the environment in the sealed container, enables the formation of a stable adsorption layer on the surface of the self-assembled monolayer modified electrode substrate. This stable adsorption layer effectively achieves orientation locking and interface passivation. Orientation locking ensures that the molecules in the self-assembled monolayer are aligned in a specific direction, guaranteeing the consistency and stability of the electrode substrate's performance. Simultaneously, the sealed container prevents continuous water and oxygen exchange with the external environment, thereby improving the stability of the self-assembled monolayer modified electrode substrate and extending its preservation time.

[0083] In order to enable those skilled in the art to clearly understand the details and operations of the above embodiments of this application, and to demonstrate the significant improvement in performance of the embodiments of this application, the above technical solutions are illustrated below through multiple embodiments.

[0084] Example 1 provides FTO conductive glass as the electrode substrate, and 4PADCB (4-(9H-Dibenzo[a,c]carbazol-9-yl)butyl)phosphonic acid (4-(9H-dibenzo[a,c]carbazol-9-yl)butyl)phosphonic acid) as the material for self-assembled monolayer, at a concentration of 0.5 mg / mL, and is applied to the FTO electrode substrate by a blade coating method in the presence of isopropanol as the solvent.

[0085] The relative humidity of the sealed aluminum-plastic composite film bag was controlled to 15% and the oxygen volume fraction to approximately 16% using desiccants and oxygen limiting agents. The water vapor transmission rate (WVTR) of the aluminum-plastic composite film bag was ≤0.05 g·m³. -2 ·day -1 Oxygen permeability (OTR) ≤ 1.0 cm 3 ·m -2 ·day -1 ·atm -1 .

[0086] After the self-assembled monolayer was coated on the electrode substrate, it was sealed and stored in an aluminum-plastic composite film bag for 30 minutes. The ratio of the head space volume in the aluminum-plastic composite film bag to the effective area of ​​the electrode substrate modified with the self-assembled monolayer was approximately 0.4 mL·cm². -2 .

[0087] A perovskite precursor solution is prepared, comprising an organic lead halide or an inorganic-organic hybrid perovskite precursor, with the solvent selected from DMF (N,N-Dimethylformamide), DMSO (Dimethyl sulfoxide), or mixtures thereof. The perovskite precursor solution is spin-coated onto a self-assembled monolayer modified electrode substrate, first at a speed of 1000–2000 r / min for 5–15 s, then at a speed of 3000–6000 r / min for 20–40 s, to form a uniform perovskite wet film. The resulting perovskite wet film is then transferred to a hot plate and annealed at 80–120 °C for 10–40 min to allow the perovskite precursor to crystallize and form a dense perovskite absorber layer.

[0088] Subsequently, an electron transport material solution, which is a fullerene derivative solution, is spin-coated onto the perovskite absorber layer. The spin-coating speed is 2000~5000 r / min, and the spin-coating time is 20~60 s. After spin-coating, the electron transport layer can be formed by annealing at 60~120℃ for 1~20 min or without annealing.

[0089] A cathode interface layer solution composed of bathocuproine (BCP) was spin-coated onto the electron transport layer at a spin speed of 2000–5000 r / min for 20–60 s. Finally, a silver electrode with a thickness of 80–120 nm was deposited on the cathode interface layer via thermal evaporation to obtain a perovskite solar cell device. The prepared perovskite cell was placed under a solar simulator to simulate a standard solar illumination condition (light intensity of 100 mW / cm²). 2 The battery's current-voltage (IV) curve is measured using a source meter to calculate the initial PCE (Power Conversion Efficiency). Based on the PCE measured at different time points, the battery's efficiency retention rate is calculated. The formula for efficiency retention rate is: Efficiency retention rate (%) = PCE at a certain time point / Initial PCE × 100%.

[0090] The difference between Example 2 and Example 1 is that the relative humidity of the sealed aluminum-plastic composite film bag is controlled to 20% and the oxygen volume fraction is about 20% by using a desiccant and an oxygen limiting agent.

[0091] The difference between Example 3 and Example 1 is that the ratio of the head space volume in the aluminum-plastic composite film bag to the effective area of ​​the self-assembled monolayer modified electrode substrate is approximately 0.6 mL·cm². -2 .

[0092] Example 4 provides ITO conductive glass as the electrode substrate, and MeO-2PACz (2-(4-Methoxyphenyl)-9H-carbazole-9-ethanol, 2-(4-methoxyphenyl)-9H-carbazole-9-ethanol) as the material for self-assembling a monolayer at a concentration of 0.5 mg / mL, and is coated onto the ITO electrode substrate by a blade coating method with isopropanol as the solvent.

[0093] The relative humidity of the sealed aluminum-plastic composite film bag was controlled to 15% and the oxygen volume fraction to approximately 16% using desiccants and oxygen limiting agents. The water vapor transmission rate (WVTR) of the aluminum-plastic composite film bag was ≤0.05 g·m³. -2 ·day -1 Oxygen permeability (OTR) ≤ 1.0 cm³·m -2 ·day -1·atm -1 .

[0094] After the self-assembled monolayer was coated on the electrode substrate, it was sealed and stored in an aluminum-plastic composite film bag for 30 minutes. The ratio of the head space volume in the aluminum-plastic composite film bag to the effective area of ​​the electrode substrate modified with the self-assembled monolayer was approximately 0.4 mL·cm². -2 .

[0095] A perovskite precursor solution is prepared, comprising an organic lead halide or an inorganic-organic hybrid perovskite precursor, with the solvent selected from DMF (N,N-Dimethylformamide), DMSO (Dimethyl sulfoxide), or mixtures thereof. The perovskite precursor solution is spin-coated onto a self-assembled monolayer modified electrode substrate, first at a speed of 1000–2000 r / min for 5–15 s, then at a speed of 3000–6000 r / min for 20–40 s, to form a uniform perovskite wet film. The resulting perovskite wet film is then transferred to a hot plate and annealed at 80–120 °C for 10–40 min to allow the perovskite precursor to crystallize and form a dense perovskite absorber layer.

[0096] Subsequently, an electron transport material solution, which is a fullerene derivative solution, is spin-coated onto the perovskite absorber layer. The spin-coating speed is 2000~5000 r / min, and the spin-coating time is 20~60 s. After spin-coating, the electron transport layer can be formed by annealing at 60~120℃ for 1~20 min or without annealing.

[0097] A cathode interface layer solution composed of bathocuproine (BCP) was spin-coated onto the electron transport layer at a spin speed of 2000–5000 r / min for 20–60 s. Finally, a silver electrode with a thickness of 80–120 nm was deposited on the cathode interface layer via thermal evaporation to obtain a perovskite solar cell device. The prepared perovskite cell was placed under a solar simulator to simulate standard solar illumination conditions (light intensity of 100 mW / cm²). 2 The battery's current-voltage (IV) curve is measured using a source meter to calculate the initial photoelectric conversion efficiency (PCE). Based on the PCE measured at different time points, the battery's efficiency retention rate is calculated. The formula for calculating the efficiency retention rate is: Efficiency retention rate (%) = PCE at a certain time point / Initial PCE × 100%.

[0098] The difference between Example 5 and Example 4 is that the relative humidity of the sealed glass container is controlled to 15% and the oxygen volume fraction to approximately 16% by using a desiccant and an oxygen limiting agent. The water vapor transmission rate of the glass container is ≤1×10⁻⁶. -4 g·m -2 ·day -1 Oxygen permeability ≤1 cm 3 ·m -2 ·day -1 ·atm -1 .

[0099] The difference between Comparative Example 1 and Example 1 is that the self-assembled monolayer was placed in N2 for storage within 30 minutes after being coated on the electrode substrate.

[0100] The difference between Comparative Example 2 and Example 1 is that the self-assembled monolayer was stored in air for 30 minutes after being coated on the electrode substrate.

[0101] The difference between Comparative Example 3 and Example 1 is that the relative humidity of the sealed aluminum-plastic composite film bag was controlled to 4% and the oxygen volume fraction to about 8% by using a desiccant and an oxygen limiting agent.

[0102] The difference between Comparative Example 4 and Example 1 is that the relative humidity of the sealed aluminum-plastic composite film bag was controlled to 30% and the oxygen volume fraction to be about 24% by using a desiccant and an oxygen limiting agent.

[0103] The difference between Comparative Example 5 and Example 4 is that the self-assembled monolayer was placed in N2 for storage within 30 minutes after being coated on the electrode substrate.

[0104] The difference between Comparative Example 6 and Example 4 is that the self-assembled monolayer was stored in air for 30 minutes after being coated on the electrode substrate.

[0105] The difference between Comparative Example 7 and Example 4 is that the relative humidity of the sealed aluminum-plastic composite film bag was controlled to 4% and the oxygen volume fraction to about 8% by using a desiccant and an oxygen limiting agent.

[0106] The difference between Comparative Example 8 and Example 4 is that the relative humidity of the sealed aluminum-plastic composite film bag was controlled to be 30% and the oxygen volume fraction was about 24% by using a desiccant and an oxygen limiting agent.

[0107] Examples 1-3 and Comparative Examples 1-4 tested the initial photoelectric conversion efficiency and the efficiency retention rate after storage for 1-5 days for the prepared perovskite solar cells. The results are shown in Table 1.

[0108] Table 1. Efficiency retention of devices using FTO conductive glass as electrode substrate.

[0109]

[0110] Table 1 shows that, compared with Example 1, the efficiency retention of the batteries in Comparative Examples 1-4 all decreased significantly within 5 days. In Comparative Example 3, the molecular orientation of the SAM layer was severely relaxed; in Comparative Example 4, the SAM layer molecules underwent hygroscopic degradation. This indicates that under the conditions of a relative humidity of 5%-25% in the sealed container, an oxygen volume fraction of 10%-21%, and a head space volume to effective electrode substrate area ratio of 0.2 mL·cm², the efficiency retention of the batteries in Comparative Examples 1-4 was significantly reduced. -2 ~0.6 mL·cm -2 In the case of the high efficiency retention of the battery, it is indicated that the self-assembled monolayer modified electrode substrate, when stored in the cases of Examples 1 to 3, effectively avoids the orientation relaxation of SAM, improves the stability of the interface, and enables the battery prepared after 5 days of storage of the electrode substrate to still have a good efficiency retention.

[0111] Examples 4-5 and Comparative Examples 5-8 tested the initial photoelectric conversion efficiency and the efficiency retention rate after storage for 5, 10, 15, 20 and 30 days, respectively. The results are shown in Table 2.

[0112] Table 2. Efficiency retention of devices using ITO conductive glass as electrode substrate.

[0113]

[0114] Table 2 shows that, compared with Example 4, the efficiency retention of batteries in Comparative Examples 5-8 all decreased significantly within 30 days. In Comparative Example 7, the molecular orientation of the SAM layer was severely relaxed; in Comparative Example 8, the SAM layer molecules underwent hygroscopic degradation. This indicates that under conditions of a relative humidity of 5%-25% in a sealed container, an oxygen volume fraction of 10%-21%, and a head space volume to effective electrode substrate area ratio of 0.2 mL·cm², the efficiency retention of batteries in Comparative Examples 5-8 was significantly reduced. -2 ~0.6 mL·cm -2 In the case of the above, the battery has a high efficiency retention rate, indicating that the self-assembled monolayer modified electrode substrate, when stored in the cases of Examples 4-5, effectively avoids the orientation relaxation of SAM and improves the stability of the interface. The battery prepared after storing the self-assembled monolayer modified electrode substrate for 30 days has a good efficiency retention rate.

Claims

1. A method for preserving an electrode substrate, characterized in that, The method includes: providing an electrode substrate, wherein the electrode substrate is a self-assembled monolayer modified electrode substrate; and storing the electrode substrate in a sealed container, wherein the relative humidity of the sealed container is 5% to 25% and the oxygen volume fraction is 10% to 21%.

2. The method for preserving the electrode substrate as described in claim 1, characterized in that, The ratio of the head space volume of the sealed container to the effective area of ​​the electrode substrate is 0.2 mL·cm². -2 ~0.6 mL·cm -2 .

3. The method for preserving the electrode substrate as described in claim 2, characterized in that, Prior to the step of storing the electrode substrate in a sealed container, the method further includes: providing a sealed container; adjusting the relative humidity and oxygen volume fraction of the sealed container using a desiccant and an oxygen limiting agent; and placing the electrode substrate, after the self-assembled monolayer modification has been completed, into the sealed container according to the ratio of the headspace volume of the sealed container to the effective area of ​​the electrode substrate.

4. The method for preserving the electrode substrate as described in claim 2, characterized in that, The sealed container includes an aluminum-plastic composite film bag or a glass container.

5. The method for preserving the electrode substrate as described in claim 4, characterized in that, The water vapor transmission rate of the aluminum-plastic composite film bag is ≤0.05 g·m. -2 ·day -1 Oxygen permeability ≤1 cm 3 ·m -2 ·day -1 ·atm -1 .

6. The method for preserving the electrode substrate as described in claim 4, characterized in that, The water vapor transmission rate of the glass container is ≤1×10⁻⁶. -4 g·m -2 ·day -1 Oxygen permeability ≤1 cm 3 ·m -2 ·day -1 ·atm -1 .

7. The method for preserving the electrode substrate as described in claim 3, characterized in that, The desiccant includes silica gel and / or molecular sieves; and / or, the oxygen limiting agent includes at least one of iron-based oxygen limiting agents, sulfites, and inert gases.

8. The method for preserving the electrode substrate as described in claim 1, characterized in that, The material of the self-assembled monolayer includes at least one of carbazole, triphenylamine, phosphate-anchored molecules, carboxylic acid-anchored molecules, and C60; and / or, the electrode substrate includes a fluorine-doped tin oxide substrate or a tin-doped indium oxide substrate.

9. The method for preserving the electrode substrate as described in claim 1, characterized in that, The electrode substrate can be stored for a maximum of 30 days.

10. The application of a method for preserving an electrode substrate as described in any one of claims 1 to 9 in the fabrication of perovskite solar cells.

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