Composite substrates, solar cells and photovoltaic modules

Abstract

This application provides a composite substrate, a solar cell, and a photovoltaic module. The composite substrate includes a first electrode and a hole transport layer stacked sequentially. The method for preparing the hole transport layer includes: depositing an inkjet precursor solution onto the surface of the first electrode by inkjet printing; the inkjet precursor solution includes a hole transport material solution and a non-coordinating polymer; the hole transport material solution includes a phosphonic acid-based self-assembled monolayer material; annealing; and cleaning the annealed hole transport precursor layer with an aprotic polar organic solvent. In the preparation of the hole transport layer of the composite substrate of this application, the non-coordinating polymer exhibits pure physical segregation and closed pores during the wet film and high-temperature annealing stages, and does not participate in the site competition between the phosphonic acid-based self-assembled monolayer material and the first electrode, ensuring that the phosphonic acid groups first occupy the interface and bond with it, thus obtaining a composite substrate with a hole transport layer of good stability.

Description

Technical Field

[0001] This application relates to the field of solar cell technology, and in particular to a composite substrate, solar cell, and photovoltaic module. Background Technology

[0002] As perovskite solar cells develop towards higher efficiency, longer lifespan, and large-area mass production, devices place comprehensive demands on functional layer interfaces, requiring energy level matching, low defect density, and environmental stability. Self-assembled monolayers (SAMs) can form sub-nanometer to nanometer-scale ordered interfaces on metal oxide surfaces through molecular dipole interactions and chemical bonding. They can control the interfacial work function, optimize film wettability, and suppress non-radiative recombination without increasing thickness or series resistance, making them a key interface layer for novel thin-film devices. In the industrialization process, the demand for pre-fabricated SAM substrates as intermediate products in the supply chain continues to increase. These substrates need to be stored for extended periods under normal temperature and humidity conditions and undergo multiple stages of transportation, disassembly, and assembly. Therefore, high-quality, patternable SAM fabrication is required, along with supporting storage and transportation protection and gentle, efficient interface restoration technologies.

[0003] Traditional SAM (Surface Acrylic Atom) preparation mainly relies on dip-coating and spin-coating processes, which have certain shortcomings in terms of material utilization, production cycle time, patterned deposition, and large-area compatibility. Inkjet printing, with its advantages of digitalization, non-contact operation, maskless operation, and high material utilization, has become the preferred solution for large-scale SAM production. However, SAM inks compatible with inkjet printing often use low-toxicity, low-boiling-point alcohol solvents, resulting in low system viscosity and surface tension, which easily leads to printing defects such as satellite droplets and coffee rings. While adding high-viscosity or high-boiling-point solvents to optimize rheological properties can broaden the inkjet compatibility window, it prolongs the drying cycle, produces solvent residue, and alters the surface state of metal oxides, thereby affecting the assembly rate, molecular orientation, and order of SAM. It also poses risks related to printhead component compatibility, increasing production line maintenance costs and operational instability. Furthermore, the extremely thin thickness of the SAM layer and its poor environmental stability make it susceptible to factors such as humidity, particle deposition, friction, and static electricity during storage, transportation, and handling, which can damage the interface cleanliness and uniformity, leading to defects in subsequent perovskite layer film formation, abnormal crystallization, and device performance degradation. Traditionally, there is also a two-step method for coating protective films, which can improve the resistance to moisture and contamination, but it increases the process load, introduces secondary interference of thermal history and solvent history on the SAM layer, and the compatibility control of the protective film with the subsequent device system is complicated, which can easily lead to swelling and cross-contamination. Summary of the Invention

[0004] Therefore, it is necessary to provide a composite substrate, solar cell, and photovoltaic module that can be fabricated using inkjet technology and contain a hole transport layer with good stability.

[0005] This application provides a composite substrate, including a stacked first electrode and a hole transport layer;

[0006] The method for preparing the hole transport layer includes the following steps:

[0007] An inkjet precursor solution is deposited on the surface of the first electrode by inkjet printing. The inkjet precursor solution includes a hole transport material solution and a non-coordinating polymer. The hole transport material solution includes a phosphonic acid-based self-assembled monolayer material. The viscosity of the inkjet precursor solution is 8 mPa·s to 12 mPa·s. A hole transport precursor layer is prepared.

[0008] The first electrode containing the hole transport precursor layer is annealed, and the annealed hole transport precursor layer is cleaned with an aprotic polar organic solvent to prepare the hole transport layer.

[0009] In one embodiment, the inkjet precursor solution satisfies one or more of the following conditions:

[0010] (1) The non-coordination polymers include one or more of polyvinyl butyral, polyvinyl formal, cellulose acetate butyrate, cellulose acetate propionate, ethylene-vinyl acetate, polyvinyl acetate and ethyl cellulose;

[0011] (2) The weight-average molecular weight of the non-coordination polymer is 10,000 g / mol to 30,000 g / mol;

[0012] (3) The mass ratio of the hole transport material solution to the non-coordinated polymer in the inkjet precursor solution is 100:(0.2~0.5);

[0013] (4) The hole transport material solution further includes one or more of ethanol, isopropanol, ethyl acetate and methyl ethyl ketone, and the concentration of the phosphonic acid-based self-assembled monolayer material in the hole transport material solution is 0.1 mg / mL to 0.6 mg / mL;

[0014] (5) The surface tension of the inkjet precursor solution is 30mN / m~35mN / m.

[0015] In one embodiment, the annealing step includes a pre-annealing step and a main annealing step.

[0016] In one embodiment, the annealing step satisfies one or more of the following conditions:

[0017] (1) The pre-annealing temperature is 50℃~70℃;

[0018] (2) The pre-annealing time is 3 min to 5 min;

[0019] (3) The temperature of the main annealing is 110℃~150℃;

[0020] (4) The main annealing time is 5 min to 10 min.

[0021] In one embodiment, the cleaning step using an aprotic polar organic solvent satisfies one or both of the following conditions:

[0022] (1) The aprotic polar organic solvent includes one or more of ethyl acetate, acetone, and butanone;

[0023] (2) The cleaning time using the aprotic polar organic solvent is 30s~120s.

[0024] In one embodiment, the phosphonic acid-based self-assembled monolayer material includes [2-(9H-carbazole-9-yl)ethyl]phosphonic acid, [2-(3,6-dimethoxy-9H-carbazole-9-yl)ethyl]phosphonic acid, [2-(3,6-dimethyl-9H-carbazole-9-yl)ethyl]phosphonic acid, [4-(9H-carbazole-9-yl)butyl]phosphonic acid, [4-(3,6-dimethyl-9H-carbazole-9-yl)butyl]phosphonic acid, and [4-(3,6-dimethyl-9H-carbazole-9-yl)butyl]phosphonic acid. [Butyl]phosphonic acid, [4-(3,6-dimethoxy-9H-carbazole-9-yl)butyl]phosphonic acid, [4-(7H-dibenzocarbazole-7-yl)butyl]phosphonic acid, [2-(9-bromocarbazole-9-yl)ethyl]phosphonic acid, [2-(9-chlorocarbazole-9-yl)ethyl]phosphonic acid, [4-(9-bromocarbazole-9-yl)butyl]phosphonic acid, and [4-(9-fluorocarbazole-9-yl)butyl]phosphonic acid.

[0025] This application also provides a solar cell, which includes a composite substrate, a light-absorbing layer, and a second electrode stacked sequentially as described above;

[0026] In the composite substrate, the hole transport layer is in contact with the light absorption layer.

[0027] In one embodiment, the light-absorbing layer is made of perovskite.

[0028] In one embodiment, an electron transport layer is further provided between the light-absorbing layer and the second electrode.

[0029] In one embodiment, the first electrode in the composite substrate comprises a transparent conductive electrode.

[0030] This application also provides a photovoltaic module, including the solar cell as described above.

[0031] In the preparation process of the hole transport layer of the composite substrate provided in this application, a hole transport material solution containing phosphonic acid self-assembled monolayer material is added to the inkjet precursor solution along with a non-coordinating polymer. In the subsequent annealing step, the non-coordinating polymer exhibits pure physical segregation and closed pores during the wet film and high-temperature annealing stages. It does not participate in the site competition between the phosphonic acid self-assembled monolayer material and the first electrode, ensuring that the phosphonic acid groups occupy the interface and bond with it first. Subsequently, the polymer will spontaneously accumulate towards the air end, avoiding the interruption of self-assembly and the decrease in order caused by premature glassization or interface gelation, thus obtaining a composite substrate with a hole transport layer with good stability. Attached Figure Description

[0032] To more clearly illustrate the technical solutions in the specific embodiments of this application or the prior art, the drawings used in the description of the specific embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of this application. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0033] Figure 1 Before step three of the solar cell in Example 1 ( Figure 1 (Left) After step three ( Figure 1 (Right) Comparison of thin film contact angle tests.

[0034] Figure 2 Before step three of the solar cell in Comparative Example 1 ( Figure 2 (Left) After step three ( Figure 2 (Right) Comparison of thin film contact angle tests.

[0035] Figure 3 This is a comparison graph of the current density-voltage curves of solar cells in Example 1 and Comparative Example 1.

[0036] Figure 4 This is a comparison graph of the current density-voltage curves of solar cells in Example 1 and Comparative Example 2. Detailed Implementation

[0037] To facilitate understanding of this application, a more complete description will be provided below with reference to the accompanying drawings. Preferred embodiments of this application are shown in the drawings. However, this application can be implemented in many different forms and is not limited to the embodiments described herein. Rather, these embodiments are provided to provide a thorough and complete understanding of the disclosure of this application.

[0038] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs. The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the application.

[0039] As used herein, the term "and / or" encompasses any one of two or more of the related listed items, as well as any and all combinations of the related listed items. These arbitrary and all combinations include any two related listed items, any more related listed items, or a combination of all related listed items. For example, "A and / or B" includes three parallel options: A, B, and "a combination of A and B".

[0040] In this document, unless otherwise stated, "one or more" means any one of the listed items or any combination of the listed items. Similarly, "one or more" and other instances of "one or more" are to be understood in the same way unless otherwise stated.

[0041] In this document, terms such as "further," "even further," "especially," "for example," "like," "example," and "exemplary" are used for descriptive purposes to indicate a connection in the coverage of different technical solutions presented earlier and later. However, they should not be construed as limitations on the preceding technical solution or on the scope of protection of this document. Unless otherwise specified, in this document, A (e.g., B) indicates that B is a non-limiting example of A, and it can be understood that A is not limited to B.

[0042] In this document, "optionally," "optionally," and "optional" mean that something is optional, that is, it is selected from either "present" or "absent." If multiple "options" appear in a technical solution, unless otherwise specified and there are no contradictions or mutual constraints, each "option" is independent. In this application, descriptions such as "optionally contains" and "optionally includes" indicate "contains or does not contain." "Optional component X" indicates whether component X exists or does not exist, or whether component X is contained or not.

[0043] In this document, the terms "first aspect," "second aspect," "third aspect," and "fourth aspect," etc., are used for descriptive purposes only and should not be construed as indicating or implying relative importance or quantity, nor should they be construed as implicitly indicating the importance or quantity of the indicated technical features. Moreover, "first," "second," "third," and "fourth" serve only as a non-exhaustive enumeration and should be understood as not constituting a closed limitation on quantity.

[0044] In this article, the technical features described in an open-ended manner include both closed technical solutions composed of the listed features and open technical solutions that include the listed features.

[0045] In this document, when referring to numerical intervals (i.e., numerical ranges), unless otherwise specified, the distribution of selectable values ​​within a numerical interval is considered continuous, and includes the two endpoints (i.e., the minimum and maximum values) of the numerical interval, as well as every value between these two endpoints. Unless otherwise specified, when a numerical interval refers only to integers within that interval, it includes the two endpoint integers of the numerical range, as well as every integer between the two endpoints, which is equivalent to directly listing every integer. When multiple numerical ranges are provided to describe features or characteristics, these numerical ranges can be merged. In other words, unless otherwise specified, the numerical ranges disclosed herein should be understood to include any and all subranges included therein. The "numerical value" in this numerical interval can be any quantitative value, such as a number, percentage, ratio, etc. The term "numerical interval" can be broadly included to include percentage intervals, ratio intervals, proportion intervals, and other numerical interval types.

[0046] This application provides a composite substrate, including a stacked first electrode and a hole transport layer;

[0047] The method for preparing a hole transport layer includes the following steps:

[0048] An inkjet precursor solution is deposited on the surface of a first electrode by inkjet printing. The inkjet precursor solution includes a hole transport material solution and a non-coordinating polymer. The hole transport material solution includes a phosphonic acid-based self-assembled monolayer material. The viscosity of the inkjet precursor solution is 8 mPa·s to 12 mPa·s. A hole transport precursor layer is prepared.

[0049] The first electrode containing the hole transport precursor layer is annealed, and the annealed hole transport precursor layer is cleaned with an aprotic polar organic solvent to prepare the hole transport layer.

[0050] In the preparation process of the hole transport layer of the composite substrate provided in this application, a hole transport material solution containing phosphonic acid self-assembled monolayer material is added to the inkjet precursor solution along with a non-coordinating polymer. In the subsequent annealing step, the non-coordinating polymer exhibits pure physical segregation and closed pores during the wet film and high-temperature annealing stages. It does not participate in the site competition between the phosphonic acid self-assembled monolayer material and the first electrode, ensuring that the phosphonic acid groups occupy the interface and bond with it first. Subsequently, the polymer will spontaneously accumulate towards the air end, avoiding the interruption of self-assembly and the decrease in order caused by premature glassization or interface gelation, thus obtaining a composite substrate with a hole transport layer with good stability.

[0051] Understandably, the first electrode is a transparent conductive electrode, and the material of the transparent conductive electrode includes one or more of the following: fluorine tin oxide transparent conductive glass (FTO), indium tin oxide transparent conductive glass (ITO), polyethylene terephthalate (PET), and polyethylene naphthalate (PEN). Further, the material of the transparent conductive electrode includes fluorine tin oxide transparent conductive glass (FTO), indium tin oxide transparent conductive glass (ITO), indium tin oxide transparent conductive glass (ITO) / polyethylene terephthalate (PET), or indium tin oxide transparent conductive glass (ITO) / polyethylene naphthalate (PEN).

[0052] Understandably, the transparent conductive electrode is scribe with P1 lines, then ultrasonically cleaned sequentially with deionized water, acetone, and isopropanol as cleaning agents, and finally dried with nitrogen. UV ozone or plasma activation is performed before SAM preparation to increase the surface hydroxyl density, which facilitates phosphonic acid condensation bonding.

[0053] Specifically, the viscosity of the inkjet precursor solution may be, but is not limited to, 8 mPa·s, 9 mPa·s, 10 mPa·s, 11 mPa·s or 12 mPa·s.

[0054] In some specific examples, the surface tension of the inkjet precursor solution is 30 mN / m to 35 mN / m. The surface tension of the inkjet precursor solution may be, but is not limited to, 30 mN / m, 31 mN / m, 32 mN / m, 33 mN / m, 34 mN / m, 35 mN / m, or 36 mN / m.

[0055] Understandably, noncoordinate polymers do not contain strong adsorption groups (such as free -OH / –COOH, amines, nitrogen-containing heterocycles, polyphenols, β-diketones, and hydroxyxamic acids) that would compete with metal oxides for coordination. In some specific examples, noncoordinate polymers include one or more of polyvinyl butyral, polyvinyl formal, cellulose acetate butyrate, cellulose acetate propionate, ethylene-vinyl acetate, polyvinyl acetate, and ethyl cellulose.

[0056] In some specific examples, the weight-average molecular weight of the non-coordination polymer is 10,000 g / mol to 30,000 g / mol. Specifically, the weight-average molecular weight of the non-coordination polymer can be, but is not limited to, 10,000 g / mol, 15,000 g / mol, 20,000 g / mol, 25,000 g / mol, or 30,000 g / mol.

[0057] In some specific examples, the mass ratio of hole transport material solution to non-coordinated polymer in the inkjet precursor solution is 100:(0.2~0.5); the mass ratio of hole transport material solution to non-coordinated polymer in the inkjet precursor solution may be, but is not limited to, 100:0.2, 100:0.3, 100:0.4 or 100:0.5.

[0058] In some specific examples, the solvent of the inkjet precursor solution includes one or more of ethanol, isopropanol, ethyl acetate, and methyl ethyl ketone, and the concentration of phosphonic acid-based self-assembled monolayer material in the hole transport material solution is 0.1 mg / mL to 0.6 mg / mL.

[0059] Furthermore, the concentration of the phosphonic acid-based self-assembled monolayer material in the hole transport material solution may be, but is not limited to, 0.1 mg / mL, 0.2 mg / mL, 0.3 mg / mL, 0.4 mg / mL, 0.5 mg / mL, or 0.6 mg / mL.

[0060] In some specific examples, the annealing process includes a pre-annealing step and a main annealing step.

[0061] Furthermore, the pre-annealing temperature is 50℃~70℃; the pre-annealing temperature can be, but is not limited to, 50℃, 52℃, 54℃, 56℃, 58℃, 60℃, 62℃, 64℃, 66℃, 68℃, or 70℃. Even further, the pre-annealing time is 3min~5min; the pre-annealing time can be, but is not limited to, 3min, 4min, or 5min. Pre-annealing can provide a wet window to promote the rapid adsorption and condensation of phosphonic acid groups in the self-assembled monolayer material on the surface of the first electrode.

[0062] Furthermore, the main annealing temperature is 110℃~150℃; the main annealing temperature may be, but is not limited to, 110℃, 115℃, 120℃, 125℃, 130℃, 135℃, 140℃, 145℃ or 150℃.

[0063] Furthermore, the main annealing time is 5 to 10 minutes. The main annealing time can be, but is not limited to, 5 minutes, 6 minutes, 7 minutes, 8 minutes, 9 minutes, or 10 minutes.

[0064] Specifically, after the aforementioned mixed inkjet precursor solution is printed, during the pre-annealing stage, the phosphonic acid groups of the self-assembled monomolecules in the SAM rapidly diffuse along the solvent phase and adsorb and condense with the hydroxyl sites on the FTO / ITO surface, generating stable POM bonds. This step is nearly irreversible, essentially giving the SAM the choice of interface. In the subsequent main annealing stage, the minimization of the system's free energy drives surface energy-oriented phase separation. The polymer, with its relatively low surface energy and lack of strong interaction with the first electrode, tends to accumulate at the air interface compared to the more polar SAM, which is already chemically bonded to the substrate. Simultaneously, the high-temperature annealing stage occurs within the polymer's plasticization temperature range. The residual solvent provides sufficient kinematic freedom to the polymer chains, allowing them to complete chain flow, pore closure, and densification within minutes, forming a continuous upper film. The combination of these two processes spontaneously results in a two-tiered structure—a lower layer of chemically bonded SAM and an upper layer of dense polymer film—within a single thermal path, in a direction away from the first electrode surface.

[0065] In some specific examples, the cleaning process using aprotic polar organic solvents is followed by a step of cleaning using protic polar organic solvents.

[0066] In some specific examples, the aprotic polar organic solvent includes one or more of ethyl acetate, acetone, and butanone. The aprotic polar organic solvent completely removes the polymer material from the hole transport precursor layer.

[0067] In some specific examples, proton-polar organic solvents include one or both of ethanol and isopropanol.

[0068] In some specific examples, the cleaning time using aprotic polar organic solvents is 30s to 120s. Specifically, the cleaning time using aprotic polar organic solvents can be, but is not limited to, 30s, 40s, 50s, 60s, 70s, 80s, 90s, 100s, 110s, or 120s.

[0069] In some specific examples, the cleaning time using proton-polar organic solvents is 30s to 120s. Specifically, the cleaning time using proton-polar organic solvents can be, but is not limited to, 30s, 40s, 50s, 60s, 70s, 80s, 90s, 100s, 110s, or 120s.

[0070] In some specific examples, phosphonic acid-based self-assembled monolayer materials include [2-(9H-carbazole-9-yl)ethyl]phosphonic acid (2PACz), [2-(3,6-dimethoxy-9H-carbazole-9-yl)ethyl]phosphonic acid (MeO-2PACz), [2-(3,6-dimethyl-9H-carbazole-9-yl)ethyl]phosphonic acid (Me-2PACz), [4-(9H-carbazole-9-yl)butyl]phosphonic acid (4PACz), [4-(3,6-dimethyl-9H-carbazole-9-yl)butyl]phosphonic acid (Me-4PACz), [4 One or more of the following: [3,6-dimethoxy-9H-carbazole-9-yl)butyl]phosphonic acid (MeO-4PACz), [4-(7H-dibenzocarbazole-7-yl)butyl]phosphonic acid (4PADCB), [2-(9-bromocarbazole-9-yl)ethyl]phosphonic acid (Br-2PACz), [2-(9-chlorocarbazole-9-yl)ethyl]phosphonic acid (Cl-2PACz), [4-(9-bromocarbazole-9-yl)butyl]phosphonic acid (Br-4PACz), and [4-(9-fluorocarbazole-9-yl)butyl]phosphonic acid (F-4PACz).

[0071] Understandably, this application provides a solar cell comprising a composite substrate, a light-absorbing layer, and a second electrode stacked sequentially, wherein a hole transport layer in the composite substrate is in contact with the light-absorbing layer.

[0072] In some specific examples, the light-absorbing layer is a perovskite layer with the chemical formula ABX3, where A is one or more of formamidinium cation, methylamine cation, and cesium ion; X is one or more of fluoride ion, chloride ion, bromide ion, and iodide ion; and B is lead ion or tin ion.

[0073] In some specific examples, the solar cell also includes an electron transport layer disposed between the light-absorbing layer and the second electrode, the electron transport layer being made of one or more of carbon 60 (C60), methyl [6,6]-phenyl C61 butyrate, and zinc oxide.

[0074] In some specific examples, the solar cell also includes a buffer layer disposed between the electron transport layer and the second electrode, the buffer layer being made of one or more of 2,9-dimethyl-4,7-diphenyl-1,10-phenanthroline (BCP) and tin dioxide (SnO2).

[0075] In some specific examples, the material of the second electrode includes one or more of silver, copper, gold, and carbon.

[0076] This application also provides a photovoltaic module, including the solar cell as described above.

[0077] The present application will be further described in detail below with reference to specific embodiments. It should be understood that these embodiments are for illustrative purposes only and are not intended to limit the scope of the present application. For experimental methods in the following embodiments where specific conditions are not specified, please refer to the guidelines given in this application, or follow experimental manuals or conventional conditions in the art, or follow the conditions recommended by the manufacturer, or refer to experimental methods known in the art.

[0078] In the specific embodiments described below, the measurement parameters of the raw material components may have slight deviations within the weighing accuracy range unless otherwise specified. For temperature and time parameters, acceptable deviations due to instrument testing accuracy or operational precision are permissible. "Ambient temperature" refers to 25°C; "atmospheric pressure" refers to 100 kPa or 101 kPa.

[0079] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0080] Example 1

[0081] This embodiment provides a method for preparing a solar cell, including the following steps:

[0082] Step 1, First Electrode Treatment: First, use a nanosecond laser to etch 100*100mm FTO glass to form the P1 line. Then, clean the first electrode FTO glass substrate with detergent, deionized water, acetone and isopropanol in an ultrasonic bath for 15 minutes each, followed by 30 minutes of ultraviolet ozone treatment.

[0083] Step 2: Preparation of the Composite SAM Hole Transport Layer: Prepare an ethanol solution of 0.3 mg / mL MeO-2PACz. Add 0.3 wt% polyvinyl butyral (PVB, Mw≈20k) to the hole transport material solution to prepare an inkjet precursor solution. The viscosity of the inkjet precursor solution should be 8 mPa·s~12 mPa·s, and the surface tension should be 30 mN / m~35 mN / m. After stirring, filter through a 0.22 μm PTFE membrane. The inkjet printing drive waveform is tuned according to Newtonian fluid dynamics, with a printing DPI of 720*720, a printhead voltage of 12V, and a printing speed of 400 mm / s. Print onto the surface of the 100*100 mm FTO glass substrate. After printing, perform segmented annealing: first anneal at 60℃ for 5 min, then anneal at 120℃ for 8 min. This forms a composite SAM hole transport layer with a polymer protective film and a thickness of approximately 70 nm.

[0084] Step 3: Removal of polymer protective film after storage: The composite substrate with polymer protective film prepared in Step 2 is stored in an atmospheric environment. After 30 days of storage, the film is removed by rinsing with ethyl acetate for 60 seconds, followed by rinsing with IPA and drying with nitrogen to obtain a composite substrate with a SAM hole transport layer with a thickness of about 1 nm.

[0085] Step 4: Prepare Cs at a concentration of 1.31M. 0.052 FA 0.95 A PbI3 perovskite precursor solution (DMF / NMP = 9:1, excess lead iodide 4%, 10 mol% MACl) was used. The perovskite precursor solution was deposited onto the SAM hole transport layer of the composite substrate from step three using a slot-coating process. Specific parameters were as follows: slot and SAM hole transport layer height 100 μm, coating speed 5 mm / s, solution supply rate 5 μL / s, coating onto the surface of the SAM hole transport layer of the aforementioned 100 × 100 mm composite substrate. The coated film was annealed at 150 °C for 10 minutes. After cooling to room temperature, it was then subjected to high vacuum conditions (5 × 10⁻⁶ Å / s) at a speed of 0.2 Å / s. -4 Pa) to prepare perovskite layers.

[0086] Step 5: A 25 nm thick C60 film is thermally evaporated and deposited on the perovskite layer as an electron transport layer and an 8 nm thick BCP film is deposited as a buffer layer. Then, a picosecond laser system is used to scribing the P2 line.

[0087] Step 6: Under high vacuum conditions (5×10⁻⁶) -4 A 100nm copper layer was thermally evaporated and deposited as a second electrode on the buffer layer, and a picosecond laser system was used to scribing P3 lines to fabricate the battery module.

[0088] Step 7: Use butyl rubber and polyolefin elastomer (POE) film to laminate and encapsulate the battery module.

[0089] Example 2

[0090] This embodiment provides a method for preparing a solar cell, including the following steps:

[0091] Step 1, First Electrode Treatment: First, FTO glass is etched using a nanosecond laser to form the P1 line. Then, the FTO glass substrate of the first electrode is cleaned in an ultrasonic bath for 15 minutes each with detergent, deionized water, acetone and isopropanol, followed by 30 minutes of ultraviolet ozone treatment.

[0092] Step 2: Preparation of the Composite SAM Hole Transport Layer: Prepare an ethanol solution of 0.3 mg / mL MeO-2PACz. Add 0.3 wt% cellulose acetate butyrate (CAB, Mw≈20k) to the hole transport material solution to prepare an inkjet precursor solution. The viscosity of the inkjet precursor solution should be 8 mPa·s~12 mPa·s, and the surface tension should be 30 mN / m~35 mN / m. After stirring, filter through a 0.22 μm PTFE membrane. The inkjet printing drive waveform is tuned according to Newtonian fluid dynamics, with a printing DPI of 720*720, a printhead voltage of 12V, and a printing speed of 400 mm / s. Print onto the surface of the 100*100 mm FTO glass substrate. After printing, perform segmented annealing: first anneal at 60℃ for 5 min, then anneal at 120℃ for 8 min. This forms a composite SAM hole transport layer with a polymer protective film and a thickness of approximately 70 nm.

[0093] Step 3: Removal of polymer protective film after storage: The composite substrate with polymer protective film prepared in Step 2 is stored in an atmospheric environment. After 30 days of storage, the film is removed by rinsing with ethyl acetate for 60 seconds, followed by rinsing with IPA and drying with nitrogen to obtain a composite substrate with a SAM hole transport layer with a thickness of about 1 nm.

[0094] Step 4: Prepare Cs at a concentration of 1.31M. 0.052 FA 0.95 A PbI3 perovskite precursor solution (DMF / NMP = 9:1, excess lead iodide 4%, 10 mol% MACl) was used. The perovskite precursor solution was deposited onto the SAM hole transport layer of the composite substrate from step three using a slot-coating process. Specific parameters were as follows: slot and SAM hole transport layer height 100 μm, coating speed 5 mm / s, solution supply rate 5 μL / s, coating onto the surface of the SAM hole transport layer of the aforementioned 100 × 100 mm composite substrate. The coated film was annealed at 150 °C for 10 minutes. After cooling to room temperature, it was then subjected to high vacuum conditions (5 × 10⁻⁶ Å / s) at a speed of 0.2 Å / s. -4 Pa) to prepare perovskite layers.

[0095] Step 5: A 25 nm thick C60 film is thermally evaporated and deposited on the perovskite layer as an electron transport layer and an 8 nm thick BCP film is deposited as a buffer layer. Then, a picosecond laser system is used to scribing the P2 line.

[0096] Step 6: Under high vacuum conditions (5×10⁻⁶) -4 A 100nm copper layer was thermally evaporated and deposited as a second electrode on the buffer layer, and a picosecond laser system was used to scribing P3 lines to fabricate the battery module.

[0097] Step 7: Use butyl rubber and polyolefin elastomer (POE) film to laminate and encapsulate the battery module.

[0098] Example 3

[0099] This embodiment provides a method for preparing a solar cell, including the following steps:

[0100] Step 1, Substrate Treatment: First, use a nanosecond laser to etch 100*100mm FTO glass to form the P1 line. Then, clean the FTO substrate with detergent, deionized water, acetone and isopropanol in an ultrasonic bath for 15 minutes each, followed by 30 minutes of ultraviolet ozone treatment.

[0101] Step 2: Preparation of the composite SAM hole transport layer: Prepare a 0.3 mg / mL MeO-2PACz solution in an ethanol:ethyl acetate ratio of 6:4 (ethyl acetate is used to promote polymer dissolution). Add 0.3 wt% polyvinyl acetate (PVAc, Mw≈20k) to the hole transport material solution to prepare an inkjet precursor solution. The viscosity of the inkjet precursor solution should be 8 mPa·s~12 mPa·s, and the surface tension should be 30 mN / m~35 mN / m. Print the solution onto the surface of the 100*100 mm FTO glass substrate. After stirring, filter the solution through a 0.22 μm PTFE membrane. The inkjet printing drive waveform is tuned according to Newtonian fluid dynamics, with a printing DPI of 720*720, a printhead voltage of 12V, and a printing speed of 400 mm / s. After printing, perform segmented annealing: first anneal at 60℃ for 5 min, then anneal at 120℃ for 8 min. A composite SAM hole transport layer with a polymer protective film is formed with a thickness of approximately 70 nm.

[0102] Step 3: Removal of polymer protective film after storage: The composite substrate with polymer protective film prepared in Step 2 is stored in an atmospheric environment. After 30 days of storage, the film is removed by rinsing with ethyl acetate for 60 seconds, followed by rinsing with IPA and drying with nitrogen to obtain a composite substrate with a SAM hole transport layer with a thickness of about 1 nm.

[0103] Step 4: Prepare Cs at a concentration of 1.31M. 0.052 FA 0.95A PbI3 perovskite precursor solution (DMF / NMP = 9:1, excess lead iodide 4%, 10 mol% MACl) was used. The perovskite precursor solution was deposited onto the SAM hole transport layer of the composite substrate from step three using a slot-coating process. Specific parameters were as follows: slot and SAM hole transport layer height 100 μm, coating speed 5 mm / s, solution supply rate 5 μL / s, coating onto the SAM hole transport layer surface of the 100 × 100 mm composite substrate. The coated film was annealed at 150 °C for 10 minutes. After cooling to room temperature, it was then subjected to high vacuum conditions (5 × 10⁻⁶ Å / s) at a speed of 0.2 Å / s. -4 Pa) to prepare perovskite layers.

[0104] Step 5: A 25 nm thick C60 film is thermally evaporated and deposited on the perovskite layer as an electron transport layer and an 8 nm thick BCP film is deposited as a buffer layer. Then, a picosecond laser system is used to scribing the P2 line.

[0105] Step 6: Under high vacuum conditions (5×10⁻⁶) -4 A 100nm copper layer was thermally evaporated and deposited as a second electrode on the buffer layer, and a picosecond laser system was used to scribing P3 lines to fabricate the battery module.

[0106] Step 7: Use butyl rubber and polyolefin elastomer (POE) film to laminate and encapsulate the battery module.

[0107] Example 4

[0108] Same as Example 1, but after preparing the composite film in step two, the film removal process is performed immediately, and no storage is carried out.

[0109] Example 5

[0110] Same as Example 1, but after printing in step two, the substrate is directly annealed at 120°C for 8 minutes.

[0111] Comparative Example 1

[0112] This comparative example provides a method for preparing a solar cell, comprising the following steps:

[0113] Step 1: Substrate Treatment

[0114] First, a 100*100mm FTO glass was etched using a nanosecond laser to form the P1 line. Then, the FTO substrate was cleaned in an ultrasonic bath for 15 minutes each with detergent, deionized water, acetone and isopropanol, followed by a 30-minute ultraviolet ozone treatment.

[0115] Step 2: SAM layer preparation: Prepare a 0.3 mg / mL MeO-2PACz ethanol solution, stir, and filter through a 0.22 μm PTFE membrane. The inkjet printing drive waveform is tuned to Newtonian fluid dynamics, with a printing DPI of 720*720, printhead voltage of 12V, and printing speed of 400 mm / s, printing onto the surface of the aforementioned 100*100 mm FTO glass substrate. After printing, perform segmented annealing: first annealing at 60℃ for 5 min, then annealing at 120℃ for 8 min, to prepare the composite SAM layer and FTO glass.

[0116] Step 3, Storage: The composite SAM layer and FTO glass prepared in Step 2 are stored in an atmospheric environment. After 30 days of storage, they are rinsed with IPA and dried with nitrogen to obtain a SAM layer and FTO glass with a thickness of about 1 nm.

[0117] Step 4: Prepare Cs at a concentration of 1.31M. 0.052 FA 0.95 A PbI3 perovskite precursor solution (DMF / NMP = 9:1, excess lead iodide 4%, 10 mol% MACl) was deposited onto the SAM layer from step three using a slot-coating process. Specific parameters were as follows: slot and SAM layer height 100 μm, coating speed 5 mm / s, solution supply rate 5 μL / s, coating to a 100 × 100 mm surface of the aforementioned SAM hole transport layer. The coated film was annealed at 150 °C for 10 minutes. After cooling to room temperature, it was then subjected to high vacuum conditions (5 × 10⁻⁶ Å / s) at a speed of 0.2 Å / s. -4 Pa), to prepare a perovskite layer.

[0118] Step 5: A 25nm thick C60 film is deposited on the perovskite layer using thermal evaporation as an electron transport layer and an 8nm BCP film is deposited as a buffer layer. Then, a picosecond laser system is used to scribing the P2 line.

[0119] Step Six: After scribing P2, the substrate is subjected to high vacuum conditions (5×10). -4 Pa) uses thermal evaporation to deposit 100 nm copper as the second electrode on the buffer layer, and uses a picosecond laser system to perform P3 scribing to prepare the module.

[0120] Step 7: Laminate the final module using butyl rubber and polyolefin elastomer (POE) film.

[0121] Comparative Example 2

[0122] Similar to Comparative Example 1, but without storing the thin film after preparation in step two, the solar cell was prepared immediately.

[0123] Comparative Example 3

[0124] This comparative example provides a method for preparing a solar cell, comprising the following steps:

[0125] Step 1, Substrate Treatment: First, use a nanosecond laser to etch 100*100mm FTO glass to form the P1 line. Then, clean the FTO substrate with detergent, deionized water, acetone and isopropanol in an ultrasonic bath for 15 minutes each, followed by 30 minutes of ultraviolet ozone treatment.

[0126] Step 2: Preparation of the composite SAM layer: A 0.3 mg / mL MeO-2PACz ethanol solution was prepared, stirred, and filtered through a 0.22 μm PTFE membrane. SAM was deposited using a blade coating process with the following parameters: blade height to substrate of 70 μm and coating speed of 10 mm / s. The solution was annealed at 60°C for 5 min, followed by annealing at 120°C for 8 min to prepare a 1 nm thick SAM layer. Then, an ethanol solution of polyvinyl butyral (PVB, high acetal grade, Mw≈20 kJ) with the same concentration as PVB in Example 1 was prepared, and a PVB protective film was deposited using the same blade coating process, followed by annealing at 120°C for 8 min. This formed a composite SAM layer with a protective film and a thickness of approximately 69 nm.

[0127] Step 3, Post-storage membrane removal: The composite SAM layer with protective membrane prepared in Step 2 is stored in an atmospheric environment. After 30 days of storage, the membrane is removed by rinsing with ethyl acetate for 60 seconds, followed by rinsing with IPA and drying with nitrogen to obtain a SAM layer with a thickness of approximately 1 nm.

[0128] Step 4: Prepare Cs at a concentration of 1.31M. 0.052 FA 0.95 A PbI3 perovskite precursor solution (DMF / NMP = 9:1, excess lead iodide 4%, 10 mol% MACl) was used. The perovskite precursor solution was deposited onto the SAM layer and substrate after the film removal in step three using a slot coating process. Specific parameters were as follows: slot and SAM layer height 100 μm, coating speed 5 mm / s, solution supply rate 5 μL / s, coating onto the SAM layer surface of the 100 × 100 mm substrate. The coated film was annealed at 150 °C for 10 minutes. After cooling to room temperature, it was then subjected to high vacuum conditions (5 × 10⁻⁶ Å / s) at a speed of 0.2 Å / s. -4 Pa), to prepare a perovskite layer.

[0129] Step 5: A 25nm thick C60 film is thermally evaporated and deposited as an electron transport layer and an 8nm BCP film is deposited as a buffer layer. P2 lines are then scribed using a picosecond laser system.

[0130] Step Six: After scribing P2, the substrate is subjected to high vacuum conditions (5×10).-4 Pa) used thermal evaporation deposition of 100 nm copper as the second electrode and a picosecond laser system was used to scribing the P3 line.

[0131] Step 7: Laminate the final module using butyl rubber and polyolefin elastomer (POE) film.

[0132] Comparative Example 4

[0133] This comparative example provides a method for preparing a solar cell, comprising the following steps:

[0134] Step 1, First Electrode Treatment: First, use a nanosecond laser to etch 100*100mm FTO glass to form the P1 line. Then, clean the first electrode FTO substrate with detergent, deionized water, acetone and isopropanol in an ultrasonic bath for 15 minutes each, followed by 30 minutes of ultraviolet ozone treatment.

[0135] Step 2: Preparation of the composite SAM hole transport layer: Prepare an ethanol solution of 0.3 mg / mL MeO-2PACz. Add 0.3 wt% polyvinylpyrrolidone (PVP, Mw≈20k) to the above ethanol solution of MeO-2PACz to prepare an inkjet precursor solution. The viscosity of the inkjet precursor solution should be 8 mPa·s~12 mPa·s, and the surface tension should be 30 mN / m~35 mN / m. After stirring, filter through a 0.22 μm PTFE membrane. The inkjet printing drive waveform is tuned according to Newtonian fluid dynamics, the printing DPI is 720*720, the printhead voltage is 12V, and the printing speed is 400 mm / s. Print onto the surface of the above-mentioned 100*100 mm FTO glass substrate. After printing, perform segmented annealing directly: first anneal at 60℃ for 5 min, then anneal at 120℃ for 8 min. A composite SAM hole transport layer with a polymer protective film is formed with a thickness of approximately 70 nm.

[0136] Step 3: Removal of polymer protective film after storage: The composite substrate with composite SAM hole transport layer prepared in Step 2 is stored in an atmospheric environment. After 30 days of storage, the film is removed by rinsing with ethyl acetate for 60 seconds, followed by rinsing with IPA and drying with nitrogen to obtain a composite substrate with a SAM hole transport layer of approximately 8 nm thickness.

[0137] Step 4: Prepare Cs at a concentration of 1.31M. 0.052 FA 0.95A PbI3 perovskite precursor solution (DMF / NMP = 9:1, excess lead iodide 4%, 10 mol% MACl) was used. The perovskite precursor solution was deposited onto the SAM hole transport layer of the composite substrate after the film removal in step three using a slot coating process. Specific parameters were as follows: slot and SAM hole transport layer height 100 μm, coating speed 5 mm / s, solution supply rate 5 μL / s, and coating up to a 100*100 mm composite substrate. SAM Hole Transport Layer Surface treatment. The coated film was annealed at 150°C for 10 minutes. After cooling to room temperature, it was subjected to high vacuum conditions (5 × 10⁻⁶ Å / s) at a rate of 0.2 Å / s. -4 Pa) to prepare perovskite layers.

[0138] Step 5: A 25 nm thick C60 film is thermally evaporated and deposited on the perovskite layer as an electron transport layer and an 8 nm thick BCP film is deposited as a buffer layer. Then, a picosecond laser system is used to scribing the P2 line.

[0139] Step 6: Under high vacuum conditions (5×10⁻⁶) -4 A 100nm copper layer was thermally evaporated and deposited as a second electrode on the buffer layer, and a picosecond laser system was used to scribing P3 lines to fabricate the battery module.

[0140] Step 7: Use butyl rubber and polyolefin elastomer (POE) film to laminate and encapsulate the battery module.

[0141] Comparative Example 5

[0142] This comparative example provides a method for preparing a solar cell, comprising the following steps:

[0143] Step 1, First Electrode Treatment: First, use a nanosecond laser to etch 100*100mm FTO glass to form the P1 line. Then, clean the first electrode FTO substrate with detergent, deionized water, acetone and isopropanol in an ultrasonic bath for 15 minutes each, followed by 30 minutes of ultraviolet ozone treatment.

[0144] Step 2: Preparation of the composite SAM hole transport layer: Prepare an ethanol solution of 0.3 mg / mL 3-mercaptopropyltrimethoxysilane. Add 0.3 wt% polyvinyl butyral (PVB, Mw≈20k) to the hole transport material solution, stir, and then filter through a 0.22 μm PTFE membrane. The inkjet printing drive waveform is tuned to Newtonian fluid dynamics, with a printing DPI of 720*720, printhead voltage of 12V, and printing speed of 400 mm / s. Print onto the surface of the 100*100 mm FTO glass substrate. After printing, perform segmented annealing: first anneal at 60℃ for 5 min, then anneal at 120℃ for 8 min. This forms a composite SAM hole transport layer with a polymer protective film and a thickness of approximately 70 nm.

[0145] Step 3: Removal of polymer protective film after storage: The composite substrate with polymer protective film prepared in Step 2 is stored in an atmospheric environment. After 30 days of storage, the film is removed by rinsing with ethyl acetate for 60 seconds, followed by rinsing with IPA and drying with nitrogen to obtain a composite substrate with a SAM hole transport layer with a thickness of about 1 nm.

[0146] Step 4: Prepare Cs at a concentration of 1.31M. 0.052 FA 0.95 A PbI3 perovskite precursor solution (DMF / NMP = 9:1, excess lead iodide 4%, 10 mol% MACl) was used. The perovskite precursor solution was deposited onto the SAM hole transport layer of the composite substrate after the film removal in step three using a slot coating process. Specific parameters were as follows: slot height to substrate height 100 μm, coating speed 5 mm / s, solution supply rate 5 μL / s, coating onto the surface of the SAM hole transport layer of the aforementioned 100*100 mm composite substrate. The coated film was annealed at 150 °C for 10 minutes. After cooling to room temperature, it was then subjected to high vacuum conditions (5 × 10⁻⁶ Å / s) at a speed of 0.2 Å / s. -4 Pa) to prepare perovskite layers.

[0147] Step 5: A 25 nm thick C60 film is thermally evaporated and deposited on the perovskite layer as an electron transport layer and an 8 nm thick BCP film is deposited as a buffer layer. Then, a picosecond laser system is used to scribing the P2 line.

[0148] Step 6: Under high vacuum conditions (5×10⁻⁶) -4 A 100nm copper layer was thermally evaporated and deposited as a second electrode on the buffer layer, and a picosecond laser system was used to scribing P3 lines to fabricate the battery module.

[0149] Step 7: Use butyl rubber and polyolefin elastomer (POE) film to laminate and encapsulate the battery module.

[0150] Device characterization and testing

[0151] The thickness of the SAM was measured using an ellipsometer, and the contact angle of the substrate surface was measured using a contact angle meter via the static drop method. The fabricated device underwent current density-voltage (JV) testing under an AM1.5G standard solar simulator at a scan rate of 100 mV / s. The viscosity and surface tension of the inks obtained in step two of the above examples and comparative examples were tested, and the thickness and contact angle of the annealed substrates were characterized using an ellipsometer. The test results are shown in Table 1.

[0152] Table 1

[0153]

[0154] Ellipsometry was used to characterize the thickness and test the contact angle of the substrates after removing the film in step three of the above embodiments and comparative examples. The test results are shown in Table 2.

[0155] Table 2

[0156]

[0157] The devices obtained from the above embodiments and comparative examples were subjected to JV testing under a calibrated AM1.5G standard solar simulator. The starting voltage was set to 12V, the cutoff voltage to -0.1V, and the scan rate to 100mV / s. The test parameters included open-circuit voltage (Voc), short-circuit current (Jsc), fill factor (FF), and photoelectric conversion efficiency (PCE). The test results are shown in Table 3.

[0158] Table 3

[0159]

[0160] Examples 1-3 illustrate different polymers used as protective layers in composite SAMs, such as... Figure 1 Before step three of the solar cell in Example 1 ( Figure 1 (Left) After step three ( Figure 1 The right side shows a comparison of the film contact angle test results. The thickness and contact angle before and after film removal in step three are roughly the same. Comparative Example 1 is an inkjet SAM process without polymer addition. Tables 1 and 2 show that the thickness of the SAM itself after annealing is approximately 1.2nm-1.4nm. Examples 1-3 also have similar thicknesses after the film removal process, confirming that the polymer has been removed. Furthermore, Figure 2 Before step three of the solar cell in Comparative Example 1 ( Figure 2 (Left) After step three ( Figure 2(Right) Comparison of film contact angle tests. Comparative Example 1 shows that the contact angle of the annealed SAM is between 70-75°, while the contact angle of Examples 1-3 after film removal also decreased from 90° to 70-75°, further confirming the removal of the polymer.

[0161] While PVP in Comparative Example 4 can increase ink viscosity and form a capping layer after annealing, its molecular chain contains lactam carbonyl groups, which easily lead to strong adsorption on the surface of conductive oxide substrates and may compete with phosphonic acid self-assembled molecules, thus affecting the orderly arrangement and chemical bonding of self-assembled monolayers on the substrate surface. Furthermore, the PVP film is difficult to completely remove during subsequent cleaning, leaving a residual layer on the substrate surface, resulting in incomplete recovery of interfacial wettability and affecting the film quality of subsequent perovskite layers and device performance. Therefore, although PVP can play a certain role in thickening and film formation, its mechanism of action differs from the neutral, weakly adsorbed, peelable polymer used in this application, and its overall effect is significantly worse, making it unsuitable as a protective layer material in the preferred embodiment of this application.

[0162] In Comparative Example 5, SAM was replaced with silane-based SAM. In practical use, the Si-OM bond formed between silane-based SAM and the substrate is prone to intermolecular self-condensation, which usually reduces the bond strength. The self-assembly quality and repeatability are often not as stable as phosphonic acid-based SAM.

[0163] like Figure 3 This is a comparison graph of the current density-voltage curves of the solar cells in Example 1 and Comparative Example 1. Figure 4 The graphs above show a comparison of the current density-voltage curves of solar cells in Example 1 and Comparative Example 2. Analysis of the JV test results using these graphs shows that Examples 1-3 were perovskite devices prepared after 30 days of storage with composite SAM followed by film removal, with efficiencies ranging from 20-21%. Comparative Example 1, without a polymer protective layer, had a perovskite device with an efficiency of only 13.30% after 30 days of storage. Even Comparative Example 2, without 30 days of storage, had an efficiency of only 17.03%. This is because Comparative Examples 1-2 used ethanol as the solvent. Without polymer, the ink viscosity and surface tension were below the optimal range for inkjet printing, leading to defects such as satellite droplets and boundary coffee rings during inkjet printing. This affected the subsequent deposition of the perovskite in Comparative Example 2, resulting in a decrease in on-state voltage and flow factor (FF).

[0164] To avoid the impact of low-viscosity SAM from inkjet printing, a comparison was also made between blade coating and Comparative Example 3. Comparing Example 1 and Comparative Example 3, it can be seen that after forming the SAM layer using blade coating, a polymer protective layer was applied, but the final device efficiency was only 16.84%. This is because this additional step introduces the burden of alignment and re-annealing processes, increasing secondary disturbance to the underlying SAM layer. As a result, although the final device's turn-on voltage and current density are normal, the flyback distance (FF) differs significantly, leading to lower device efficiency. Furthermore, because Comparative Example 1 lacked polymer protection during storage, its efficiency decreased from 17.03% to 13.30%, while the device in Example 1, with polymer protection, maintained the same efficiency as the freshly prepared device (Example 4).

[0165] Furthermore, a comparison of Examples 1-3 and 5 with Example 4 in the preparation of solar cells shows that by first preparing the composite substrate and then storing it for a period of time or directly forming other device structures on its surface, the overall performance of the device is not significantly affected. It can be seen that the composite substrate provided in this application can be prepared first and then stored, and then the preparation process can be carried out according to the subsequent process or structural requirements.

[0166] The hole transport layer fabrication process in this application does not rely on high-boiling-point or strongly polar solvents to obtain the inkjet window, thus avoiding the negative impact of solvent residue on self-assembly order and subsequent film stability. Compared to the two-step method of "SAM first, then protective coating," this application completes the construction of two-layer structures in a single ink and single thermal path, reducing process steps, heating history, and alignment risks. Compared to routes using surfactants, ionic liquids, or particulate thickeners, the hole transport layer fabrication method in this application achieves pure physical self-layering through the structural constraints and thermodynamic driving of neutral polymers, avoiding competitive coordination, charged residues, and printhead reliability issues. The solar cells fabricated using the optimized method bring quantifiable technical benefits, including improved jetting stability and linewidth controllability, significant convergence of interface parameter drift during storage and transportation, and consistent interface characterization and device performance after film removal with freshly prepared samples. It not only solves the key contradictions of existing approaches but also possesses robustness for engineering scale-up and cross-scenario adaptability.

[0167] In this document, for methods involving multiple steps, unless otherwise explicitly stated herein, there is no strict order constraint on the execution of these steps; they may be executed in any order other than those described. Moreover, any step may include multiple sub-steps or multiple stages, which are not necessarily completed at the same time, but may be executed at different times, and their execution order is not necessarily sequential, but may be executed in turn, alternately, or simultaneously with other steps or parts of the sub-steps or stages of other steps.

[0168] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0169] The above embodiments merely illustrate several implementation methods of this application, and while the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the invention patent. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of this application, and these all fall within the protection scope of this application. Therefore, the protection scope of this patent application should be determined by the appended claims, and the specification and drawings can be used to interpret the scope of the claims.

Claims

1. A composite substrate, characterized in that, Includes a stacked first electrode and a hole transport layer; The method for preparing the hole transport layer includes the following steps: An inkjet precursor solution is deposited on the surface of the first electrode by inkjet printing. The inkjet precursor solution includes a hole transport material solution and a non-coordinating polymer. The hole transport material solution includes a phosphonic acid-based self-assembled monolayer material. The viscosity of the inkjet precursor solution is 8 mPa·s to 12 mPa·s. A hole transport precursor layer is prepared. The first electrode containing the hole transport precursor layer is annealed, and the annealed hole transport precursor layer is cleaned with an aprotic polar organic solvent to prepare the hole transport layer.

2. The composite substrate as described in claim 1, characterized in that, The inkjet precursor solution satisfies one or more of the following conditions: (1) The non-coordination polymers include one or more of polyvinyl butyral, polyvinyl formal, cellulose acetate butyrate, cellulose acetate propionate, ethylene-vinyl acetate, polyvinyl acetate and ethyl cellulose; (2) The weight-average molecular weight of the non-coordination polymer is 10,000 g / mol to 30,000 g / mol; (3) The mass ratio of the hole transport material solution to the non-coordinated polymer in the inkjet precursor solution is 100:(0.2~0.5); (4) The hole transport material solution further includes one or more of ethanol, isopropanol, ethyl acetate and methyl ethyl ketone, and the concentration of the phosphonic acid-based self-assembled monolayer material in the hole transport material solution is 0.1 mg / mL to 0.6 mg / mL; (5) The surface tension of the inkjet precursor solution is 30mN / m~35mN / m.

3. The composite substrate as described in claim 1, characterized in that, The annealing process includes a pre-annealing step and a main annealing step.

4. The composite substrate as described in claim 3, characterized in that, The annealing step satisfies one or more of the following conditions: (1) The pre-annealing temperature is 50℃~70℃; (2) The pre-annealing time is 3 min to 5 min; (3) The temperature of the main annealing is 110℃~150℃; (4) The main annealing time is 5 min to 10 min.

5. The composite substrate as described in claim 1, characterized in that, The cleaning procedure using aprotic polar organic solvents must meet one or both of the following conditions: (1) The aprotic polar organic solvent includes one or more of ethyl acetate, acetone, and butanone; (2) The cleaning time using the aprotic polar organic solvent is 30s~120s.

6. The composite substrate according to any one of claims 1 to 5, characterized in that, The phosphonic acid-based self-assembled monolayer materials include [2-(9H-carbazole-9-yl)ethyl]phosphonic acid, [2-(3,6-dimethoxy-9H-carbazole-9-yl)ethyl]phosphonic acid, [2-(3,6-dimethyl-9H-carbazole-9-yl)ethyl]phosphonic acid, [4-(9H-carbazole-9-yl)butyl]phosphonic acid, and [4-(3,6-dimethyl-9H-carbazole-9-yl)butyl]phosphonic acid. One or more of the following: [4-(3,6-dimethoxy-9H-carbazole-9-yl)butyl]phosphonic acid, [4-(7H-dibenzocarbazole-7-yl)butyl]phosphonic acid, [2-(9-bromocarbazole-9-yl)ethyl]phosphonic acid, [2-(9-chlorocarbazole-9-yl)ethyl]phosphonic acid, [4-(9-bromocarbazole-9-yl)butyl]phosphonic acid, and [4-(9-fluorocarbazole-9-yl)butyl]phosphonic acid.

7. A solar cell, characterized in that, The composite substrate, light-absorbing layer, and second electrode as described in any one of claims 1 to 6 are stacked sequentially. In the composite substrate, the hole transport layer is in contact with the light absorption layer.

8. The solar cell as claimed in claim 7, characterized in that, The light-absorbing layer is made of perovskite.

9. The solar cell as claimed in claim 7 or 8, characterized in that, It also includes an electron transport layer disposed between the light absorption layer and the second electrode.

10. A photovoltaic module, characterized in that, Including the solar cell as described in any one of claims 7 to 9.

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