Passivation solution and application thereof, passivation layer and preparation method and application thereof, and perovskite solar cell

Abstract

The invention discloses a passivation solution and application thereof, a passivation layer and a preparation method and application thereof, and a perovskite solar cell, and relates to the technical field of perovskite solar devices, the passivation solution is used for passivating a perovskite light absorption layer of the perovskite solar cell, and comprises acetylsalicylic acid; acetylsalicylic acid is adopted as the main component of the passivation solution to passivate the perovskite light absorption layer of the perovskite solar cell, carboxyl and ester groups in the molecular structure of acetylsalicylic acid both have lone pair electrons, and have strong coordination with uncoordinated Pb < + > defects on the surface of the perovskite light absorption layer, so that the deep energy level defects are effectively passivated, and the perovskite light absorption layer of the perovskite solar cell is passivated. And non-radiative recombination of current carriers is reduced. A benzene ring structure in acetylsalicylic acid molecules forms a compact and hydrophobic protective layer on the surface of the perovskite light absorption layer through pi-pi interaction, and erosion of moisture and oxygen in a solvent and an external environment in the subsequent processing process is effectively blocked, so that the environmental stability of the perovskite solar device is remarkably improved.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of perovskite solar devices, in particular to a passivation liquid and application thereof, a passivation layer and preparation method and application thereof, and a perovskite solar cell. BACKGROUND

[0002] Perovskite materials have great application potential in the field of optoelectronic devices due to their excellent photoelectric properties (such as high absorption coefficient, long carrier diffusion length, and tunable band gap). However, a large number of defects in the bulk and interface of perovskite thin films seriously limit the photoelectric conversion efficiency (PCE) and long-term stability of the devices. To solve the core problem of bulk and interface defects of perovskite thin films, interface passivation technology has become a key strategy to improve the photoelectric properties and operational stability of the devices. Existing passivation strategies have problems such as poor stability, high cost, and high toxicity, so there is an urgent need for a multifunctional interface passivation agent that is efficient, stable, low-cost, and environmentally friendly. SUMMARY

[0003] The main purpose of the present application is to provide a passivation liquid and application thereof, a passivation layer and preparation method and application thereof, and a perovskite solar cell, which aims to solve the problem of poor stability of existing passivation liquids.

[0004] To achieve the above-mentioned purpose, the passivation liquid provided by the present application is used to passivate the perovskite light-absorbing layer of a perovskite solar cell, and includes acetylsalicylic acid.

[0005] Preferably, the concentration of acetylsalicylic acid in the passivation liquid is 0.1-4 mg / mL.

[0006] The present application also provides a passivation layer disposed on the perovskite light-absorbing layer of a perovskite solar cell, which includes acetylsalicylic acid.

[0007] The present application also provides a preparation method of the passivation layer provided by the present application, which includes: coating an acetylsalicylic acid solution on the surface of the perovskite light-absorbing layer, and obtaining the passivation layer through annealing treatment.

[0008] Preferably, the concentration of acetylsalicylic acid in the acetylsalicylic acid solution is 0.1-4 mg / mL. The acetylsalicylic acid solution includes an organic solvent, and the organic solvent includes one or more of isopropyl alcohol, ethanol, ethyl acetate, and chloroform.

[0009] Preferably, the coating method includes one or more of doctor blade coating, spraying, spin coating, and printing.

[0010] Preferably, the annealing treatment is performed at a temperature of 50-100℃ for 5-30 min.

[0011] This application also proposes the application of the passivation liquid, passivation layer, and passivation layer preparation method proposed in this application in the fabrication of perovskite solar devices.

[0012] This application also proposes a perovskite solar cell, comprising a transparent conductive substrate, a hole transport layer, a perovskite light-absorbing layer, a passivation layer proposed in this application, an electron transport layer, and a metal electrode stacked sequentially.

[0013] Preferably, the transparent conductive substrate includes one or more of ITO glass and FTO glass; The hole transport layer includes NiO. x PEDOT: One or more of PSS, PTAA, CuSCN, and CuI; The perovskite light-absorbing layer includes MAPbI3, FAPbI3, and (Cs) a FA b MA c One or more of PbX3, wherein a, b, and c are natural numbers greater than 0, a+b+c=1, and X is selected from one or more of I, Cl, and Br; The electron transport layer includes PCBM, C 60 SnO x One or more of the following: fullerene derivatives, TiO2, and ZnO; The metal electrode includes one or more of gold, silver, copper, and aluminum.

[0014] The technical solution of this application uses acetylsalicylic acid as the main component of the passivation solution to passivate the perovskite light-absorbing layer of the perovskite solar cell. The carboxyl group (-COOH) and ester group (-COO-) in the acetylsalicylic acid molecule both possess lone pair electrons and can act as Lewis bases, interacting with uncoordinated Pb²⁺ on the surface of the perovskite light-absorbing layer. + Strong coordination between defects effectively passivates deep-level defects, reduces non-radiative recombination of charge carriers, and thus improves photoelectric conversion efficiency. Furthermore, the benzene ring structure in the acetylsalicylic acid molecule forms a dense, hydrophobic protective layer on the surface of the perovskite light-absorbing layer through π-π interactions. This layer effectively blocks solvents and moisture and oxygen from the external environment during subsequent processing, significantly enhancing the environmental stability of perovskite solar devices. Attached Figure Description

[0015] 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, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on the structures shown in these drawings without creative effort.

[0016] Figure 1 A schematic diagram of the structure of the perovskite solar cell provided in this application; Figure 2 A schematic diagram of another embodiment of the perovskite solar cell provided in this application; Figure 3 The JV characteristic curve test diagram of the perovskite solar cell prepared in the embodiment of this application.

[0017] The realization of the purpose, functional features and advantages of this application will be further explained in conjunction with the embodiments and with reference to the accompanying drawings. Detailed Implementation

[0018] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of this application, and not all of the embodiments. Based on the embodiments of this application, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of this application.

[0019] It should be noted that if the embodiments of this application involve directional indicators (such as up, down, left, right, front, back, etc.), the directional indicators are only used to explain the relative positional relationship and movement of the components in a specific posture. If the specific posture changes, the directional indicators will also change accordingly.

[0020] Furthermore, if the embodiments of this application involve descriptions such as "first" or "second," these descriptions are for descriptive purposes only and should not be construed as indicating or implying their relative importance or implicitly specifying the number of technical features indicated. Therefore, a feature defined with "first" or "second" may explicitly or implicitly include at least one of those features. Additionally, the use of "and / or" or "and / or" throughout the text includes three parallel solutions. For example, "A and / or B" includes solution A, solution B, or a solution that simultaneously satisfies A and B. Furthermore, the technical solutions of the various embodiments can be combined with each other, but this must be based on the ability of those skilled in the art to implement them. When the combination of technical solutions is contradictory or impossible to implement, it should be considered that such a combination of technical solutions does not exist and is not within the scope of protection claimed in this application.

[0021] Perovskite materials exhibit great potential in optoelectronic devices due to their excellent photoelectric properties (such as high absorption coefficient, long carrier diffusion length, and tunable bandgap). However, numerous defects in perovskite films and their interfaces severely limit the photoelectric conversion efficiency (PCE) and long-term stability of these devices. These defects, especially uncoordinated lead ions and halogen vacancies located on the perovskite surface and grain boundaries, act as non-radiative recombination centers, trapping photogenerated carriers and leading to losses in open-circuit voltage (Voc) and fill factor (FF), thereby reducing device efficiency.

[0022] To address the core issue of bulk and interface defects in perovskite thin films, interface passivation technology has become a key strategy for improving the optoelectronic performance and operational stability of devices. The core idea of ​​this strategy is to introduce specific passivating agents that interact with highly active defect sites (primarily uncoordinated Pb). 2+ Selective interactions occur between ions and halogen vacancies, thereby "neutralizing" their electrical activity and effectively suppressing nonradiative recombination of photogenerated carriers at these defect sites. Currently, widely studied passivating molecules can be mainly classified into the following categories: 1. Lewis base molecules: such as thiols, thioureas, pyridine and their derivatives. The electron-rich atoms in these molecules (such as S and N) can act as electron donors, reacting with uncoordinated Pb² atoms, which are Lewis acids. + Ions form stable coordination bonds, "locking" them in place and preventing them from becoming carrier trapping centers.

[0023] 2. Ammonium halide salts: such as phenylethylamine iodide, butylammonium bromide, etc. These molecules typically contain large organic cations and halide anions. Their mechanism of action is dual: on the one hand, the organic cations can occupy A-site vacancies on the surface or grain boundaries of the perovskite lattice, acting as steric hindrance and stabilizing the structure; on the other hand, halide anions (such as I-)... - ,Br - This can directly fill halogen vacancies, eliminating such defects at their source.

[0024] However, existing passivation strategies still have certain limitations: 1. Stability Risks: Some small-molecule passivating agents may migrate or decompose during long-term device operation, leading to passivation failure or even introducing new instabilities, such as the phenylethylamine ions (PEA) in traditionally used phenylethyl ammonium iodide (PEAI). + Under thermal stress, it will migrate from the two-dimensional phase on the surface to the three-dimensional perovskite in the bulk phase, leading to phase transformation and performance degradation, which directly proves the root cause of the instability of small molecule passivators.

[0025] 2. Cost and Toxicity: Some complex passivating agents are expensive or toxic, hindering large-scale production and application. For example, the cyano group in 2-cyanothiazolidine may decompose and release highly toxic hydrogen cyanide under certain conditions; crown ethers can effectively passivate Pb². + However, it is somewhat toxic and expensive, etc.

[0026] Based on this, this application proposes a passivation solution. This passivation solution is used to passivate the perovskite light-absorbing layer of a perovskite solar cell, and the passivation solution includes acetylsalicylic acid.

[0027] The carboxyl (-COOH) and ester (-COO-) groups in the acetylsalicylic acid (ACA) molecule both possess lone pairs of electrons, allowing them to act as Lewis bases and interact with uncoordinated Pb² groups in the perovskite absorber layer. + Strong coordination occurs between defects, effectively passivating these deep-level defects and reducing nonradiative recombination of charge carriers. Simultaneously, the benzene ring structure in the acetylsalicylic acid molecule forms a dense, hydrophobic protective layer on the perovskite light-absorbing layer through π-π interactions. This layer effectively blocks solvents and external moisture and oxygen from subsequent processing, significantly improving the device's environmental stability. Furthermore, acetylsalicylic acid (aspirin) is a commercially available chemical produced in large quantities, with extremely low prices, far lower than commonly used laboratory passivation materials, greatly reducing production costs and making it more environmentally friendly compared to some existing toxic or synthetically complex passivating agents.

[0028] In some embodiments, the concentration of acetylsalicylic acid in the passivation solution is 0.1 to 4 mg / mL. For example, the concentration of acetylsalicylic acid in the passivation solution can be 0.1 mg / mL, 0.5 mg / mL, 1 mg / mL, 2 mg / mL, 3 mg / mL, or 4 mg / mL, etc. Preferably, the concentration of acetylsalicylic acid in the passivation solution is 1 to 2 mg / mL.

[0029] In some embodiments, the passivation solution also includes an organic solvent, which includes one or more of isopropanol, ethanol, ethyl acetate, and chloroform.

[0030] This application also proposes a passivation layer disposed on the perovskite light-absorbing layer of a perovskite solar cell, wherein the passivation layer includes acetylsalicylic acid.

[0031] By forming an ultrathin passivation layer of acetylsalicylic acid on a perovskite light-absorbing layer, the carboxyl groups (-COOH) and ester groups (-COO-) in acetylsalicylic acid can interact with the uncoordinated Pb²⁺ on the perovskite surface. +The defects exhibit strong coordination, passivating deep-level defects and reducing nonradiative recombination of charge carriers. Simultaneously, the passivation layer possesses hydrophobicity, effectively preventing corrosion from solvents and external moisture and oxygen during subsequent processing, thus significantly improving the device's environmental stability.

[0032] Furthermore, this application also proposes a method for preparing the passivation layer as described above, comprising: coating an acetylsalicylic acid solution onto the surface of a perovskite light-absorbing layer, and then annealing the passivation layer to obtain the passivation layer.

[0033] The passivation layer preparation method provided in this application involves coating an acetylsalicylic acid solution onto the surface of a perovskite light-absorbing layer, followed by low-temperature annealing to form an ultra-thin passivation layer on the surface of the perovskite light-absorbing layer. The preparation process is simple, perfectly compatible with the mainstream preparation process of inverted devices, and easy to integrate into existing production lines.

[0034] In some embodiments, the concentration of acetylsalicylic acid in the acetylsalicylic acid solution is 0.1 to 4 mg / mL. For example, the concentration of acetylsalicylic acid in the acetylsalicylic acid solution can be 0.1 mg / mL, 0.5 mg / mL, 1 mg / mL, 2 mg / mL, 3 mg / mL, or 4 mg / mL, etc. Preferably, the concentration of acetylsalicylic acid in the acetylsalicylic acid solution is 1 to 2 mg / mL.

[0035] In some embodiments, the acetylsalicylic acid solution further includes an organic solvent, including one or more of isopropanol, ethanol, ethyl acetate, and chloroform. All selected solvents are low-polarity solvents and will not damage the underlying perovskite film. In some embodiments, the coating method includes one or more of the following: blade coating, spray coating, spin coating, and printing.

[0036] In some embodiments, the annealing temperature is 50~100℃ and the time is 5~30 min. For example, the annealing temperature can be 50℃, 60℃, 70℃, 80℃, 90℃ or 100℃, etc. The annealing time can be 5 min, 10 min, 15 min, 20 min, 25 min or 30 min, etc.

[0037] This application also proposes the application of the passivation liquid, passivation layer, and passivation layer preparation method described above in the fabrication of perovskite solar devices. Since this application employs all the technical solutions of the above embodiments, it possesses at least all the beneficial effects brought about by the technical solutions of the above embodiments, which will not be elaborated upon here. The perovskite solar device can be a perovskite solar cell, particularly an inverted perovskite solar cell.

[0038] This application also proposes a perovskite solar cell, such as Figure 1 As shown, it generally includes a transparent conductive substrate, a hole transport layer, a perovskite light-absorbing layer, a passivation layer as described above, an electron transport layer, and a metal electrode stacked sequentially.

[0039] In some embodiments, the transparent conductive substrate includes one or more of ITO glass and FTO glass; the hole transport layer includes NiO. x PEDOT: One or more of PSS, PTAA, CuSCN, and CuI; the perovskite light-absorbing layer includes MAPbI3 (methylammonium lead iodide), FAPbI3 (formamidinium lead iodide), and (Cs) x One or more of FAyMAz)PbX3, wherein a, b, and c are natural numbers greater than 0, a+b+c=1, and X is selected from one or more of I, Cl, and Br; the electron transport layer includes PCBM, C 60 SnO x One or more of fullerene derivatives, TiO2, and ZnO; the metal electrode includes one or more of gold, silver, copper, and aluminum.

[0040] In some implementations, please refer to Figure 2 The perovskite solar cell also includes a self-assembled monolayer disposed between the hole transport layer and the perovskite light-absorbing layer. The self-assembled monolayer includes one or more of 2PACz, MeO-2PACz, and Me-4PACz.

[0041] The following specific examples provide further details.

[0042] Example 1 This embodiment describes the fabrication of a perovskite solar cell, and the specific steps are as follows: 1. Substrate preparation: Using a patterned FTO / glass substrate, clean it sequentially with detergent, deionized water, ethanol and isopropanol. After removal, dry it with nitrogen gas and treat it with ultraviolet ozone for 15 min.

[0043] 2. Preparation of the hole transport layer: Weigh NiO x Nanoparticles were dissolved in 1 mL of deionized water and ultrasonically vibrated for 15 min; then 60 μL of NiO was added dropwise. x The solution was applied to an FTO substrate, spin-coated at 3000 rpm for 30 s, and then annealed at 150°C for 30 min. The substrate with the hole transport layer was then transferred to a glove box under a nitrogen atmosphere.

[0044] 3. Preparation of self-assembled monolayer: 0.5 mg of [2-(9H-carbazole-9-yl)ethyl]phosphonic acid (2PACz) was dissolved in 1 mL of ethanol solution. 80 μL of 2PACz solution was added dropwise onto the hole transport layer. The mixture was spin-coated at 4000 rpm for 30 s and annealed at 100 °C for 10 min.

[0045] 4. Preparation of the perovskite absorbing layer: Accurately weigh 664.0 mg PbI2, 220.6 mg FAI (formamidinium iodide), 15.6 mg CsI, and 48.4 mg MACl (chloromethylamine), and dissolve them together in 1 mL of a 4:1 DMF:DMSO mixed solvent. Stir at 60°C until completely dissolved. Add 60 μL of the perovskite precursor solution to the self-assembled monolayer. The spin-coating process is divided into two stages: the first stage spin-coating speed is 1000 rpm and the spin-coating time is 10 s; the second stage spin-coating speed is 5000 rpm and the spin-coating time is 40 s. In the second stage, 150 μL of chlorobenzene is added dropwise at the 5th second before the end of the spin-coating period, and the mixture is annealed at 120°C for 20 min to complete the preparation of the perovskite absorbing layer.

[0046] 5. Preparation of passivation layer: Prepare a 2 mg / mL solution of aspirin in anhydrous ethanol, spin-coat at 4000 rpm for 30 s, and anneal at 100℃ for 10 min.

[0047] 6. Fabrication of the electron transport layer: An electron transport layer of 15 nm was deposited on the passivation layer using a vacuum deposition method to prepare a C0 layer. 60 (0.5 Å / s, 6E-4 Pa), preparation of 20 nm SnO x (0.5 Å / s, 2E-2 Pa).

[0048] 7. Electrode fabrication: An Ag electrode was deposited on a substrate with an electron transport layer by thermal evaporation to deposit Ag with a thickness of 100 nm (1 Å / s, 6E-4 Pa).

[0049] Example 2 This embodiment describes the fabrication of a perovskite solar cell, and the specific steps are as follows: 1. Substrate preparation: Using a patterned FTO / glass substrate, clean it sequentially with detergent, deionized water, ethanol and isopropanol. After removal, dry it with nitrogen gas and treat it with ultraviolet ozone for 15 min.

[0050] 2. Preparation of the hole transport layer: Weigh NiO x Nanoparticles were dissolved in 1 mL of deionized water and ultrasonically vibrated for 15 min; then 60 μL of NiO was added dropwise. xThe solution was applied to an FTO substrate, spin-coated at 3000 rpm for 30 s, and then annealed at 150°C for 30 min. The substrate with the hole transport layer was then transferred to a glove box under a nitrogen atmosphere.

[0051] 3. Preparation of self-assembled monolayer: 0.5 mg of [2-(9H-carbazole-9-yl)ethyl]phosphonic acid (2PACz) was dissolved in 1 mL of ethanol solution. 80 μL of 2PACz solution was added dropwise onto the hole transport layer. The mixture was spin-coated at 4000 rpm for 30 s and annealed at 100 °C for 10 min.

[0052] 4. Preparation of the perovskite absorbing layer: Accurately weigh 664.0 mg PbI2, 220.6 mg FAI, 15.6 mg CsI, and 48.4 mg MACl, and dissolve them together in 1 mL of a 4:1 DMF:DMSO mixed solvent. Stir at 60°C until completely dissolved. Add 60 μL of the perovskite precursor solution to the self-assembled monolayer. The spin-coating process is divided into two stages: the first stage spin-coating speed is 1000 rpm and the spin-coating time is 10 s; the second stage spin-coating speed is 5000 rpm and the spin-coating time is 40 s. In the second stage, 150 μL of chlorobenzene is added dropwise at the 5th second before the end of the spin-coating period, and the mixture is annealed at 120°C for 20 min to complete the preparation of the perovskite absorbing layer.

[0053] 5. Preparation of passivation layer: Prepare a 0.5 mg / mL solution of aspirin in anhydrous ethanol, spin-coat at 4000 rpm for 30 s, and anneal at 100℃ for 10 min.

[0054] 6. Fabrication of the electron transport layer: An electron transport layer of 15 nm was deposited on the passivation layer using a vacuum deposition method to prepare a C0 layer. 60 (0.5 Å / s, 6E-4 Pa), preparation of 20 nm SnO x (0.5 Å / s, 2E-2 Pa).

[0055] 7. Electrode fabrication: An Ag electrode was deposited on a substrate with an electron transport layer by thermal evaporation to deposit Ag with a thickness of 100 nm (1 Å / s, 6E-4 Pa).

[0056] Example 3 This embodiment describes the fabrication of a perovskite solar cell, and the specific steps are as follows: 1. Substrate preparation: Using a patterned FTO / glass substrate, clean it sequentially with detergent, deionized water, ethanol and isopropanol. After removal, dry it with nitrogen gas and treat it with ultraviolet ozone for 15 min.

[0057] 2. Preparation of the hole transport layer: Weigh NiO x Nanoparticles were dissolved in 1 mL of deionized water and ultrasonically vibrated for 15 min; then 60 μL of NiO was added dropwise. x The solution was applied to an FTO substrate, spin-coated at 3000 rpm for 30 s, and then annealed at 150°C for 30 min. The substrate with the hole transport layer was then transferred to a glove box under a nitrogen atmosphere.

[0058] 3. Preparation of self-assembled monolayer: 0.5 mg of [2-(9H-carbazole-9-yl)ethyl]phosphonic acid (2PACz) was dissolved in 1 mL of ethanol solution. 80 μL of 2PACz solution was added dropwise onto the hole transport layer. The mixture was spin-coated at 4000 rpm for 30 s and annealed at 100 °C for 10 min.

[0059] 4. Preparation of the perovskite absorbing layer: Accurately weigh 664.0 mg PbI2, 220.6 mg FAI, 15.6 mg CsI, and 48.4 mg MACl, and dissolve them together in 1 mL of a 4:1 DMF:DMSO mixed solvent. Stir at 60°C until completely dissolved. Add 60 μL of the perovskite precursor solution to the self-assembled monolayer. The spin-coating process is divided into two stages: the first stage spin-coating speed is 1000 rpm and the spin-coating time is 10 s; the second stage spin-coating speed is 5000 rpm and the spin-coating time is 40 s. In the second stage, 150 μL of chlorobenzene is added dropwise at the 5th second before the end of the spin-coating period, and the mixture is annealed at 120°C for 20 min to complete the preparation of the perovskite absorbing layer.

[0060] 5. Preparation of passivation layer: Prepare a 1 mg / mL solution of aspirin in anhydrous ethanol, spin-coat at 4000 rpm for 30 s, and anneal at 100℃ for 10 min.

[0061] 6. Fabrication of the electron transport layer: An electron transport layer of 15 nm was deposited on the passivation layer using a vacuum deposition method to prepare a C0 layer. 60 (0.5 Å / s, 6E-4 Pa), preparation of 20 nm SnO x (0.5 Å / s, 2E-2 Pa).

[0062] 7. Electrode fabrication: An Ag electrode was deposited on a substrate with an electron transport layer by thermal evaporation to deposit Ag with a thickness of 100 nm (1 Å / s, 6E-4 Pa).

[0063] Example 4 This embodiment describes the fabrication of a perovskite solar cell, and the specific steps are as follows: 1. Substrate preparation: Using a patterned FTO / glass substrate, clean it sequentially with detergent, deionized water, ethanol and isopropanol. After removal, dry it with nitrogen gas and treat it with ultraviolet ozone for 15 min.

[0064] 2. Preparation of the hole transport layer: Weigh NiO x Nanoparticles were dissolved in 1 mL of deionized water and ultrasonically vibrated for 15 min; then 60 μL of NiO was added dropwise. x The solution was applied to an FTO substrate, spin-coated at 3000 rpm for 30 s, and then annealed at 150°C for 30 min. The substrate with the hole transport layer was then transferred to a glove box under a nitrogen atmosphere.

[0065] 3. Preparation of self-assembled monolayer: 0.5 mg of [2-(9H-carbazole-9-yl)ethyl]phosphonic acid (2PACz) was dissolved in 1 mL of ethanol solution. 80 μL of 2PACz solution was added dropwise onto the hole transport layer. The mixture was spin-coated at 4000 rpm for 30 s and annealed at 100 °C for 10 min.

[0066] 4. Preparation of the perovskite absorbing layer: Accurately weigh 664.0 mg PbI2, 220.6 mg FAI, 15.6 mg CsI, and 48.4 mg MACl, and dissolve them together in 1 mL of a 4:1 DMF:DMSO mixed solvent. Stir at 60°C until completely dissolved. Add 60 μL of the perovskite precursor solution to the self-assembled monolayer. The spin-coating process is divided into two stages: the first stage spin-coating speed is 1000 rpm and the spin-coating time is 10 s; the second stage spin-coating speed is 5000 rpm and the spin-coating time is 40 s. In the second stage, 150 μL of chlorobenzene is added dropwise at the 5th second before the end of the spin-coating period, and the mixture is annealed at 120°C for 20 min to complete the preparation of the perovskite absorbing layer.

[0067] 5. Preparation of passivation layer: Prepare a 4 mg / mL aspirin anhydrous ethanol solution, spin-coat at 4000 rpm for 30 s, and anneal at 100℃ for 10 min.

[0068] 6. Fabrication of the electron transport layer: An electron transport layer of 15 nm was deposited on the passivation layer using a vacuum deposition method to prepare a C0 layer. 60 (0.5 Å / s, 6E-4 Pa), preparation of 20 nm SnO x (0.5 Å / s, 2E-2 Pa).

[0069] 7. Electrode fabrication: An Ag electrode was deposited on a substrate with an electron transport layer by thermal evaporation to deposit Ag with a thickness of 100 nm (1 Å / s, 6E-4 Pa).

[0070] Comparative Example 1 This embodiment describes the fabrication of a perovskite solar cell, and the specific steps are as follows: 1. Substrate preparation: Using a patterned FTO / glass substrate, clean it sequentially with detergent, deionized water, ethanol and isopropanol. After removal, dry it with nitrogen gas and treat it with ultraviolet ozone for 15 min.

[0071] 2. Preparation of the hole transport layer: Weigh NiO x Nanoparticles were dissolved in 1 mL of deionized water and ultrasonically vibrated for 15 min; then 60 μL of NiO was added dropwise. x The solution was applied to an FTO substrate, spin-coated at 3000 rpm for 30 s, and then annealed at 150°C for 30 min. The substrate with the hole transport layer was then transferred to a glove box under a nitrogen atmosphere.

[0072] 3. Preparation of self-assembled monolayer: 0.5 mg of [2-(9H-carbazole-9-yl)ethyl]phosphonic acid (2PACz) was dissolved in 1 mL of ethanol solution. 80 μL of 2PACz solution was added dropwise onto the hole transport layer. The mixture was spin-coated at 4000 rpm for 30 s and annealed at 100 °C for 10 min.

[0073] 4. Preparation of the perovskite absorbing layer: Accurately weigh 664.0 mg PbI2, 220.6 mg FAI, 15.6 mg CsI, and 48.4 mg MACl, and dissolve them together in 1 mL of a 4:1 DMF:DMSO mixed solvent. Stir at 60°C until completely dissolved. Add 60 μL of the perovskite precursor solution to the self-assembled monolayer. The spin-coating process is divided into two stages: the first stage spin-coating speed is 1000 rpm and the spin-coating time is 10 s; the second stage spin-coating speed is 5000 rpm and the spin-coating time is 40 s. In the second stage, 150 μL of chlorobenzene is added dropwise at the 5th second before the end of the spin-coating period, and the mixture is annealed at 120°C for 20 min to complete the preparation of the perovskite absorbing layer.

[0074] 5. Fabrication of the electron transport layer: An electron transport layer of 15 nm was deposited on the passivation layer using a vacuum deposition method to prepare the electron transport layer. 60 (0.5 Å / s, 6E-4 Pa), preparation of 20 nm SnO x (0.5 Å / s, 2E-2 Pa).

[0075] 6. Electrode fabrication: An Ag electrode was deposited on a substrate with an electron transport layer by thermal evaporation to deposit Ag with a thickness of 100 nm (1 Å / s, 6E-4 Pa).

[0076] The performance of the perovskite solar cells prepared in Examples 1 to 4 and Comparative Example 1 was tested under standard test conditions (AM 1.5 G, 100 mW / cm²), and the results are shown in Table 1 and... Figure 3 As shown.

[0077] Table 1 Performance Tests of Perovskite Solar Cells

[0078] From Table 1 and Figure 3 It can be seen that the parameters of the perovskite solar cells prepared in Examples 1-4 are all superior to those of the perovskite solar cell prepared in Comparative Example 1 (without a passivation layer), indicating that the passivation layer containing acetylsalicylic acid significantly improves the open-circuit voltage and fill factor of the perovskite solar cell. Furthermore, the performance parameters of the perovskite solar cells prepared in Examples 1 and 3 are significantly higher than those in other examples, demonstrating that when the concentration of acetylsalicylic acid used in the preparation process is 1-2 mg / mL, the optimal effect on improving the photoelectric performance parameters of the final perovskite solar cell is achieved.

[0079] The above description is merely an exemplary embodiment of this application and does not limit the patent scope of this application. Any equivalent structural transformations made based on the technical concept of this application and the contents of the specification and drawings of this application, or direct / indirect applications in other related technical fields, are included within the patent protection scope of this application.

Claims

1. A passivation liquid, characterized by, The passivation liquid is used for passivating a perovskite light-absorbing layer of a perovskite solar cell, and includes acetylsalicylic acid.

2. The passivation solution according to claim 1, wherein The concentration of acetylsalicylic acid in the passivation liquid is 0.1-4 mg / mL.

3. A passivation layer, characterized in that The passivation layer is disposed on a perovskite light-absorbing layer of a perovskite solar cell, and includes acetylsalicylic acid.

4. A method of producing the passivation layer according to claim 3, characterized in that The passivation layer is prepared by: applying a solution of acetylsalicylic acid to the surface of the perovskite light-absorbing layer, and annealing the solution to obtain the passivation layer.

5. The method for producing a passivation layer according to claim 4, wherein The concentration of acetylsalicylic acid in the solution is 0.1-4 mg / mL. The solution of acetylsalicylic acid includes an organic solvent, and the organic solvent includes one or more of isopropyl alcohol, ethanol, ethyl acetate, and chloroform.

6. The method for preparing the passivation layer as described in claim 4, characterized in that, The method of applying includes one or more of doctor blading, spraying, spin coating, and printing.

7. The method for preparing the passivation layer as described in claim 4, characterized in that, The annealing is performed at a temperature of 50-100℃ for a time of 5-30 min.

8. Use of the passivation liquid of claim 1 or 2, the passivation layer of claim 3, or the method of claim 4-7 for preparing a perovskite solar device.

9. A perovskite solar cell, characterized by, The perovskite solar device includes, in order, a transparent conductive substrate, a hole transport layer, a perovskite light-absorbing layer, the passivation layer of claim 3, an electron transport layer, and a metal electrode. The passivation layer is deposited on the perovskite light-absorbing layer.

10. The perovskite solar cell of claim 9, wherein the perovskite layer is formed by a two-step method. The transparent conductive substrate includes one or more of ITO glass and FTO glass. The hole transport layer comprises one or more of NiO x , PEDOT:PSS, PTAA, CuSCN, CuI The perovskite light-absorbing layer comprises one or more of MAPbI3, FAPbI3, (Cs a FA b MA c )PbX3, wherein a, b, c are natural numbers greater than 0, a+b+c=1, and X is selected from one or more of I, Cl, Br. The electron transport layer comprises one or more of PCBM, C 60 , SnO x , a fullerene derivative, TiO2, ZnO. The metal electrode includes one or more of gold, silver, copper, and aluminum.

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