Phenothiazine-3-ketone-based compound, perovskite cell and preparation method thereof

Abstract

The invention belongs to the technical field of solar cells, and discloses a phenothiazine-3-ketone-based compound, a perovskite cell and a preparation method of the phenothiazine-3-ketone-based compound, and the phenothiazine-3-ketone-based compound forms a self-assembly layer, can passivate NiOx and perovskite surfaces at the same time, and reduces interface defects. The anchoring group (sulfonic group) can be anchored on the surface of the NiOx film to form a strong and stable covalent bond, and selective contact is realized to reduce interface recombination and reduce surface defects of the NiOx film. And electron-rich carbonyl,-S-and the like in the Y group can passivate the defects of Pb < 2 + > and the like on the surface of the perovskite, so that the quality of the film is improved. In addition, due to the existence of minority carriers near an interface, direct interface recombination with majority carriers can be caused, N + in the compound repels hole carriers, and interface recombination is reduced through field effect passivation. The perovskite solar cell passivated based on the compound has excellent performance.

Description

Technical Field

[0001] This invention generally relates to the field of solar cell technology. More specifically, this invention relates to a compound based on phenothiazine-3-one, a perovskite solar cell, and a method for preparing the same. Background Technology

[0002] Perovskite solar cells have attracted widespread attention due to their excellent photoelectric properties, such as high light absorption coefficient, long carrier lifetime, and high defect tolerance. Since their introduction in 2009, the power conversion efficiency (PCE) of perovskite solar cells has increased from 3.8% to 26.1%, which is very close to the efficiency record of 26.81% for crystalline silicon solar cells. Furthermore, their advantage of being able to be fabricated using solution methods gives them broad prospects for industrialization.

[0003] With the continuous advancement of perovskite industrialization, pin-type planar heterojunction perovskite solar cells have attracted widespread attention due to their simple structure and compatibility with large-area manufacturing processes. In the reported hole transport layers used in inverted pin structures, nickel oxide (NiO) in p-type inorganic semiconductors... x NiO has been particularly favored due to its advantages of low cost, high transmittance, stable chemical properties, and ease of large-area preparation. However, NiO... x It also has serious drawbacks, including low intrinsic conductivity, high defect density, energy level mismatch with the perovskite interface, and reaction with perovskite precursors. Even though perovskite materials themselves have relatively high defect tolerance, untreated NiO... x Numerous defects and deep potential wells at the NiO-perovskite interface induce high levels of nonradiative recombination, thus limiting the potential of NiO. x Photovoltaic performance of perovskite solar cells.

[0004] Introducing an interface layer for modification and enhancement is an optimization method for NiO. x Self-assembled materials (SAMs) are an important means of improving the photovoltaic performance of perovskite solar cells. They are one option for modifying and altering interfacial layers, offering the advantage of allowing for the design of various combinations of assembly groups to achieve different functions depending on the substrate. Using SAMs as interfacial modifiers in PSCs has proven to be a simple and effective strategy, where self-assembled hole transport materials with anchoring groups are anchored to NiO. x Strong and stable covalent bonds can be formed on the surface of thin films, enabling selective contact to reduce interfacial recombination and promote charge transfer, thereby improving the efficiency of perovskite solar cell devices.

[0005] Therefore, there is an urgent need for self-assembled materials that passivate the interface between the hole transport layer and the perovskite layer of nickel oxide, in order to achieve a technical solution that reduces interfacial recombination and improves the efficiency of perovskite solar cells. Summary of the Invention

[0006] To at least address one or more of the technical problems mentioned above, embodiments of the present invention provide a compound based on phenothiazine-3-one, the general formula of which is shown in formula (i):

[0007]

[0008] in,

[0009] Z - Includes F - Cl - ,Br - I - HCOO - BF4 - SCN - HSO3 - PF6 - One or more of the following;

[0010] The Y group includes one of the following: -H, -OH, -COOH, -NH2, -S-CH3, -F, and -CN;

[0011] n is an integer from 2 to 6.

[0012] According to one embodiment of the present invention, Z in the aforementioned compound - For I - And n is 3.

[0013] According to one embodiment of the present invention, the aforementioned compounds include any one or more of compounds A to G shown in (iii).

[0014] According to another aspect of the invention, the application of the above-described phenothiazine-3-one-based compounds in perovskite solar cells is provided.

[0015] According to another aspect of the present invention, a perovskite solar cell is provided, comprising a first electrode layer, a hole transport layer, a self-assembled layer, a perovskite layer, an electron transport layer, and a second electrode layer stacked sequentially, wherein the hole transport layer comprises nickel oxide; and / or the perovskite layer comprises at least one of lead ions, tin ions, and germanium ions; and the self-assembled layer comprises the aforementioned compound.

[0016] According to another aspect of the present invention, a method for fabricating a perovskite solar cell is provided, comprising: fabricating a first electrode layer as a substrate; depositing nickel oxide on the first electrode to form a hole transport layer; forming a self-assembled layer comprising the aforementioned compound on the hole transport layer; forming a perovskite layer comprising perovskite on the self-assembled layer; depositing an n-type inorganic semiconductor or an n-type organic semiconductor on the perovskite layer to form an electron transport layer; and printing electrode material on the electron transport layer to form a second electrode.

[0017] According to one embodiment of the present invention, forming a self-assembled layer comprising the aforementioned compound on the hole transport layer includes: dissolving the aforementioned phenothiazine-3-one-based compound in a solvent to obtain a self-assembled layer precursor solution with a molar concentration of 1–5 mM; coating the self-assembled layer precursor solution onto the hole transport layer; and annealing it at a controlled temperature of 80–150°C for 10–20 min; and cleaning the surface of the hole transport layer with the solvent to form the self-assembled layer; wherein the solvent is selected from isopropanol or diethyl ether. Preferably, the annealing temperature is controlled at 100–120°C, and the annealing time is 15 min.

[0018] According to one embodiment of the present invention, forming a perovskite layer comprising perovskite on the self-assembled layer comprises: dissolving the perovskite in one or more of N,N-dimethylformamide, dimethyl sulfoxide, N-methyl-2-pyrrolidone, γ-butyrolactone, 1,3-dimethyl-2-imidazolinone, dimethylacetamide, N,N-dimethylpropenylurea, acetonitrile, or 2-mercaptoethanol to obtain a perovskite precursor solution; coating the perovskite precursor solution onto the self-assembled layer and annealing it by heating to form the perovskite layer; wherein the perovskite has the general formula ABX3, wherein A is selected from CH3NH3. + CH(NH2)2 + Cs + or Rb + B is any one or more of Pb, where B is selected from Pb. 2+ Sn 2+ Or Ge 2+ X is any one or more of the following, where X is selected from Cl. - ,Br - Or I - Any one or more of them.

[0019] According to one embodiment of the present invention, the n-type inorganic semiconductor is selected from C 60 One of PCBM, TiO2, SnO2, ZnO, or ZnO-ZnS.

[0020] According to one embodiment of the present invention, the first electrode is made of transparent conductive glass, such as ITO glass, FTO glass, or AZO glass; the electrode material is selected from any one of Al, Au, Ag, or low-temperature carbon electrodes. In this invention, the transparent conductive glass includes FTO conductive glass, ITO conductive glass, or other transparent conductive glasses, wherein FTO represents fluorine-doped SnO2 conductive glass (SnO2:F), and ITO represents indium-doped SnO2 conductive glass (SnO2:In).

[0021] According to one embodiment of the present invention, the thickness of the perovskite layer is 200–900 nm.

[0022] The compounds based on phenothiazine-3-one, as provided above, can be used as self-assembled layers to simultaneously passivate NiO. x Thin films and perovskite surfaces reduce interface defects. Anchoring groups (sulfonic acid groups) can anchor onto NiO. x Strong and stable covalent bonds are formed on the thin film surface, enabling selective contact to mitigate interfacial recombination and reduce NiO. x Thin film surface defects. Electron-rich carbonyl groups and -S- groups in the Y group can passivate Pb on the perovskite surface. 2+ This addresses defects such as [missing information], improving film quality. Furthermore, the presence of minority carriers (electrons in the perovskite layer) near the interface leads to direct interfacial recombination with majority carriers (holes in the hole transport layer), and the N in this compound [missing information]. + It repels hole carriers and reduces interfacial recombination through field-effect passivation. Perovskite solar cells passivated with this compound exhibit excellent performance. Attached Figure Description

[0023] The above and other objects, features, and advantages of exemplary embodiments of the present invention will become readily apparent upon reading the following detailed description with reference to the accompanying drawings. In the drawings, several embodiments of the invention are illustrated by way of example and not limitation, and like or corresponding reference numerals denote like or corresponding parts, wherein:

[0024] Figure 1 The XRD comparison diagrams of the perovskite layers of Example 1 and Comparative Example 1 are shown;

[0025] Figure 2 A schematic diagram of the ultraviolet light absorption-wavelength distribution of the perovskite layers in Example 1 and Comparative Example 1 is shown.

[0026] Figure 3 A schematic diagram of the photoluminescence intensity-wavelength distribution of the perovskite layers in Example 1 and Comparative Example 1 is shown.

[0027] Figure 4A schematic diagram of the fluorescence lifetime of the perovskite layer in Example 1 and Comparative Example 1 is shown.

[0028] Figure 5 The stability comparison graphs of perovskite solar cells of Examples 1 to 7 and Comparative Example 1 are shown. Detailed Implementation

[0029] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0030] It should be understood that the terms "comprising" and "including" as used in the specification and claims of this invention indicate the presence of the described features, integrals, steps, operations, elements and / or components, but do not exclude the presence or addition of one or more other features, integrals, steps, operations, elements, components and / or collections thereof.

[0031] It should also be understood that the terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit the invention. As used in this specification and claims, the singular forms “a,” “an,” and “the” are intended to include the plural forms unless the context clearly indicates otherwise. It should also be understood that the term “and / or” as used in this specification and claims refers to any combination and all possible combinations of one or more of the associated listed items, and includes such combinations.

[0032] As used in this specification and claims, the term "if" may be interpreted, depending on the context, as "when," "once," "in response to determination," or "in response to detection." Similarly, the phrase "if determined" or "if [described condition or event] is detected" may be interpreted, depending on the context, as "once determined," "in response to determination," "once [described condition or event] is detected," or "in response to detection of [described condition or event]."

[0033] The specific embodiments of the present invention will now be described in detail with reference to the accompanying drawings.

[0034] In an embodiment of the present invention, a compound based on phenothiazine-3-one is provided, belonging to a type of self-assembled material (SAM), with the general formula shown in formula (i):

[0035]

[0036] Among them, Z- Includes F - Cl - ,Br - I - HCOO - BF4 - SCN - HSO3 - PF6 - One or more of the following; the Y group includes one of -H, -OH, -COOH, -NH2, -S-CH3, -F, and -CN; n is an integer from 2 to 6.

[0037] In embodiments of the present invention, current research shows that the individual and synergistic mechanisms of action of each ion have not been clearly described and characterized, but they at least have the following effects: F - Cl - ,Br - I - Halogen ions primarily function to fill halogen vacancies. HCOO - It can slow down the crystallization rate, making it easier to prepare perovskite thin films with larger dimensions and fewer defects. BF4 - SCN - HSO3 - PF6 - Ions can also help anchor or passivate interface defects.

[0038] In the embodiments of the present invention, the -OH, -COOH, -NH2, -S-CH3, -F, -CN, etc. in the Y group mainly interact with the perovskite surface. For example, each functional group can interact with the undercoordinated Sn on the perovskite surface. 2+ Pb 2+ Plasma interactions stabilize the perovskite / hole transport layer interface, thereby passivating interface defects.

[0039] According to one embodiment of the present invention, Z - For I - n is 3.

[0040] According to another aspect of the present invention, the application of the aforementioned phenothiazine-3-one-based compound in a perovskite solar cell is provided. By forming a self-assembled layer between the perovskite layer and the hole transport layer in the perovskite solar cell, the aforementioned phenothiazine-3-one-based compound serves to stabilize and passivate the interface.

[0041] According to another aspect of the present invention, a perovskite solar cell is provided, the perovskite solar cell comprising, in sequence, a first electrode layer, a hole transport layer, a self-assembled layer, a perovskite layer, an electron transport layer, and a second electrode layer. The hole transport layer comprises nickel oxide. The perovskite layer comprises at least one of lead ions, tin ions, and germanium ions. The self-assembled layer comprises the aforementioned compounds.

[0042] In the aforementioned compounds based on phenothiazine-3-one, a sulfonic acid group is provided at one end as an anchoring group, which interacts with NiO in the hole transport layer. x Anchoring occurs, forming stable covalent bonds. A Y group is positioned at the other end; these electron-rich carbonyl groups and -S-, etc., can passivate the Pb on the perovskite surface. 2+ Defects such as these are addressed to improve the film quality of the perovskite layer. Specifically, the equivalents of lead and tin ions in the perovskite layer include ions with similar defects that can be passivated by Y groups.

[0043] According to another aspect of the present invention, a perovskite solar cell is provided, the perovskite solar cell comprising a first electrode layer, a hole transport layer, a self-assembled layer, a perovskite layer, an electron transport layer, and a second electrode layer stacked sequentially, wherein the hole transport layer comprises nickel oxide and / or the perovskite layer comprises at least one of lead ions and tin ions. The self-assembled layer comprises the aforementioned phenothiazine-3-one-based compound.

[0044] In embodiments of the present invention, the self-assembled layer comprising the aforementioned phenothiazine-3-one-based compound has the function of reducing film defects in the hole transport layer comprising nickel oxide. It also has the function of compensating for film defects in perovskite layers comprising at least one of lead ions, tin ions, and germanium ions. Whether the above two conditions exist simultaneously or individually, the self-assembled layer comprising the aforementioned phenothiazine-3-one-based compound in the embodiments of the present invention can achieve the effect of reducing interfacial recombination. When both conditions exist simultaneously, it is the preferred embodiment of the present invention, and its effect is optimal.

[0045] According to another aspect of the present invention, a method for fabricating a perovskite solar cell is provided, comprising: fabricating a first electrode layer as a substrate; depositing nickel oxide on the first electrode to form a hole transport layer; forming a self-assembled layer comprising the aforementioned phenothiazine-3-one-based compound on the hole transport layer; forming a perovskite layer comprising perovskite on the self-assembled layer; depositing an n-type inorganic semiconductor or an n-type organic semiconductor on the perovskite layer to form an electron transport layer; and printing electrode material on the electron transport layer to form a second electrode.

[0046] In embodiments of the present invention, a transparent electrode is selected as the first base layer, and a metal electrode is selected as the second electrode layer, both serving to collect charge. The most commonly used transparent electrodes are ITO (In-doped SnO2) and FTO (F-doped SnO2). Common metal electrodes include Al, Ag, and Au, as well as Ag nanowire electrodes, carbon electrodes, carbon nanotubes, and Ag / Al alloy electrodes. The use of these novel electrodes effectively improves charge collection efficiency, significantly enhancing the fill factor and stability of the battery device. The deposition process of the hole transport layer is a conventional technique, including physical vapor deposition, chemical vapor deposition, and atomic layer deposition. Forming the hole transport layer also includes subsequent conventional treatments, such as annealing. According to one embodiment of the present invention, the first electrode is made of transparent conductive glass; the electrode material is selected from any one of Al, Ag, Au, or low-temperature carbon electrodes.

[0047] The formation process of the self-assembled layer adopts existing thin film preparation technology, such as preparing a precursor solution, forming a film by spin coating, slot coating, blade coating, spraying, etc., and then processing it through annealing, cleaning and other processes.

[0048] The perovskite layer is formed using existing thin film preparation processes, such as spin-coating followed by annealing or deposition followed by annealing.

[0049] The electron transport layer can be prepared from any existing or future invented material; this is not limited in the embodiments of the present invention, as long as it possesses the function of an electron transport layer. According to one embodiment of the present invention, the n-type inorganic semiconductor is selected from C… 60 One of PCBM, TiO2, SnO2, ZnO, or ZnO-ZnS.

[0050] According to one embodiment of the present invention, forming a self-assembled layer comprising the aforementioned compound on the hole transport layer includes: dissolving the aforementioned phenothiazine-3-one-based compound in a solvent to obtain a self-assembled layer precursor solution with a molar concentration of 1-5 mM; coating the self-assembled layer precursor solution onto the hole transport layer and annealing it at a controlled temperature of 80-150°C for 10-20 min; and cleaning the surface of the hole transport layer with the solvent to form the self-assembled layer; wherein the solvent is selected from isopropanol or diethyl ether. Preferably, the annealing temperature is controlled at 100-120°C and the annealing time is 15 min. If the concentration in the self-assembled layer precursor solution is too high, it will cause the self-assembled molecules to accumulate, severely affecting the hole transport efficiency and thus leading to a decrease in battery efficiency. If the concentration is too low, it will cause the self-assembled molecules to affect NiO. xThe anchoring effect is poor, and the passivation effect on the perovskite layer is weakened, affecting the film quality. In the embodiments of the present invention, the concentration is set to 1-5 mM, which can achieve a better effect of reducing interfacial recombination.

[0051] In an embodiment of the present invention, the self-assembled layer precursor solution is coated onto the hole transport layer. After annealing, a self-assembled layer and unbound phenothiazine-3-one-based compounds are formed on the surface of the hole transport layer. Cleaning with a solvent can make the formed self-assembled layer film purer, thus better reducing interfacial recombination. Using an evaporable solvent can reduce solvent residue in the self-assembled layer.

[0052] Coating methods include spin coating, slot coating, scraping, and spraying.

[0053] According to one embodiment of the present invention, forming a perovskite layer comprising perovskite on the self-assembled layer comprises: dissolving the perovskite in one or more of N,N-dimethylformamide, dimethyl sulfoxide, N-methyl-2-pyrrolidone, γ-butyrolactone, 1,3-dimethyl-2-imidazolinone, dimethylacetamide, N,N-dimethylpropenylurea, acetonitrile, or 2-mercaptoethanol to obtain a perovskite precursor solution; coating the perovskite precursor solution onto the self-assembled layer and annealing it by heating to form the perovskite layer; wherein the perovskite has the general formula ABX3, wherein A is selected from CH3NH3. + CH(NH2)2 + Cs + or Rb + B is any one or more of Pb, where B is selected from Pb. 2+ Sn 2+ Or Ge 2+ X is any one or more of the following, where X is selected from Cl. - ,Br - Or I - Any one or more of them.

[0054] In embodiments of the present invention, the thickness of the perovskite layer is 200–900 nm. The perovskite is selected from materials containing one or more of lead ions, tin ions, and germanium ions. Defects formed on its surface can be passivated by the Y groups of the aforementioned compounds, thereby reducing interfacial recombination. Preferably, the B in the perovskite is lead ions (Pb). 2+ X is an iodide ion (I - In the aforementioned compound, Z represents the iodide ion (I0.05). - The Y group is -S-CH3. Selecting the same iodide ion as in the aforementioned compounds from perovskites allows for rapid replenishment of halogens. Furthermore, the "-S-" group is particularly effective at compensating for defects caused by lead ions.

[0055] According to one embodiment of the present invention, a method for preparing compounds based on phenothiazine-3-one is as follows:

[0056]

[0057] As shown in formula (ii), under a nitrogen atmosphere, 2.5 mmol of reactant I, 8.2 mmol of reactant II and 20 mL of toluene were added to a 50 mL double-necked round-bottom flask and reacted. After the reaction was completed, a mixture was obtained.

[0058] The resulting mixture was washed several times with excess toluene and dichloromethane to remove unreacted reactants. The mixture was then dried under vacuum at 60°C for 12 hours to obtain the product.

[0059] The obtained product was dispersed in 20 mL of diethyl ether, and 3 mL of HZ solution was added. The mixture was stirred vigorously at room temperature for 24 h, and filtered to obtain a mixture containing compound III. The mixture was washed several times with excess diethyl ether until its acid content remained constant, and then dried under vacuum at 60 °C for 12 h to obtain compound III, which is the aforementioned compound based on phenothiazine-3-one. (Reference: Chemical Engineering Journal 479(2024)147782)(DOI: 10.1016 / j.cej.2023.147782)

[0060] By using the above method, compounds A to G as shown in formula (iii) can be prepared by selecting different Z, n, and Y from the following options:

[0061] Z - Includes F - Cl - ,Br - I - HCOO - BF4 - SCN - HSO3 - PF6 - One or more of the following;

[0062] The Y group includes one of the following: -H, -OH, -COOH, -NH2, -S-CH3, -F, and -CN;

[0063] n is an integer from 2 to 6.

[0064]

[0065] Specifically, in the preparation of compound A, 2.5 mmol of phenothiazine-3-one, 8.2 mmol of 1,3-propanesulfonate lactone, and 20 mL of toluene were added to a 50 mL double-necked round-bottom flask under a nitrogen atmosphere. After the reaction was complete, the resulting mixture was washed several times with excess toluene and dichloromethane, dried under vacuum at 60 °C for 12 h, and then dispersed in 20 mL of diethyl ether. 3 mL of HI solution was added, and the resulting mixture was stirred vigorously at room temperature for 24 h. After filtration, the mixture was washed several times with excess diethyl ether until its acid content remained constant, and then dried under vacuum at 60 °C for 12 h to obtain compound A.

[0066] When preparing compound B, the same method as for preparing A was used, except that phenothiazine-3-one was replaced with an equal amount of 7-hydroxy-3-onephenothiazine.

[0067] When preparing compound C, the same method as for preparing A was used, except that phenothiazine-3-one was replaced with an equal amount of 7-amino-3-onephenothiazine.

[0068] When preparing compound D, the same method as for preparing A was used, except that phenothiazine-3-one was replaced with an equal amount of 7-cyano-3-onephenothiazine.

[0069] When preparing compound E, the same method as for preparing A was used, except that phenothiazine-3-one was replaced with an equal amount of 7-carboxy-3-onephenothiazine.

[0070] When preparing compound F, the same method as for preparing A was used, except that phenothiazine-3-one was replaced with an equal amount of 7-methylthio-3-onephenothiazine.

[0071] When preparing compound G, the same method as for preparing A was used, except that phenothiazine-3-one was replaced with an equal amount of 7-fluoro-3-onephenothiazine.

[0072] The following examples demonstrate the fabrication of perovskite solar cells using compounds A through G as self-assembly layer materials.

[0073] Example 1.

[0074] Preparation of perovskite solar cells using compound A as the self-assembled layer material:

[0075] Step 1: Clean the transparent conductive glass ITO.

[0076] Specifically, the process involves ultrasonic cleaning with detergent, deionized water, acetone, and anhydrous ethanol, followed by drying with a nitrogen gun. The ultrasonic cleaning power is 100 Hz, and the ultrasonic cleaning time is 15 minutes, resulting in the first electrode layer as the substrate.

[0077] Step 2: Deposit a hole transport layer on the surface of conductive glass ITO by spin coating.

[0078] Specifically, 125 mg Ni(OCOCH3)2·4H2O, 5 mL anhydrous ethanol, and 30 μL diethanolamine were mixed and stirred at room temperature for 2 h to obtain a NiO-containing product. x The precursor solution.

[0079] NiO x The precursor solution was spin-coated onto conductive glass ITO at a speed of 5000 rpm for 30 s, and then annealed at 400℃ for 40 min to form a hole transport layer with a thickness of 15 nm.

[0080] Step 3: Form a self-assembly layer on the surface of the hole transport layer.

[0081] Specifically, compound A was dispersed in isopropanol and stirred at room temperature for 10 hours to completely dissolve it, and a 3 mM solution was prepared to obtain a precursor solution containing compound A.

[0082] 100 μL of a precursor solution containing compound A was spin-coated onto the hole transport layer at 2000 rpm for 30 s, and then annealed at 100 °C for 10 min.

[0083] Spin-coating with isopropanol solvent to remove excess uncoated NiO x The covalently bonded compound A was annealed at 100°C for 1 min to form a self-assembled layer.

[0084] Step 4: Form a perovskite layer on the self-assembled layer.

[0085] Specifically, methylamine iodide (MAI), formamidine iodide (FAI), methylamine chloride (MACl), and lead iodide (PbI2) are dissolved in a mixed solvent composed of dimethyl sulfoxide (DMSO) and dimethylformamide (DMF), heated at 70°C and stirred continuously for 1 hour to completely dissolve them, thus obtaining a perovskite precursor solution.

[0086] The concentration ratio of FAI:MAI:MACl is 0.95:0.05:0.14, the concentrations of FAI and PbI2 are both 1.5M (M is the molar concentration, i.e., mol / L), and the volume ratio of dimethyl sulfoxide (DMSO) to dimethylformamide (DMF) in the mixed solvent is 1:9.

[0087] The perovskite precursor solution was spin-coated onto the self-assembled layer at 5000 rpm for 50 seconds, followed by annealing at 120°C for 15 minutes, resulting in the formation of a FA layer with a thickness of approximately 450 nm. 0.95 MA 0.05 PbI3 perovskite layer.

[0088] Step 5: Deposit an electron transport layer on the surface of the perovskite layer using a vacuum evaporation method.

[0089] The electron transport layer is selected from fullerene (C 60 ), vapor deposition at a vacuum degree of 5×10 -4 The process was carried out under Pa conditions at a rate of 0.15 A / s, forming an electron transport layer with a thickness of approximately 20 nm.

[0090] Step 6: Deposit a hole-blocking layer (BCP, 2,9-dimethyl-4,7-diphenyl-1,10-phenanthroline) on the surface of the electron transport layer by vacuum evaporation at a vacuum degree of 5 × 10⁻⁶. -4 The process is carried out under Pa conditions at an evaporation rate of 0.2 A / s, forming a hole-blocking layer with a thickness of approximately 8 nm. Step 6 is a preferred option and can be omitted.

[0091] Step 7: Prepare a metal electrode on the upper surface of the hole blocking layer by physical vapor deposition (PVD).

[0092] In a metal evaporation chamber, a silver electrode with a thickness of 80 nm to 100 nm is formed on the surface of the electron transport layer opposite to the perovskite layer using a thermal evaporation process, forming a second electrode layer. The vacuum level of the evaporation chamber is 5 × 10⁻⁴ Pa, and the evaporation rate is 2 A / s.

[0093] Through the above steps, a perovskite solar cell with compound A as the self-assembled layer material is obtained.

[0094] Example 2.

[0095] Fabrication of perovskite solar cells using compound B as a self-assembled layer material:

[0096] The preparation process is basically the same as in Example 1, except that compound A in step 3 is replaced by compound B.

[0097] Example 3.

[0098] Fabrication of perovskite solar cells using compound C as the self-assembly layer material:

[0099] The preparation process is basically the same as in Example 1, except that compound A in step 3 is replaced with compound C.

[0100] Example 4.

[0101] Fabrication of perovskite solar cells using compound D as the self-assembled layer material:

[0102] The preparation process is basically the same as in Example 1, except that compound A in step 3 is replaced with compound D.

[0103] Example 5

[0104] Fabrication of perovskite solar cells using compound E as the self-assembly layer material:

[0105] The preparation process is basically the same as in Example 1, except that compound A in step 3 is replaced with compound E.

[0106] Example 6

[0107] Fabrication of perovskite solar cells using compound F as the self-assembled layer material:

[0108] The preparation process is basically the same as in Example 1, except that compound A in step 3 is replaced with compound F.

[0109] Example 7

[0110] Fabrication of perovskite solar cells using compound G as a self-assembled layer material:

[0111] The preparation process is basically the same as in Example 1, except that compound A in step 3 is replaced with compound G.

[0112] Comparative Example 1

[0113] Fabrication of perovskite solar cells without self-assembled layers:

[0114] The preparation process is basically the same as in Example 1, except that step 3 is not included, and step 4 is performed directly on NiO. x A perovskite layer is directly deposited on the upper surface of the hole transport layer.

[0115] The perovskite solar cells obtained in Examples 1 to 7 and Comparative Example 1 were tested, including:

[0116] 1. XRD, UV spectroscopy, fluorescence spectroscopy, and fluorescence lifetime tests were performed on the perovskite layers in the perovskite solar cells provided in Example 1 and Comparative Example 1, respectively. The test methods are as follows:

[0117] XRD testing: using Cu Kα As an X-ray source, the θ-2θ scanning mode is mainly used to scan and test perovskite thin film samples and metal oxide samples.

[0118] Ultraviolet spectroscopy testing: The measurement range for ultraviolet light is 400-900 nm;

[0119] Fluorescence spectroscopy test: The steady-state fluorescence spectrum of the perovskite layer was tested using a xenon lamp (Xe 900) with a wavelength of 500 nm;

[0120] Fluorescence lifetime test: Fluorescence lifetime was measured using a picosecond pulsed laser (EPL 405).

[0121] 2. Performance tests were conducted on the perovskite solar cells provided in Examples 1 to 7 and Comparative Example 1 of the present invention. The JV performance of the solar cell device is mainly measured by the following four parameters: power conversion efficiency (PCE), short-circuit current density (Jsc), open-circuit voltage (Voc), and fill factor (FF).

[0122] Measurements were performed using a solar energy simulation testing system. The light source was a 500W xenon lamp solar spectrum simulator, calibrated with a standard KG-5 silicon cell. Measurements were conducted under a solar intensity of 100mW / cm². A continuously varying voltage (-0.5V-1.2V) was applied across the cell terminals, and the cell's output current was measured (using a Keithley 2400 power supply). The product of these two measurements yielded the JV test curve, displaying the photoelectric conversion efficiency of the device under different conditions.

[0123] The battery stability test conditions are as follows: the test is conducted in a glove box without encapsulation.

[0124] Test results are as follows Figures 1 to 5 And as shown in Table 1:

[0125] Figure 1 The XRD comparison diagrams of the perovskite layers of Example 1 and Comparative Example 1 are shown.

[0126] like Figure 1 As shown, the XRD diffraction peak positions of the perovskite layers in Example 1 and Comparative Example 1 are the same, and there are no other impurity peaks, indicating that the single molecule of the compound based on phenothiazine-3-one has not entered the perovskite lattice.

[0127] In the perovskite layer of Example 1, the relative height of the PbI2 diffraction peak was significantly reduced, indicating that the phenthiazin-3-one-based compound can passivate the Pb on the perovskite surface. 2+ Defects, reduce non-radiative interface recombination.

[0128] Figure 2 A schematic diagram of the ultraviolet light absorption-wavelength distribution of the perovskite layers of Example 1 and Comparative Example 1 is shown.

[0129] Figure 3 A schematic diagram of the photoluminescence intensity-wavelength distribution of the perovskite layers in Example 1 and Comparative Example 1 is shown.

[0130] Figure 4A schematic diagram of the fluorescence lifetime of the perovskite layers in Example 1 and Comparative Example 1 is shown.

[0131] like Figure 2 As shown, the insertion of the self-assembled layer in Example 1 caused a slight red shift in the UV absorption peak of the perovskite film, indicating that the compound based on phenothiazine-3-one effectively promoted the crystallization of the perovskite film, resulting in a larger size of the final perovskite.

[0132] like Figure 3 As shown, in Comparative Example 1, a very high photoluminescence intensity was exhibited when there was no self-assembled layer between the perovskite layer and the hole transport layer. In Example 1, the insertion of the self-assembled layer made the perovskite / NiO... x The photoluminescence intensity quenching at the interface was significantly enhanced. This quenching is considered to originate from the perovskite layer to NiO. x Hole charge transfer in the layer reduces radiative relaxation from the excited state to the ground state.

[0133] like Figure 4 As shown, the average carrier lifetime of the perovskite film in Example 1 is 131 ns. The average carrier lifetime of the perovskite film in Comparative Example 1 is 264 ns. The reduced lifetime of Example 1 compared to Comparative Example 1 indicates that the introduction of the self-assembled layer effectively promotes the NiO... x Hole separation at the perovskite interface.

[0134] Table 1 shows a comparison of the performance parameters of the perovskite solar cells of Examples 1 to 7 and Comparative Example 1.

[0135] Table 1.

[0136] Serial Number Voc(V) Jsc(mA / cm2) FF (%) PCE (%) Example 1 1.20 25.1 77.5 23.3 Example 2 1.20 25.2 77.9 23.5 Example 3 1.19 24.9 78.2 23.2 Example 4 1.21 24.8 77.9 23.4 Example 5 1.20 24.9 77.7 23.2 Example 6 1.19 24.9 78.6 23.3 Example 7 1.19 25.0 78.5 23.4 Comparative Example 1 1.13 23.9 75.9 20.5

[0137] Table 1 shows that the perovskite thin-film solar cells with the addition of the self-assembled layer exhibit significant improvements in open-circuit voltage (Voc), short-circuit current (Jsc), fill factor (FF), and power conversion efficiency (PCE). This performance improvement may be attributed to the anchoring groups in the phenothiazine-3-one compound structure, which anchor to NiO. x Strong and stable covalent bonds form on the thin film surface, enabling selective contact to reduce surface defects and promote charge transfer. A key reason for the increased Voc is the formation of a more favorable energy level arrangement in NiO. x The large number of charge carriers stacked at the perovskite interface are highly selectively extracted through self-assembled layers, reducing nonradiative recombination at the interface, while N-based compounds of phenothiazine-3-one... + It repels hole carriers and reduces interface recombination through field-effect passivation, thereby improving device efficiency.

[0138] Figure 5The stability comparison graphs of perovskite solar cells of Examples 1 to 7 and Comparative Example 1 are shown.

[0139] like Figure 5 The figure shows the power conversion efficiency (PCE) curve of perovskite solar cells (PSCs) over time.

[0140] The perovskite solar cells of Examples 1 to 7 maintained more than 90% of their initial values ​​after 1000 hours, while the perovskite solar cell of Comparative Example 1 degraded faster.

[0141] The enhanced stability of perovskite solar cell devices can be attributed to the increased crystallinity of the perovskite layer and the NiO content. x The reduction of defects in the thin film improves the stability of the perovskite lattice, while the presence of electron-rich carbonyl groups and -S- can passivate Pb on the perovskite surface. 2+ Defects that hinder the perovskite layer from penetrating into the inner perovskite layer, thus impeding the NiO film quality. x The reaction with the perovskite precursor reduces the degradation of the perovskite film, extends the lifespan of perovskite devices, and improves the stability of the battery.

[0142] While numerous embodiments of the invention have been shown and described herein, it will be apparent to those skilled in the art that such embodiments are provided by way of example only. Many modifications, alterations, and alternatives will occur to those skilled in the art without departing from the spirit and essence of the invention. It should be understood that various alternatives to the embodiments of the invention described herein may be employed in the practice of the invention. The appended claims are intended to define the scope of protection of the invention and therefore cover equivalents or alternatives within the scope of these claims.

[0143] The collection and acquisition of various data in this application comply with relevant laws and regulations and are authorized by the data providers. Any organization or individual that needs to obtain external data shall obtain authorization in accordance with the law and ensure data security, and shall not illegally collect, use, process, or transmit unauthorized or unprotected data, nor shall it illegally buy, sell, provide, or disclose unauthorized or unprotected data.

Claims

1. A compound based on phenothiazine-3-one, characterized in that, The general formula of the compound is shown in formula (i): (i) in, Z - Includes F - Cl - ,Br - I - HCOO - BF4 - SCN - HSO3 - PF6 - One or more of the following; The Y group includes one of the following: -H, -OH, -COOH, -NH2, -S-CH3, -F, and -CN; n is an integer from 2 to 6.

2. The compound according to claim 1, characterized in that, Z - For I - And n is 3.

3. The application of the compound based on phenothiazine-3-one as described in claim 1 in perovskite solar cells.

4. A perovskite solar cell, characterized in that, The perovskite solar cell comprises a first electrode layer, a hole transport layer, a self-assembled layer, a perovskite layer, an electron transport layer, and a second electrode layer stacked sequentially. The hole transport layer comprises nickel oxide; And / or the perovskite layer contains at least one of lead ions, tin ions and germanium ions; The self-assembled layer comprises the compound of claim 1 or 2.

5. A method for preparing a perovskite solar cell, characterized in that, include: Prepare the first electrode layer as a substrate; Nickel oxide is deposited on the first electrode to form a hole transport layer; A self-assembled layer comprising the compound of claim 1 is formed on the hole transport layer; A perovskite layer containing perovskite is formed on the self-assembled layer; An n-type inorganic semiconductor or an n-type organic semiconductor is deposited on the perovskite layer to form an electron transport layer; A second electrode containing electrode material is formed on the electron transport layer.

6. The preparation method according to claim 5, characterized in that, The perovskite layer contains at least one of lead ions, tin ions, and germanium ions.

7. The preparation method according to claim 5, characterized in that, Forming a self-assembled layer comprising the compound of claim 1 on the hole transport layer, comprising: The compound of claim 1 is dissolved in a solvent to obtain a self-assembled layer precursor solution with a molar concentration of 1-5 mM; The self-assembled layer precursor solution is coated onto the hole transport layer, and then heated and annealed at a controlled temperature of 80-150°C for 10-20 minutes. The surface of the hole transport layer is cleaned using the solvent to form a self-assembly layer; The solvent is selected from isopropanol or diethyl ether.

8. The preparation method according to claim 5, characterized in that, Forming a perovskite layer comprising perovskite on the self-assembled layer includes: The perovskite is dissolved in one or more of N,N-dimethylformamide, dimethyl sulfoxide, N-methyl-2-pyrrolidone, γ-butyrolactone, 1,3-dimethyl-2-imidazolinone, dimethylacetamide, N,N-dimethylpropenylurea, acetonitrile or 2-mercaptoethanol to obtain a perovskite precursor solution. The perovskite precursor solution is coated onto the self-assembled layer and then heated and annealed to form a perovskite layer. The perovskite has the general formula ABX3, where A is selected from CH3NH3. + CH(NH2)2 + Cs + or Rb + B is any one or more of Pb, where B is selected from Pb. 2+ Sn 2+ Or Ge 2+ X is any one or more of the following, where X is selected from Cl. - ,Br - Or I - Any one or more of them.

9. The preparation method according to claim 5, characterized in that, n-type inorganic semiconductors are selected from C 60 One of PCBM, TiO2, SnO2, ZnO, or ZnO-ZnS.

10. The preparation method according to claim 5, characterized in that, The first electrode is made of transparent conductive glass; The electrode material is selected from any one of Al, Au, Ag or low-temperature carbon electrodes.

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