A hole transport layer material and a preparation method, a perovskite battery and a preparation method

Abstract

The application relates to a hole transport layer material and a preparation method, a perovskite battery and a preparation method, the hole transport layer material lowers a HOMO energy level, has better energy level matching with a wide-bandgap perovskite, can accelerate extraction of holes, and improves the efficiency of the wide-bandgap perovskite battery.

Description

Background Technology

[0001] Solar energy boasts advantages such as cleanliness and abundant reserves. Photovoltaic power generation, which converts solar energy into electrical energy, is an ideal energy conversion method. Currently, silicon-based solar cells dominate the solar cell market, accounting for 90% of the photovoltaic market. However, due to limited room for cost reduction and its efficiency already reaching 27.3%, very close to its efficiency limit of 29.4%, the development of new photovoltaic materials with low cost and high efficiency is crucial for the further development of the photovoltaic field. Perovskite is one such promising optoelectronic material.

[0002] Perovskite solar cells possess advantages such as solution-processability, simple device structure, high efficiency, and low cost, demonstrating enormous commercial potential. Their structure consists of a hole transport layer, a perovskite active layer, an electron transport layer, and electrodes. The hole transport layer plays a crucial role in achieving effective electron-hole separation and efficient hole collection and transport, and is decisive for the cell's stability. Currently, most hole transport layers utilize self-assembled monolayers such as MeO-2PACz to achieve good functionality. However, most commercially available hole transport layers are matched to conventional bandgap perovskites, leading to energy level mismatch when used in wide bandgap perovskites. This results in a significant deviation between the open-circuit voltage and the ideal open-circuit voltage, which is detrimental to the efficiency improvement and application of perovskite solar cells.

[0003] An ideal hole transport layer needs to meet the following conditions: (1) It can effectively extract holes and achieve efficient collection and transport of holes; (2) It has a suitable energy level alignment with the perovskite; (3) It has good stability; (4) It can effectively passivate the defects of the perovskite. Summary of the Invention

[0004] To improve the efficiency of wide-bandgap perovskite solar cells and achieve better energy level matching between the hole transport layer and the wide-bandgap perovskite layer, this invention provides a novel hole transport layer material. This material lowers the HOMO energy level, resulting in better energy level matching with the wide-bandgap perovskite and accelerating hole extraction.

[0005] In the first aspect, the hole transport layer material provided by this invention contains compound M. It may contain only compound M or be doped with one or more other materials. The structural formula of compound M is:

[0006] In the formula, R is selected from -Cl, -Br, -F, -CN, and n≥2.

[0007] A further preferred structural formula is:

[0008] n = 1 or n = 2;

[0009] A further preferred option is CN-4PAPT, with the following structural formula:

[0010]

[0011] Secondly, the present invention provides a method for preparing a hole transport layer material, which can produce one or more of the aforementioned hole transport layer materials. The preparation method includes the following steps:

[0012] S01 involves reacting a phenothiazine homologue with a haloalkanes in the presence of a phase-transfer catalyst. Reaction 1 is a unimolecular nucleophilic substitution reaction. The electrophilicity of the haloalkanes is enhanced under the action of the phase-transfer catalyst, and the halogen atoms are substituted to obtain compound M1.

[0013] SO2 reacts compound M1 with triethyl phosphite at a set temperature to undergo reaction 2, which is a nucleophilic substitution reaction. During the reaction, a new bond is formed between phosphorus and bromine atoms, and a bromide anion is generated, ultimately yielding phosphite compound M2.

[0014] Furthermore, the specific steps of each reaction are as follows: (1) 2-Cyanophenothiazide reacts with the phase transfer catalyst tetrabutylammonium bromide under an alkaline environment to obtain compound M1;

[0015]

[0016] (2) Compound M1 reacts with triethyl phosphite under high temperature conditions to give M2;

[0017]

[0018] (3) Dissolve compound M2 in an organic solvent and mix it with trimethylbromosilane to react three times to obtain compound M;

[0019]

[0020] As a preferred method, tetrabutylammonium bromide is used as a phase transfer catalyst to promote the substitution reaction between 2-cyanophithiazine and dibromobutane. The molar ratio of 2-cyanophithiazine to tetrabutylammonium bromide is preferably 1:(5-10), and the molar ratio of 2-cyanophithiazine to dibromobutane is 1:1.

[0021] As a preferred approach, reaction one preferably occurs under a weakly alkaline environment, and more preferably at a pH of 7–10. Reaction one is a nucleophilic substitution reaction. On one hand, tetrabutylammonium bromide, acting as a phase transfer catalyst, promotes the reaction between two immiscible phases. Under alkaline conditions, this catalyst can promote the formation of ion pairs, thereby facilitating the transfer of the electrophile from the aqueous phase to the organic phase. On the other hand, an alkaline environment helps increase the activity of the nucleophile. Suppressing side reactions and the generation of acidic byproducts also avoids competing reactions that could affect the final product performance.

[0022] As a preferred method, in reaction one, the pH of the reaction solution is adjusted by adding KOH reagent or an aqueous solution of KOH. It is preferred to use a (30-70)% KOH solution for adjustment, and even more preferably a 50% KOH solution for adjustment.

[0023] As a preferred method, the system environment in which reaction one takes place needs to be in a low-oxygen or oxygen-free environment. In this invention, it is preferably carried out in an N2 atmosphere.

[0024] As a preferred method, the operation steps of reaction one are as follows:

[0025] A dissolves tetrabutylammonium bromide in dibromobutane to form a first mixture;

[0026] B. The first mixture is mixed with 2-cyanophenothiazine in a two-necked flask to form a second mixture;

[0027] C. Add 50% KOH aqueous solution dropwise to the second mixture to adjust the pH of the second mixture, and obtain the reaction solution;

[0028] The reaction solution D was refluxed and stirred under N2 atmosphere, and after the reaction was fully completed, compound M1 was obtained;

[0029] E uses deionized water to quench reaction one;

[0030] F used dichloromethane and deionized water to quench the reaction solution, combined the organic layers, and then purified the product to obtain compound M1.

[0031] In step D, the reaction solution is refluxed and stirred at 55–70°C. Temperatures below this range reduce the molecular velocity of reactants, decreasing the number of effective collisions and slowing the reaction rate, thus affecting the yield. High temperatures promote unnecessary side reactions, and the catalyst may decompose or deactivate at high temperatures, reducing its catalytic efficiency. Temperatures above this range can cause the decomposition of some thermally unstable products, affecting the yield and product purity. A further preferred temperature is 65°C.

[0032] As a preferred approach, the reaction conditions for reaction two are: a nitrogen atmosphere and 150–165 °C. In this reaction, triethyl phosphite acts as a nucleophile, attacking the charged center (carbon atom) of the bromine alkyl chain, leading to the replacement of the bromine atom and the formation of the corresponding alkyl phosphate ester. The 150–165 °C temperature helps overcome the activation energy barrier and accelerates the reaction rate. Furthermore, it helps to enhance the nucleophilicity of triethyl phosphite, making it more readily attackable on the substrate. A further preferred reaction temperature is 160 °C.

[0033] As a preferred method, the obtained compound M2 is dissolved in an organic solvent and trimethylbromosilane is added, resulting in reaction three. After reaction three is completed, the mixture is washed and filtered to obtain compound M.

[0034] Thirdly, the present invention provides a perovskite solar cell made using any of the hole transport layer materials described above.

[0035] Fourthly, the present invention provides a method for preparing a corresponding perovskite solar cell, comprising the following steps:

[0036] (1) Obtain ITO transparent conductive glass as a transparent electrode;

[0037] (2) The prepared compound M is coated on ITO transparent conductive glass and annealed to obtain a hole transport layer.

[0038] (3) A wide-bandgap perovskite precursor solution was spin-coated onto the hole transport layer using an anti-solvent method, and then annealed to obtain a wide-bandgap perovskite film.

[0039] (4) A perovskite solar cell was prepared by sequentially depositing C60 and BCP electron transport layers and copper electrodes on a wide-bandgap perovskite film by thermal evaporation.

[0040] As a preferred method, the spin coating speed in step (2) is 4000 rpm, the spin coating speed in step (3) is 1000-4000 rpm, and the spin coating time in steps (2) and (3) is 30-50 s.

[0041] As a preferred method, the hole transport layer obtained by spin coating in step (2) has a thickness of 1-5 nm, the wide bandgap perovskite film obtained in step (3) has a thickness of 300-400 nm, the C60 electron transport layer in step (4) has a thickness of 20-30 nm, the BCP electron transport layer has a thickness of 8-10 nm, and the copper electrode has a thickness of 550-600 nm.

[0042] The beneficial effects of this invention include: the hole transport layer material in this invention effectively solves the problems of poor cell performance caused by energy level mismatch and interfacial carrier recombination in existing wide-bandgap perovskite solar cells;

[0043] The hole transport layer material in this invention uses phenthiazide as the core group. Phenthiazide has high chemical stability and very high hole mobility, can be well dissolved in common organic solvents, and has good film-forming properties.

[0044] In this invention, the phosphate groups of the hole transport layer material are bonded to ITO, and the S and benzene ring ends are bonded to the perovskite material. The bond between S and the perovskite material can also passivate defects in the perovskite, resulting in fewer defects at the interface and enabling better interface transport.

[0045] The CN group in CN-4PAPAT of this invention has a strong electron-withdrawing ability, which can lower the HOMO energy level of the molecule and theoretically have a more matching energy level with the wide-bandgap perovskite, reducing nonradiative recombination, reducing open-circuit voltage loss, and improving device performance. CN-4PAPT has a larger dipole moment, and the dipole moment formed at the interface is an additional electric field, which can achieve faster hole extraction. Attached Figure Description

[0046] Figure 1(a) Work functions of CN-4PAPAT and MeO-2PACz;

[0047] Figure 1(b) shows the difference between the valence band top and Fermi level of CN-4PAPAT and MeO-2PACz;

[0048] Figure 1(c) Comparison of HOMO energy levels between CN-4PAPAT and MeO-2PACz;

[0049] Figure 2(a) Molecular structure diagram of CN-4PAPAT;

[0050] Figure 2(b) Schematic diagram of the dipole moment of the CN-4PAPT molecule;

[0051] Figure 2(c) Molecular structure diagram of MeO-2PACz;

[0052] Figure 2(d) Schematic diagram of the dipole moment of MeO-2PACz;

[0053] Figure 3(a) shows the PL spectra of the perovskite film formed on the CN-4PAPAT hole transport layer and the perovskite film formed on the MeO-2PACz hole transport layer.

[0054] Figure 3(b) TRPL spectra of the perovskite film formed on the CN-4PAPAT hole transport layer and the perovskite film formed on the MeO-2PACz hole transport layer.

[0055] Figure 4 JV curves of perovskite solar cells prepared in Example 2 and Comparative Example 1;

[0056] Figure 5 JV curves of the perovskite solar cells prepared in Example 3 and Comparative Example 2. Detailed Implementation

[0057] The present invention will be further explained in detail below with reference to the accompanying drawings and specific embodiments, but it should be understood that the scope of protection of the present invention is not limited to the specific embodiments. Unless otherwise specified, any range described in the present invention includes the endpoints and any values ​​between the endpoints, as well as any sub-ranges formed by the endpoints or any values ​​between the endpoints. There are no particular limitations on the purity of any raw materials used in the present invention; however, analytical grade is preferred. The sources and abbreviations of all raw materials used in the present invention are conventional sources and abbreviations in the art, and are clearly defined in their respective fields of application. Those skilled in the art can obtain them from commercially available sources or prepare them using conventional methods based on the abbreviations and corresponding uses. Unless otherwise specified, all percentages in the present invention are mass percentages.

[0058] Example 1

[0059] The preparation method of hole transport layer material is as follows:

[0060] S01 Preparation of compound M1

[0061] A dissolved 0.32 g of tetrabutylammonium bromide (i.e., 0.27 mmol) in 15 mL of dibromobutane to obtain mixture one;

[0062] B. Add 1.00 g of 2-cyanophophorhizine (i.e., 2.72 mmol) to a 100 mL two-necked flask, pour in Mixture 1 into the two-necked flask, and mix with 2-cyanophophorhizine to obtain Mixture 2;

[0063] C. Add 5 mL of 50% KOH aqueous solution to mixture two;

[0064] D. The reaction system was placed under a nitrogen atmosphere and refluxed with stirring at a reaction temperature of 65°C for 12 hours. After quenching the reaction with deionized water, the mixture was washed three times with dichloromethane and deionized water, and the organic layers were combined.

[0065] E dried the organic layer with anhydrous magnesium sulfate for 5 hours, and then removed the organic solvent using a rotary evaporator to obtain the crude product.

[0066] F used a silica gel column to separate and purify the crude product. During purification, an eluent of petroleum ether and dichloromethane in a volume ratio of 10:1 was used to obtain the target product M1. In this example, the target product mass obtained was 1.20 g, with a recovery rate of 90%.

[0067] The reaction formula for compound M1 is:

[0068]

[0069] SO2 was used to prepare compound M2

[0070] 1.20 g of compound M1 (2.39 mmol) and 10 mL of triethyl phosphite were added to a 100 mL Schlenk tube to form a mixture. The mixture was then heated to 160 °C and stirred overnight under a nitrogen atmosphere. Excess triethyl phosphite was removed by vacuum distillation to give a pale yellow oily compound M2, which required no further purification. The reaction formula for this step is:

[0071]

[0072] To prepare compound MA using SO3, compound M2 was dissolved in 10 mL of anhydrous 1,4-dioxane at room temperature, and 3.66 g of trimethylbromosilane (i.e., 23.90 mmol) was slowly added dropwise. The reaction was carried out under a nitrogen atmosphere at room temperature with stirring for 12 hours.

[0073] B. Remove 1,4-dioxane using a rotary evaporator. Add an appropriate amount of methanol and continue stirring for 2 hours to stop the reaction. Add deionized water to the mixture and stir overnight. Filter to obtain the crude product and wash with deionized water.

[0074] C dissolved the crude product in tetrahydrofuran (THF) for recrystallization, then precipitated it in acetone, followed by filtration and vacuum drying to obtain a yellow solid powder, namely compound MCN-4PAPT. In this example, 0.94 g of CN-4PAPT was obtained, with a recovery rate of 65%.

[0075] The reaction formula for this step is:

[0076]

[0077] Example 2

[0078] A method for fabricating a perovskite solar cell includes the following steps:

[0079] S01 Preparation of precursor solution

[0080] A. Hole transport layer solution: The CN-4PAPT prepared in Example 1 was dissolved in ethanol solvent to obtain a hole transport layer solution with a concentration of 0.5 mg / mL.

[0081] B. Preparation of perovskite precursor solution: Dissolve 250 mg FAI (formamidinium hydroiodide), 25 mg CsI (cesium iodide), 29 mg MABr (methyl ammonium bromide), 548.6 mg PbI2 (lead iodide), and 185 mg PbBr2 (lead bromide) in 800 μL of DMF (N,N-dimethylformamide) and 200 μL of DMSO (dimethyl sulfoxide), with a volume ratio of DMF:DMSO = 4:1.

[0082] S02 yields ITO transparent conductive glass;

[0083] S02 involves spin-coating a hole transport layer solution onto ITO transparent conductive glass, followed by annealing to obtain a 2 nm thick hole transport layer. The spin-coating speed is 4000 rpm, the spin-coating acceleration is 1000 rpm / s, the annealing temperature is 10 °C, and the annealing time is 20 min. S03 involves spin-coating a wide-bandgap perovskite precursor solution onto the hole transport layer using an anti-solvent method, followed by annealing to obtain a 300 nm thick wide-bandgap perovskite film. The annealing temperature is 100 °C.

[0084] S04 uses a thermal evaporation method to sequentially deposit a 30 nm C60 electron transport layer and an 8 nm BCP (2,9-dimethyl-4,7-biphenyl-1,10-o-diaminophenanthroline) electron transport layer on a wide-bandgap perovskite film.

[0085] S05 uses a thermal evaporation method to deposit a 600 nm thick copper electrode on the BCP electron transport layer.

[0086] Example 3

[0087] A method for fabricating a perovskite solar cell includes the following steps:

[0088] S01 Preparation of precursor solution

[0089] A. Hole transport layer solution: CN-4PAPT prepared in Example 1 was dissolved in ethanol solvent, and the concentration of CN-4PAPT in ethanol solvent was 0.3 mg / mL;

[0090] B. Perovskite precursor solution: 250 mg FAI (formamidinium hydroiodide), 25 mg CsI (cesium iodide), 29 mg MABr (methylammonium bromide), 548.6 mg PbI2 (lead iodide), 185 mg PbBr2 (lead bromide). Dissolved in 900 μL of DMF (N,N-dimethylformamide) and 100 μL of NMP (N-methylpyrrolidone), DMF:NMP = 9:1. C. Passivating agent material layer solution: p-CF3OPEAI was dissolved in a mixed solution of isopropanol and chlorobenzene, where the isopropanol:chlorobenzene ratio was 1:1, and the concentration of p-CF3OPEAI was 0.75 mg / ml. p-CF3OPEAI was commercially available. SO2 yields ITO transparent conductive glass;

[0091] A hole transport layer solution was spin-coated onto ITO transparent conductive glass using S03, and a hole transport layer with a thickness of 5 nm was obtained after annealing. The spin-coating speed was 4000 rpm, the annealing temperature was 120℃, and the annealing time was 20 min.

[0092] S04 uses an anti-solvent method to spin-coat a perovskite precursor solution onto the hole transport layer, followed by annealing to obtain a 400 nm thick wide-bandgap perovskite film at an annealing temperature of 100 °C.

[0093] S05 is used to spin-coat a passivating agent material solution onto a perovskite film. After annealing, it achieves the effect of passivating defects in the perovskite layer. The spin-coating speed is 4000 rpm, the annealing temperature is 100℃, and the annealing time is 30s.

[0094] S06 employs thermal evaporation to sequentially deposit a 30nm C60 electron transport layer and a 15nm BCP electron transport layer on a passivated perovskite substrate.

[0095] S07 deposits a 600 nm thick copper electrode on the BCP electron transport layer;

[0096] Perovskite solar cells were fabricated.

[0097] Comparative Example 1

[0098] A method for fabricating a perovskite solar cell includes the following steps:

[0099] S01 Preparation of precursor solution

[0100] A. Hole transport layer solution: MeO-2PACz was dissolved in ethanol to obtain a hole transport layer solution. The concentration of MeO-2PACz in the hole transport layer solution was 0.5 mg / mL. MeO-2PACz is a commercially available hole transport layer material. B. Perovskite precursor solution:

[0101] S02 yields ITO transparent conductive glass;

[0102] A hole transport layer solution was spin-coated onto ITO transparent conductive glass using S03. After annealing, a hole transport layer with a thickness of 2 nm was obtained. The spin-coating speed was 4000 rpm, the spin-coating acceleration was 1000 rpm / s, the annealing temperature was 10℃, and the annealing time was 20 min.

[0103] S04 uses an anti-solvent method to spin-coat a perovskite precursor solution onto the hole transport layer, and after annealing, a wide-bandgap perovskite film with a thickness of 300 nm is obtained at an annealing temperature of 100℃.

[0104] S05 uses a thermal evaporation method to sequentially deposit a 30 nm thick C60 electron transport layer and a 15 nm thick BCP electron transport layer on a perovskite thin film.

[0105] S06 uses a thermal evaporation method to deposit a 600 nm thick copper electrode on a perovskite film.

[0106] Comparative Example 2

[0107] A method for fabricating a perovskite solar cell includes the following steps:

[0108] S01 Preparation of precursor solution

[0109] A. Hole transport layer solution: prepared by dissolving commercially available MeO-2PACz in ethanol solvent, with a concentration of 0.5 mg / mL in the hole transport layer solution.

[0110] B. Passivating agent material solution: Dissolve commercially available p-CF3OPEAI in a mixed solution of isopropanol and chlorobenzene, wherein the ratio of isopropanol to chlorobenzene is 1:1, and the concentration of p-CF3OPEAI is 0.75 mg / ml.

[0111] C perovskite precursor solution:

[0112] S02 obtains ITO transparent conductive glass

[0113] A hole transport layer solution was spin-coated onto ITO transparent conductive glass using S03. After annealing, a hole transport layer with a thickness of 5 nm was obtained. The spin-coating speed was 4000 rpm, the annealing temperature was 120℃, and the annealing time was 20 min.

[0114] S04 uses an anti-solvent method to spin-coat a perovskite precursor solution onto the hole transport layer, and after annealing, a wide-bandgap perovskite film of 400 nm is obtained at an annealing temperature of 100 °C.

[0115] S05 is used to spin-coat a passivating agent solution onto a perovskite film. After annealing, it achieves the effect of passivating defects in the perovskite film. The spin-coating speed is 4000 rpm, the annealing temperature is 100℃, and the annealing time is 30s.

[0116] S06 uses a thermal evaporation method to sequentially deposit a 30 nm thick C60 electron transport layer and a 15 nm thick BCP electron transport layer on the passivated perovskite film.

[0117] S07 uses a thermal evaporation method to deposit a 600nm copper electrode on the BCP electron transport layer;

[0118] Perovskite solar cells were fabricated.

[0119] Performance testing

[0120] 1. The HOMO level of CN-4PAPT prepared in Example 1 was determined when it was used as a hole transport layer material.

[0121] The synthesized molecule CN-4PAPT was dissolved in ethanol to obtain a CN-4PAPT solution with a concentration of 0.5 mg / ml. The solution was spin-coated onto ITO transparent conductive glass and subjected to He I radiation (hv = 21.22 eV) from a He discharge lamp using ultraviolet photoelectron spectroscopy (UPS) to generate an energy shift of the HOMO relative to the Fermi level.

[0122] The test results are shown in Figure 1(a) and Figure 1(b). From Figure 1(a) and Figure 1(b), we can obtain a comparison diagram of the HOMO energy levels of the synthesized CN-4PAPT and MeO-2PACz in Figure 1(c). As can be seen from the figure, CN-4PAPT has a lower HOMO energy level than MeO-2PACz, which proves that the synthesized new molecule CN-4PAPT lowers the HOMO energy level and can have a better energy level match with wide-bandgap perovskites.

[0123] 2. Determine the performance of CN-4PAPT obtained in Example 1 as a hole transport layer material.

[0124] The dipole moments of CN-4PAPT and MeO-2PACz molecules were calculated using DFT. The dipole moment formed at the interface is an additional electric field that enables faster hole extraction. The results are shown in Figures 2(a), 2(b), 2(c), and 2(d). The dipole moment of CN-4PAPT molecule is 7.08D, which is much stronger than that of MeO-2PACZ (3.96D). This indicates that CN-4PAPT obtained in Example 1 can achieve faster hole extraction as a hole transport layer.

[0125] 3. Determine the properties of perovskite thin films.

[0126] The photoluminescence (PL) and time-resolved photoluminescence (TRPL) spectra were performed with an excitation wavelength of 375 nm and a center wavelength of 750 nm. Figures 3(a) and 3(b) show the PL and TRPL spectra of the perovskite thin film formed after spin-coating the perovskite precursor solution onto the hole transport layer, respectively. As can be seen from the figures, the intensity of the PL peak of CN-4PAPT is significantly higher than that of MeO-2PACz, which proves that the perovskite on CN-4PAPT has better crystallinity and less carrier interfacial recombination. Time-resolved photoluminescence (TRPL) spectra were fitted with a double exponential model. The results showed that the T1 of CN-4PAPT was shorter than that of MeO-2PACz, while the T2 was longer. T1 is generally considered to be the hole extraction time, and T2 is generally considered to be the superposition of extraction and recombination. This demonstrates that CN-4PAPT has faster hole extraction and slower carrier recombination. Furthermore, recombination is generally caused by interface defects, which also proves that CN-4PAPT has fewer interface defects and effectively passivates the surface defects of perovskites.

[0127] 4. The photovoltaic performance of the perovskite solar cell prepared in Example 2 was measured.

[0128] The current-voltage (JV) characteristics of the perovskite solar cells were determined using a xenon lamp solar simulator in a nitrogen-filled glovebox at room temperature. The optical power was calibrated to 100 mW cm⁻² (1 sun) using a silicon reference cell. All devices were measured using a Keithley 2400 source meter in both reverse scan (1.3 to -0.1 V) and forward scan (-0.1 to 1.3 V) modes at a scan rate of 0.01 V s⁻¹ and a delay of 20 ms. Figure 4 The figure shows the JV curves of the perovskite solar cells prepared in Example 2 and Comparative Example 1. As can be seen from the figure, the device with CN-4PAPT as the hole transport layer has higher photoelectric conversion efficiency and open-circuit voltage than MeO-2PACz, and has better device performance.

[0129] 5. The photovoltaic performance of the perovskite solar cell prepared in Example 3 was measured.

[0130] The current-voltage (JV) characteristics of the photovoltaic devices were determined using a xenon lamp solar simulator in a nitrogen-filled glovebox at room temperature. The optical power was calibrated to 100 mW cm⁻² (1 sun) using a silicon reference cell. All devices were measured using a Keithley 2450 source meter in both reverse scan (1.3 to -0.1 V) and forward scan (-0.1 to 1.3 V) modes, at a scan rate of 0.01 V s⁻¹ and a delay of 20 ms. Figure 5The figure shows the JV curves of the perovskite solar cells prepared in Example 3 and Comparative Example 2. As can be seen from the figure, the performance of both photovoltaic devices is improved after p-CF3OPEAI passivation treatment. However, the device with CN-4PAPT as the hole transport layer still has higher photoelectric conversion efficiency and open circuit voltage than MeO-2PACz, and has better device performance.

[0131] The above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit it. Although the present invention has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions can be made to the technical solutions of the present invention without departing from the spirit and scope of the technical solutions of the present invention.

Claims

1. A perovskite solar cell, characterized by: The perovskite solar cell comprises a transparent electrode layer, a hole transport layer, a perovskite film layer, an electron transport layer and a metal electrode which are sequentially stacked, the material of the hole transport layer is a compound M, and the structural formula of the compound M is: ； The perovskite precursor solution for preparing the perovskite film layer is 250 mg of FAI, 25 mg of CsI, 29 mg of MABr, 548.6 mg of PbI2 and 185 mg of PbBr2, which are dissolved in 900 μL of DMF and 100 μL of NMP.

2. The perovskite solar cell according to claim 1, characterized in that: The preparation method of the compound M is: S01, a monomolecular nucleophilic substitution reaction of a homolog of phenothiazine and a haloalkane is carried out under the action of a phase transfer catalyst to obtain a compound M1; S02, a nucleophilic substitution reaction of the compound M1 and triethyl phosphite is carried out at a set temperature to obtain a phosphite compound M2; S03, an acidification reaction of the phosphite compound M2 and trimethylsilyl bromide is carried out to obtain the compound M.

3. The perovskite solar cell according to claim 2, characterized in that: The structural formula of the homolog of phenothiazine is: wherein R is -CN.

4. The perovskite solar cell according to claim 2, characterized in that: In step S01, the phase transfer catalyst is tetrabutylammonium bromide, the homolog of phenothiazine is 2-cyanophenothiazine, and the haloalkane is dibromobutane, and step S01 specifically comprises the following steps: A, tetrabutylammonium bromide is dissolved in dibromobutane to form a first mixed solution; B, the first mixed solution and 2-cyanophenothiazine are mixed in a two-necked flask to form a second mixed solution; C, KOH aqueous solution is added dropwise to the second mixed solution to adjust the pH of the second mixed solution to obtain a reaction solution; D, the reaction solution is refluxed and stirred under N2 atmosphere, and the compound M1 is prepared after sufficient reaction; E, deionized water is used to quench the reaction I; F, dichloromethane and deionized water are used to quench the reaction solution, the organic layer is combined, and then the product is purified to obtain the compound M1.

5. The perovskite solar cell according to claim 2, characterized in that: The reaction I in step S01 is: ； The reaction II in step S02 is: ； The reaction III in step S03 is: 。 6. A method of producing the perovskite solar cell according to any one of claims 1 to 5, characterized by: The preparation method comprises the following steps: S01, a transparent electrode layer is prepared; S02, a hole transport layer material is coated on the transparent electrode layer; S03, a perovskite material is coated on the hole transport layer material to obtain a perovskite film layer; S04, an electron transport layer is coated on the perovskite film layer; S05, a metal electrode is prepared on the electron transport layer; The perovskite solar cell is prepared; The perovskite material in SO3 comprises a combination of FAI, CsI, MABr, PbI2 and PbBr2, the hole transport layer material comprises a compound M, and the structural formula of the compound M is: 。 7. The method of claim 6, wherein: The preparation method of the compound M is: S01, a monomolecular nucleophilic substitution reaction of a homolog of phenothiazine and a haloalkane is carried out under the action of a phase transfer catalyst to obtain a compound M1; S02, a nucleophilic substitution reaction of the compound M1 and triethyl phosphite is carried out at a set temperature to obtain a phosphite compound M2; S03, an acidification reaction of the phosphite compound M2 and trimethylsilyl bromide is carried out to obtain the compound M.

8. The method of claim 6, wherein: The synthesis process of the compound M is: ； ； 。

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