A D'-A'-DAD-A'-D' type condensed ring interface material and its preparation method and application in photovoltaic cells

Abstract

The present invention provides a D'-A'-DAD-A'-D'-type fused ring interface material, its preparation method, and its application in photovoltaic cells. The fused ring interface material has the structure shown in the following general formula I. The D'-A'-DAD-A'-D'-type fused ring interface material provided by the present invention is prepared through a simple and efficient coupling reaction and exhibits self-assembly, self-doping, excellent film-forming properties, and high electron mobility. As a highly efficient cathode-modified interface material, it can be applied to perovskite photovoltaic cells. It can effectively reduce energy level barriers, lower energy losses, and enhance charge transfer performance, thereby enhancing the device's energy conversion efficiency and long-term stability. This type of interface material is suitable for various types of perovskite photovoltaic cells. #imgabs0#

Description

Technical Field

[0001] The present invention belongs to the technical field of photovoltaic cell materials and relates to a D'-A'-DAD-A'-D' type condensed ring interface material and a preparation method thereof and application in photovoltaic cells. Background Art

[0002] Perovskite solar cells, as an efficient, clean, and sustainable third-generation photovoltaic cell technology, have attracted widespread attention from researchers in the photovoltaic field due to their advantages, including high efficiency, low cost, the ability to fabricate large-area thick films, and adaptability to flexible substrates. In recent years, perovskite solar cells have experienced rapid development, demonstrating enormous potential for applications in solar power generation, lighting systems, aerospace, electric vehicles, and mobile communications. Continuous innovations in perovskite materials and device fabrication processes have driven the continuous improvement of perovskite solar cell efficiency. Interface materials play a key role in enhancing interfacial contact, charge transport, and device stability. Compared to the development of perovskite materials, the development of organic interface materials has lagged behind. The development of organic interface materials for perovskite solar cells faces several challenges: 1. Organic interface materials exhibit poor film morphology and solid-state aggregation, resulting in increased interface layer thickness and a significant decrease in interface performance; 2. Organic interface materials exhibit low charge transport and conductivity; 3. Organic interface materials also face stability and production cost challenges; and 4. Organic interface materials with excellent interfacial properties and general applicability are scarce and underdeveloped. The above key issues limit the subsequent development of organic interface materials and affect the commercialization process of perovskite solar cells.

[0003] In response to the above-mentioned technical problems existing in the prior art, we invented a DAD-type condensed-ring aromatic imide interface material (application number: 202310669869.4) based on our previous work. This patented technology combines the advantages of condensed-ring aromatic diimide and conjugated zwitterionic units to creatively develop a class of condensed-ring aromatic imide small molecule cathode interface materials. To a certain extent, it can solve the problems that restrict the application of organic interface materials, such as high thickness sensitivity, low conductivity and poor stability. However, its disadvantages are that the condensed-ring conjugated structure is small, but the synthesis is difficult, and the product performance needs to be further improved.

[0004] Therefore, the development of small molecule cathode interface materials with larger fused ring conjugated structures, self-assembly, self-doping, high carrier mobility, and good film-forming properties is of great significance to the development of perovskite solar cells. Summary of the Invention

[0005] In response to the deficiencies in the prior art, the present invention provides a D'-A'-DAD-A'-D' type condensed ring interface material, a preparation method thereof, and its application in photovoltaic cells. The interface material of the present invention is a small molecule cathode interface material with a larger condensed ring conjugated structure. It is a D'-A'-DAD-A'-D' type condensed ring interface material with self-assembly, self-doping, high carrier mobility, and good film-forming properties. The condensed ring interface material of the present invention, its self-assembly and good film-forming properties are conducive to regulating the aggregation state and film morphology, and promoting a more regular and orderly molecular arrangement; the condensed ring conjugated skeleton and self-doping properties are beneficial to improving the electrical conductivity and charge transfer properties of the material; the combination of the condensed ring large conjugated unit and the fluorene conjugated skeleton can better enhance the stability of the material and reduce the material cost. The material of the present invention can solve the key problems faced by organic interface materials, and its application in perovskite solar cells can improve the efficiency and long-term stability of the device.

[0006] The technical solutions of the present invention are as follows:

[0007] A D'-A'-DAD-A'-D' type condensed ring interface material, wherein the condensed ring interface material has a structure shown in the following general formula I:

[0008]

[0009] In the general formula I, R1 and R2 are independently selected from C1 to C 15 Straight chain alkanes, C1~C 25 Branched-chain alkanes, Wherein n is 1, 2, 3 or 4; R4 is H or C1~C 12 Straight-chain alkane; R5 is H, CH3, CH(CH3)2, CH2CH(CH3)2, CH(CH3)CH2CH3, phenyl or benzyl; R6 is H or C1~C 12 straight-chain alkanes;

[0010] R3 is any one of the following groups:

[0011]

[0012] Where m is 1, 2, 3 or 4, X - Cl - Br - or I - .

[0013] According to the present invention, preferably, in the general formula I:

[0014] R1 is C9~C 12 Straight chain alkane; R2 is C8~C 20 branched-chain alkanes;

[0015] R3 is any one of the following groups:

[0016]

[0017] Where m is 1, 2, 3 or 4, X - Cl - Br - or I - .

[0018] According to the present invention, the synthesis method of the above-mentioned D'-A'-DAD-A'-D' type fused ring interface material comprises the following steps:

[0019] In a solvent, under the catalysis of a palladium catalyst and alkaline conditions, a substitution reaction is carried out between a dibromo-fused ring Y-series intermediate II and a fluorene borate intermediate III to obtain a D'-A'-DAD-A'-D' type fused ring interface material I;

[0020]

[0021] Among them, the substituents R1 and R2 in the structural formula of the dibromo-fused ring Y series intermediate II are the same as those in the general formula I; the substituent R3 in the structural formula of the fluorene borate intermediate III is the same as that in the general formula I.

[0022] According to the preferred embodiment of the present invention, the solvent is tetrahydrofuran, 1,4-dioxane, N,N-dimethylformamide or dimethyl sulfoxide; the ratio of the volume of the solvent to the molar number of the dibromo-fused ring Y-based intermediate II is 15-40 mL:1 mmol.

[0023] According to the present invention, the palladium catalyst is preferably tetrakis(triphenylphosphine)palladium, bis(triphenylphosphine)palladium dichloride or [1,1'-bis(diphenylphosphino)ferrocene]palladium dichloride; the molar ratio of the palladium catalyst to the dibromofused ring Y-based intermediate II is 0.01 to 0.1:1.

[0024] Preferably, according to the present invention, the alkaline conditions are provided by an alkaline solution, the base is sodium carbonate, potassium carbonate or potassium phosphate, the molar ratio of the base to the dibromofused ring Y-series intermediate II is 5 to 16:1; the concentration of the alkaline solution is 2 mol / L.

[0025] Preferably, according to the present invention, the molar ratio of the dibromo-fused-ring Y-based intermediate II to the fluorene borate intermediate III is 1:2.1-2.6.

[0026] Preferably, according to the present invention, the temperature of the substitution reaction is 60 to 100° C., and the time of the substitution reaction is 20 to 30 hours.

[0027] According to the present invention, after the dibrominated fused ring Y-series intermediate II and the fluorene borate intermediate III undergo a substitution reaction, the target product can be separated and purified according to a conventional separation and purification method; preferably, after the dibrominated fused ring Y-series intermediate II and the fluorene borate intermediate III undergo a substitution reaction, the post-treatment steps of the reaction solution obtained are as follows: dichloromethane and water are added to the reaction solution, the organic phase obtained after separation is washed with water and dried, and the solvent is removed, and the crude product is purified by silica gel column chromatography, with the eluent being dichloromethane:methanol=20-100:1, v / v, to obtain D'-A'-DAD-A'-D'-type fused ring interface material I.

[0028] The synthetic route of the present invention is as follows:

[0029]

[0030] In the above formula, in general formula I, R1 and R2 are independently selected from C1 to C 15 Straight chain alkanes, C1~C 25 Branched-chain alkanes, Wherein n is 1, 2, 3 or 4; R4 is H or C1~C 12 Straight-chain alkane; R5 is H, CH3, CH(CH3)2, CH2CH(CH3)2, CH(CH3)CH2CH3, phenyl or benzyl; R6 is H or C1~C 12 straight-chain alkanes;

[0031] R3 is any one of the following groups:

[0032]

[0033] Where m is 1, 2, 3 or 4, X - Cl - Br - or I - ;

[0034] The substituents R1 and R2 in the structural formula of the dibromo-fused ring Y series intermediate II are the same as those in the general formula I; the substituent R3 in the structural formula of the fluorene borate intermediate III is the same as that in the general formula I.

[0035] The preparation method of dibromo-fused ring Y-based intermediate II is an existing technology in the field and can be prepared by reference to the literature (Angew. Chem. Int. Ed. 2022, 61, e202201844).

[0036] According to the present invention, the above-mentioned D'-A'-DAD-A'-D' type fused ring interface material is used as a cathode interface material; it can improve interface contact, modify the metal electrode work function, balance carrier transport, and achieve a significant improvement in the energy conversion efficiency and long-term stability of perovskite photovoltaic cells, and can be used to prepare perovskite photovoltaic cells with different perovskite materials.

[0037] According to the present invention, the above-mentioned D'-A'-DAD-A'-D' type condensed ring interface material is made into a cathode interface layer for a perovskite solar cell device; wherein, the specific preparation process of the cathode interface layer is: dissolving the D'-A'-DAD-A'-D' type condensed ring interface material in an alcohol solvent, preparing the cathode interface layer by a solution processing method, and then preparing the perovskite solar cell device; the alcohol solvent is one or more of methanol, ethanol, isopropanol, and trifluoroethanol; the D'-A'-DAD-A'-D' type condensed ring interface material provided by the present invention can be dissolved in most organic solvents, so it has good film-forming processing performance.

[0038] Further preferably, the cathode interface layer prepared from the D'-A'-DAD-A'-D' type condensed ring interface material has a thickness of 5 to 50 nm.

[0039] Further preferably, the perovskite material of the perovskite solar cell is a ternary cation perovskite material FA 0.80 MA 0.13 Cs 0.07 PbI 0.27 Br 0.13 Or other perovskite materials commonly used in the art.

[0040] Compared with the prior art, the technical solution of the present invention has the following beneficial technical effects:

[0041] 1. By combining the advantages of large fused-ring conjugated units and conjugated zwitterionic units, this invention successfully developed a high-carrier-mobility fused-ring small-molecule cathode interface material, addressing key challenges in the field of perovskite photovoltaic interfaces, such as high thickness sensitivity, low mobility, and poor stability. By separately regulating and optimizing halogen substitution, ionic units, and side chain engineering, the resulting D'-A'-DAD-A'-D' fused-ring cathode interface material exhibits advantages such as self-assembly, self-doping, high carrier mobility, and good film-forming properties. Its application in large-area, thick-film perovskite battery modules can improve battery efficiency and long-term stability.

[0042] 2. The D'-A'-DAD-A'-D' type condensed ring interface material of the present invention has good solubility and film-forming properties, has a suitable molecular energy level and a high carrier mobility, and can improve the interface contact and modify the metal electrode work function. It is expected that the self-assembly property will increase the effective thickness of the film; the condensed ring conjugated skeleton and self-doping property will improve the carrier mobility of the film; the conjugated ion unit structure will improve the film-forming property and stability of the film; therefore, it can be used to prepare high-efficiency perovskite solar cells and is a cathode interface material with great commercial application potential.

[0043] 3. Compared with commercial cathode interface materials, the D'-A'-DAD-A'-D' type condensed ring interface material of the present invention has the advantages of thickness insensitivity, high carrier mobility and good stability, and has excellent interface performance. The finished product can be used to prepare large-area thick-film perovskite battery modules.

[0044] 4. Compared with our previously applied invention patent "DAD-type condensed ring aromatic imide interface material and its preparation method and application" (application number: 202310669869.4), the D'-A'-DAD-A'-D' type condensed ring interface material of the present invention has relatively low synthesis difficulty, and the synthesis process is relatively easy to control, the synthesis cost is relatively lower, and the product performance is better. BRIEF DESCRIPTION OF THE DRAWINGS

[0045] Figure 1 This is the H-NMR spectrum of the interface material FY1 prepared in Example 1.

[0046] Figure 2 This is the NMR carbon spectrum of the interface material FY1 prepared in Example 1.

[0047] Figure 3 This is the absorption spectrum of the dichloromethane solution of the interface material FY1 prepared in Example 1.

[0048] Figure 4 This is the electrochemical curve of the interface material FY1 prepared in Example 1.

[0049] Figure 5 This is the current density-voltage curve of the electron mobility of the interface material FY1 prepared in Example 1.

[0050] Figure 6 The current-voltage (JV) curve of the perovskite solar cell prepared in Example 1.

[0051] Figure 7 The external quantum efficiency (EQE) curve of the perovskite solar cell prepared in Example 1 is shown.

[0052] Figure 8The current-voltage (JV) curve of the perovskite battery module prepared in Example 1. DETAILED DESCRIPTION

[0053] The following embodiments of the present invention are described in detail in conjunction with the technical solutions and accompanying drawings. It should be noted that the present invention is illustrated by the following examples but is not limited thereto, wherein all parts and percentages are by weight unless otherwise indicated. In addition, the solvents and small molecule intermediates used in the following examples were purchased from Anhui Zesheng Technology Co., Ltd. (Annaiji Chemical) and were used directly without further purification before use.

[0054] Example 1

[0055] Preparation of D'-A'-DAD-A'-D' Type Condensed Ring Interface Material FY1

[0056] The reaction route is as follows:

[0057]

[0058] That is, in the general formula Ⅰ, R1 is ---C 11 H 23 ; R2 is R3 is

[0059] The preparation method of interface material FY1 is as follows:

[0060] The dibromo-fused ring Y intermediate IIa (100 mg, 0.06 mmol), fluorene borate intermediate IIIa (62 mg, 0.13 mmol) and tetrakis(triphenylphosphine)palladium (4 mg, 0.003 mmol) were added to a reactor, and then a 2 mol / L potassium carbonate aqueous solution (0.33 mL) and tetrahydrofuran (1.7 mL) were added, and the mixture was heated at 70°C for 24 hours; the reaction was stopped, 20 mL of dichloromethane and 10 mL of water were added, the liquids were separated, and the obtained organic phase was washed with 10 mL of water, and anhydrous magnesium sulfate was added to the obtained organic phase for drying. The solvent was removed by rotary evaporation, and the obtained crude product was purified by silica gel column chromatography with an eluent of dichloromethane:methanol = 50:1, v / v, to obtain a brown solid powder, which is the D'-A'-DAD-A'-D' type fused ring interface material FY1, with a yield of 73%.

[0061] The H-NMR spectrum and C-NMR spectrum of the interface material FY1 obtained in this example are as follows: Figure 1-Figure 2 The specific data are as follows:

[0062] 1H NMR (400MHz, CDCl3, 25℃): δ (ppm) = 7.74-7.40 (m, 22H), 4.71-4.25 (m, 12H), 3. 20-2.88(m,12H),2.13-2.09(m,34H),1.26-1.16(m,68H),0.87-0.59(m,18H);

[0063] 13 C NMR (101MHz, CDCl3, 25℃): δ (ppm) = 197.82, 184.26, 162.93, 156.66, 153.29, 147.43, 141.70, 136.78, 134.01, 131.35, 128. 22,123.01,120.68,114.48,101.61,73.37,58.58,54.64,50.86,50.78,44.87,43.93,31.91,29.32,29.26,22.69,14.13;

[0064] MALDI-TOF-MS:Calcd for C 136 H 166 N 12 O2S5,2159.1860[M - ],found 2159.1811.

[0065] Example 2

[0066] Preparation of D'-A'-DAD-A'-D' Type Condensed Ring Interface Material FY2

[0067] The reaction route is as follows:

[0068]

[0069] That is, R1 in the general formula Ⅰ is -----C 11 H 23 ; R2 is R3 is hour;

[0070] The preparation method of interface material FY2 is as follows:

[0071] The dibromo-fused ring Y intermediate IIb (100 mg, 0.065 mmol), fluorene borate intermediate IIIa (83 mg, 0.16 mmol) and tetrakis(triphenylphosphine)palladium (4 mg, 0.003 mmol) were added to a reactor, and then a 2 mol / L potassium carbonate aqueous solution (0.25 mL) and tetrahydrofuran (1.3 mL) were added, and the reaction was heated at 70°C for 24 hours; 20 mL of dichloromethane and 10 mL of water were added, the liquids were separated, and the obtained organic phase was washed with 10 mL of water, and anhydrous magnesium sulfate was added to the obtained organic phase for drying. The solvent was removed by rotary evaporation, and the obtained crude product was purified by silica gel column chromatography with dichloromethane:methanol = 50:1, v / v as the eluent to obtain a brown solid powder, which is the D'-A'-DAD-A'-D' type fused ring interface material FY2, with a yield of 77%.

[0072] MALDI-TOF-MS:Calcd for C 136 H 142 N 12 O2S5,2134.9982[M - ],found 2134.9912.

[0073] Example 3

[0074] Preparation of D'-A'-DAD-A'-D' Type Condensed Ring Interface Material FY3

[0075] The reaction route is as follows:

[0076]

[0077] That is, in the general formula I, R1 is -----C9H9; R2 is R3 is

[0078] The preparation method of interface material FY3 is as follows:

[0079] The dibromo-fused ring Y intermediate IIc (100 mg, 0.063 mmol), fluorene borate intermediate IIIc (100 mg, 0.15 mmol) and tetrakis(triphenylphosphine)palladium (4 mg, 0.003 mmol) were added to a reactor, and then a 2 mol / L potassium carbonate aqueous solution (0.36 mL) and tetrahydrofuran (1.8 mL) were added, and the reaction was heated at 70°C for 24 hours; the reaction was stopped, 20 mL of dichloromethane and 10 mL of water were added, the liquids were separated, and the obtained organic phase was washed with 10 mL of water, and anhydrous magnesium sulfate was added to the obtained organic phase for drying. The solvent was removed by rotary evaporation, and the obtained crude product was purified by silica gel column chromatography with dichloromethane:methanol = 50:1, v / v as the eluent to obtain a brown solid powder, which is the D'-A'-DAD-A'-D' type fused ring interface material FY3, with a yield of 74%.

[0080] MALDI-TOF-MS:Calcd for C 140 H 185 Br4N 16 O2S5,2570.8091[M - ],found 2570.8067.

[0081] Example 4

[0082] Preparation of D'-A'-DAD-A'-D' Type Condensed Ring Interface Material FY4

[0083] The reaction route is as follows:

[0084]

[0085] That is, R1 in the general formula Ⅰ is -----C9H 19 ; R2 is R3 is

[0086] The preparation method of interface material FY4 is as follows:

[0087] The dibromo-fused ring Y intermediate IId (100 mg, 0.055 mmol), fluorene borate intermediate IIId (101 mg, 0.12 mmol) and tetrakis(triphenylphosphine)palladium (4 mg, 0.003 mmol) were added to a reactor, and then a 2 mol / L potassium carbonate aqueous solution (0.3 mL) and N,N-dimethylformamide (1.5 mL) were added, and the reaction was heated at 70°C for 24 hours. The reaction was stopped, and 20 mL of dichloromethane and 10 mL of water were added. The layers were separated, and the resulting organic phase was washed with 10 mL of water and dried over anhydrous magnesium sulfate. The solvent was removed by rotary evaporation, and the crude product was purified by silica gel column chromatography with dichloromethane:methanol = 50:1, v / v as the eluent to obtain a brown solid powder, which is the D'-A'-DAD-A'-D' type fused ring interface material FY4, with a yield of 79%.

[0088] MALDI-TOF-MS:Calcd for C 160 H 218 I4N8O2P4S5,3075.0935[M - ],found 3075.0913.

[0089] Example 5

[0090] Preparation of D'-A'-DAD-A'-D' Type Condensed Ring Interface Material FY5

[0091] The reaction route is as follows:

[0092]

[0093] That is, R1 in the general formula Ⅰ is -----C 11 H 23 ; R2 is R3 is

[0094] The preparation method of interface material FY5 is as follows:

[0095] The dibromo-fused ring Y intermediate IIe (100 mg, 0.057 mmol), fluorene borate intermediate IIIe (146 mg, 0.14 mmol) and tetrakis(triphenylphosphine)palladium (4 mg, 0.003 mmol) were added to a reactor, and then a 2 mol / L potassium carbonate aqueous solution (0.36 mL) and N,N-dimethylformamide (1.8 mL) were added, and the reaction was heated at 90°C for 24 hours; the reaction was stopped, 20 mL of dichloromethane and 10 mL of water were added, the liquids were separated, and the obtained organic phase was washed with 10 mL of water, and anhydrous magnesium sulfate was added to the obtained organic phase for drying. The solvent was removed by rotary evaporation, and the obtained crude product was purified by silica gel column chromatography with dichloromethane:methanol = 50:1, v / v as the eluent to obtain a brown solid powder, which is the D'-A'-DAD-A'-D' type fused ring interface material FY5, with a yield of 71%.

[0096] MALDI-TOF-MS:Calcd for C 204 H 210 Br4N8O2P4S5,3403.0864[M - ],found 3403.0815.

[0097] Test Example 1

[0098] The following further details the properties and applications of the D'-A'-DAD-A'-D' type condensed ring interface material synthesized in this embodiment. It should be noted that since the structures of the synthesized D'-A'-DAD-A'-D' type condensed ring interface materials prepared by the method of the present invention are very similar and their properties are relatively close, the present invention only describes in detail the products prepared in the best embodiment. However, based on the description of the present invention, those skilled in the art can reasonably infer the properties and application effects of other similar products having structural formula I for which protection is sought in the present invention, and no further details are given here.

[0099] Performance testing and application testing of FY1 interface materials.

[0100] a. UV-visible absorption spectrum test. The instrument model used was an American HP8453 UV spectrophotometer. The product of Example 1 was accurately weighed and prepared into 1×10 -5mol / L dichloromethane solution was tested using a 1 cm glass cuvette at room temperature. The molar extinction coefficient (ε) of the material was calculated using the formula: A = εcb, where A is the absorbance at the maximum absorption peak; c is the molar concentration of the material; and b is the thickness of the cuvette. The optical band gap was calculated using the maximum absorption sideband method according to the formula E g =1240 / λmax eV. The maximum absorption wavelength of the product is 350nm, the absorption range is 300~800nm, and its molar absorption coefficient is calculated to be 8.3×10 4 M -1 cm -1 , optical band gap E g The absorption spectrum of the dichloromethane solution is shown in Figure 1. Figure 3 shown.

[0101] b. Cyclic voltammetry test. The instrument model used is BSA100B / W electrochemical analysis system. A three-electrode test system is used, with a glassy carbon electrode as the working electrode, a silver-silver chloride electrode as the reference electrode, and a platinum wire electrode as the counter electrode. The product of Example 1 is accurately weighed and prepared into a 10 mg / mL dichloromethane solution, and tetrabutylammonium hexafluorophosphate is added as an electrolyte with an electrolyte concentration of 40 mg / mL. Ferrocene is used as the internal standard electrode pair. The absolute value of the ferrocene electrode pair relative to vacuum is 4.8 eV according to the literature. According to the formula E LUMO =-(4.8+E ox -E 1 / 2 Fc+ / Fc )eV, the cyclic voltammetry curve of the material obtained its first reduction peak half-wave potential (E onsetre ) is -0.82V, and the LUMO energy level is calculated to be -3.50eV. According to the formula E HOMO =-(4.8+E red -E 1 / 2 Fc+ / Fc )eV, the highest occupied molecular orbital (HOMO) energy level is -5.08eV, which proves that the material has good redox properties. The electrochemical curve is shown in Figure 4 shown.

[0102] c. Space charge limited current method test. The electron mobility of organic semiconductor materials is measured using the American Keithley 2400 (IV) digital source meter. The device structure of the single electron device is: ITO / ZnO / FY1 / Ca / Al. The device fabrication method is as follows: the ITO substrate is ultrasonically cleaned with ethanol, acetone, and ultrapure water in sequence; after being purged with nitrogen, it is treated with ozone for 30 minutes; 0.25 mol / L zinc oxide is spin-coated to a thickness of approximately 20 nm; after annealing in air at 200°C for 1 hour, a chloroform solution of FY1 compound is spin-coated in a glove box at a concentration of 20 mg / mL and a thickness of approximately 200 nm; the spin-coated substrate is transferred to a vacuum evaporation chamber, and the vacuum degree reaches 1×10 -4 When Pa, Ca (10nm) / Al (100nm) electrodes were evaporated; the current density-voltage curve of the device was tested using a digital source meter, and the results were as follows Figure 5 As shown. Electron mobility is based on the Mott-Gurney formula:

[0103]

[0104] Where J represents the current density; ε r represents the dielectric constant of the material (in organic semiconductors, this value can be set to 3); ε0 represents the vacuum permittivity; μ represents the electron mobility of the material; L represents the thickness of the active layer; V represents the voltage applied to the active ends. 1 / 2 The electron mobility of the material can be calculated by plotting the V vs V curve. According to the Mott-Gurney formula, the corresponding curve was fitted using SigmaPlot software. The fitted curve is consistent with the measured value, indicating that the test data is authentic. The electron mobility of the material is calculated to be 1.46×10 -3 cm 2 V -1 s -1 , proving that the material has excellent electron transport properties.

[0105] d. Preparation and testing of perovskite solar cells. Inverse perovskite solar cells were prepared with a cell structure of ITO / PTAA:F4-TCNQ / perovskite / PCBM-FY1 / Ag, where indium tin oxide (ITO) and silver metal served as electrodes, PTAA:F4-TCNQ, PCBM and FY1 served as hole transport layer, electron transport layer and cathode modification layer, and the perovskite layer was FA 0.80 MA 0.13 Cs 0.07 PbI 0.27 Br 0.13The battery production process: The ITO substrate is ultrasonically cleaned with ethanol, acetone and ultrapure water in sequence; after nitrogen purge, it is treated with ozone for 15 minutes; PTAA:F4-TCNQ chlorobenzene solution is spin-coated in a nitrogen glove box to a thickness of about 30nm and annealed for 2 minutes; FA is spin-coated using the sec-butanol anti-solvent method. 0.80 MA 0.13 Cs 0.07 PbI 0.27 Br 0.13 The precursor solution (solvent is a mixture of DMF and NMP at 0.87:0.13 v / v) is applied to a thickness of about 700 nm. The PCBM chlorobenzene solution is spin-coated to a thickness of 70-100 nm. The FY1 ethanol solution of different concentrations is spin-coated to a thickness of 5-50 nm. The spin-coated substrate is transferred to a vacuum evaporation chamber and the vacuum degree reaches 1×10 -4 When Pa, silver electrode (100nm) was evaporated. Battery performance test method and process: All batteries were not encapsulated and the performance test was carried out in a glove box filled with nitrogen. After the battery was obtained, its JV curve and EQE curve were tested, that is, Figures 6 to 8 The JV curve was measured using a Zolix Solar IV-150A-ZZU system, with a photocurrent of 100mWcm -2 The external quantum efficiency (EQE) spectra were measured using a Zolix SCS10-X150-DSSC-ZZU system under AM 1.5G illumination using a Zolix-HPS-300XA solar simulator and calibrated using a Zolix QE-B1 silicon solar cell.

[0106] Depend on Figures 6 to 8 As can be seen, FY1 exhibits excellent interface properties as a cathode interface modification layer for perovskite solar cells. Compared to existing cathode interface materials reported in the literature, FY1 can simultaneously maintain a higher short-circuit current density and fill factor. This is due to FY1's large fused-ring trapezoidal conjugated plane, good self-doping properties, and self-assembly characteristics.

[0107] Table 1 lists the optimal performance parameters of perovskite solar cells using different cathode interface layers, while Table 2 lists the optimal performance parameters of perovskite solar cells using FY1 cathode interface layers of varying thicknesses. As shown in Tables 1 and 2, the perovskite solar cells exhibit excellent photovoltaic performance. When the FY1 cathode interface layer thickness reaches 20nm, the cell still maintains an energy conversion efficiency exceeding 90%. These results demonstrate that this technology can achieve the preparation of high-conductivity, thickness-insensitive, and universally applicable high-efficiency cathode interface materials.

[0108] Table 1

[0109] cathode interface layer Active layer <![CDATA[J sc [mA cm -2 ]]> <![CDATA[V oc [V]]> FF[%] PCE [%] w / o Ternary cation perovskite 23.65 1.170 75.2 20.81 Bphen Ternary cation perovskite 23.77 1.196 80.6 22.93 FY1 Ternary cation perovskite 23.86 1.208 82.3 23.72

[0110] Table 2

[0111]

[0112]

[0113] Comparative Example 1

[0114] The following comparative examples illustrate in detail the technological advancement of the D'-A'-DAD-A'-D' type condensed ring interface material of the present invention relative to the DAD type organic cathode interface material synthesized in our early stage. The following is a detailed description of the DAD type organic cathode interface material NDTI1 as an example. The structural formula of the NDTI1 material is as follows. For its synthesis method, please refer to the invention patent "DAD type condensed ring aromatic imide interface material and its preparation method and application" (application number: 202310669869.4) we submitted to the State Intellectual Property Office of China in the early stage.

[0115]

[0116] NDTI1 is used as a cathode modification layer in organic solar cells, but not in perovskite solar cells. However, comparison shows that the D'-A'-DAD-A'-D' type condensed ring interface material has a larger conjugated skeleton and stronger intramolecular interaction, which is conducive to enhancing the crystallinity of the material and further improving the carrier mobility and conductivity of the interface material, which can effectively improve the interface performance of the material. It can be seen that the material performance of the D'-A'-DAD-A'-D' type condensed ring interface material with the structure provided by the present invention after application is significantly higher than that of the DAD type condensed ring aromatic imide interface material.

Claims

1. A D'-A'-DAD-A'-D' type condensed ring interface material, characterized in that: The fused ring interface material has the structure shown in the following general formula I: In the general formula I, R1 and R2 are independently selected from C1 to C 15 Straight chain alkanes, C1~C 25 Branched-chain alkanes, Wherein n is 1, 2, 3 or 4; R4 is H or C1~C 12 Straight-chain alkane; R5 is H, CH3, CH(CH3)2, CH2CH(CH3)2, CH(CH3)CH2CH3, phenyl or benzyl; R6 is H or C1~C 12 straight-chain alkanes; R3 is any one of the following groups: Where m is 1, 2, 3 or 4, X - Cl - Br - or I - .

2. The D'-A'-DAD-A'-D' type condensed ring interface material according to claim 1, characterized in that: In general formula I: R1 is C9~C 12 Straight chain alkane; R2 is C8~C 20 branched-chain alkanes; R3 is any one of the following groups: Where m is 1, 2, 3 or 4, X - Cl - Br - or I - .

3. A method for synthesizing the D'-A'-DAD-A'-D' type fused ring interface material according to claim 1 or 2, comprising the following steps: In a solvent, under the catalysis of a palladium catalyst and alkaline conditions, a substitution reaction is carried out between a dibromo-fused ring Y-series intermediate II and a fluorene borate intermediate III to obtain a D'-A'-DAD-A'-D' type fused ring interface material I; in, The substituents R1 and R2 in the structural formula of the dibromo-fused ring Y series intermediate II are the same as those in the general formula I; the substituent R3 in the structural formula of the fluorene borate intermediate III is the same as that in the general formula I.

4. The method for synthesizing the D'-A'-DAD-A'-D' type fused ring interface material according to claim 3, characterized in that: The solvent is tetrahydrofuran, 1,4-dioxane, N,N-dimethylformamide or dimethyl sulfoxide; the ratio of the volume of the solvent to the molar number of the dibromo-fused ring Y-series intermediate II is 15-40 mL:1 mmol; The palladium catalyst is tetrakis(triphenylphosphine)palladium, bis(triphenylphosphine)palladium dichloride or [1,1'-bis(diphenylphosphino)ferrocene]palladium dichloride; the molar ratio of the palladium catalyst to the dibromofused ring Y series intermediate II is 0.01-0.1:

1.

5. The method for synthesizing the D'-A'-DAD-A'-D' type fused ring interface material according to claim 3, characterized in that: The alkaline conditions are provided by an alkaline solution, wherein the alkaline is sodium carbonate, potassium carbonate or potassium phosphate, and the molar ratio of the alkaline to the dibromofused ring Y-series intermediate II is 5 to 16:1; and the concentration of the alkaline solution is 2 mol / L.

6. The method for synthesizing the D'-A'-DAD-A'-D' type condensed ring interface material according to claim 3, characterized in that: The molar ratio of the dibromo-fused ring Y-based intermediate II to the fluorene borate intermediate III is 1:2.1-2.

6.

7. The method for synthesizing the D'-A'-DAD-A'-D' type condensed ring interface material according to claim 3, characterized in that: The temperature of the substitution reaction is 60 to 100° C., and the time of the substitution reaction is 20 to 30 hours; The post-treatment steps of the reaction solution obtained after the substitution reaction of the dibromo-fused ring Y-series intermediate II and the fluorene borate intermediate III are as follows: dichloromethane and water are added to the obtained reaction solution, the organic phase obtained after separation is washed with water and dried, and the solvent is removed. The obtained crude product is purified by silica gel column chromatography with an eluent of dichloromethane:methanol = 20-100:1, v / v, to obtain a D'-A'-DAD-A'-D' type fused ring interface material I.

8. Use of the D'-A'-DAD-A'-D' type fused ring interface material according to claim 1 or 2 as a cathode interface material.

9. The application according to claim 8, characterized in that: The D'-A'-DAD-A'-D' type fused ring interface material according to claim 1 or 2 is made into a cathode interface layer for use in a perovskite solar cell device.

10. The use according to claim 9, characterized in that: The specific preparation process of the cathode interface layer is as follows: dissolving the D'-A'-DAD-A'-D' type condensed ring interface material in an alcohol solvent, preparing the cathode interface layer by solution processing, and then preparing a perovskite solar cell device; the alcohol solvent is one or more of methanol, ethanol, isopropanol, and trifluoroethanol; the cathode interface layer prepared by the D'-A'-DAD-A'-D' type condensed ring interface material has a thickness of 5 to 50 nm; the perovskite material of the perovskite solar cell is a ternary cation perovskite material FA 0.80 MA 0.13 Cs 0.07 PbI 0.27 Br 0.13 .

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