A-DAapos, which is functionalized at the beta-position, is used as a template; d-A type micromolecule electron acceptor material and preparation method and application thereof

Abstract

The invention discloses a beta-position functionalized A-DA 'D-A type micromolecule electron acceptor material and a preparation method and application thereof.The micromolecule electron acceptor material has the structural formula shown in the formula (I), and the preparation method of the micromolecule electron acceptor material comprises the step that a beta-position functionalized intermediate M1 and a compound N1 containing an A unit are subjected to Knoevenagel condensation reaction under the action of a solvent and a catalyst to obtain the beta-position functionalized A-DA' D-A type micromolecule electron acceptor material. By changing a beta-position functionalized group R of thienothiophene in a central core DA 'D unit, a substituent R'on a pyrrole ring and an electron-withdrawing terminal A, the molecular structure, the absorption spectrum, the front molecular orbital energy level, the solid-state accumulation, the carrier transport and other properties of the beta-position functionalized A-DA' D-A type small molecule electron acceptor material can be regulated and controlled; the micromolecular electron acceptor material with excellent photoelectric properties can be prepared and can be applied to preparation of efficient organic solar cells.

Description

Technical Field

[0001] This invention relates to the field of organic solar cell technology, and more particularly to... β Functionalized A-DA'DA type small molecule electron acceptor materials, their preparation methods and applications. Background Technology

[0002] Organic solar cells are devices that directly convert solar energy into electrical energy using the photovoltaic effect based on organic molecules. They possess advantages such as flexibility, semi-transparency, light weight, simple fabrication processes, and good tunability of the chemical structure of the materials. They can be used in portable electronics, building-integrated photovoltaics (BIPV), agricultural photovoltaics, and greenhouses. Since the 1990s, after more than 30 years of unremitting efforts, the power conversion efficiency (PCE) of organic solar cells has steadily improved, demonstrating broad application and research prospects. In recent years, thanks to the rapid development of organic small molecule electron acceptor materials, especially A-DA'DA type small molecule acceptors, the PCE of bulk heterojunction organic solar cells based on polymer electron donors: small molecule electron acceptors has reached 21% (Wang L., Chen C., Gan Z.). et al . Diluted TernaryHeterojunctions to Suppress Charge Recombination for Organic Solar Cells with21% Efficiency. Adv. Mater. 2025, 37 , 2419923). At present, structural modifications of A-DA'DA type small molecule receptors focus on three aspects: (1) alkyl chains on the nitrogen atoms of the pyrrole ring in the central DA'D unit; (2) electron-deficient A' units in the central DA'D unit; (3) electron-withdrawing terminal A units. The thiophene-thiophene units in the central DA'D unit of most highly efficient A-DA'DA type small molecule receptors β The - positions are all alkyl groups, and their main function is to regulate the solubility of small molecule acceptors, molecular solidification, carrier mobility, and active layer morphology, ultimately optimizing the photovoltaic performance of organic solar cell devices. However, β Small molecules with an alkyl group at the --position suffer from high costs due to expensive raw materials, complex synthesis processes, and difficulties in separation and purification; further research is needed to address these issues. β Other functions of the --position substituent, such as reducing nonradiative energy loss and increasing molecular conformation stability, can improve device efficiency and stability. Therefore, there is a need to develop novel, high-efficiency devices with low cost and excellent optoelectronic performance. β - A functionalized small molecule electron acceptor material. Summary of the Invention

[0003] The technical problem to be solved by this invention is to overcome the high cost of preparing A-DA'DA type small molecule electron acceptor materials in the prior art. β The limited variety of functionalized receptor materials necessitates the provision of a certain solution. β - Functionalized A-DA'DA type small molecule electron acceptor materials, their preparation methods, and applications. This involves modifying the thiophene-thiophene in the central DA'D unit. β The presence of functionalized groups (R), substituents on the pyrrole ring (R'), and electron-withdrawing terminals (A) can enable the regulation of the structure, absorption spectrum, frontier molecular orbital energy levels, molecular solid-state packing, and carrier transport properties of this type of small molecule acceptor material. This allows for the preparation of small molecule electron acceptor materials with excellent photoelectric properties, which can be applied to the fabrication of high-efficiency organic solar cells.

[0004] To address the aforementioned technical problems, the present invention provides the following technical solutions.

[0005] A sort of β - A-DA'DA type small molecule electron acceptor material with functionalization at position, the β - Functionalized A-DA'DA type small molecule electron acceptor materials have the following structural formula (I): Formula (I) In the formula (I): R' is selected from any of the following groups: , , , , , , , , ; R is selected from any of the following groups: (bromine atom) , , , , , , , , , , , , , , , , , , , , , ; X is selected from any one of the following groups: H, F, Cl.

[0006] As a general technical concept, the present invention also provides the above-mentioned β A method for preparing a functionalized A-DA'DA type small molecule electron acceptor material, wherein β - Functionalized A-DA'DA type small molecule electron acceptor materials are prepared by Knoevenagel condensation reaction of intermediate M1 and A-unit-containing compound N1 (commercially available) in the presence of a solvent and a catalyst. The intermediate M1 has the structural formula shown in formula (II), and the A-unit-containing compound N1 has the structural formula shown in formula (III). Equation (II) Formula (III); In the above formula (II): R' is selected from any of the following groups: , , , , , , , , ; R is selected from any of the following groups: , , , , , , , , , , , , , , , , , , , , , , ; In formula (III): X is any one of H, F and Cl.

[0007] The synthesis route is as follows: The above β A method for preparing a functionalized A-DA'DA type small molecule electron acceptor material, preferably wherein the molar ratio of the intermediate M1 to the compound N1 containing the A unit is 1:2 to 4.

[0008] The above β A method for preparing a functionalized A-DA'DA type small molecule electron acceptor material, preferably wherein the molar ratio of the catalyst to the intermediate M1 is 25 to 35:1.

[0009] The above β A method for preparing a functionalized A-DA'DA type small molecule electron acceptor material, preferably, wherein the catalyst is one of pyridine, piperidine, and triethylamine.

[0010] The above β A method for preparing a functionalized A-DA'DA type small molecule electron acceptor material, preferably, wherein the solvent is one of chloroform, dichloromethane and toluene.

[0011] The above β A method for preparing a functionalized A-DA'DA type small molecule electron acceptor material, preferably, when R is a group other than -Br, the intermediate M1 is prepared by the following method: S1. Under an inert gas atmosphere, compound 1 (preferably prepared from thiophene-thiophene, but not limited thereto), compound 2 (4,7-dibromo-5,6-dinitro-2,1,3-benzothiadiazole, commercially available), catalyst tris(dibenzylacetone)dipalladium (Pd2(dba)3), and ligand tris(o-methylphenyl)phosphine (P( o -tol)3) reacted with toluene upon heating to give compound 3; S2. Under inert gas protection, compound 3 and triphenylphosphine (PPh3) were reacted at high temperature in o-dichlorobenzene at 160-190°C to obtain compound 4; S3. Under inert gas protection, compound 4, bromoalkane (R′-Br), potassium carbonate (K2CO3), and potassium iodide (KI) are... N , N Compound 5 is obtained by heating dimethylformamide (DMF). S4. Under the protection of an inert gas, compound 5 and N- Bromosuccinimide (NBS) was reacted in tetrahydrofuran (THF) in an ice bath followed by a reaction at room temperature to give compound 6; S5. Under inert gas protection, compound 6 and lithium diisopropylamino (LDA) were reacted in tetrahydrofuran (THF) at a low temperature of -40 °C to -80 °C, and then added... N , N -Dimethylformamide (DMF), after returning to room temperature, the reaction continues to yield compound 7; S6. Under inert gas protection, compound 7, borate compound 8-1 (commercially available) or borate ester compound 8-2 (commercially available), potassium carbonate K2CO3, catalyst tetra(triphenylphosphine)palladium (Pd(PPh3)4), water (preferably deionized water), methyltrioctylammonium chloride and toluene are heated to react and obtain intermediate M1; Compound 1 is: ; Compound 2 is: ; The compound 3 is: ; Compound 4 is: ; Compound 5 is: ; Compound 6 is: ; The compound 7 is: ; The boric acid compound 8-1 is: RB(OH)2; The borate ester compound 8-2 is: .

[0012] The synthetic route for intermediate M1 is as follows: The above β A method for preparing a functionalized A-DA'DA type small molecule electron acceptor material, preferably, in step S1, the molar ratio of compound 1 to compound 2 is 2-4:1, the molar ratio of the catalyst tris(dibenzylacetone)dipalladium (Pd2(dba)3) to compound 2 is 1-3:100, and the molar ratio of the catalyst tris(dibenzylacetone)dipalladium to the ligand tris(o-methylphenyl)phosphine (P( o The molar ratio of -tol)3) is 1:3 to 5, the heating reaction time is 1 to 4 hours, and the heating reaction temperature is 90℃ to 110℃.

[0013] The above βA method for preparing a functionalized A-DA'DA type small molecule electron acceptor material, preferably, in step S2, the molar ratio of compound 3 to triphenylphosphine (PPh3) is 1:5 to 8, and the high-temperature reaction time is 2 to 6 hours.

[0014] The above β A method for preparing a functionalized A-DA'DA type small molecule electron acceptor material, preferably, in step S3, the molar ratio of compound 4, the bromoalkane (R′-Br), the potassium carbonate (K2CO3), and the potassium iodide (KI) is 1:2 to 4:10 to 20:0.03 to 0.1, the heating reaction time is 2 to 6 hours, and the heating reaction temperature is 130°C to 150°C.

[0015] The above β A method for preparing a functionalized A-DA'DA type small molecule electron acceptor material, preferably, in step S4, compound 5 and... N The molar ratio of β-bromosuccinimide (NBS) is 1:2 to 2.5, and the reaction time at room temperature is 6 to 12 hours. N - Bromosuccinimide addition N , N The solution is dissolved in dimethylformamide and then added dropwise, with the ice bath time preferably being the dropwise addition time.

[0016] The above β A method for preparing a functionalized A-DA'DA type small molecule electron acceptor material, preferably, in step S5, compound 6, lithium diisopropylamino (LDA), and... N , N The molar ratio of dimethylformamide (DMF) is 1:6 to 10:30 to 60, the low-temperature reaction time is 1 to 2 hours, and the room-temperature reaction time is 0.5 to 1 hour.

[0017] The above β A method for preparing a functionalized A-DA'DA type small molecule electron acceptor material, preferably, in step S6, the molar ratio of compound 7, borate compound 8-1 or borate ester compound 8-2, potassium carbonate (K2CO3), and catalyst tetrakis(triphenylphosphine)palladium (Pd(PPh3)4) is 1:3 to 6:6 to 10:0.03 to 0.1; the molar ratio of methyltrioctylammonium chloride to compound 7 is 1:1 to 3; the amount of water used is such that the concentration of potassium carbonate is 2 mol / L; the temperature of the heating reaction is 100℃ to 120℃; and the heating reaction time is 12h to 36h.

[0018] The aboveβ A method for preparing a functionalized A-DA'DA type small molecule electron acceptor material, preferably, when R is -Br, the intermediate M1 is prepared by the following method: S1. Compound 1, Compound 2, catalyst tris(dibenzylacetone)dipalladium and ligand tris(o-methylphenyl)phosphine were heated in toluene under an inert gas atmosphere to give Compound 3. S2. Under inert gas protection, compound 3 and triphenylphosphine were reacted in o-dichlorobenzene at a high temperature of 160℃~190℃ to obtain compound 4; S3. Under the protection of an inert gas, compound 4, bromoalkane, potassium carbonate, and potassium iodide are placed in... N , N Compound 5 is obtained by heating dimethylformamide. S4. Under the protection of an inert gas, compound 5 and N - Bromosuccinimide was reacted in tetrahydrofuran in an ice bath followed by a reaction at room temperature to give compound 6; S5. Under inert gas protection, compound 6 and diisopropylaminolithium were reacted in tetrahydrofuran at a low temperature of -40°C to -80°C, and then added... N , N -Dimethylformamide, after being restored to room temperature and the reaction continued, yielded compound 7, which is intermediate M1; Compound 1 is: ; Compound 2 is: ; The compound 3 is: ; Compound 4 is: ; Compound 5 is: ; Compound 6 is: ; The compound 7 is: .

[0019] The above β A method for preparing a functionalized A-DA'DA type small molecule electron acceptor material, preferably, when R is -Br, the intermediate M1 is prepared by the following method: S1. Compound 1, Compound 2, catalyst tris(dibenzylacetone)dipalladium and ligand tris(o-methylphenyl)phosphine were heated in toluene under an inert gas atmosphere to give Compound 3. S2. Under inert gas protection, compound 3 and triphenylphosphine were reacted in o-dichlorobenzene at a high temperature of 160℃~190℃ to obtain compound 4; S3. Under the protection of an inert gas, compound 4, bromoalkane, potassium carbonate, and potassium iodide are placed in... N , N Compound 5 is obtained by heating dimethylformamide. S4. Under the protection of an inert gas, compound 5 and N - Bromosuccinimide was reacted in tetrahydrofuran in an ice bath followed by a reaction at room temperature to give compound 6; S5. Under inert gas protection, compound 6 and diisopropylaminolithium were reacted in tetrahydrofuran at a low temperature of -40°C to -80°C, and then added... N , N -Dimethylformamide, after being restored to room temperature and the reaction continued, yielded compound 7, which is intermediate M1; Compound 1 is: ; Compound 2 is: ; The compound 3 is: ; Compound 4 is: ; Compound 5 is: ; Compound 6 is: ; The compound 7 is: .

[0020] The above β A method for preparing a functionalized A-DA'DA type small molecule electron acceptor material, preferably, in step S1, the molar ratio of compound 1 to compound 2 is 2-4:1, the molar ratio of the catalyst tris(dibenzylacetone)dipalladium (Pd2(dba)3) to compound 2 is 1-3:100, and the molar ratio of the catalyst tris(dibenzylacetone)dipalladium to the ligand tris(o-methylphenyl)phosphine (P( o The molar ratio of -tol)3) is 1:3 to 5, the heating reaction time is 1 to 4 hours, and the heating reaction temperature is 90℃ to 110℃.

[0021] The above β A method for preparing a functionalized A-DA'DA type small molecule electron acceptor material, preferably, in step S2, the molar ratio of compound 3 to triphenylphosphine (PPh3) is 1:5 to 8, and the high-temperature reaction time is 2 to 6 hours.

[0022] The above βA method for preparing a functionalized A-DA'DA type small molecule electron acceptor material, preferably, in step S3, the molar ratio of compound 4, the bromoalkane (R′-Br), the potassium carbonate (K2CO3), and the potassium iodide (KI) is 1:2 to 4:10 to 20:0.03 to 0.1, the heating reaction time is 2 to 6 hours, and the heating reaction temperature is 130°C to 150°C.

[0023] The above β A method for preparing a functionalized A-DA'DA type small molecule electron acceptor material, preferably, in step S4, compound 5 and... N The molar ratio of β-bromosuccinimide (NBS) is 1:2 to 2.5, and the reaction time at room temperature is 6 to 12 hours. N - Bromosuccinimide addition N , N The solution is dissolved in dimethylformamide and then added dropwise, with the ice bath time preferably being the dropwise addition time.

[0024] The above β A method for preparing a functionalized A-DA'DA type small molecule electron acceptor material, preferably, in step S5, compound 6, lithium diisopropylamino (LDA), and... N , N The molar ratio of dimethylformamide (DMF) is 1:6 to 10:30 to 60, the low-temperature reaction time is 1 to 2 hours, and the room-temperature reaction time is 0.5 to 1 hour.

[0025] As a general technical concept, the present invention also provides the above-mentioned β --functionalized A-DA'DA type small molecule electron acceptor materials or prepared by the above-mentioned methods β Application of functionalized A-DA'DA type small molecule electron acceptor materials in the fabrication of solar cells.

[0026] Preferably, the above application includes the following steps: (1) A layer of PEDOT:PSS polymer conductive film is spin-coated onto the ITO conductive glass on the anode; (2) Spin coat another layer of the above-mentioned material β A photoactive layer composed of a functionalized A-DA'DA type small molecule electron acceptor material and a polymer donor PBDB-T or PM6 or D18; (3) Next, spin-coat the PFN-Br cathode modification layer; (4) Finally, the cathode metal Ag is vapor-deposited to obtain an organic solar cell device.

[0027] Compared with the prior art, the advantages of the present invention are as follows: (1) This invention provides a β - Functionalized A-DA'DA type small molecule electron acceptor materials, by changing different β --functionalized groups (R) can reduce the preparation cost and development of A-DA'DA type small molecules. β - Substituents at the - position serve multiple purposes, including improving material stability, reducing non-radiative energy loss, and increasing device efficiency. β - Functionalized A-DA'DA type small molecule electron acceptor materials based on heptaneously fused di(thiophene-3-)thiophene[3.2- b ]-pyrrole) and benzothiadiazole (dithienothiophen[3.2- b The ]-pyrrolobenzothiadiazole unit is the central DA'D unit, 3-(dicyanomethylene)indone or 5,6-dihalo-3-(dicyanomethylene)indone are electron-withdrawing terminal A units, and bromo, fluorophenyl, tetraphenylphenyl, triphenylamine, etc. are electron-withdrawing terminal A units. β By modifying the electron-withdrawing ends (A) of the substituents (R′) on the pyrrole ring in the central core DA'D, the structure, absorption spectrum, frontier molecular orbital energy levels, molecular solid-state packing, and carrier transport properties of this type of small molecule acceptor material can be controlled, thus enabling the preparation of small molecule electron acceptor materials with excellent photoelectric properties.

[0028] The present invention β Functionalized A-DA'DA type small molecule electron acceptor materials possess tunable absorption spectra (500–1000 nm) and the lowest unoccupied orbital energy level (-3.6–-4.2 eV), while also exhibiting good optical and thermal stability, which is beneficial for obtaining high short-circuit current densities. J SC ), high open circuit voltage ( V OC And high-efficiency and stable solar cell devices.

[0029] (2) The present invention provides a β The method for preparing A-DA'DA type small molecule electron acceptor materials with functionalization has the advantages of templated synthetic route, wide availability of raw materials and simple synthetic process. Therefore, this method has high scalability and reproducibility.

[0030] (3) The present invention provides a βThe application of functionalized A-DA'DA type small molecule electron acceptor materials in the fabrication of organic solar cells: Bulk heterojunction binary organic solar cells constructed using these A-DA'DA type small molecules as acceptor phase materials and common donor phase materials (such as PBDB-T, PM6, D18, etc.) have achieved a photovoltaic performance of 14.63% by optimizing the donor-acceptor ratio, additives, and thermal annealing. V OC Reaching 0.915 V, J SC Reaching 22.25 mA / cm 2 The fill factor (FF) reached 71.8%. These results indicate that this type of material has great research and application prospects in the preparation of high-voltage, high-efficiency binary organic solar cell materials. Attached Figure Description

[0031] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings.

[0032] Figure 1 The images show the ultraviolet-visible (UV-Vis) absorption spectra of the acceptor materials synthesized in Examples 1-4 of this invention in chloroform solution.

[0033] Figure 2 The images show the ultraviolet-visible (UV-Vis) absorption spectra of the thin films of the acceptor materials synthesized in Examples 1 to 4 of this invention on quartz plates.

[0034] Figure 3 The cyclic voltammetry (CV) curves of the receptor materials synthesized in Examples 1 to 4 of this invention are shown.

[0035] Figure 4 The current-voltage characteristics of organic solar cells prepared based on the acceptor materials synthesized in Examples 1-4 of this invention ( J - V (Line graph) Detailed Implementation

[0036] The present invention will be further described below with reference to the accompanying drawings and specific preferred embodiments, but this does not limit the scope of protection of the present invention. The embodiments described below are intended to facilitate understanding of the present invention and do not constitute any limitation thereon. Unless otherwise specified, the methods described are conventional methods.

[0037] Unless otherwise specified, all reactants are commercially available. Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art. The terminology used herein in the description of the invention is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. The term "and / or" as used herein includes any and all combinations of one or more of the associated listed items.

[0038] Example 1: An invention β - Functionalized A-DA'DA type small molecule electron acceptor materials, specifically β A-DA'DA type small molecule electron acceptor material functionalized with bromine atom at position - β -SL-Br has the following structural formula as shown in equation (I): Formula (I) In equation (I), R' is R is -Br, and X is F.

[0039] The synthesis route is shown below: .

[0040] One embodiment of this invention β - Functionalized A-DA'DA type small molecule electron acceptor materials β The preparation method of -SL-Br, and the specific synthesis steps are as follows: Step S1: Synthesize compound 3 Under argon protection, thiophene(8.41 g, 60 mmol) and 60 mL THF were added sequentially to a 100 mL three-necked round-bottom flask. After stirring at -78 °C for 0.5 hours, n-butyllithium (2.4 M, 27.5 mL, 66 mmol) was added dropwise. After stirring for 1 hour, tributyltin chloride (29.29 g, 90 mmol) was added dropwise. The mixture was then heated to room temperature and stirred for 12 hours. The reaction was subsequently quenched with deionized water, and the mixture was extracted three times with petroleum ether. The organic phases were combined, and the solvent was removed by rotary evaporation to obtain compound 1. After further purification, it was used directly in the next reaction.

[0041] Under argon protection, compound 1 (25.75 g, 60 mmol) and compound 2 (5.75 g, 15 mmol), 50 mL of toluene, tris(dibenzylacetone)palladium Pd2(dba)3 (274 mg, 0.3 mmol), and tris(o-methylphenyl)phosphine P( oCompound 3 (365 mg, 1.2 mmol) was heated at 90 °C for 2 hours. After the reaction was complete, the reaction mixture was added to methanol for precipitation three times, washed three times with hot dichloromethane, filtered, and dried under vacuum to give a black crude solid, which was compound 3, 7.01 g, with a yield of 93%. This compound did not require further purification and could be used directly in the next reaction.

[0042] Step S2: Synthesize compound 4 Under argon protection, compound 3 (5.02 g, 10 mmol), triphenylphosphine (15.73 g, 60 mmol), and 30 mL of o-dichlorobenzene were added sequentially to a 100 mL three-necked round-bottom flask. The mixture was heated to 180 °C and reacted for 4 hours. The reaction was then stopped, and after the reaction mixture was slightly cooled, methanol was added to precipitate the mixture three times. The mixture was then washed three times with hot dichloromethane, filtered, and dried under vacuum to obtain a reddish-brown powder, which was compound 4, 4.16 g, with a yield of 95%. This compound did not require further purification and could be used directly in the next reaction.

[0043] Step S3: Synthesize compound 5 Under argon protection, compound 4 (4.38 g, 10 mmol), potassium carbonate (20.73 g, 150 mmol), potassium iodide (0.083 g, 0.5 mmol), 1-bromo-2-hexyldecane (9.16 g, 30 mmol), and 30 mL of [unspecified substance] were added sequentially to a 100 mL three-necked round-bottom flask. N , N -Dimethylformamide was heated to 140 °C and reacted for 4 h. The reaction was stopped, and after the reactant compound cooled to room temperature, it was poured into 200 mL of water and extracted twice with dichloromethane. The organic layers were combined, washed twice with brine, and dried over anhydrous sodium sulfate. After removing most of the solvent by rotary evaporation, the mixture was added to methanol to precipitate a reddish-brown solid. After vacuum drying for 12 hours, compound 5 was obtained and used directly in the next step.

[0044] Step S4: Synthesize compound 6 Under argon protection, compound 5 (4.43 g, 5 mmol) and 20 mL of tetrahydrofuran were added sequentially to a 100 mL three-necked round-bottom flask. After cooling to 0 °C and stirring for 15 minutes, 10 mL of [unspecified ingredient] was added dropwise. N , N -Dimethylformamide dissolved NA solution of 1.95 g (11 mmol) of bromosuccinimide was added, and the mixture was allowed to return to room temperature for 12 hours after the addition was complete. The reaction was then stopped, and the reaction mixture was poured into 100 mL of water and extracted three times with dichloromethane. The organic phases were combined and dried over anhydrous sodium sulfate. The solvent was removed by rotary evaporation, and the mixture was purified by silica gel column chromatography using petroleum ether / dichloromethane (v / v) as the eluent to give compound 6, an orange-yellow solid, 4.45 g, in 86% yield.

[0045] The structural characterization data of this compound are as follows: , , , , , .

[0046] Step S5: Synthesize compound 7 Under argon protection, compound 6 (1.04 g, 1 mmol) and 30 mL of tetrahydrofuran were added sequentially to a 100 mL three-necked round-bottom flask. A solution of diisopropylaminolithium (8 mmol) in n-hexane was then added dropwise at -78 °C. After the addition was complete, the reaction was maintained at this temperature for 1 hour, and then 4 mL (52 mmol) of the solution was added. N , N -Dimethylformamide. The reaction mixture was then brought to room temperature and stirred for 1 hour. The reaction was stopped, the reaction mixture was quenched with aqueous ammonium chloride solution, and extracted three times with dichloromethane. The organic layers were combined and dried over anhydrous sodium sulfate, filtered, and the solvent was removed under reduced pressure. The crude product was purified by silica gel column chromatography using petroleum ether / dichloromethane (4:1 v / v) as the eluent to give compound 7, an orange-yellow solid, 0.56 g, yield 51%. This compound 7 is intermediate M1.

[0047] The structural characterization data of this compound are as follows: , 4.61-4.59 (d, J = 8.0 Hz, 4H), 2.00 (br, 2H), 1.75-1.74 (m, 8H), 1.28-1.27 (m,16H), 1.26-1.25 (m, 24H), 0.95-0.84 (m, 12H); , 146.98, 143.91, 140.82, 136.49, 136.60, 133.89, 132.90, 128.86, 128.83, 128.80, 128.67, 127.52, 112.75, 55.43, 39.01, 31.79, 31.59, 31.56, 30.40, 30.37, 30.31, 30.27, 29.75, 29.43, 29.38, 29.20, 25.52, 25.48, 25.44, 25.40, 22.66, 22.61, 22.51, 14.13, 14.11, 13.97; Theoretical value 1100.229, measured value 1101.596.

[0048] Step S6: Synthesize receptor material β -SL-Br Under argon protection, compound 7 (220 mg, 0.2 mmol), 5,6-difluoro-3-(dicyanomethylene)indene-1-one (115.1 mg, 0.5 mmol), 15 mL of chloroform, and 0.5 mL (6.2 mmol) of pyridine were added sequentially to a 100 mL three-necked round-bottom flask. The mixture was heated to 65 °C and reacted for 12 hours. The reaction was then stopped, and after the reaction mixture cooled to room temperature, most of the solvent was removed by rotary evaporation. The residue precipitated in methanol to obtain the crude product. The crude product was purified by silica gel column chromatography using petroleum ether / dichloromethane (4:1 v / v) as the eluent to obtain a dark blue solid, which is the crude product. β - Brominated small molecule receptor β -SL-Br, 253 mg, yield 83%.

[0049] , 8.60 (t, J = 16.0 Hz, 2H), 7.78-7.74 (t, J = 16.0 Hz, 2H), 4.79-4.77 (d, J = 4.0 Hz, 4H), 2.16 (m, 2H), 1.27 (m, 8H), 1.17-1.15 (m, 16H), 1.03-0.88 (m, 24H), 0.83-0.79 (m, 6H), 0.74-0.70 (m, 6H); : 185.90, 146.98, 141.39, 137.15, 135.05, 133.99, 133.87, 132.31, 130.34, 129.97, 127.46, 121.47, 114.99, 114.77, 113.94, 113.74, 113.54, 70.48, 67.80, 55.54, 51.51, 39.02, 31.67, 31.60, 31.34, 31.17, 30.65, 30.35, 30.29, 29.98, 29.45, 29.16, 29.11, 25.35, 24.91, 24.00, 23.83, 22.44, 22.24, 13.84, 13.76.

[0050] Theoretical value: 1524.266, measured value: 1526.700.

[0051] Example 2: An invention β - Functionalized A-DA'DA type small molecule electron acceptor materials, specifically β - Triphenylamine-functionalized A-DA'DA type small molecule electron acceptor material β -SL-TPA has the following structural formula as shown in equation (I): Formula (I) In equation (I), R' is R is X is F.

[0052] The synthesis route is shown below: One embodiment of this invention β - Functionalized A-DA'DA type small molecule electron acceptor materials β The preparation method of -SL-TPA, and the specific synthesis steps are as follows: Steps S1 to S5 are the same as in Example 1.

[0053] Step S6: Synthesize intermediate M1: Under argon protection, compound 7 (660.8 mg, 0.6 mmol), 4-triphenylamine boric acid (867.4 mg, 3 mmol), tetrakis(triphenylphosphine)palladium Pd(PPh3)4 (34.7 mg, 0.03 mmol), K2CO3 (746.3 mg, 5.4 mmol), 30 mL toluene, 2.7 mL deionized water, and 0.1 mL (0.22 mmol) methyltrioctylammonium chloride were added sequentially to a 100 mL three-necked round-bottom flask. The mixture was heated to 100 °C and reacted for 12 hours. After the mixture cooled to room temperature, it was poured into water and extracted three times with dichloromethane. The organic phases were combined and dried over anhydrous sodium sulfate, and the solvent was removed by rotary evaporation. The crude product was purified by silica gel column chromatography using petroleum ether / dichloromethane (v / v 4:1) as the eluent to obtain an orange-red solid, which was intermediate M1, 0.68 g, yield 80%.

[0054] The structural characterization data of this compound are as follows: : : 10.01 (s, 2H),7.61-7.59 (m, 4H), 7.37-7.33 (m, 8H), 7.23-7.20 (m, 12H), 7.15-7.12 (m, 4H),4.67-4.66 (m, 4H), 2.08 (br, 2H), 1.28-1.11 (m, 8H), 1.05-1.00 (m, 16H), 0.99-0.83 (m, 24H), 0.80-0.74 (m, 12H); : 184.05, 149.47, 147.52, 146.97, 145.53, 142.90, 136.90, 136.61, 132.98, 130.55, 129.65, 129.19, 127.99, 125.48, 124.61, 124.16, 122.07, 112.48, 55.33, 39.02, 31.81, 31.61, 30.36, 29.75, 29.44, 29.38, 29.21, 25.45, 22.62, 22.54, 14.16, 14.03.

[0055] Theoretical value: 1428.620, measured value: 1429.621.

[0056] Step S7: Synthesize receptor materials β -SL-TPA Under argon protection, intermediate M1 (143 mg, 0.1 mmol), 5,6-difluoro-3-(dicyanomethylene)indene-1-one (92.1 mg, 0.4 mmol), 15 mL of chloroform, and 0.2 mL (2.5 mmol) of pyridine were added sequentially to a 100 mL three-necked round-bottom flask. The mixture was heated to 65 °C and reacted for 12 hours. The reaction was then stopped, and after the reaction mixture cooled to room temperature, most of the solvent was removed by rotary evaporation. The residue precipitated in methanol to obtain the crude product. The crude product was purified by silica gel column chromatography using petroleum ether / dichloromethane (2:1 v / v) as the eluent to obtain a dark blue solid, which is the crude product. β - Triphenylamine-functionalized small molecule receptor β -SL-TPA, 132 mg, yield 71%.

[0057] The structural characterization data of this compound are as follows: :8.95 (s, 2H), 8.57-8.53 (t, J = 8.0 Hz, 2H), 7.72-7.69 (t, J = 8.0 Hz, 2H), 7.52-7.50 (d, J = 8.0 Hz,4H), 7.40-7.36 (m, 8H), 7.30-7.27 (m, 12H), 7.17-7.14 (m, 4H), 4.80-4.78 (d, J = 8.0 Hz, 4H), 2.15 (br, 2H), 1.26-1.15 (m, 16H), 1.00 (m, 32H), 0.83-0.66(m, 12H); : 185.96, 158.53, 152.22,150.49, 147.53, 146.96, 144.30, 139.06, 137.67, 135.04, 134.10, 133.10,131.63, 131.34, 129.59, 125.64, 125.06, 124.18, 122.68, 120.59, 114.91,113.76, 113.51, 68.89, 55.63, 39.27, 31.86, 31.64, 30.58, 29.82, 29.72,29.48, 29.43, 29.23, 25.56, 22.60, 22.52, 14.11, 14.04; Theoretical value: 1853.660, measured value: 1853.314.

[0058] Example 3: An invention β - Functionalized A-DA'DA type small molecule electron acceptor materials, specifically β -A-DA'DA type small molecule electron acceptor material functionalized with o-trifluorobenzene β -SL-TFB has the following structural formula as shown in equation (I): Formula (I) In equation (I), R' is R is X is F.

[0059] The synthesis route is shown below: One embodiment of this invention β - Functionalized A-DA'DA type small molecule electron acceptor material β The preparation method of -SL-TFB, and the specific synthesis steps are as follows: Steps S1 to S5 are the same as in Example 1.

[0060] Step S6: Synthesize intermediate M1 Under argon protection, compound 7 (551 mg, 0.5 mmol), 3,4,5-trifluorophenylboronic acid (440 mg, 2.5 mmol), Pd(PPh3)4 (28.9 mg, 0.025 mmol), K2CO3 (622 mg, 4.5 mmol), 20 mL toluene, 2.25 mL water, and 0.1 mL (0.22 mmol) methyltrioctylammonium chloride were added sequentially to a 100 mL three-necked round-bottom flask. The mixture was heated to 100 °C and reacted for 12 hours. After the mixture cooled to room temperature, it was poured into water. The aqueous phase was extracted three times with dichloromethane. The organic phases were combined and dried over anhydrous sodium sulfate, and the solvent was removed by rotary evaporation. The crude product was purified by silica gel column chromatography using petroleum ether / dichloromethane (v / v 4:1) as the eluent to obtain an orange-red solid, which was intermediate M1, 475 mg, yield 79%.

[0061] The structural characterization data of this compound are as follows: : 9.94 (s, 2H), 7.43-7.39 (m, 4H), 4.68-4.66 (d, J= 8.0 Hz, 4H), 2.04 (m, 2H), 1.14-1.12 (m, 8H), 0.9-0.94 (m, 16H), 0.86-0.83 (m, 24H), 0.82-0.79 (m, 12H); : 182.33, 152.81, 152.75, 152.71, 150.33, 150.29, 150.23, 150.19, 147.04, 142.17, 141.00, 137.91, 136.43, 132.85, 129.32, 127.78, 127.53, 127.48, 124.21, 123.72, 113.94, 113.88, 113.78, 113.72, 112.41, 65.46, 55.15, 40.28, 38.80, 34.61, 34.26, 31.65, 31.62, 31.52, 31.30, 31.17, 30.68, 30.10, 30.07, 29.92, 29.82, 29.49, 29.42, 29.36, 29.11, 29.08, 28.91, 26.63, 26.60, 25.18, 22.42, 22.40, 22.32, 22.23, 13.85, 13.81, 13.70; Theoretical value: 1202.416, measured value: 1202.827.

[0062] Step S7: Synthesize receptor materials β -SL-TFB Under argon protection, intermediate M1 (241 mg, 0.2 mmol), 5,6-difluoro-3-(dicyanomethylene)indene-1-one (115.1 mg, 0.5 mmol), 15 mL of chloroform, and 0.5 mL (6.2 mmol) of pyridine were added sequentially to a 100 mL three-necked round-bottom flask. The mixture was heated to 65 °C and reacted for 12 hours. The reaction was then stopped, and after the reaction mixture cooled to room temperature, most of the solvent was removed by rotary evaporation. The residue precipitated in methanol to obtain the crude product. The crude product was purified by silica gel column chromatography using petroleum ether / dichloromethane (2:1 v / v) as the eluent to obtain a dark blue solid, which is the crude product. β - Trifluorobenzene-functionalized small molecule acceptor β -SL-TFB, 260 mg, 80% yield.

[0063] The structural characterization data of this compound are as follows: : 8.84 (s, 2H), 8.60-8.56 (t, J = 16.0 Hz, 2H), 7.77-7.73 (t, J = 16.0 Hz, 2H), 7.33-7.30 (m, 4H), 4.83-4.82 (d, J = 4.0 Hz, 4H), 2.15 (m, 2H), 1.27 (m, 8H), 1.17-1.15 (m,16H), 1.03 (m, 24H), 0.82-0.78 (m, 6H), 0.72-0.68 (m, 6H); : 185.64, 157.69, 155.62, 153.15, 152.86, 150.71, 147.05, 146.56, 143.20, 139.81, 137.21, 136.50, 134.62, 133.80, 132.30, 130.96, 127.66, 121.76, 114.90, 113.84, 112.48, 70.28, 55.47, 39.09, 31.67, 31.61, 31.39, 30.36, 29.54, 29.21, 29.16, 28.97, 25.35, 227.44, 22.34, 22.25, 13.86, 13.81, 13.78.

[0064] Theoretical value: 1626.454, measured value: 1626.845.

[0065] Example 4: An invention β - Functionalized A-DA'DA type small molecule electron acceptor materials, specifically β --Tetraphenylene-functionalized A-DA'DA type small molecule electron acceptor material β -SL-TPE has the following structural formula as shown in equation (I): Formula (I) In equation (I), R' is R is X is F.

[0066] The synthesis route is shown below: One embodiment of this invention β - Functionalized A-DA'DA type small molecule electron acceptor materials β The preparation method of -SL-TPE, and the specific synthesis steps are as follows: Steps S1 to S5 are the same as in Example 1.

[0067] Step S6: Synthesize intermediate M1 Under argon protection, compound 7 (330 mg, 0.3 mmol), 1-(4-phenylboronic acid pinacol ester)-1,2,2-tristyrene (550 mg, 1.2 mmol), Pd(PPh3)4 (17.3 mg, 0.015 mmol), K2CO3 (248 mg, 1.8 mmol), 15 mL toluene, 0.9 mL water, and 0.1 mL (0.22 mmol) methyltrioctylammonium chloride were added sequentially to a 100 mL three-necked round-bottom flask. The mixture was heated to 110 °C and reacted for 24 hours. After the mixture cooled to room temperature, it was poured into water. The aqueous phase was extracted three times with dichloromethane. The organic phases were combined and dried over anhydrous sodium sulfate, and the solvent was removed by rotary evaporation. The crude product was purified by silica gel column chromatography using petroleum ether / dichloromethane (v / v 5:2) as the eluent to obtain an orange-red solid, which was intermediate M1, 356 mg, in 82% yield.

[0068] The structural characterization data of this compound are as follows: : 9.89 (s, 2H), 7.54-7.50(m, 4H), 7.27 (m, 2H), 7.20-7.16 (m, 12 H), 7.15-7.13 (m, 8H), 7.10-7.08 (m,8H), 7.05-7.02 (m, 4H), 4.68- 4.66 (d, J = 8.0 Hz, 4H), 2.07 (m, 2H), 1.32-1.26 (m, 8H), 1.13-1.04 (m, 16H), 0.96-0.88 (m, 24H), 0.81-0.77 (m, 12H); : 183.76, 147.26, 145.51, 145.18, 143.10, 143.08, 142.89, 142.71, 142.20, 139.69, 137.04, 136.60, 133.88, 132.79, 132.11, 132.02, 131.18, 131.16, 131.14, 131.10, 130.49, 129.63, 128.95, 128.81, 128.75, 128.00, 127.87, 127.72, 127.66, 127.54, 127.51, 127.41, 126.77, 126.60, 126.54, 126.30, 126.22, 125.08, 112.29, 83.46, 55.09, 38.76, 31.54, 31.33, 30.13, 29.47, 29.16, 29.11, 28.94, 25.20, 24.68, 22.36, 22.28, 21.25, 13.90, 13.76; Theoretical value: 1603.695, measured value: 1604.133.

[0069] Step S7: Synthesize receptor materials β -SL-TPE Under argon protection, intermediate M1 (321 mg, 0.2 mmol), 5,6-difluoro-3-(dicyanomethylene)inden-1-one (115.1 mg, 0.5 mmol), 15 mL of chloroform, and 0.5 mL (6.2 mmol) of pyridine were added sequentially to a 100 mL three-necked round-bottom flask. The mixture was heated to 65 °C and reacted for 12 hours. The reaction was then stopped, and after the reaction mixture cooled to room temperature, most of the solvent was removed by rotary evaporation. The residue precipitated in methanol to obtain the crude product. The crude product was purified by silica gel column chromatography using petroleum ether / dichloromethane (2:1 v / v) as the eluent to obtain a dark blue solid, which is the crude product. β -Tetraphenylene-functionalized small molecule acceptor β -SL-TPE, 342 mg, yield 84%.

[0070] The structural characterization data of this compound are as follows: : 8.86 (s, 2H), 8.55-8.51 (t, J = 16.0 Hz, 2H), 7.72-7.68 (t, J= 16.0 Hz, 2H), 7.43-7.41 (m, 4H), 7.32-7.30 (m, 4H), 7.24-7.20 (m, 6H), 7.18-7.14 (m, 20H), 7.11-7.08 (m, 4H), 4.78-4.76 (d, J = 8.0 Hz, 4H), 2.13 (m, 2H), 1.25 (m, 8H), 1.13-1.10 (m,16H), 0.99-0.98 (m, 24H), 0.77-0.75 (m, 6H), 0.68-0.64 (m, 6H); : 185.45, 158.60, 151.24, 147.26, 146.23, 145.43, 143.35, 143.08, 143.05, 142.20, 139.65, 138.34, 137.30, 134.61, 134.17, 133.88, 133.00, 132.56, 131.47, 131.41, 131.31, 131.14, 130.06, 129.46, 127.75, 127.59, 127.47, 126.64, 126.51, 126.44, 120.93, 114.66, 114.39, 113.31, 113.25, 113.31, 70.22, 55.38, 53.18, 39.01, 31.58, 31.36, 30.32, 29.54, 29.46, 29.20, 29.15, 29.07, 29.95, 25.31, 22.45, 22.33, 22.25, 13.88, 13.84, 13.77.

[0071] Theoretical value: 2027.732, measured value: 2028.544.

[0072] Performance testing Test the products prepared in Examples 1-4 above. β - Functionalized A-DA'DA type small molecule receptor materials ( β -SL-Br、 β -SL-TPA, β -SL-TFB、 β The various performance characteristics of the SL-TPE were tested and compared. The tested performance characteristics are as follows: 1. Absorption properties are determined by UV-Vis absorption. Spectroscopy for testing use The absorption spectrophotometer was used to test the absorption spectra of the material in solution and solid film states. For the solution absorption spectrum, chloroform was used as the solvent, and the small molecule acceptor material was prepared into a 10 μg / mL solution. For the film absorption test, a 15 mg / mL chloroform solution of the small molecule acceptor material was spin-coated onto a quartz plate at 3000 rpm for 30 seconds.

[0073] Prepared in Examples 1-4 β The UV-Vis absorption spectrum of the functionalized A-DA'DA type small molecule receptor in chloroform solution is shown below. Figure 1 As shown. By Figure 1 It can be seen that the various prepared β - Functionalized A-DA'DA type small molecule acceptor materials exhibit strong absorption in the 500–800 nm range, and their thin-film absorption (e.g. Figure 2 Compared to solution absorption, it exhibits a significant redshift, with its absorption edge shifting to around 1000 nm, indicating strong intermolecular interactions and aggregation. Figure 2 middle β -SL-Br and β The maximum absorption peak positions of -SL-TFB are 834 nm and 832 nm, respectively, which is higher than that of -SL-TFB. β - Position with large resistance β -SL-TPA (788 nm) and β The significant redshift of -SL-TPE (788 nm) increases the range of light absorption, which is beneficial for improving the short-circuit current of the material and thus enhancing the photovoltaic performance of organic solar cell devices. These results demonstrate... β Functionalization at the - position is beneficial for controlling absorption properties, and the introduction of sterically hindered groups can weaken the solid-state aggregation of molecules.

[0074] 2. The HOMO and LUMO energy levels were measured using cyclic voltammetry (CV). On an electrochemical workstation, a three-electrode system was used for testing: a platinum electrode with a thin film coating of a small molecule acceptor material as the working electrode, a Pt wire as the counter electrode, and an Ag / AgCl electrode as the reference electrode, with a ferrocene redox couple (Fc / Fc) as the reference electrode. + () was used as an internal standard. The test was performed in 0.1 mol / L tetrabutylammonium hexafluorophosphate (Bu4NPF6) acetonitrile solution at a scan rate of 50 mV / s.

[0075] Prepared in Examples 1-4 β The CV curve of a functionalized A-DA'DA type small molecule receptor material is shown in the figure. Figure 3 As shown. First from Figure 3 The initial oxidation / reduction potentials of each material were obtained from the CV curves. Then, the HOMO / LUMO energy levels of the material are calculated using the formula: The final calculations yielded the small molecule receptor materials prepared in Examples 1-4. β -SL-Br、 β -SL-TPA, β -SL-TFB and β The HOMO / LUMO levels of -SL-TPE are -5.29 / -4.10 eV, -5.28 / -3.83 eV, -5.33 / -4.12 eV, and -5.56 / -3.69 eV, respectively. It is not difficult to see... β Introducing functional groups with different steric hindrance and electronic properties is beneficial for modulating the HOMO and LUMO energy levels of acceptor materials, especially the introduction of triphenylamine, which has large steric hindrance and luminescent properties. β -SL-TPA) and tetraphenylethylene ( β The -SL-TPE group can significantly raise the LUMO energy level, which is beneficial for obtaining a higher open-circuit voltage.

[0076] 3. Fabrication and photovoltaic performance testing of organic solar cell devices The A-DA'DA type small molecule acceptor materials prepared in Examples 1-4 were used to fabricate organic solar cell photovoltaic devices, and their photovoltaic performance was tested. The fabrication process of the solar photovoltaic devices is as follows: (1) The anode is indium tin oxide conductive glass (ITO), and a layer of anode modification layer PEDOT:PSS polymer conductive film is spin-coated on it and treated at 150°C for 15 minutes; (2) Spin-coat a photoactive layer made of a blend of polymer donor PM6 and one of the small molecule acceptor materials prepared in Examples 1 to 4 (the weight ratio of donor and acceptor materials is 1:1.2, and the weight ratio can be between 1:0.8 and 2, with chlorobenzene or chloroform as solvent and a total concentration of donor and acceptor of 10 to 30 mg / mL). If necessary, add an appropriate amount (0.25 to 0.3%, by volume) of 1,8-diiodooctane (DIO) or 1-chloronaphthalene (CN) to the active layer as an additive. (3) After drying for half an hour, spin-coat a layer of PFN-Br with a thickness of about 10 nm as a cathode modification layer; (4) Finally, the cathode metal silver (about 100 nm) is evaporated and deposited as the device cathode to obtain the solar cell device.

[0077] The photovoltaic performance of this organic solar cell under simulated sunlight (AM 1.5G, 100 mW / cm²) is as follows. 2Tested using Keithley 2602 table source, etc.

[0078] The chemical structure of PM6, the polymer donor material used in the aforementioned solar cell devices, is as follows: The effective area of ​​the three types of solar cell devices prepared above is 0.04 cm². 2 The photovoltaic performance of the solar cell under simulated sunlight (AM 1.5G, 100 mW / cm²) was compared. 2 The light intensity was tested using a standard monocrystalline silicon solar cell; the short-circuit current density-open-circuit voltage characteristics were also tested. JV The curves were measured using a Keithley 2450. The open-circuit voltage of the aforementioned solar cell device was obtained through testing. V OC ), short-circuit current density ( J SC The three parameters, including the fill factor (FF), are used to calculate the corresponding power conversion efficiency (PCE).

[0079] Figure 4 Based on the preparations in Examples 1-4 β - Functionalized A-DA'DA type small molecule acceptor materials applied to organic solar cells JV Curve. For example... Figure 4 As shown, the photovoltaic performance of binary OSCs based on various acceptor materials is as follows: PM6: β -SL-Br: J SC 24.14 mA / cm 2 , V OC The voltage is 0.726V, the open circuit voltage (FF) is 72.6%, and the corresponding PCE is 12.72%. PM6: β -SL-TPA: J SC 22.25 mA / cm 2 , V OC The voltage is 0.915 V, the open circuit factor (FF) is 71.8%, and the corresponding PCE is 14.63%. PM6: β -SL-TFB: J SC 26.19 mA / cm 2 , V OC The voltage is 0.634 V, the power factor (FF) is 67.1%, and the corresponding PCE is 11.14%. PM6: β -SL-TPE: J SC 23.48 mA / cm 2 , V OC The voltage is 0.871 V, the power factor (FF) is 57.4%, and the corresponding PCE is 11.74%. The results from the above devices show that, β -Four small molecule receptors with functionalization β -SL-Br、 β -SL-TPA, β -SL-TFB and β -SL-TPE achieved energy conversion efficiencies of 12.72%, 14.63%, 11.14%, and 11.74%, respectively. β -SL-Br has the highest FF. β -SL-TPA has the highest V OC ,and β -SL-TFB has the highest J SC .final β -SL-TPA achieved optimal device efficiency. These results indicate that... β - A functionalized version of FF V OC and J SC All of these can have a significant impact, therefore it is necessary to conduct research on them. β Only through proper functionalization can the three performance parameters be comprehensively coordinated to ultimately obtain optimal photovoltaic performance. Furthermore, if compared with common... β Compared to similar receptors with alkyl substitution at the - position (e.g., Y6, Yuan J., Zhang Y., Zhou L., et al , Single-junction organic solar cell with over 15% efficiency using fused-ring acceptor with electron-deficient core, Joule 2019, 3 (1140-1151), functional groups with large steric hindrance and luminescent properties can be found. β -SL-TPA and β -SL-TPE's open-circuit voltage is significantly higher than that of Y6 ( V OC(around 0.85 V), which is attributed to their high LUMO energy level, and also indicates that through β Introducing luminescent groups at the --position is beneficial for increasing the open-circuit voltage of A-DA'DA type acceptor materials. Therefore, there is reason to believe that through... β The introduction of a functional substitution synergistically balances FF. V OC and J SC Ultimately, this can lead to the acquisition of highly efficient receptor materials.

[0080] This invention uses synthetic β Multiple organic solar cell devices were fabricated using functionalized A-DA'DA type small molecules as acceptor materials, achieving a highest power conversion efficiency of 14.63% and an open-circuit voltage as high as 0.915 V. All experimental results demonstrate that this invention provides… β Functionalized A-DA'DA type small molecules are effective small molecule acceptor materials, showing great application value in organic solar cells. The acceptor materials described in this invention not only have a simple and effective synthesis method, but also yield a series of solar cell devices with excellent photovoltaic performance based on these materials. This is significant for studying the structure of such small molecule acceptor materials (especially...). β The relationship between functionalization and performance is of great significance and can further guide the development of highly efficient small molecule electron acceptor materials.

[0081] It should be noted that the above embodiments are merely preferred embodiments of the present invention and are not intended to limit the present invention in any way. 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, and all such modifications or substitutions should be covered within the scope of the claims of the present invention.

Claims

1. A kind β A-DA'DA type small molecule electron acceptor material with 1-position functionalization, characterized in that... The β - Functionalized A-DA'DA type small molecule electron acceptor materials have the following structural formula (I): Formula (I) In the formula (I): R' is selected from any of the following groups: , , , , , , , , ; R is selected from any of the following groups: , , , , , , , , , , , , , , , , , , , , , , ; X is selected from any one of the following groups: H, F, Cl.

2. A device as described in claim 1 β A method for preparing a functionalized A-DA'DA type small molecule electron acceptor material, characterized in that... The β - Functionalized A-DA'DA type small molecule electron acceptor materials are prepared by Knoevenagel condensation reaction of intermediate M1 and compound N1 containing A unit in the presence of solvent and catalyst. The intermediate M1 has the structural formula shown in formula (II), and the compound N1 containing A unit has the structural formula shown in formula (III). Equation (II) Formula (III); In the above formula (II): R' is selected from any of the following groups: , , , , , , , , ; R is selected from any of the following groups: , , , , , , , , , , , , , , , , , , , , , , ; In formula (III): X is any one of H, F and Cl.

3. As described in claim 2 β A method for preparing a functionalized A-DA'DA type small molecule electron acceptor material, characterized in that... The molar ratio of intermediate M1 to compound N1 containing unit A is 1:2 to 4; And / or, the molar ratio of the catalyst to the intermediate M1 is 25 to 35:1; And / or, the catalyst is one of pyridine, piperidine, and triethylamine; And / or, the solvent is one of chloroform, dichloromethane and toluene.

4. As described in claim 2 β A method for preparing a functionalized A-DA'DA type small molecule electron acceptor material, characterized in that... When R is divisible When other than the specified groups, the intermediate M1 is prepared by the following method: S1. Compound 1, Compound 2, catalyst tris(dibenzylacetone)dipalladium and ligand tris(o-methylphenyl)phosphine were heated in toluene under an inert gas atmosphere to give Compound 3. S2. Under inert gas protection, compound 3 and triphenylphosphine were reacted in o-dichlorobenzene at a high temperature of 160℃~190℃ to obtain compound 4; S3. Under the protection of an inert gas, compound 4, bromoalkane, potassium carbonate, and potassium iodide are placed in... N , N Compound 5 is obtained by heating dimethylformamide. S4. Under the protection of an inert gas, compound 5 and N - Bromosuccinimide was reacted in tetrahydrofuran in an ice bath followed by a reaction at room temperature to give compound 6; S5. Under inert gas protection, compound 6 and diisopropylaminolithium were reacted in tetrahydrofuran at a low temperature of -40°C to -80°C, and then added... N , N -Dimethylformamide, after being restored to room temperature and the reaction continued, yielded compound 7; S6. Under inert gas protection, compound 7, borate compound 8-1 or borate ester compound 8-2, potassium carbonate, catalyst tetra(triphenylphosphine)palladium, water, methyltrioctylammonium chloride and toluene are heated to react and obtain intermediate M1; Compound 1 is: ; Compound 2 is: ; The compound 3 is: ; Compound 4 is: ; Compound 5 is: ; Compound 6 is: ; The compound 7 is: ; The borate compound 8-1 is: ; The borate ester compound 8-2 is: .

5. The method according to claim 4 β A method for preparing a functionalized A-DA'DA type small molecule electron acceptor material, characterized in that... In step S1, the molar ratio of compound 1 to compound 2 is 2-4:1, the molar ratio of catalyst tris(dibenzylacetone)dipalladium to compound 2 is 1-3:100, the molar ratio of catalyst tris(dibenzylacetone)dipalladium to ligand tris(o-methylphenyl)phosphine is 1:3-5, the heating reaction time is 1-4 hours, and the heating reaction temperature is 90℃-110℃. And / or, in S2, the molar ratio of compound 3 to triphenylphosphine is 1:5 to 8, and the high-temperature reaction time is 2 to 6 hours; And / or, in S3, the molar ratio of compound 4, the bromoalkane, the potassium carbonate, and the potassium iodide is 1:2 to 4:10 to 20:0.03 to 0.1, the heating reaction time is 2 to 6 hours, and the heating reaction temperature is 130°C to 150°C; And / or, in S4, compound 5 and the N The molar ratio of 1:2 to 2.5 for bromosuccinimide is 1:2 to 2.5, and the reaction time at room temperature is 6 to 12 hours. And / or, in S5, the compound 6, the lithium diisopropylamino, the N , N The molar ratio of dimethylformamide is 1:6 to 10:30 to 60, the low-temperature reaction time is 1 hour to 2 hours, and the room-temperature reaction time is 0.5 hours to 1 hour; And / or, in S6, the molar ratio of compound 7, borate compound 8-1 or borate ester compound 8-2, potassium carbonate, and catalyst tetra(triphenylphosphine)palladium is 1:3 to 6:6 to 10:0.03 to 0.1, the molar ratio of methyltrioctylammonium chloride to compound 7 is 1:1 to 3, the amount of water used is such that the concentration of potassium carbonate is 2 mol / L, the temperature of the heating reaction is 100℃ to 120℃, and the heating reaction time is 12h to 36h.

6. The method according to claim 2 β A method for preparing a functionalized A-DA'DA type small molecule electron acceptor material, characterized in that... When R is -Br, the intermediate M1 is prepared by the following method: S1. Compound 1, Compound 2, catalyst tris(dibenzylacetone)dipalladium and ligand tris(o-methylphenyl)phosphine were heated in toluene under an inert gas atmosphere to give Compound 3. S2. Under inert gas protection, compound 3 and triphenylphosphine were reacted in o-dichlorobenzene at a high temperature of 160℃~190℃ to obtain compound 4; S3. Under the protection of an inert gas, compound 4, bromoalkane, potassium carbonate, and potassium iodide are placed in... N , N Compound 5 is obtained by heating dimethylformamide. S4. Under the protection of an inert gas, compound 5 and N - Bromosuccinimide was reacted in tetrahydrofuran in an ice bath followed by a reaction at room temperature to give compound 6; S5. Under inert gas protection, compound 6 and diisopropylaminolithium were reacted in tetrahydrofuran at a low temperature of -40°C to -80°C, and then added... N , N -Dimethylformamide, after being restored to room temperature and the reaction continued, yielded compound 7, which is intermediate M1; Compound 1 is: ; Compound 2 is: ; The compound 3 is: ; Compound 4 is: ; Compound 5 is: ; Compound 6 is: ; The compound 7 is: .

7. The method according to claim 6 β A method for preparing a functionalized A-DA'DA type small molecule electron acceptor material, characterized in that... In step S1, the molar ratio of compound 1 to compound 2 is 2-4:1, the molar ratio of catalyst tris(dibenzylacetone)dipalladium to compound 2 is 1-3:100, the molar ratio of catalyst tris(dibenzylacetone)dipalladium to ligand tris(o-methylphenyl)phosphine is 1:3-5, the heating reaction time is 1-4 hours, and the heating reaction temperature is 90℃-110℃. And / or, in S2, the molar ratio of compound 3 to triphenylphosphine is 1:5 to 8, and the high-temperature reaction time is 2 to 6 hours; And / or, in S3, the molar ratio of compound 4, the bromoalkane, the potassium carbonate, and the potassium iodide is 1:2 to 4:10 to 20:0.03 to 0.1, the heating reaction time is 2 to 6 hours, and the heating reaction temperature is 130°C to 150°C; And / or, in S4, compound 5 and the N The molar ratio of 1:2 to 2.5 for bromosuccinimide is 1:2 to 2.5, and the reaction time at room temperature is 6 to 12 hours. And / or, in S5, the compound 6, the lithium diisopropylamino, the N , N The molar ratio of dimethylformamide is 1:6 to 10:30 to 60, the low-temperature reaction time is 1 to 2 hours, and the room-temperature reaction time is 0.5 to 1 hour.

8. A device as described in claim 1 β - Functionalized A-DA'DA type small molecule electron acceptor material or prepared by the preparation method as described in any one of claims 2 to 7 β Application of functionalized A-DA'DA type small molecule electron acceptor materials in the fabrication of solar cells.

9. The application according to claim 8, characterized in that, The application includes the following steps: (1) A layer of PEDOT:PSS polymer conductive film is spin-coated onto the ITO conductive glass on the anode; (2) Spin coat another layer of the above-mentioned material β A photoactive layer composed of a functionalized A-DA'DA type small molecule electron acceptor material and a polymer donor PBDB-T or PM6 or D18; (3) Next, spin-coat the PFN-Br cathode modification layer; (4) Finally, the cathode metal Ag is vapor-deposited to obtain an organic solar cell device.

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