Small organic molecule donor photovoltaic material containing five-membered fused heterocycle electron donor unit and preparation and application of small organic molecule donor photovoltaic material

Abstract

The invention belongs to the field of solar cells, and particularly relates to an organic small molecule donor photovoltaic material containing a five-membered fused heterocycle electron donor unit and a preparation method and application of the organic small molecule donor photovoltaic material. The invention particularly relates to a compound shown in a formula I (D-A-A ', D, A and A' are defined in the specification) or an isomer thereof, a preparation method thereof and application of the compound as an organic solar donor material.

Description

A Class of Organic Small Molecule Photovoltaic Materials Containing Five-Member Fused Heterocyclic Electron-Donating Units and Their Preparation and Application Technical Field

[0001] This invention belongs to the field of solar cells, specifically relating to a class of organic small molecule donor photovoltaic materials containing five-membered fused heterocyclic electron-donating units, their preparation methods, and applications. Background Technology

[0002] Organic solar cells based on vacuum evaporation were first reported in 1986, with a conversion efficiency of only 1%. The novel solar cell structure developed in this work promoted the development of organic solar cells.

[0003] Vacuum-deposited organic solar cells (ODCs) are a key research focus in the field of organic solar cells due to the advantages of their fabrication process and the inherent properties of small-molecule materials. Compared to solution-based ODCs, vacuum-deposited ODCs exhibit higher stability, and the technology has been successfully applied in the commercialization of organic light-emitting diodes (OLEDs), thus possessing greater practical commercial application potential. However, the photoelectric conversion efficiency of current vacuum-deposited ODCs is relatively low. Process limitations restrict the molecular weight of donor and acceptor materials, resulting in weaker light absorption and consequently affecting the short-circuit current density of the solar cell. This also limits the availability of suitable donor molecules for vacuum deposition. Summary of the Invention

[0004] This invention designs and synthesizes small molecule donor materials suitable for the preparation of organic solar cells by vacuum evaporation. By selecting appropriate electron-donating and electron-withdrawing groups, the light absorption capacity of the molecules is further improved, thereby promoting the photoelectric conversion efficiency of organic solar cells prepared by vacuum evaporation.

[0005] The first aspect of this application provides a compound or an isomer thereof represented by Formula I.

[0006] DAA′

[0007] Formula I

[0008] Wherein, the D group is selected from any one of the groups shown in formulas (a), (b), (c), (d), and (e):

[0009]

[0010] Among them, X1, X2, X3, X4, and X5 are independently selected from O, S, Se, NH, NR', CH2, C(R')2, Si(R')2, C=O, and C=C(CN)2, respectively, and R' is independently selected from C1-10 alkyl groups (e.g., C4-7 alkyl groups);

[0011] R1, R2, and R3 are independently selected from H, halogen, C1-10 alkyl, halo-C1-10 alkyl, CN, and C=(CN)2, respectively.

[0012] Furthermore, the D group does not have the following structure:

[0013] Where M is S or N, B is independently selected from C1-6 alkyl groups, and m is 0 or 1;

[0014] Group A has the following structure:

[0015] Wherein, Z is selected from O, S, Se, NH, NR'', R'' is selected from C1-10 alkyl groups; R4 and R5 are independently selected from H, F, Cl, Br, I, CN, respectively;

[0016] The A' group is selected from the following structures:

[0017] , , .

[0018] In Formula I, the D group can serve as an electron-donating unit group in a fused heterocycle, and the A-A' groups can serve as electron-withdrawing unit groups, where the A' group is an acceptor unit group. By selecting appropriate electron-donating and electron-withdrawing groups, the light absorption capacity of the molecule can be improved.

[0019] In some embodiments, R1, R2, and R3 in the D group are independently selected from F, Cl, Br, I, CH3, CF3, CF2H, CCl3, CN, and C=(CN)2, respectively.

[0020] In some embodiments, X1, X2, X3, X4, and X5 in the D group are independently selected from S, NR', and C(R')2, respectively. In some embodiments, X1, X2, X3, X4, and X5 are independently selected from S, N(C4-5 alkyl), and C(C6-7 alkyl)2, respectively.

[0021] In some embodiments, the D group has a structure as shown in formula (a), wherein X1 and X3 are independently NR' and X2 is S. In some embodiments, the D group has a structure as shown in formula (a), wherein X1 and X3 are independently N (C4-5 alkyl) and X2 is S.

[0022] In some embodiments, the D group has the structure shown in formula (b), wherein X2 and X4 are each S, and X1 and X3 are independently selected from NR' and C(R')2, respectively, and X1 and X3 may be the same or different. In some embodiments, the D group has the structure shown in formula (b), where X1 and X3 are independently NR'. In some embodiments, the D group has the structure shown in formula (b), where X1 and X3 are independently N (C4-7 alkyl). In some embodiments, the D group has the structure shown in formula (b), where X1 is NR' and X3 is C(R')2. In some embodiments, the D group has the structure shown in formula (b), where X1 is N (C4-5 alkyl) and X3 is C (C6-7 alkyl)2.

[0023] In some embodiments, the D group has the structure shown in formula (b), wherein R1 and R2 are independently selected from H and halogen, respectively. In some embodiments, the D group has the structure shown in formula (b), wherein R1 and R2 are independently selected from H and F, respectively. In some embodiments, the D group has the structure shown in formula (b), wherein R1 and R2 are both H.

[0024] In some embodiments, the D group has the structure shown in formula (c), wherein X2 and X4 are each S, and X1, X3, and X5 are each independently NR'. In some embodiments, the D group has the structure shown in formula (c), wherein X1, X3, and X5 are each independently N (C4-5 alkyl).

[0025] In some embodiments, the D group has a structure as shown in formula (c), wherein R1 is H.

[0026] In some embodiments, the D group has a structure as shown in formula (d), wherein X1 and X4 are each S, and X2 and X3 are each independently NR'. In some embodiments, the D group has a structure as shown in formula (d), wherein X2 and X3 are each independently N (C4-5 alkyl).

[0027] In some embodiments, the D group has a structure as shown in formula (d), wherein R1, R2, and R3 are all H.

[0028] In some embodiments, the D group has the structure shown in formula (e), wherein X1 and X3 are each S, and X2 and X4 are each independently NR'. In some embodiments, the D group has the structure shown in formula (e), wherein X2 and X4 are each independently N (C4-5 alkyl).

[0029] In some embodiments, the D group has a structure as shown in formula (e), wherein R1 is H.

[0030] In some implementations, Z in group A is S.

[0031] In some embodiments, R4 and R5 in group A are independently selected from H and halogen, respectively.

[0032] In some implementations, the A' group is .

[0033] In some embodiments, the compounds of the present invention are selected from:

[0034] .

[0035] A second aspect of this application provides a method for preparing the above-mentioned compound or its isomers, the method comprising the following steps:

[0036] (1) Compound 1 and compound 2 are coupled together to obtain compound 3. The reaction route is as follows:

[0037]

[0038] (2) Compound 3 is condensed with the precursor compound of the A′ group to obtain the compound of formula I. The reaction route is as follows:

[0039] .

[0041] The precursor compound of the A′ group refers to the compound that can generate the A′ group after undergoing a condensation reaction with compound 3.

[0042] In some embodiments, the coupling reaction in step (1) is carried out in the presence of a catalyst, such as a palladium catalyst, for example, Pd(PPh3)4 or Pd(PPh3)2Cl2.

[0043] In some implementations, in step (1), the molar mass ratio of compound 1 to compound 2 is 1:(1-2).

[0044] In some embodiments, the coupling reaction in step (1) is carried out in the presence of a solvent, exemplary solvents including any one or a combination of at least two of 1,4-dioxane, water or toluene.

[0045] In some implementations, the coupling reaction in step (1) is carried out at a temperature of 80-130°C.

[0046] In some implementations, the coupling reaction in step (1) is carried out for 8-24 hours (e.g., 12 hours).

[0047] In some embodiments, in step (2), the molar ratio of compound 3 to the precursor compound of the A′ group is 1:2.

[0048] In some implementations, the condensation reaction in step (2) is carried out in the presence of a solvent, an exemplary solvent including chloroform.

[0049] In some implementations, the condensation reaction in step (2) is carried out at a temperature of 10-30°C.

[0050] In some implementations, the condensation reaction in step (2) is carried out for 0.5-3 hours (e.g., 1 hour).

[0051] A third aspect of this application provides a solar cell donor material, including any of the above-described compounds or isomers thereof. In some embodiments, the solar cell donor material is an organic solar cell donor material, such as a vacuum-deposited organic solar cell donor material.

[0052] A fourth aspect of this application provides a solar cell comprising any of the compounds described above or isomers thereof, or any of the solar cell donor materials described above. In some embodiments, the solar cell is an organic solar cell, such as a vacuum-deposited organic solar cell, or a vacuum-deposited bulk heterojunction organic solar cell.

[0053] In some embodiments, the solar cell includes a solar cell acceptor material, which is C70.

[0054] In some implementations, the mass ratio of the solar cell donor material to the solar cell acceptor material is 1:3.

[0055] In some implementations, the solar cell donor material and the solar cell acceptor material are blended by vacuum evaporation.

[0056] In some embodiments, the solar cell includes an indium tin oxide conductive glass substrate.

[0057] In some implementations, the solar cell includes a molybdenum oxide anode layer.

[0058] In some implementations, the solar cell includes a BCP / Ag cathode layer.

[0059] An exemplary organic solar cell has a device structure of Glass / ITO / MoO3 (10nm) / Compounds:C 70 (80nm) / BCP(5nm) / Ag(100 nm). Includes an indium tin oxide conductive glass substrate (ITO), a molybdenum oxide anode layer (MoO3), and a cathode layer of BCP(5nm) / Ag(100 nm); the activation layer material is any of the above-mentioned DAA′ type molecules and fullerene molecules C. 70 The blending weight ratio is 1:3.

[0060] The fifth aspect of this application provides an electrical device including the solar cell of the fourth aspect of this application.

[0061] The sixth aspect of this application provides the use of any of the above-mentioned compounds or isomers thereof, or solar cell donor materials, in the fabrication of solar cells. In some embodiments, the solar cell is an organic solar cell, such as a vacuum-deposited organic solar cell, or a vacuum-deposited bulk heterojunction organic solar cell.

[0062] A seventh aspect of this application provides a method for preparing an organic solar cell, comprising using any of the above-described compounds or isomers thereof as a donor material. In some embodiments, the method is a vacuum evaporation method.

[0063] Terminology Definition

[0064] Unless otherwise defined below, all technical and scientific terms used herein are intended to have the same meaning as commonly understood by one of ordinary skill in the art. References to technical terms herein refer to techniques commonly understood in the art, including variations or equivalent substitutions of techniques that are obvious to one of ordinary skill in the art. While it is believed that the following terms will be well understood by one of ordinary skill in the art, the following definitions are set forth to better explain the invention.

[0065] The terms “comprising,” “including,” “having,” “containing,” or “involving,” and their other variations herein, are inclusive or open-ended and do not exclude other unlisted elements or method steps, although such other unlisted elements or method steps may not necessarily exist (i.e., these terms also cover the terms “consistently made up of” and “composed of”).

[0066] The term "alkyl" refers to a group formed by removing one hydrogen atom from a straight-chain or branched alkane molecule. Examples include C1-10 alkyl, C1-6 alkyl, C1-4 alkyl, and C4-7 alkyl, which respectively refer to alkyl groups having 1-10, 1-6, 1-4, or 4-7 carbon atoms. Specific examples of alkyl groups include, but are not limited to, methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, sec-butyl, tert-butyl, etc. , , , , , .

[0067] The term "halogenation" refers to the substitution of hydrogen atoms in a group or compound by one or more halogen atoms (e.g., F, Cl, Br, I), including full halogenation and partial halogenation.

[0068] The term "halogenated alkyl" refers to an alkyl group that is substituted with one or more (such as 1 to 3) identical or different halogen atoms.

[0069] If a substituent is described as being “independently selected” from a group, then each substituent is selected independently of the others. Therefore, each substituent may be the same as or different from another (other) substituent.

[0070] The term "stereoisomer" refers to an isomer formed due to at least one asymmetric center. In compounds having one or more (e.g., one, two, three, or four) asymmetric centers, this can result in exo / meta-racemic mixtures, single enantiomers, diastereomer mixtures, and single diastereomers. Specific individual molecules can also exist as geometric isomers (cis / trans). Similarly, the compounds of the present invention can exist as mixtures of two or more structurally different forms in rapid equilibrium (commonly referred to as tautomers). Representative examples of tautomers include keto-enol tautomers, phenol-keto tautomers, nitroso-oxime tautomers, imine-enamine tautomers, etc. For example, nitroso-oximes can exist in equilibrium in solution in the following tautomeric forms:

[0071] .

[0072] It should be understood that the scope of this application covers all such isomers or mixtures thereof in any proportion (e.g., 60%, 65%, 70%, 75%, 80%, 85%, 90%, 95%, 96%, 97%, 98%, 99%).

[0073] Solid lines can be used ( ), solid wedge ( ) or virtual wedge ( The chemical bonds of the compounds of the present invention are depicted. Solid lines are used to depict bonds to asymmetric carbon atoms to indicate that all possible stereoisomers (e.g., specific enantiomers, racemic mixtures, etc.) are included at that carbon atom. Solid or dashed wedges are used to depict bonds to asymmetric carbon atoms to indicate the presence of the indicated stereoisomers. When present in racemic mixtures, solid and dashed wedges are used to define relative stereochemistry, not absolute stereochemistry. Unless otherwise specified, the compounds of the present invention are intended to exist as stereoisomers (including cis and trans isomers, optical isomers (e.g., R and S enantiomers), diastereomers, geometric isomers, rotational isomers, conformational isomers, trans-blocking isomers, and mixtures thereof). The compounds of the present invention may exhibit more than one type of isomerism and may consist of mixtures thereof (e.g., racemic mixtures and diastereomer pairs).

[0074] In the various chemical structural formulas of this application, " "" indicates the bond that connects the structure to other groups.

[0075] The present invention has achieved the following beneficial effects:

[0076] This invention improves the photoelectric conversion efficiency of vacuum-deposited organic solar cells by extending the electron-donating unit of the fused ring and leveraging the light absorption capability of small molecules to increase the short-circuit current density. Detailed Implementation

[0077] The embodiments of the present invention will be described in detail below with reference to examples. However, those skilled in the art will understand that the following examples are for illustrative purposes only and should not be considered as limiting the scope of the invention. Unless otherwise specified in the examples, conventional conditions or conditions recommended by the manufacturer are followed. Reagents or instruments whose manufacturers are not specified are all commercially available conventional products.

[0078] Example 1 Synthesis of compound M1

[0079]

[0080] Synthesis route:

[0081]

[0082] (1) Synthesis of intermediate compound 1:

[0083] 5,6-Diisobutyl-3-(4,4,5,5-tetramethyl-1,3,2-dioxaborane-2-yl)-5,6-dihydrothieno[3,2-b:4,5-b'-]diindole (500 mg, 1.0 mmol), 7-bromobenzo[c][1,2,5]thiadiazole-4-carboxaldehyde (267.3 mg, 1.1 mmol), potassium carbonate (552 mg, 4.0 mmol), and Pd(PPh3)4 (57.8 mg, 0.05 mmol) were added to 60 mL of water. The mixture was stirred in mL of degassed 1,4-dioxane and water (9:1) solvent and refluxed under a nitrogen atmosphere for 12 hours. After cooling, the reaction mixture was poured into water and extracted with dichloromethane. The organic phase was dried over anhydrous MgSO4 to remove water, and the solvent was removed by rotary evaporation. The mixture was then purified by silica gel column chromatography with dichloromethane / petroleum ether (volume ratio 2:1) as the eluent, yielding a red solid as intermediate compound 1 with a mass of 350 mg and a yield of 65%. 1 H NMR (400 MHz, CDCl3): δ 10.82 (s,1H), 8.37 (d, J = 7.4 Hz, 1H), 8.34 (s, 1H), 8.03 (d, J = 7.4 Hz, 1H), 7.92(d, J = 8.3 Hz, 1H), 7.84-7.78 (m, 2H), 7.51 (d, J = 8.3 Hz, 1H), 7.38-7.33(m, 1H), 7.27-7.22 (m, 1H), 4.47 (d, J = 7.7 Hz, 2H), 4.39 (d, J = 7.7 Hz,2H), 2.45-2.35 (m, 2H), 0.96 (d, J = 6.6 Hz, 6H), 0.92 (d, J = 6.6 Hz, 6H).MALDI-TOF-MS (m / z): Found: 535.55; calcd. for (C 31 H 28 N4OS2): 536.17.

[0084] (2) Synthesis of compound M1:

[0085] Intermediate compound 1 (268 mg, 0.5 mmol) and malononitrile (66 mg, 1.0 mmol) were dissolved in 50 mL of chloroform, and a few drops of triethylamine were added. The mixture was stirred at room temperature for 1 hour. After the reaction was completed, the mixture was poured into water (50 mL), extracted with dichloromethane, dried over anhydrous MgSO4 and concentrated under reduced pressure to remove the solvent, purified by silica gel column chromatography with dichloromethane / petroleum ether (volume ratio 2:1) as eluent, and precipitated with methanol to give a dark purple solid, compound M1, with a mass of 248 mg and a yield of 85%. 1 H NMR (400 MHz, CDCl3): δ 8.90 (s, 1H), 8.88(d, J = 7.8 Hz, 1H), 8.37 (s, 1H), 8.06 (d, J = 7.9 Hz, 1H), 7.93-7.86 (m,2H), 7.79 (d, J = 7.8 Hz, 1H), 7.51 (d, J = 8.3 Hz, 1H), 7.39-7.34 (m, 1H), 7.27-7.23 (m, 1H), 4.47 (d, J = 7.7 Hz, 2H), 4.39 (d, J = 7.7 Hz, 2H), 2.46-2.35 (m, 2H), 0.96 (d, J = 6.6 Hz, 6H), 0.93 (d, J = 6.7 Hz, 6H). MALDI-TOF-MS (m / z): Found: 583.30; calcd. for (C 34 H 28 N6S2): 584.18.

[0086] Example 2 Synthesis of compound M2

[0087]

[0088] Synthesis route:

[0089]

[0090] (1) Synthesis of intermediate compound 2:

[0091] 4,5-Di(heptan-4-yl)-2-(tributyltinyl)-4,5-dihydrothieno[2'', 3'': 4', 5']pyrrolo[2', 3': 4,5]thieno[3,2-b]indole (754 mg, 1.0 mmol), 7-bromobenzo[c][1,2,5]thiadiazole-4-carboxaldehyde (267.3 mg, 1.1 mmol) and Pd(PPh3)2Cl2 (70.2 mg, 0.1 mmol) were added to 60 The mixture was stirred in anhydrous toluene solvent and refluxed under a nitrogen atmosphere for 8 hours. After the reaction was cooled, the reaction mixture was poured into water and extracted with dichloromethane. The organic phase was dried over anhydrous MgSO4 to remove water. After removing the solvent by rotary evaporation, the mixture was purified by silica gel column chromatography with dichloromethane / petroleum ether (volume ratio 1:1) as the eluent. The black solid was intermediate compound 2, with a mass of 453 mg and a yield of 72%. 1 H NMR (400 MHz, CDCl3): δ 10.71 (s, 1H), 8.72 (s, 1H), 8.24 (d, J = 7.6Hz, 1H), 7.98 (d, J = 7.6 Hz, 1H), 7.75-7.70 (m, 1H), 7.64-7.58 (m, 1H),7.27-7.20 (m, 2H), 4.89-4.79 (m, 2H), 2.32-2.20 (m, 4H), 2.12-2.03 (m, 4H),1.39-1.22 (m, 8H), 0.95-0.87 (m, 12H). MALDI-TOF-MS (m / z): Found: ; calcd.for (C 35 H 38 N4OS3): 626.22.

[0092] (2) Synthesis of compound M2:

[0093] Intermediate compound 2 (313 mg, 0.5 mmol) and malononitrile (66 mg, 1.0 mmol) were dissolved in 50 mL of chloroform, and a few drops of triethylamine were added. The mixture was stirred at room temperature for 1 hour. After the reaction was completed, the mixture was poured into water (50 mL), extracted with dichloromethane, dried over anhydrous MgSO4 and concentrated under reduced pressure to remove the solvent, purified by silica gel column chromatography with dichloromethane / petroleum ether (volume ratio 2:1) as eluent, and precipitated with methanol to give a purple solid, compound M2, with a mass of 279 mg and a yield of 83%. 1H NMR (400 MHz, CDCl3): δ 8.80-8.76 (m, 2H), 8.71 (s, 1H), 7.96 (d, J = 8.2 Hz, 1H), 7.76-7.70 (m, 1H), 7.63 (d, J = 8.2Hz, 1H), MALDI-TOF-MS (m / z): Found: ;calcd. for (C 38 H 38 N6S3): 674.23.

[0094] Example 3 Synthesis of compound M3

[0095]

[0096] Synthesis route:

[0097]

[0098] (1) Synthesis of intermediate compound 3:

[0099] 7-Fluoro-4,5-diisobutyl-2-(tributyltinyl)-4,5-dihydrothiopheno[2'',3'':4',5']pyrrolo[2',3':4,5]thiopheno[3,2-b]indole (688 mg, 1.0 mmol), 7-bromobenzo[c][1,2,5]thiadiazole-4-carboxaldehyde (267.3 mg, 1.1 mmol) and Pd(PPh3)2Cl2 (70.2 mg, 0.1 mmol) were added to 60 The mixture was stirred in anhydrous toluene solvent and refluxed under a nitrogen atmosphere for 8 hours. After the reaction was cooled, the reaction mixture was poured into water and extracted with dichloromethane. The organic phase was dried over anhydrous MgSO4 to remove water. After removing the solvent by rotary evaporation, the mixture was purified by silica gel column chromatography with dichloromethane / petroleum ether (volume ratio 2:1) as the eluent. The black solid was intermediate compound 3, with a mass of 420 mg and a yield of 75%. 1H NMR (400 MHz, CDCl3): δ 10.71 (s, 1H), 8.59 (s, 1H), 8.24 (d, J = 7.6Hz, 1H), 7.98 (d, J = 7.6 Hz, 1H), 7.67-7.61 (m, 1H), 7.17-7.11 (m, 1H),7.03-6.95 (m, 1H), 4.36 (d, J = 7.7 Hz, 2H), 4.24 (d, J = 7.8 Hz, 2H), 2.42-2.32 (m, 2H), 1.00 (d, J = 6.6 Hz, 6H), 0.93 (d, J = 6.6 Hz, 6H). MALDI-TOF-MS (m / z): Found: 559.34; calcd. for (C 29 H 25 FN4OS3): 560.12.

[0100] (2) Synthesis of compound M3:

[0101] Intermediate compound 3 (280 mg, 0.5 mmol) and malononitrile (66 mg, 1.0 mmol) were dissolved in 50 mL of chloroform, and a few drops of triethylamine were added. The mixture was stirred at room temperature for 1 hour. After the reaction was completed, the mixture was poured into water (50 mL), extracted with dichloromethane, dried over anhydrous MgSO4 and concentrated under reduced pressure to remove the solvent, purified by silica gel column chromatography with dichloromethane / petroleum ether (volume ratio 2:1) as eluent, and precipitated with methanol to give a reddish-brown solid, compound M3, with a mass of 261 mg and a yield of 86%. 1 H NMR (400 MHz, CDCl3): δ 8.84-8.76 (m, 2H), 8.59 (s, 1H), 8.00-7.92 (m, 1H), 7.67-7.60 (m, 1H), 7.18-7.12 (m, 1H), 7.03-6.97 (m, 1H), 4.35 (d, J = 7.7 Hz, 2H), 4.24 (d, J = 7.8 Hz, 2H), 2.39-2.31(m, 2H), 1.00 (d, J = 6.6 Hz, 6H), 0.93 (d, J = 6.6 Hz, 6H). MALDI-TOF-MS (m / z): Found: 607.07; calcd. for (C 32 H 25FN6S3): 608.13.

[0102] Example 4 Synthesis of compound M4

[0103]

[0104] Synthesis route:

[0105]

[0106] (1) Synthesis of intermediate compound 4:

[0107] 7,8-Difluoro-4,5-diisobutyl-2-(tributyltinyl)-4,5-dihydrothiopheno[2'',3'':4',5']pyrrolo[2',3':4,5]thiopheno[3,2-b]indole (578 mg, 1.0 mmol), 7-bromobenzo[c][1,2,5]thiadiazole-4-carboxaldehyde (267.3 mg, 1.1 mmol) and Pd(PPh3)2Cl2 (70.2 mg, 0.1 mmol) were added to 60 The mixture was stirred in anhydrous toluene solvent and refluxed under a nitrogen atmosphere for 8 hours. After cooling, the reaction mixture was poured into water and extracted with dichloromethane. The organic phase was dried over anhydrous MgSO4 to remove water. After removing the solvent by rotary evaporation, the mixture was purified by silica gel column chromatography with dichloromethane / petroleum ether (volume ratio 2:1) as the eluent. The resulting purple solid was intermediate compound 2, with a mass of 398 mg and a yield of 69%. 1 H NMR (400 MHz, CDCl3): δ 10.70 (s, 1H), 8.59 (s, 1H), 8.24 (d, J =7.6 Hz, 1H), 7.99 (d, J = 7.6 Hz, 1H), 7.50-7.42 (m, 1H), 7.27-7.19 (m, MALDI-TOF-MS (m / z): Found:577.33; calcd. for (C 29 H 24 F2N4OS3): 578.11.

[0108] (2) Synthesis of compound M4:

[0109] Intermediate compound 2 (289 mg, 0.5 mmol) and malononitrile (66 mg, 1.0 mmol) were dissolved in 50 mL of chloroform, and a few drops of triethylamine were added. The mixture was stirred at room temperature for 1 hour. After the reaction was completed, the mixture was poured into water (50 mL), extracted with dichloromethane, dried over anhydrous MgSO4 and concentrated under reduced pressure to remove the solvent, purified by silica gel column chromatography with dichloromethane / petroleum ether (volume ratio 2:1) as eluent, and precipitated with methanol to give a reddish-brown solid, compound M4, with a mass of 272 mg and a yield of 87%. 1 H NMR (400 MHz, CDCl3): δ 8.78 (d, J = 15.0Hz, 2H), 8.59 (s, 1H), 7.97 (s, 1H), 7.52-7.42 (m, 1H), 7.26-7.19 (m, 1H), 4.34 (d, J = 7.7 Hz, for (C 32 H 24 F2N6S3): 626.12.

[0110] Example 5 Synthesis of compound M5

[0111]

[0112] Synthesis route:

[0113]

[0114] (1) Synthesis of intermediate compound 5:

[0115] 4,5-Diisobutyl-2-(tributyltinyl)-4,5-dihydrothieno[2'', 3'': 4', 5']pyrrolo[2', 3': 4,5]thieno[3,2-b]indole (754 mg, 1.0 mmol), 7-bromo-5,6-difluorobenzo[c][1,2,5]thiadiazole-4-carboxaldehyde (305.7 mg, 1.1 mmol) and Pd(PPh3)2Cl2 (70.2 mg, 0.1 mmol) were added to 60 The mixture was stirred in anhydrous toluene solvent and refluxed under a nitrogen atmosphere for 8 hours. After cooling, the reaction mixture was poured into water and extracted with dichloromethane. The organic phase was dried over anhydrous MgSO4 to remove water. After removing the solvent by rotary evaporation, the mixture was purified by silica gel column chromatography with dichloromethane / petroleum ether (volume ratio 2:1) as the eluent. The resulting blackish-purple solid was intermediate compound 5, with a mass of 433 mg and a yield of 75%. 1 H NMR (400 MHz, CDCl3): δ 10.68 (s, 1H), 8.58 (s, 1H), 7.73-7.67 (m, 1H), 7.49-7.42 (m, 1H), 7.36-7.30 (m, 1H), 7.25-7.19 (m, 1H), 4.37 (d, J =7.6 Hz, 2H), 4.31 (d, J = 7.7 Hz, 2H), 2.45-2.31 (m, 2H), 1.01 (d, J = 6.6Hz, 6H), 0.93 (d, J = 6.7 Hz, 6H). MALDI-TOF-MS (m / z): Found: ; calcd. for(C 29 H 24 F2N4OS3): 578.11.

[0116] (2) Synthesis of compound M5:

[0117] Intermediate compound 5 (289 mg, 0.5 mmol) and malononitrile (66 mg, 1.0 mmol) were dissolved in 50 mL of chloroform, and a few drops of triethylamine were added. The mixture was stirred at room temperature for 1 hour. After the reaction was completed, the mixture was poured into water (50 mL), extracted with dichloromethane, dried over anhydrous MgSO4 and concentrated under reduced pressure to remove the solvent, purified by silica gel column chromatography with dichloromethane / petroleum ether (volume ratio 2:1) as eluent, and precipitated with methanol to give a purple-black solid, compound M5, with a mass of 260 mg and a yield of 83%. 1H NMR (400 MHz, CDCl3): δ 8.58 (s, 1H), 8.28(s, 1H), 7.76-7.69 (m, 1H), 7.51-7.45 (m, 1H), 7.38-7.31 (m, 1H), 7.27-7.21(m, 1H), MALDI-TOF-MS (m / z):Found: ; calcd. for (C 38 H 38 N6S3): 626.12.

[0118] Example 6 Synthesis of compound M6

[0119]

[0120] Synthesis route:

[0121]

[0122] (1) Synthesis of intermediate compound 6:

[0123] 5-Isobutyl-4,4-dimethyl-2-(tributyltinyl)-4,5-dihydrothieno[2'',3'':3'',4'']cyclopentane[1',2'':4,5]thieno[3,2-b]indole (641 mg, 1.0 mmol), 7-bromobenzo[c][1,2,5]thiadiazole-4-carboxaldehyde (267.3 mg, 1.1 mmol) and Pd(PPh3)2Cl2 (70.2 mg, 0.1 mmol) were added to 60 The mixture was stirred in anhydrous toluene solvent and refluxed under a nitrogen atmosphere for 8 hours. After cooling, the reaction mixture was poured into water and extracted with dichloromethane. The organic phase was dried over anhydrous MgSO4 to remove water. After removing the solvent by rotary evaporation, the mixture was purified by silica gel column chromatography with dichloromethane / petroleum ether (volume ratio 2:1) as the eluent. The resulting black solid was intermediate compound 6, with a mass of 374 mg and a yield of 73%. 1H NMR (400 MHz, CDCl3): δ 10.71 (s, 1H), 8.36 (s, 1H), 8.23 ​​(d, J =7.7 Hz, 1H), 7.99 (d, J = 7.6 Hz, 1H), 7.75-7.71 (m, 1H), 7.48-7.43 (m, 1H),7.35-7.30 (m, 1H), 7.25-7.18 (m, 1H), 4.32 (d, J = 7.9 Hz, 2H), 2.55-2.46 (m,1H), 1.82 (s, 6H), 0.98 (d, J = 6.7 Hz, 6H). MALDI-TOF-MS (m / z): Found: ;calcd. for (C 28 H 23 N3OS3): 513.10.

[0124] (2) Synthesis of compound M6:

[0125] Intermediate compound 6 (256 mg, 0.5 mmol) and malononitrile (66 mg, 1.0 mmol) were dissolved in 50 mL of chloroform, and a few drops of triethylamine were added. The mixture was stirred at room temperature for 1 hour. After the reaction was completed, the mixture was poured into water (50 mL), extracted with dichloromethane, dried over anhydrous MgSO4 and concentrated under reduced pressure to remove the solvent, purified by silica gel column chromatography with dichloromethane / petroleum ether (volume ratio 2:1) as eluent, and precipitated with methanol to give a purple solid, compound M6, with a mass of 241 mg and a yield of 86%. 1 H NMR (400 MHz, CDCl3): δ 8.80-8.72 (m, 2H), 8.39-8.34 (m, 1H), 8.00-7.91 (m, 1H), 7.78-7.68 (m, 1H), 7.46 (d, J = 8.2 Hz, 1H), MALDI-TOF-MS (m / z): Found: ;calcd. for (C 31 H 23 N5S3): 561.11.

[0126] Example 7 Synthesis of compound M7

[0127]

[0128] Synthesis route:

[0129]

[0130] (1) Synthesis of intermediate compound 7:

[0131] 5-Isobutyl-4,4-dimethyl-2-(tributyltinyl)-4,5-dihydrothieno[2'', 3'': 3'', 4'']cyclopentaeno[1', 2'': 4,5]thieno[3,2-b]indole (641 mg, 1.0 mmol), 7-bromo-6-fluorobenzo[c][1,2,5]thiadiazole-4-carboxaldehyde (286.0 mg, 1.1 mmol) and Pd(PPh3)2Cl2 (70.2 mg, 0.1 mmol) were added to 60 The mixture was stirred in anhydrous toluene solvent and refluxed under a nitrogen atmosphere for 8 hours. After the reaction was cooled, the reaction mixture was poured into water and extracted with dichloromethane. The organic phase was dried over anhydrous MgSO4 to remove water. After removing the solvent by rotary evaporation, the mixture was purified by silica gel column chromatography with dichloromethane / petroleum ether (volume ratio 2:1) as the eluent. The resulting black solid was intermediate compound 7, with a mass of 377 mg and a yield of 71%. 1 H NMR (400 MHz, CDCl3): δ 10.72 (s, 1H), 8.50 (s, 1H), 8.14 (d, J= 12.4 Hz, 1H), 7.75-7.67 (m, 1H), 7.45 (d, J = 8.3 Hz, 1H), 7.37-7.29 MALDI-TOF-MS (m / z): Found: ; calcd.for(C 28 H 22 FN3OS3): 531.09.

[0132] (2) Synthesis of compound M7:

[0133] Intermediate compound 7 (266 mg, 0.5 mmol) and malononitrile (66 mg, 1.0 mmol) were dissolved in 50 mL of chloroform, and a few drops of triethylamine were added. The mixture was stirred at room temperature for 1 hour. After the reaction was completed, the mixture was poured into water (50 mL), extracted with dichloromethane, dried over anhydrous MgSO4 and concentrated under reduced pressure to remove the solvent, purified by silica gel column chromatography with dichloromethane / petroleum ether (volume ratio 2:1) as eluent, and precipitated with methanol to give a purple solid, compound M7, with a mass of 243 mg and a yield of 84%. 1 H NMR (400 MHz, CDCl3): δ 8.77-8.62 (m, 2H), 8.53 (s, 1H), 7.72 (s, 1H), 7.53-7.38 (m, 2H), 7.25-7.19 (m, 1H), 4.32 (d, J= 7.8 Hz, 2H), 2.54-2.46 (m, 1H), 1.83 (s, 6H), 0.99 (d, J = 6.6 Hz, 6H).MALDI-TOF-MS (m / z): Found: ; calcd. for (C 31 H 22 FN5S3): 579.10.

[0134] Example 8 Synthesis of compound M8

[0135]

[0136] Synthesis route:

[0137]

[0138] (1) Synthesis of intermediate compound 8:

[0139] 4,5-Dibutyl-2-(tributyltinyl)-4,5-dihydrothieno[2,3-d:2',3'-d']thieno[3,2-b:4,5-b']dipyrrole (676 mg, 1.0 mmol), 7-bromobenzo[c][1,2,5]thiadiazole-4-carboxaldehyde (267.3 mg, 1.1 mmol), and Pd(PPh3)2Cl2 (70.2 mg, 0.1 mmol) were added to 60 mL of anhydrous toluene solvent and stirred. The mixture was refluxed under a nitrogen atmosphere for 8 hours. After cooling, the reaction mixture was poured into water and extracted with dichloromethane. The organic phase was dried over anhydrous MgSO4 to remove water. After removing the solvent by rotary evaporation, the mixture was purified by silica gel column chromatography with dichloromethane / petroleum ether (volume ratio 3:1) as the eluent. The resulting black solid was intermediate compound 8, with a mass of 411 mg and a yield of 75%. 1 H NMR (400MHz, CDCl3): δ 10.66 (s, 1H), 8.56 (s, 1H), 8.19 (d, J = 8.7 Hz, 1H), 7.92 (d,J = 9.0 Hz, 1H), 7.10 (d, J = 59.7 Hz, 2H), 4.30 (d, J = 8.1 Hz, 2H), 4.21(d, J = 7.5 Hz, 2H), 2.42-2.27 (m, 2H), 0.96 (d, J = 21.5 Hz, 12H). MALDI-TOF-MS (m / z): Found: 547.50; calcd. for (C 27 H 24 N4OS4): 548.08.

[0140] (2) Synthesis of compound M8:

[0141] Intermediate compound 8 (274 mg, 0.5 mmol) and malononitrile (66 mg, 1.0 mmol) were dissolved in 50 mL of chloroform, and a few drops of triethylamine were added. The mixture was stirred at room temperature for 1 hour. After the reaction was completed, the mixture was poured into water (50 mL), extracted with dichloromethane, dried over anhydrous MgSO4 and concentrated under reduced pressure to remove the solvent, purified by silica gel column chromatography with dichloromethane / petroleum ether (volume ratio 3:1) as eluent, and precipitated with methanol to give a purple solid, compound M8, with a mass of 259 mg and a yield of 87%. 1H NMR (400 MHz, CDCl3): δ 8.77-8.72 (m, 2H), 8.56 (s, 1H), 7.90 (d, J = 8.2 Hz, 1H), 7.22 (d, J = 5.3 Hz, 1H), 7.04 (d, J= 5.3 Hz, 1H), 4.29 (d, J = 7.7 Hz, 2H), 4.21 (d, J = 7.7 Hz, 2H), 2.40-2.28(m, 2H), 1.00 (d, J = 6.6 Hz, 6H), 0.95 (d, J = 6.6 Hz, 6H). MALDI-TOF-MS(m / z): Found: 595.26; calcd. for (C 30 H 26 N6S4): 596.09.

[0142] Example 9 Synthesis of compound M9

[0143]

[0144] Synthesis route of donor material M9:

[0145]

[0146] (1) Synthesis of intermediate compound 9:

[0147] 9,10-Diisobutyl-2-(tributyltinyl)-9,10-dihydrothieno[2',3':4,5]pyrrolo[3,2-g]thieno[3,2-b]indole (670 mg, 1.0 mmol), 7-bromobenzo[c][1,2,5]thiadiazole-4-carboxaldehyde (267.3 mg, 1.1 mmol), and Pd(PPh3)2Cl2 (70.2 mg, 0.1 mmol) were added to 60 mL of anhydrous toluene solvent and stirred. The mixture was refluxed under a nitrogen atmosphere for 8 hours. After cooling, the reaction mixture was poured into water and extracted with dichloromethane. The organic phase was dried over anhydrous MgSO4 to remove water. After removing the solvent by rotary evaporation, the mixture was purified by silica gel column chromatography with dichloromethane / petroleum ether (volume ratio 2:1) as the eluent. The resulting black solid was intermediate compound 9, with a mass of 417 mg and a yield of 77%. 1 H NMR (400 MHz, CDCl3): δ . MALDI-TOF-MS (m / z): Found: 541.49; calcd. for(C 29 H26 N4OS3): 542.13.

[0148] (2) Synthesis of compound M9:

[0149] Intermediate compound 2 (271 mg, 0.5 mmol) and malononitrile (66 mg, 1.0 mmol) were dissolved in 50 mL of chloroform, and a few drops of triethylamine were added. The mixture was stirred at room temperature for 1 hour. After the reaction was completed, the mixture was poured into water (50 mL), extracted with dichloromethane, dried over anhydrous MgSO4 and concentrated under reduced pressure to remove the solvent, purified by silica gel column chromatography with dichloromethane / petroleum ether (volume ratio 2:1) as eluent, and precipitated with methanol to give a purple solid, compound M9, with a mass of 257 mg and a yield of 87%. 1 H NMR (400 MHz, CDCl3): δ 8.84-8.77 (m, 2H),8.64 (s, 1H), 8.06 (d, J = 8.1 Hz, 1H), 7.62 (s, 2H), 7.40 (d, J = 5.1 Hz,1H), 7.16 (d, J = 5.2 Hz, 1H), 4.44 (d, J = 7.7 Hz, 2H), 4.36 (d, J = 7.6 Hz,2H), 2.39-2.25 (m, 2H), 0.69 (d, J = 6.6 Hz, 6H), 0.65 (d, J = 6.6 Hz, 6H).MALDI-TOF-MS (m / z): Found: 589.58; calcd. for (C 32 H 26 N6S3): 590.14.

[0150] Example 10 Synthesis of compound M10

[0151]

[0152] Synthesis route of donor material M10:

[0153]

[0154] (1) Synthesis of intermediate compound 10:

[0155] 4,5-Diisobutyl-7-(4,4,5,5-tetramethyl-1,3,2-dioxaborane-2-yl)-4,5-dihydrothieno[2',3':4',5']pyrrolo[2',3':4,5]thieno[3,2-b]indole (506 mg, 1.0 mmol), 7-bromobenzo[c][1,2,5]thiadiazole-4-carboxaldehyde (267.3 mg, 1.1 mmol), potassium carbonate (552 mg, 4.0 mmol), and Pd(PPh3)4 (57.8 mg, 0.05 mmol) were added to 60 The mixture was stirred in mL of degassed 1,4-dioxane and water (9:1) solvent and refluxed under a nitrogen atmosphere for 12 hours. After cooling, the reaction mixture was poured into water and extracted with dichloromethane. The organic phase was dried over anhydrous MgSO4 to remove water, and the solvent was removed by rotary evaporation. The mixture was then purified by silica gel column chromatography with dichloromethane / petroleum ether (volume ratio 2:1) as the eluent, yielding a black solid as intermediate compound 10 with a mass of 379 mg and a yield of 70%. 1 H NMR (400 MHz, CDCl3): δ 10.81 (s, 1H), 8.36 (d, J = 7.4 Hz, 1H), 8.31 (s, 1H), 8.01 (d, J = 7.4 Hz, 1H), 7.83 (d, J = 9.6 Hz, 2H), MALDI-TOF-MS (m / z): Found: 541.48; calcd. for (C 29 H 26 N4OS3): 542.13.

[0156] (2) Synthesis of compound M10:

[0157] Intermediate compound 10 (271 mg, 0.5 mmol) and malononitrile (66 mg, 1.0 mmol) were dissolved in 50 mL of chloroform, and a few drops of triethylamine were added. The mixture was stirred at room temperature for 1 hour. After the reaction was completed, the mixture was poured into water (50 mL), extracted with dichloromethane, dried over anhydrous MgSO4 and concentrated under reduced pressure to remove the solvent, purified by silica gel column chromatography with dichloromethane / petroleum ether (volume ratio 2:1) as eluent, and precipitated with methanol to give a reddish-brown solid, compound M10, with a mass of 250 mg and a yield of 85%. 1H NMR (400 MHz, CDCl3): δ 8.88 (s, 1H), 8.86 (d, J = 7.9 Hz, 1H), 8.34 (d, J = 1.4 Hz, 1H), 8.03 (d, J = 7.8 Hz, 1H), 7.88-7.81 (m, 2H), 7.23 (d, J = 5.3 Hz, 1H), 7.07 (d, J = 5.3 Hz, 1H), 4.40 (d, J = 7.8 Hz, 2H), 4.29 (d, J = 7.7 Hz, 2H), 2.47-2.28 (m, 2H), 0.99-0.92(m, 12H). MALDI-TOF-MS (m / z): Found: 589.57; calcd. for (C 32 H 26 N6S3): 590.14.

[0158] The compounds synthesized in Examples 1-10 were used as donor materials for characterization and performance testing. The experimental methods and results are as follows:

[0159] Test Example 1: Measurement of Ultraviolet-Visible Absorption Spectroscopy

[0160] The UV-Vis absorption spectra of each compound were measured using a Varian Cary 5000 UV-Vis spectrophotometer. The absorption peaks of each compound are shown in Table 1.

[0161] Table 1

[0162] Test Example 2: Photovoltaic Performance Testing of Organic Solar Cells

[0163] (1) Fabrication of photovoltaic devices: First, the ITO conductive glass was etched with zinc powder and hydrochloric acid. The etched ITO conductive glass (sheet resistance of 7 Ω / sq) was ultrasonically cleaned for 15 min each with glass cleaning solution, deionized water, acetone, and isopropanol, then dried with a nitrogen gun and placed in a forced-air drying oven at 150 ℃ for 5 min. Then, the ITO conductive glass was treated in an ultraviolet-ozone cleaner for 15 min and transferred to a glove box for later use. In the first step, a 10 nm thick layer of MoO3 was deposited on the ITO conductive glass as an anode buffer layer by vacuum thermal evaporation, with a background vacuum of 2.0 × 10- 5 Pa, evaporation rate is 0.2 nm / s; second step, M1, M2, M3, M4, M5, M6, M7, M8, M9, and M10 are used as donor materials, respectively, with C70 Using C as the acceptor, a hybrid photoactive layer was prepared on the MoO3 anolyte buffer layer via a vacuum dual-source co-evaporation method. 70 The thickness is 80 nm, and the background vacuum is 2.0 × 10⁻⁶. -5 Pa, with a total evaporation rate of 1.0 nm / s; the third step involves vacuum thermal evaporation to deposit a photoactive layer (Compounds: C). 70 A 5 nm thick layer of BCP (Bathocuproine) was deposited on top as an exciton blocking layer, with a background vacuum of 2.0 × 10⁻⁶. -5 Pa, with an evaporation rate of 0.1 nm / s. Finally, at 2.0 × 10 -5 A 100 nm Ag electrode was deposited under a background vacuum of Pa.

[0164] Thus, an organic solar cell device is obtained, with a device structure of Glass / ITO / MoO3 (10nm) / Compounds:C 70 (80nm) / BCP(5nm) / Ag(100 nm). Includes an indium tin oxide conductive glass substrate (ITO), a molybdenum oxide anode layer (MoO3), and a cathode layer of BCP(5nm) / Ag(100 nm); the activation layer material is a DAA′ type molecule and a fullerene molecule C synthesized in the examples. 70 The blending weight ratio is 1:3.

[0165] (2) The photovoltaic performance of organic solar cells was tested using an AM 1.5G solar simulator (100 mW / cm²). 2 The current-voltage characteristic test was conducted using a Kiethley 2420 current source meter. The test results are shown in Table 2.

[0166] Table 2

[0167] The compounds prepared in Examples 1-10, as donor materials, can promote the increase of short-circuit current density to a certain extent by expanding the fused ring electron-donating unit and utilizing the light absorption capability of small molecules, thereby improving the photoelectric conversion efficiency of vacuum-deposited organic solar cells.

[0168] The above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit it. Any modifications or equivalent substitutions to the technical solutions of the present invention that do not depart from the spirit and scope of the technical solutions of the present invention should be covered within the protection scope of the present invention.

Claims

1. The compound or its isomer represented by Formula I, wherein DAA′ Formula I, The D group is selected from any one of the groups shown in formulas (a), (b), (c), (d), and (e): Wherein, X1, X2, X3, X4, and X5 are independently selected from O, S, Se, NH, NR', CH2, C(R')2, Si(R')2, C=O, and C=C(CN)2, respectively; R' is independently selected from C1-10 alkyl groups (e.g., C4-7 alkyl groups); R1, R2, and R3 are independently selected from H, halogens, C1-10 alkyl groups, halo-C1-10 alkyl groups, CN, and C=(CN)2, respectively; and the D group does not have the following structures: Wherein, M is S or N, B is independently selected from C1-6 alkyl groups, and m is 0 or 1; group A has the following structure: Wherein, Z is selected from O, S, Se, NH, NR'', R'' is selected from C1-10 alkyl groups; R4 and R5 are independently selected from H, F, Cl, Br, I, CN, respectively; and the A' group is selected from the following structures: 、 、 。 2. The compound or its isomers according to claim 1, wherein R1, R2, and R3 in the D group are independently selected from F, Cl, Br, I, CH3, CF3, CF2H, CCl3, CN, and C=(CN)2, respectively; preferably, X1, X2, X3, X4, and X5 in the D group are independently selected from S, NR', and C(R')2, respectively; preferably, X1, X2, X3, X4, and X5 are independently selected from S, N(C4-5 alkyl), and C(C6-7 alkyl)2, respectively.

3. The compound or its isomer according to claim 1 or 2, wherein the D group has a structure as shown in formula (a), wherein, X1 and X3 are independently NR', and X2 is S.

4. The compound or its isomer according to claim 1 or 2, wherein the D group has a structure as shown in formula (b), wherein, X2 and X4 are S, X1 and X3 are independently selected from NR' and C(R')2, respectively, and X1 and X3 are the same or different; and / or R1 and R2 are independently selected from H and halogen, respectively.

5. The compound or its isomer according to claim 1 or 2, wherein the D group has a structure as shown in formula (c), wherein, X2 and X4 are S respectively, X1, X3, and X5 are NR' independently; and / or, R1 is H.

6. The compound or its isomer according to claim 1 or 2, wherein the D group has a structure as shown in formula (d), X1 and X4 are S respectively, X2 and X3 are NR' independently; and / or R1, R2, and R3 are all H.

7. The compound or its isomer according to claim 1 or 2, wherein the D group has a structure as shown in formula (e), wherein, X1 and X3 are S respectively, X2 and X4 are NR' independently; and / or, R1 is H.

8. The compound or its isomers according to any one of claims 1-7, wherein Z in group A is S; and / or, R4 and R5 in group A are independently selected from H and halogen, respectively.

9. The compound or its isomer according to any one of claims 1-8, wherein the A' group is... 。 10. The compound or isomer thereof according to any one of claims 1-9, wherein the compound is selected from: 。 11. A method for preparing the compound or isomer of any one of claims 1-10, the method comprising the following steps: (1) Compound 1 and compound 2 are coupled together to obtain compound 3. The reaction route is as follows: (2) Compound 3 is condensed with the precursor compound of the A′ group to obtain the compound of formula I. The reaction route is as follows: 。 12. The method according to claim 11, wherein the method has one or more of the following features: (1) the coupling reaction in step (1) is carried out in the presence of a catalyst, preferably a palladium catalyst, such as Pd(PPh3)4 or Pd(PPh3)2Cl2; (2) in step (1), the molar mass ratio of compound 1 to compound 2 is 1:(1-2); (3) the coupling reaction in step (1) is carried out in the presence of a solvent, preferably the solvent comprising any one of 1,4-dioxane, water or toluene. Or at least a combination of two; (4) The coupling reaction in step (1) is carried out at a temperature of 80-130°C; (5) The coupling reaction in step (1) is carried out for 8-24 hours; (6) In step (2), the molar ratio of compound 3 and the precursor compound of A′ group is 1:2; (7) The condensation reaction in step (2) is carried out in the presence of a solvent, preferably chloroform; (8) The condensation reaction in step (2) is carried out at a temperature of 10-30°C; (9) The condensation reaction in step (2) is carried out for 0.5-3 hours.

13. A solar cell donor material comprising the compound or isomer thereof as described in any one of claims 1-10; preferably, the solar cell donor material is an organic solar cell donor material, such as a vacuum-deposited organic solar cell donor material.

14. A solar cell comprising the compound or isomer thereof as described in any one of claims 1-10, or the solar cell donor material as described in claim 13; preferably, the solar cell is an organic solar cell, such as a vacuum-deposited organic solar cell, such as a vacuum-deposited bulk heterojunction organic solar cell.

15. An electrical device comprising the solar cell of claim 14.

16. Use of the compound or isomer thereof according to any one of claims 1-10 or the solar cell donor material according to claim 13 in the preparation of a solar cell; preferably, the solar cell is an organic solar cell, such as a vacuum-deposited organic solar cell, such as a vacuum-deposited bulk heterojunction organic solar cell.

17. A method for preparing an organic solar cell, comprising using the compound or isomer thereof as described in any one of claims 1-10 as a donor material; preferably, the method is a vacuum evaporation method.

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