Dimer acceptor material and application thereof

Abstract

The invention relates to the field of organic photovoltaic materials, in particular to a dimer acceptor material and application thereof. The invention provides a dimer acceptor material as shown in a formula (I), a specific silicon-containing or oxygen-containing flexible chain is introduced into the acceptor material by optimizing a connecting site and a connecting unit, and the crystallinity and aggregation of molecules are improved. When the dimer acceptor material provided by the invention is applied to an organic photovoltaic cell as an acceptor material, the dimer acceptor material shows excellent photoelectric conversion efficiency.

Description

Technical Field

[0001] This invention relates to the field of organic photovoltaic materials, specifically to a dimer acceptor material and its applications. Background Technology

[0002] Organic photovoltaic (OPV) cells, with their advantages of being lightweight, flexible, stretchable, and capable of large-area solution processing, have shown enormous application potential in fields such as new energy and wearable devices. In recent years, with innovations in material systems and optimizations in device processes, the highest certified efficiency (PCE) of a single junction for OPV cells has exceeded 20%, demonstrating broad development prospects.

[0003] In recent years, dimer electron acceptor materials have attracted much attention as a novel class of acceptor materials due to their combination of the advantages of small molecules and polymer materials. Dimeric electron acceptor materials not only possess a regular and compact molecular packing structure, typically exhibiting higher electron mobility than polymer acceptors; but also, due to their larger molecular volume, their glass transition temperature (T0) is relatively high. g The electron acceptor density is generally higher than that of small molecule acceptors. These properties give organic photovoltaic cells based on dimer electron acceptor materials excellent light and thermal stability, as well as outstanding batch-to-batch stability.

[0004] Currently reported dimer acceptor materials mainly achieve polymerization through coupling with the terminal groups of non-fullerene acceptor small molecules. This connection method has two limitations: First, the stacking between terminal groups is hindered: in small molecule acceptors, the stacking of terminal groups is an indispensable stacking method, and oligomer acceptors constructed using terminal groups will inevitably hinder effective end-to-end stacking; second, halogen atom loss: the number and position of halogen atoms on the terminal groups play a crucial role in optimizing molecular energy levels and stacking methods, however, the connection method using terminal groups will inevitably result in the loss or alteration of the number and position of halogen atoms.

[0005] Therefore, there is an urgent need to develop novel and efficient dimer acceptor materials with new connection methods and connection units in the existing technology. Summary of the Invention

[0006] The purpose of this invention is to overcome the problem that most dimer acceptor materials in the prior art are based on end-to-end polymerization, which affects the effective stacking of molecules and results in insufficient photoelectric performance of the acceptor material, leading to low photoelectric conversion efficiency of organic photovoltaic cells when applied to them. Therefore, this invention provides a novel dimer acceptor material that can effectively improve the photoelectric conversion efficiency of organic photovoltaic devices when used as an acceptor material.

[0007] The technical solution of this invention is as follows:

[0008] The first aspect of this invention relates to a dimer acceptor material having a structure as shown in general formula (I):

[0009]

[0010] in:

[0011] L is selected from

[0012] m is selected from any integer between 3 and 20;

[0013] Each occurrence of X1 is independently selected from CR4R5, SiR6R7 or O, and L contains at least two SiR6R7 or at least one O.

[0014] R4, R5, R6, and R7 are each independently selected from -H, -D, or alkyl groups having 1 to 10 carbon atoms;

[0015] Each time Ar2 appears, it is independently selected from R. a Aromatic groups having 6-20 carbon atoms, substituted or unsubstituted, or containing R a Substituted or unsubstituted heteroaromatic groups having 5-20 ring atoms;

[0016] R a Each time it appears, it is independently selected from -D, -F, -Cl, alkyl groups having 1-10 carbon atoms, or alkoxy groups having 1-10 carbon atoms;

[0017] * indicates a connection point;

[0018] Each time R3 appears, it is independently selected from -D, -F, -Cl, or an alkyl group having 1-10 carbon atoms, or an alkoxy group having 1-10 carbon atoms;

[0019] r is selected from 0, 1, 2, or 3;

[0020] Each time Z appears, it is independently selected from O, S, or Se;

[0021] Each time R1 appears, it is independently selected from R. b Substituted or unsubstituted straight-chain or branched alkyl groups having 3-30 carbon atoms;

[0022] R b Each occurrence is independently selected from one or a combination of at least two of the following: -D, -F, -Cl, vinyl, ethynyl, cycloalkyl having 3-30 carbon atoms, aromatic group having 6-20 carbon atoms, and heteroaromatic group having 5-20 ring atoms;

[0023] Each occurrence of R2 is independently selected from -H, -D, alkyl groups having 1-30 carbon atoms, alkoxy groups having 1-30 carbon atoms, alkylthio groups having 1-30 carbon atoms, or groups influenced by R. c Aromatic groups having 6-20 carbon atoms, substituted or unsubstituted, or containing R c Substituted or unsubstituted heteroaromatic groups having 5-20 ring atoms;

[0024] R c Each time it appears, it is independently selected from -D, -F, -Cl, alkyl groups having 1-30 carbon atoms, alkoxy groups having 1-30 carbon atoms, or alkylthio groups having 1-30 carbon atoms;

[0025] Each time M appears, it is independently selected from O or C(CN)2;

[0026] Each time Ar1 appears, it is independently selected from R. d Aromatic groups having 6-20 carbon atoms, substituted or unsubstituted, or containing R d Substituted or unsubstituted heteroaromatic groups having 5-20 ring atoms;

[0027] R d Each occurrence is independently selected from -D, -F, -Cl, -Br, -I, -CF3, -CN, straight-chain alkyl with 1-10 carbon atoms, branched alkyl with 3-10 carbon atoms, straight-chain alkoxy with 1-10 carbon atoms, or branched alkoxy with 3-10 carbon atoms.

[0028] In one embodiment, the dimer acceptor material is selected from materials with structures as shown in general formula (II-1) or (II-2):

[0029]

[0030]

[0031] In an optional embodiment, the L is selected from... or Where: a is selected from 1, 2, 3, 4, 5 or 6; b is selected from 1, 2, 3, 4, 5 or 6; c is selected from 3, 4, 5, 6, 7, 8, 9 or 10.

[0032] Furthermore, R6 and R7 are selected from methyl groups.

[0033] In one embodiment, each occurrence of Ar2 is independently selected from R. a Substituted or unsubstituted phenyl groups are subjected to R a Substituted or unsubstituted thiophene group, R a Substituted or unsubstituted furanyl, or Ra Substituted or unsubstituted selenophene group; R a Each time it appears, it is independently selected from -D, -F, -Cl, alkyl groups having 1-10 carbon atoms, or alkoxy groups having 1-10 carbon atoms.

[0034] In one specific embodiment, the Ar2 is selected from thiophene groups.

[0035] In an optional embodiment, the L is selected from, but is not limited to, the following groups:

[0036]

[0037] In one embodiment, each occurrence of R3 is independently selected from -F or -Cl.

[0038] In one specific embodiment, R3 is selected from -F.

[0039] In one embodiment, Z is selected from S or Se.

[0040] In one specific embodiment, Z is selected from S.

[0041] In one embodiment, each occurrence of R1 is independently selected from the one that was R. b Substituted or unsubstituted branched alkyl groups having 8-30 carbon atoms; R b Each occurrence is independently selected from -D, -F, -Cl, vinyl, ethynyl, cycloalkyl with 3-10 carbon atoms, aromatic group with 6-10 carbon atoms, or heteroaromatic group with 5-10 cyclic atoms.

[0042] In one specific embodiment, each occurrence of R1 is independently selected from branched alkyl groups having 12-30 carbon atoms.

[0043] Furthermore, each occurrence of R1 is independently selected from any of the following groups, but is not limited to:

[0044]

[0045] In one embodiment, each occurrence of R2 is independently selected from -H, -D, alkyl groups having 1-20 carbon atoms, alkoxy groups having 1-20 carbon atoms, alkylthio groups having 1-20 carbon atoms, or groups affected by R. c Substituted or unsubstituted aromatic groups having 6-10 carbon atoms, or those modified by R c Substituted or unsubstituted heteroaromatic groups having 5-10 ring atoms; R c Each time it appears, it is independently selected from -D, -F, -Cl, alkyl groups having 1-20 carbon atoms, alkoxy groups having 1-20 carbon atoms, or alkylthio groups having 1-20 carbon atoms.

[0046] Furthermore, each occurrence of R2 is independently selected from -H, -D, straight-chain alkyl groups having 1-20 carbon atoms, branched-chain alkyl groups having 3-20 carbon atoms, straight-chain alkoxy groups having 1-20 carbon atoms, branched-chain alkoxy groups having 3-20 carbon atoms, straight-chain alkylthio groups having 1-20 carbon atoms, branched-chain alkylthio groups having 3-20 carbon atoms, or R c Substituted or unsubstituted phenyl, or substituted by R c Substituted or unsubstituted thiophene groups; the R c Each occurrence is independently selected from straight-chain alkyl groups having 1-20 carbon atoms, branched alkyl groups having 3-20 carbon atoms, straight-chain alkoxy groups having 1-20 carbon atoms, branched alkoxy groups having 3-20 carbon atoms, straight-chain alkylthio groups having 1-20 carbon atoms, or branched alkylthio groups having 3-20 carbon atoms.

[0047] Furthermore, each occurrence of R2 is independently selected from -H, -D, or any of the following groups, but not limited to:

[0048]

[0049] In one embodiment, the Selected from

[0050] Furthermore, each occurrence of Ar1 is independently selected from R. d Substituted or unsubstituted aromatic groups having 6-10 carbon atoms, or those modified by R d Substituted or unsubstituted heteroaromatic groups having 5-10 ring atoms; R d Each occurrence is independently selected from -D, -F, -Cl, -Br, -I, -CF3, -CN, straight-chain alkyl with 1-6 carbon atoms, branched alkyl with 3-6 carbon atoms, straight-chain alkoxy with 1-6 carbon atoms, or branched alkoxy with 3-6 carbon atoms.

[0051] In an alternative embodiment, each occurrence of Ar1 is independently selected from, but not limited to, the following groups:

[0052]

[0053] # indicates a fusion site, which is selected from carbon atoms;

[0054] Wherein: R8 is selected independently each time it appears from -H, -D, -F, -Cl, -Br, -I, -CF3, -CN, straight-chain alkyl with 1-6 carbon atoms, branched alkyl with 3-6 carbon atoms, straight-chain alkoxy with 1-6 carbon atoms, or branched alkoxy with 3-6 carbon atoms.

[0055] In an alternative embodiment, the It can be selected from the following structures, but is not limited to them:

[0056]

[0057] In one specific embodiment, the dimer acceptor material according to the present invention is selected from the structure shown in (III-1):

[0058]

[0059] In an optional embodiment, the dimer acceptor material represented by formula (III-1) is selected from the structures shown in Table 1, but is not limited thereto:

[0060] Table 1

[0061]

[0062]

[0063] In one specific embodiment, the dimer acceptor material according to the present invention is selected from the structure shown in (III-2):

[0064] Preferably, the dimer acceptor material represented by formula (III-2) is selected from the structures shown in Table 2, but is not limited thereto:

[0065] Table 2

[0066]

[0067]

[0068] In one specific embodiment, the dimer acceptor material according to the present invention is selected from the structure shown in (III-3):

[0069]

[0070] Preferably, the dimer acceptor material represented by formula (III-3) is selected from the structures shown in Table 3, but is not limited thereto:

[0071] Table 3

[0072]

[0073]

[0074] In one specific embodiment, the dimer acceptor material according to the present invention is selected from the structure shown in (III-4):

[0075]

[0076] Preferably, the dimer acceptor material represented by formula (III-4) is selected from the structures shown in Table 4, but is not limited thereto:

[0077] Table 4

[0078]

[0079]

[0080] In one specific embodiment, the dimer acceptor material according to the present invention is selected from the structure shown in (III-5):

[0081]

[0082] Preferably, the dimer acceptor material represented by formula (III-5) is selected from the structures shown in Table 5, but is not limited thereto:

[0083] Table 5

[0084]

[0085]

[0086] In one specific embodiment, the dimer acceptor material according to the present invention is selected from the structure shown in (III-6):

[0087]

[0088] Preferably, the dimer acceptor material represented by formula (III-6) is selected from the structures shown in Table 6, but is not limited thereto:

[0089] Table 6

[0090]

[0091]

[0092] In one specific embodiment, the dimer acceptor material according to the present invention is selected from the structure shown in (III-7):

[0093]

[0094] Preferably, the dimer acceptor material represented by formula (III-7) is selected from the structures shown in Table 7, but is not limited thereto:

[0095] Table 7 In one specific embodiment, the dimer acceptor material according to the present invention is selected from the structure shown in (III-8):

[0096]

[0097] Preferably, the dimer acceptor material represented by formula (III-8) is selected from the structures shown in Table 8, but is not limited thereto:

[0098] Table 8

[0099]

[0100] In one specific embodiment, the dimer acceptor material according to the present invention is selected from the structure shown in (III-9):

[0101]

[0102] Preferably, the dimer acceptor material represented by formula (III-9) is selected from the structures shown in Table 9, but is not limited thereto:

[0103] Table 9

[0104]

[0105] A second aspect of the present invention relates to a mixture comprising a dimer acceptor material as described in the first aspect and at least one other organic functional material selected from photoactive layer donor materials and / or photoactive layer acceptor materials.

[0106] In one embodiment, the mixture comprises a dimer acceptor material as described in the first aspect and at least one photoactive layer donor material.

[0107] Furthermore, the photoactive layer donor material is selected from polymer donor materials. The polymer donor material can be selected from polythiophene material systems, such as P3AT, P3HT, P3OT, P3DDT, etc.; fluorene-containing polymer material systems, such as PF8BT, etc.; novel structural narrow bandgap polymer material systems, such as benzodithiophene (BDT), benzothiadiazoles (BT, BBT), quinoxalines (QU, PQ), pyrazines (TP, PQ), and copolymers with electron-rich groups (such as thiophene derivatives), such as PM6, PM7, PBDB-T, D18, D18-Cl, PTQ10, PTQ11, PBQx-TCl, PBQx-TF, etc., but is not limited to these.

[0108] In another embodiment, the mixture comprises a dimer acceptor material as described in the first aspect, at least one photoactive layer donor material, and at least one non-fullerene acceptor material.

[0109] The non-fullerene receptor material is selected from one or more of the following: ITIC-based receptor materials, including but not limited to: ITIC, ITIC-4F, ITIC-4Cl, ITIC-2F, ITIC-M, ITCC, ITCC-Cl, etc.; Y-type receptor materials, including but not limited to: Y6, L8-BO, BTP-eC9, N3, N4, Y6-O, HDO-4Cl, BTP-H2, PY-IT, etc.; and FCC-type receptor materials, including but not limited to: FCC-Cl, FTCC-Br, etc.

[0110] For further information on the conventional selection of acceptor materials for the active layer, please refer to: Chem. Rev. 2022, 122, 18, 14180–14274.

[0111] A third aspect of the present invention relates to a composition comprising a dimer acceptor material as described in the first aspect, or a mixture as described in the second aspect, and at least one organic solvent.

[0112] The organic solvents include tetrahydronaphthalene, 1,5-dimethyltetrahydrofuran, methyltetrahydrofuran, decahydronaphthalene, chlorobenzene, o-dichlorobenzene, 1,2,4-trichlorobenzene, 1,4-dimethylnaphthalene, toluene, o-xylene, m-xylene, p-xylene, mesitylene, o-diethylbenzene, m-diethylbenzene, p-diethylbenzene, 1,2,3,4-tetramethylbenzene, 1,2,3,5-tetramethylbenzene, 1,2,4,5-tetramethylbenzene, acetophenone, diphenyl ether, 2-methylthiophene, 3-methylthiophene, monochloromethane, dichloromethane, chloroform, dichloroethylene, trichloroethylene, and 1,1,1-trichlorotrifluoro. The following are included in the list of ethane, 1,2-dichloroethane, 1,1,1-trichloroethane, 1,1,2,2-tetrachloroethane, carbon tetrachloride, tetrahydrofuran, anisole, 2,4-dimethylanisole, 1-methylnaphthalene, morpholine, 1,4-dioxane, N-methylpyrrolidone, acetone, cyclopentanone, cyclohexanone, methyl ethyl ketone, ethyl acetate, n-butyl acetate, carbon disulfide, carbon tetrachloride, N,N-dimethylformamide, dimethylacetamide, dimethyl sulfoxide, indane, methyl benzoate, ethyl benzoate, acetonitrile, and hexamethylphosphoramide, or combinations of at least two of these, but not limited thereto.

[0113] Furthermore, the composition may further include additives for adjusting viscosity, adjusting film-forming properties, improving adhesion, etc. Additives include, but are not limited to, 1,8-diiodooctane (DIO), diphenyl ether (DPE), anthracene, 1,4-diiodobenzene (DIB), 1,3-dibromo-5-chlorobenzene (DBCl), 3,5-dichlorobromobenzene (DCBB), 1-chloronaphthalene (1-CN), and 1,3,5-tribromobenzene (TBB).

[0114] The fourth aspect of the present invention relates to an organic photovoltaic cell comprising a cathode, an anode, and a photoactive layer located between the cathode and the anode, wherein the photoactive layer material comprises a dimer acceptor material as described in the first aspect, or a mixture as described in the second aspect, or is prepared from a composition as described in the third aspect.

[0115] The method for preparing the photoactive layer material solution is as follows: the photoactive layer donor material and acceptor material are dissolved in an organic solvent at a certain mass ratio, and the mixture is stirred until fully dissolved to obtain the photoactive layer solution.

[0116] The above solution is used to prepare the photoactive layer by printing or coating methods. These printing or coating methods can include, but are not limited to, inkjet printing, gravure printing, inkjet printing, letterpress printing, screen printing, dip coating, spin coating, doctor blade coating, roller printing, torsional roller printing, offset printing, flexographic printing, rotary printing, spraying, brush coating, pad printing, and slot-loaded extrusion coating. Slot-loaded coating, spin coating, and inkjet printing are preferred.

[0117] The preferred mass ratio of donor material to acceptor material in the photoactive layer in the organic solvent is 1:0.8 to 1:1.5; further, the preferred mass ratio of donor material to acceptor material in the photoactive layer in the organic solvent is 1:1 to 1:1.5; the preferred mass ratio of donor material to acceptor material in the photoactive layer in the organic solvent is 1:1 to 1:1.2.

[0118] The concentration of the photoactive layer donor material in the organic solvent is preferably 3 to 15 mg / mL; further, the concentration of the photoactive layer donor material in the organic solvent is preferably 4 to 10 mg / mL.

[0119] At least one of the anode and cathode is transparent or translucent to facilitate light incidence. The material used to fabricate the electrode can be selected from metals such as vanadium (V), chromium (Cr), zinc (Zn), silver (Ag), aluminum (Al), platinum (Pt), tungsten (W), copper (Cu), molybdenum (Mo), gold (Au), nickel (Ni), palladium (Pd), or alloys of the above metals; conductive nanomaterials such as metal nanowires, nanoparticle slurries, graphene, carbon nanotubes; metal oxides such as zinc oxide, indium oxide, indium tin oxide (ITO), indium zinc oxide (IZO); combinations of metals and oxides, such as ZnO:Al or SnO2:Sb; conductive polymers such as PEDOT:PSS, polypyrrole, and polyaniline; or materials with multilayer structures such as LiF / Al, Li2O / Al, LiF / Fe, MoO3 / Al, Al / Li, Al / BaF2, and Al / BaF2 / Ba, but not limited to these.

[0120] In one embodiment, the organic photovoltaic cell includes an anode, an anode buffer layer, a photoactive layer, a cathode buffer layer, and a cathode stacked sequentially. The photoactive layer material comprises a dimer acceptor material as described in the first aspect, or a mixture as described in the second aspect, or is prepared from a composition as described in the third aspect.

[0121] Preferably, the cathode buffer layer material can be selected from low work function metal complexes, metal oxides, metal salts, etc., such as metal complexes of 8-hydroxyquinoline, complexes containing Alq3, metal complexes containing Liq, LiF, Ca, and titanium oxide (TiO2). x It can be zinc oxide (ZnO), cesium carbonate (Cs2CO3), etc.; it can also be polymer materials, such as PFN-Br or PFN or PDINN or PDINO or PNDIT-F3N-Br or PNDIT-F3N, etc., but is not limited to these.

[0122] The anode buffer layer material includes PEDOT:PSS and molybdenum oxide (MoO). x ), vanadium oxide (V₂O₅), nickel oxide (NiO), tungsten oxide (WO₂) x Preferably, x is selected from 2 or 3), small molecule self-assembled materials such as 2PACz, MeO-2PACz, etc., but not limited to these.

[0123] It should be noted that, in order to improve the performance of organic photovoltaic cells, the organic photovoltaic cells may further include other functional layers, including but not limited to charge blocking layers and charge transport layers.

[0124] Furthermore, the organic photovoltaic cell also includes a substrate. In one embodiment, the substrate is disposed on the side of the anode away from the photoactive layer. In another embodiment, the substrate is disposed on the side of the cathode away from the photoactive layer.

[0125] In one embodiment, a substrate with excellent transparency, surface smoothness, ease of handling, and water resistance can be used as the substrate. Specifically, a glass substrate, a thin-film glass substrate, or a transparent plastic substrate can be used. The plastic substrate may include, but is not limited to, single-layer or multi-layer films such as polyethylene terephthalate (PET), polyethylene naphthalate (PEN), polyetheretherketone (PEEK), polyimide (PI), parylene, etc., and substrates commonly used in organic solar cells may also be used.

[0126] The organic photovoltaic cells described in this invention are mainly used in fields such as indoor photovoltaics, wearable devices, smart IoT, smart homes, smart agriculture, building photovoltaics, and new energy vehicles.

[0127] The beneficial effects of this invention are:

[0128] This invention provides a dimer acceptor material as described in formula (I). By optimizing the connection sites and connecting units, specific silicon- or oxygen-containing flexible chains are introduced into the acceptor material, thereby enabling two non-fullerene acceptor units to polymerize through a central connection, thus constructing a novel, highly efficient small-molecule acceptor oligomer. This connection method promotes intermolecular electronic coupling, resulting in good electron mobility for the dimer acceptor and providing excellent exciton / charge dynamics. Furthermore, the use of alkoxy or silicon-oxygen flexible connections reduces steric hindrance, significantly improving the crystallinity and aggregation of the molecules, and enhancing the molecular packing of the fiber morphology. In summary, when the dimer acceptor material provided by this invention is applied as an acceptor material in organic photovoltaic cells, a photoelectric conversion efficiency exceeding 18% is achieved. Attached Figure Description

[0129] To more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the specific embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0130] Figure 1 This is a schematic diagram of the structure of an embodiment of the organic photovoltaic cell device of the present invention;

[0131] Wherein: 101-substrate, 102-anode layer, 103-anode buffer layer, 104-photoactive layer, 105-cathode buffer layer, 106-cathode layer. Detailed Implementation

[0132] To make the objectives, technical solutions, and effects of this application clearer and more explicit, the following provides a further detailed description of this application. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the scope of this application. All other embodiments obtained by those skilled in the art based on the described embodiments of the present invention without inventive effort are within the scope of protection of this invention.

[0133] The terms "and / or," "or / and," and "and / or" as used herein include any one of two or more of the related listed items, as well as any and all combinations of the related listed items. These arbitrary and all combinations include any two related listed items, any more related listed items, or a combination of all related listed items. It should be noted that when at least three items are connected by at least two conjunctions selected from "and / or," "or / and," and "and / or," it should be understood that in this application, the technical solution undoubtedly includes technical solutions connected by "logical AND," and also undoubtedly includes technical solutions connected by "logical OR." For example, "A and / or B" includes three parallel solutions: A, B, and A+B. For example, the technical solution of "A, and / or, B, and / or, C, and / or, D" includes any one of A, B, C, and D (that is, a technical solution that is connected by "logical OR"), as well as any and all combinations of A, B, C, and D, that is, combinations of any two or three of A, B, C, and D, and also combinations of all four of A, B, C, and D (that is, a technical solution that is connected by "logical AND").

[0134] In this invention, organic photovoltaic devices, organic photovoltaic cells, organic solar cells, OPV, and OSC have the same meaning and can be used interchangeably.

[0135] In this invention, the terms "photoactive layer" and "active layer" have the same meaning and can be used interchangeably.

[0136] In this invention, when the same group contains multiple substituents with the same symbol, the substituents can be the same as or different from each other, for example... The six R's on the benzene ring can be the same or different from each other.

[0137] In this invention, "substitution" means that one or more hydrogen atoms in the substituent are replaced by the substituent.

[0138] In this invention, "ring atom number" refers to the number of atoms in the ring itself of a structural compound (e.g., monocyclic compound, fused-ring compound, cross-linked compound, carbocyclic compound, heterocyclic compound) obtained by atomic bonding to form a ring. When the ring is substituted by a substituent, the atoms contained in the substituent are not included in the ring-forming atoms. The same applies to the "ring atom number" described below unless otherwise specified. In aromatic groups, the ring atom number is the same as the carbon atom number; in heteroaromatic groups, the ring atom number is the carbon atom number plus the heteroatom number; for example, the ring atom number of a benzene ring is 6, the ring atom number of a naphthalene ring is 10, the ring atom number of a quinoline ring is 10, the ring atom number of a thiophene group is 5, and the ring atom number of a thiophene is 8.

[0139] In this invention, "aromatic group" refers to any optional functional group or substituent derived from an aromatic carbon ring. The aromatic group can be a monocyclic aryl (e.g., phenyl) or a polycyclic aryl; in other words, the aromatic group can be a monocyclic aromatic group, a fused-ring aromatic group, two or more monocyclic aromatic groups conjugated by carbon-carbon bonds, a monocyclic aromatic group and a fused-ring aromatic group conjugated by carbon-carbon bonds, or two or more fused-ring aromatic groups conjugated by carbon-carbon bonds. That is, unless otherwise stated, two or more aromatic groups conjugated by carbon-carbon bonds can also be considered as the aromatic group of this application. Preferably, the aromatic group is selected from aromatic groups having 6-30 carbon atoms; further, it is selected from aromatic groups having 6-20 carbon atoms; further, it is selected from aromatic groups having 6-10 carbon atoms; the aromatic group includes, but is not limited to: phenyl, biphenyl, terphenyl, naphthyl, anthraceneyl, phenanthrene, fluoranyl, triphenylene, pyrene, perylene, tetraphenyl, fluorenyl, dinaphthylphenyl, acenaphthyl, and their derivatives.

[0140] In this invention, a "heteroaromatic group" refers to a heteroaromatic ring or its derivative containing one, two, three, four, five, six or more heteroatoms, wherein the heteroatoms can be at least one of B, O, N, P, Si, Se and S. The heteroaromatic group can be a monocyclic heteroaryl or a polycyclic heteroaryl. The term "heteroaromatic group" as used herein also includes groups formed by the fusion of one or more heteroaromatic groups with one or more aromatic rings, aliphatic rings or heterocycles. Preferably, the heteroaromatic group is selected from those having 5-30 ring atoms; further, it is selected from those having 5-20 ring atoms; and further, it is selected from those having 5-10 ring atoms. Heteroaromatic groups include, but are not limited to: thiophene, furanyl, pyrrolyl, diazolyl, triazolyl, imidazolyl, pyridinyl, bipyridinyl, pyrimidinyl, triazinyl, acridineyl, pyridazinyl, quinolinyl, isoquinolinyl, quinazolinyl, quinoxalinyl, phthalazinyl, pyridinylpyrimidinyl, pyridinylpyrazinyl, benzothiophene, benzofuranyl, indolyl, pyrroloimidazolyl, pyrrolopyrrol, thienopyrrol, thienopyrrol, furanol, furanol, thienofuranyl, benzoisoxazolyl, benzoisothiazolyl, benzoimidazolyl, o-diazonyl, phenanthridine, primidyl, quinazolinone, dibenzothiophene, dibenzofuranyl, carbazole and their derivatives.

[0141] In this invention, alkyl groups include straight-chain alkyl groups, branched-chain alkyl groups, cycloalkyl groups, combinations of straight-chain alkyl groups and cycloalkyl groups, and combinations of branched-chain alkyl groups and cycloalkyl groups; the number of carbon atoms in a straight-chain alkyl group can be 1 to 30, 1 to 20, 1 to 16, 1 to 10, or 1 to 6. The number of carbon atoms in a branched-chain alkyl group can be 3 to 30, 3 to 20, 3 to 16, 3 to 10, or 3 to 6. Non-limiting examples of straight-chain alkyl groups include methyl (-CH3), ethyl (-C2H5), n-propyl (-C3H7), n-butyl (-C4H9), and n-pentyl (-C5H9). 11 ), n-hexyl (-C6H) 13 ), heptyl (-C7H) 15 ), n-octyl (-C8H) 17 ), non-nonyl (-C9H) 19 -C 10 H 21 -C 11 H 23 -C 12 H 25 -C 13 H 27 -C 14 H 29 -C 15 H 31 -C 16 H 33Non-limiting examples of branched alkyl groups include: isopropyl, branched alkyl groups containing 4 carbon atoms, branched alkyl groups containing 5 carbon atoms, branched alkyl groups containing 6 carbon atoms, branched alkyl groups containing 7 carbon atoms, branched alkyl groups containing 8 carbon atoms, branched alkyl groups containing 9 carbon atoms, branched alkyl groups containing 10 carbon atoms, branched alkyl groups containing 11 carbon atoms, branched alkyl groups containing 12 carbon atoms, branched alkyl groups containing 13 carbon atoms, branched alkyl groups containing 14 carbon atoms, branched alkyl groups containing 15 carbon atoms, and branched alkyl groups containing 16 carbon atoms; non-limiting examples of cycloalkyl groups include: cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, adamantyl, etc., but are not limited thereto.

[0142] The term "alkoxy" refers to a group with the structure "-O-alkyl", that is, an alkyl group as defined above that is attached to other groups via an oxygen atom. The straight-chain alkoxy means that the alkyl group in "-O-alkyl" is selected from straight-chain alkyl groups, wherein the number of carbon atoms in the straight-chain alkyl group can be 1 to 20, 1 to 16, 1 to 10, or 1 to 6; the branched-chain alkoxy means that the alkyl group in "-O-alkyl" is selected from branched-chain alkyl groups, wherein the number of carbon atoms in the branched-chain alkyl group can be 3 to 20, 3 to 16, 3 to 10, or 3 to 6.

[0143] The term "alkoxythio" refers to a group with the structure "-S-alkyl", that is, an alkyl group as defined above that is attached to other groups via a sulfur atom. The straight-chain alkoxythio group indicates that the alkyl group in the "-S-alkyl" is selected from straight-chain alkyl groups, wherein the number of carbon atoms in the straight-chain alkyl group can be 1 to 20, 1 to 16, 1 to 10, or 1 to 6; the branched-chain alkoxythio group indicates that the alkyl group in the "-S-alkyl" is selected from branched-chain alkyl groups, wherein the number of carbon atoms in the branched-chain alkyl group can be 3 to 20, 3 to 16, 3 to 10, or 3 to 6.

[0144] In this invention, when no linking site is specified in the group, it means that any linkable site in the group is selected as the linking site.

[0145] In this invention, the phrase "independently selected" means that when one or more groups appear simultaneously and in multiple places in the compound, they are all independently selected and can be the same or different.

[0146] In this invention, the single bond connecting the substituents extends through the corresponding ring, indicating that the substituent can be connected to any position on the ring, for example... R is attached to any substituted site on the benzene ring.

[0147] In describing the structural elements of the present invention, the terms "comprising" or "including" or similar terms used in the present invention mean that the device or material preceding the word covers the device or material listed after the word and its equivalents, but does not exclude other devices or materials.

[0148] In the description of this invention, it should be understood that the terms "upper," "lower," "between layers," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings, or the orientation or positional relationship commonly used when organic solar cell devices are in use, or the orientation or positional relationship commonly understood by those skilled in the art. They are only used to facilitate the description of this invention and to simplify the description, and are not intended to indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limiting this invention.

[0149] The terms “combinations thereof,” “any combination thereof,” “any combination thereof,” and “combination” used in this invention include all suitable combinations of any two, any three, or any three or more groups listed.

[0150] In this invention, terms such as "further," "even more," and "particularly" are used for descriptive purposes and to indicate differences in content, but should not be construed as limiting the scope of protection of this invention.

[0151] In this invention, "optionally," "optionally," and "optional" mean that they are optional, that is, they are selected from either "with" or "without." If multiple "options" appear in a technical solution, unless otherwise specified and there are no contradictions or mutual constraints, each "option" is independent.

[0152] In this invention, the technical features described in an open-ended manner include both closed-ended technical solutions composed of the listed features and open-ended technical solutions that include the listed features.

[0153] Examples of Dimeric Acceptor Material Synthesis

[0154] The following embodiments are provided to facilitate a better understanding of the disclosure of this invention, but are not intended to limit it in any way. Unless otherwise specified, the experimental methods used in the following embodiments are conventional methods, and the materials and reagents used are prior art and commercially available unless otherwise specified.

[0155] Synthesis of compound L-1:

[0156]

[0157] Synthesis of compound 1a:

[0158] Accurately weigh 3.26 g (20 mmol) of 2-bromothiophene and dissolve it in ultradry THF (30 mL). Purge with nitrogen three times. Add n-BuLi (2.5 M, 8 mL, 20 mmol) dropwise at -78 °C and stir for 1 h. Then, add compound 1 (3.51 g, 10 mmol) dissolved in ultradry THF (10 mL) dropwise at -78 °C, maintain the temperature and stir for 1 h, allow to return to room temperature naturally, and stir overnight. After the reaction is complete, quench the reaction mixture in water and extract with ethyl acetate. Dry the combined organic phases with anhydrous MgSO4, remove excess solvent by vacuum distillation, and purify by silica gel column chromatography with stirring to give approximately 548 mg of compound 1a, in 12.3% yield. MS: 447.05.

[0159] Synthesis of compound L-1:

[0160] Compound 1a (540 mg, 1.20 mmol) was accurately weighed and dissolved in ultradry THF (90 mL). Nitrogen gas was purged three times. n-BuLi (2.5 M, 1.0 mL, 2.52 mmol) was added dropwise at -78 °C. After stirring for 2 h, trimethyltin chloride solution (1 M, 3.12 mL, 3.12 mmol) was added dropwise at -78 °C. The mixture was kept at this temperature and stirred for 1 h, then allowed to return to room temperature and stirred overnight. After the reaction was complete, the reaction solution was quenched in an aqueous potassium fluoride solution and extracted with dichloromethane. The combined organic phases were dried over anhydrous MgSO4, and excess solvent was removed by vacuum distillation to give approximately 836 mg of compound L-1, in 90.1% yield. MS: 772.83.

[0161] Synthesis of compound L-2:

[0162]

[0163] Synthesis of compound 2a:

[0164] Compound 2 (2.0 g, 13.3 mmol), 2-bromothiophene (5.42 g, 33.2 mmol), 8-hydroxyquinoline (386 mg, 2.66 mmol), potassium phosphate (8.46 g, 39.9 mmol), and cuprous iodide (253 mg, 1.33 mmol) were accurately weighed and dissolved in toluene (90 mL). The mixture was purged with nitrogen three times and refluxed for 12 h. After the reaction was complete, the mixture was cooled to room temperature, quenched in water, and extracted with ethyl acetate. The combined organic phases were dried over anhydrous MgSO4, and excess solvent was removed by vacuum distillation. The resulting product was then subjected to silica gel column chromatography with stirring to give approximately 912 mg of compound 2a, in 21.8% yield. MS: 314.88.

[0165] Synthesis of compound L-2:

[0166] Compound 2a (600 mg, 1.90 mmol) was accurately weighed and dissolved in ultradry THF (20 mL). Nitrogen gas was purged three times. n-BuLi (2.5 M, 1.60 mL, 4.00 mmol) was added dropwise at -78 °C. After stirring for 2 h, trimethyltin chloride solution (1 M, 4.94 mL, 4.94 mmol) was added dropwise at -78 °C. The mixture was kept at this temperature and stirred for 1 h. Subsequent synthetic steps followed the same route as compound L-1, yielding approximately 1.08 g of compound L-2, with a yield of 88.7%. MS: 640.52.

[0167] Synthesis of compound L-3:

[0168]

[0169] Synthesis of compound 3a:

[0170] Compound 3 (9.6 g, 81.2 mmol) was accurately weighed and dissolved in ultradry THF (20 mL). A nitrogen stream was bubbled into the reaction solution, and sodium metal (3.36 g, 146 mmol) was added in portions. The mixture was stirred at room temperature. After the sodium metal had reacted completely, the mixture was heated to 120 °C, and 2-bromothiophene (33.0 g, 203 mmol) was added dropwise, followed by copper bromide (5.44 g, 24.3 mmol). The mixture was reacted at 120 °C for 4 h, then cooled to room temperature and stirred overnight. After the reaction was complete, the reaction solution was poured into a 0.5 M sodium cyanide aqueous solution (200 mL) under stirring. After stirring for 1 h, pentane was added for extraction. The combined organic phases were dried over anhydrous MgSO4, and excess solvent was removed by rotary evaporation under reduced pressure. The mixture was then subjected to silica gel column chromatography with stirring to give approximately 4.16 g of compound 3a, with a yield of 18.1%. MS: 282.64.

[0171] Synthesis of compound L-3:

[0172] Compound 3a (1.0 g, 3.54 mmol) was accurately weighed and dissolved in ultradry THF (20 mL). Nitrogen gas was purged three times. n-BuLi (2.5 M, 2.97 mL, 7.43 mmol) was added dropwise at -78 °C. After stirring for 2 h, trimethyltin chloride solution (1 M, 9.20 mL, 9.20 mmol) was added dropwise at -78 °C. The mixture was kept at this temperature and stirred for 1 h. Subsequent synthetic steps followed the synthetic route for compound L-1, yielding approximately 1.79 g of compound L-3, with a yield of 83.1%. MS: 608.59.

[0173] Example 1: Synthesis of Dimeric Acceptor Material (6)

[0174]

[0175] Synthesis of compounds 1-2:

[0176] Compound 1-1 (196 mg, 0.16 mmol) was accurately weighed and dissolved in ultradry THF (20 mL). Nitrogen was purged three times. LiAlH4 (60 mg, 1.6 mmol) was added to the reaction mixture, and nitrogen was purged three times. The mixture was refluxed for 24 h. After the reaction was complete, the mixture was cooled to room temperature, the reaction solution was quenched in water and extracted with dichloromethane. The organic phase was dried over anhydrous MgSO4, and excess solvent was removed by vacuum distillation to obtain the crude product. The crude product was dissolved in chloroform (10 mL), and 4-bromophenyl-1,2-diamine (41 mg, 0.22 mmol) was accurately weighed and added. The mixture was reacted at room temperature for 12 h. After the reaction was complete, excess solvent was removed by vacuum distillation, and the mixture was subjected to silica gel column chromatography with stirring to obtain approximately 174 mg of compound 1-2, with a yield of 80.8%. MADLI-TOF-MS: 1346.71.

[0177] Synthesis of compounds 1-3:

[0178] Accurately weigh 162 mg (0.12 mmol) of compounds 1-2 and dissolve them in 30 mL of 1,2-dichloroethane. Then, add 0.24 mL of POCl3 and 0.6 mL of DMF sequentially, purging with nitrogen three times, and react under reflux overnight. After the reaction is complete, cool to room temperature, quench the reaction mixture in a saturated sodium carbonate aqueous solution, and extract with dichloromethane. Dry the organic phase with anhydrous MgSO4 and remove excess solvent by vacuum distillation. Purify the crude product by silica gel column chromatography with stirring to give approximately 117 mg of compounds 1-3, with a yield of 69.5%. MADLI-TOF-MS: 1403.15.

[0179] Synthesis of compounds 1-4:

[0180] Compounds 1-3 (112 mg, 0.08 mmol) and L-1 (31 mg, 0.04 mmol) were accurately weighed and dissolved in ultra-dry chlorobenzene (5 mL). The solution was purged with nitrogen three times. Pd₂(dba)₃ (3.6 mg, 0.004 mmol) and tris(o-methylphenyl)phosphine (4.8 mg, 0.016 mmol) were added, and the solution was purged with nitrogen three times. The reaction was carried out at 130 °C for 12 h. After the reaction was complete, potassium fluoride solution was added and stirring was continued for 20 min. Dichloromethane was then added for extraction. The organic phase was dried over anhydrous MgSO₄, and excess solvent was removed by vacuum distillation. The solution was purified by silica gel column chromatography with stirring to obtain approximately 91 mg of compounds 1-4, with a yield of 73.6%. MADLI-TOF-MS: 3091.06.

[0181] Synthesis of compound (6):

[0182] Compounds 1-4 (80 mg, 0.026 mmol) and 5,6-difluoro-3-(dicyanomethylene)indophenone (47.6 mg, 0.207 mmol) were accurately weighed and dissolved in chloroform (15 mL). The mixture was purged with nitrogen three times. Anhydrous pyridine (0.15 mL) was added, and the mixture was purged with nitrogen three times. The mixture was refluxed overnight. After the reaction was completed, the mixture was cooled to room temperature, and excess solvent was removed by vacuum distillation. The mixture was purified by silica gel column chromatography with stirring. After recrystallization twice with methanol, approximately 78 mg of compound (6) was obtained, with a yield of 76.1%. MADLI-TOF-MS: 3940.25.

[0183] Dimeric acceptor synthesis Example 2: Synthesis of compound (20)

[0184]

[0185] Synthesis of compound 2-2:

[0186] Compound 1-1 (800 mg, 0.65 mmol) was accurately weighed and dissolved in ultradry THF (80 mL). Nitrogen was purged, and LiAlH4 (246 mg, 6.5 mmol) was added to the reaction mixture. Nitrogen was purged three times, and the mixture was refluxed for 24 h. After the reaction was complete, the mixture was cooled to room temperature, the reaction solution was quenched in water, and extracted with dichloromethane. The organic phase was dried over anhydrous MgSO4, and excess solvent was removed by vacuum distillation to obtain the crude product. The crude product was dissolved in chloroform (20 mL), and 4-bromo-5-fluorobenzene-1,2-diamine (183 mg, 0.89 mmol) was accurately weighed and added. The mixture was reacted at room temperature for 12 h. After the reaction was complete, excess solvent was removed by vacuum distillation, and the mixture was subjected to silica gel column chromatography with stirring to obtain approximately 743 mg of compound 2-2, with a yield of 83.7%. MADLI-TOF-MS: 1365.36.

[0187] Synthesis of compounds 2-3:

[0188] Compound 2-2 (724 mg, 0.53 mmol) was accurately weighed and dissolved in 1,2-dichloroethane (30 mL). Subsequent synthetic steps followed the same route as for compounds 1-3, yielding approximately 606 mg of compound 2-3, in 80.5% yield. MADLI-TOF-MS: 1420.82.

[0189] Synthesis of compounds 2-4:

[0190] Compounds 2-3 (114 mg, 0.08 mmol) and L-1 (31 mg, 0.04 mmol) were accurately weighed and dissolved in ultra-dry chlorobenzene (5 mL). Subsequent synthetic steps followed the synthetic route for compounds 1-4, yielding approximately 96 mg of compounds 2-4, with a yield of 76.8%. MADLI-TOF-MS: 3126.90.

[0191] Synthesis of compound (20):

[0192] Compounds 2-4 (81 mg, 0.026 mmol) and 5,6-difluoro-3-(dicyanomethylene)indone (47.6 mg, 0.207 mmol) were accurately weighed and dissolved in chloroform (15 mL). Subsequent synthetic steps followed the synthetic route of compound (6), yielding approximately 78 mg of compound (20) with a yield of 75.5%. MADLI-TOF-MS: 3975.48.

[0193] Dimeric acceptor synthesis Example 3: Synthesis of compound (18)

[0194]

[0195] Synthesis of compound 3-2:

[0196] Compound 3-1 (204 mg, 0.17 mmol) was accurately weighed and dissolved in ultra-dry THF (20 mL). Nitrogen was purged, and LiAlH4 (64 mg, 1.7 mmol) was added to the reaction mixture. Nitrogen was purged three times, and the mixture was refluxed for 24 h. After the reaction was complete, the mixture was cooled to room temperature, the reaction solution was quenched in water, and extracted with dichloromethane. The organic phase was dried over anhydrous MgSO4, and excess solvent was removed by vacuum distillation to obtain the crude product. The crude product was dissolved in chloroform (10 mL), and 4-bromo-5-fluorobenzene-1,2-diamine (47 mg, 0.23 mmol) was accurately weighed and added. The mixture was reacted at room temperature for 12 h. After the reaction was complete, excess solvent was removed by vacuum distillation, and the mixture was subjected to silica gel column chromatography with stirring to obtain approximately 188 mg of compound 3-2, with a yield of 82.7%. MADLI-TOF-MS: 1336.62.

[0197] Synthesis of compound 3-3:

[0198] Compound 3-2 (174 mg, 0.13 mmol) was accurately weighed and dissolved in 1,2-dichloroethane (30 mL). Subsequent synthetic steps followed the synthetic route for compounds 1-3, yielding approximately 143 mg of compound 3-3, with a yield of 79.0%. MADLI-TOF-MS: 1393.05.

[0199] Synthesis of compounds 3-4:

[0200] Compound 3-3 (126 mg, 0.09 mmol) and compound L-1 (35 mg, 0.045 mmol) were accurately weighed and dissolved in ultra-dry chlorobenzene (5 mL). Subsequent synthetic steps followed the synthetic route for compounds 1-4, yielding approximately 106 mg of compound 3-4, with a yield of 76.7%. MADLI-TOF-MS: 3071.22.

[0201] Synthesis of compound (18):

[0202] Compounds 3-4 (93 mg, 0.03 mmol) and 5,6-dichloro-3-(dicyanomethylene)indone (63 mg, 0.24 mmol) were accurately weighed and dissolved in chloroform (15 mL). Subsequent synthetic steps followed the synthetic route of compound (6), yielding approximately 84 mg of compound (18), with a yield of 69.2%. MADLI-TOF-MS: 4050.87.

[0203] Dimeric acceptor synthesis Example 4: Synthesis of compound (23)

[0204]

[0205] Synthesis of compound 4-2:

[0206] Compound 4-1 (2.0 g, 2.56 mmol), potassium hydroxide (1.0 g, 17.9 mmol), and 1-bromo-2-hexyldecane (2.35 g, 7.68 mmol) were accurately weighed and dissolved in dimethyl sulfoxide (100 mL). The mixture was then purged with nitrogen and reacted at 80 °C for 16 h. After the reaction was complete, the mixture was cooled to room temperature and extracted with dichloromethane. Excess solvent was removed by vacuum distillation of the organic phase, and the mixture was purified by silica gel column chromatography with stirring to give approximately 1.63 g of compound 4-2, with a yield of 51.8%. MADLI-TOF-MS: 1228.30.

[0207] Synthesis of compound 4-3:

[0208] Compound 4-2 (246 mg, 0.2 mmol) was accurately weighed and dissolved in ultradry THF (20 mL). Nitrogen gas was purged, and LiAlH4 (76 mg, 2.0 mmol) was added to the reaction mixture. Nitrogen gas was purged three times, and the mixture was refluxed for 24 h. After the reaction was complete, the mixture was cooled to room temperature, the reaction solution was quenched in water, and extracted with dichloromethane. The organic phase was dried over anhydrous MgSO4, and excess solvent was removed by vacuum distillation to obtain the crude product. The crude product was dissolved in chloroform (10 mL), and 4-bromo-5-fluorophenyl-1,2-diamine (56 mg, 0.27 mmol) was accurately weighed and added. The mixture was reacted at room temperature for 12 h. After the reaction was complete, excess solvent was removed by vacuum distillation, and the mixture was subjected to silica gel column chromatography with stirring to obtain approximately 228 mg of compound 4-3, with a yield of 83.2%. MADLI-TOF-MS: 1369.51.

[0209] Synthesis of compound 4-4:

[0210] Compound 4-3 (164 mg, 0.12 mmol) was accurately weighed and dissolved in 1,2-dichloroethane (30 mL). Subsequent synthetic steps followed the synthetic route for compound 1-3, yielding approximately 141 mg of compound 4-4, with a yield of 82.5%. MADLI-TOF-MS: 1424.85.

[0211] Synthesis of compounds 4-5:

[0212] Compound 4-4 (114 mg, 0.08 mmol) and compound L-1 (31 mg, 0.04 mmol) were accurately weighed and dissolved in ultra-dry chlorobenzene (5 mL). Subsequent synthetic steps followed the synthetic route for compounds 1-4, yielding approximately 92 mg of compound 4-5, with a yield of 73.4%. MADLI-TOF-MS: 3134.79.

[0213] Synthesis of compound (23):

[0214] Compounds 4-5 (82 mg, 0.026 mmol) and 5,6-difluoro-3-(dicyanomethylene)indone (48 mg, 0.208 mmol) were accurately weighed and dissolved in chloroform (15 mL). Subsequent synthetic steps followed the synthetic route of compound (6), yielding approximately 81 mg of compound (23), with a yield of 78.2%. MADLI-TOF-MS: 3983.14.

[0215] Dimeric acceptor synthesis Example 5: Synthesis of compound (33)

[0216]

[0217] Synthesis of compound 5-1:

[0218] Compounds 2-3 (142 mg, 0.1 mmol) and L-2 (32 mg, 0.05 mmol) were accurately weighed and dissolved in ultra-dry chlorobenzene (5 mL). Subsequent synthetic steps followed the synthetic route for compounds 1-4, yielding approximately 120 mg of compound 5-1, with a yield of 80.1%. MADLI-TOF-MS: 2995.08.

[0219] Synthesis of compound (33):

[0220] Compound 5-1 (100 mg, 0.033 mmol) and 5,6-difluoro-3-(dicyanomethylene)indone (61 mg, 0.264 mmol) were accurately weighed and dissolved in chloroform (15 mL). Subsequent synthetic steps followed the synthetic route of compound (6), yielding approximately 94 mg of compound (33), with a yield of 74.3%. MADLI-TOF-MS: 3842.67.

[0221] Dimeric acceptor synthesis Example 6: Synthesis of compound (47)

[0222]

[0223] Synthesis of compound 6-1:

[0224] Compounds 2-3 (142 mg, 0.1 mmol) and L-3 (30 mg, 0.05 mmol) were accurately weighed and dissolved in ultra-dry chlorobenzene (5 mL). Subsequent synthetic steps followed the synthetic route for compounds 1-4, yielding approximately 114 mg of compound 6-1, with a yield of 77.0%. MADLI-TOF-MS: 2962.34.

[0225] Synthesis of compound (47):

[0226] Compound 6-1 (98 mg, 0.033 mmol) and 5,6-difluoro-3-(dicyanomethylene)indone (61 mg, 0.264 mmol) were accurately weighed and dissolved in chloroform (15 mL). Subsequent synthetic steps followed the synthetic route of compound (6) to obtain approximately 94 mg of compound (47), with a yield of 74.6%. MADLI-TOF-MS: 3811.50.

[0227] Dimeric acceptor synthesis Example 7: Synthesis of compound (59)

[0228]

[0229] Synthesis of compound 6-2:

[0230] Compound 1-1 (245 mg, 0.2 mmol) was accurately weighed and dissolved in ultradry THF (20 mL). Nitrogen gas was purged, and LiAlH4 (76 mg, 2.0 mmol) was added to the reaction mixture. Nitrogen gas was purged three times, and the mixture was refluxed for 24 h. After the reaction was complete, the mixture was cooled to room temperature, the reaction solution was quenched in water, and extracted with dichloromethane. The organic phase was dried over anhydrous MgSO4, and excess solvent was removed by vacuum distillation to obtain the crude product. The crude product was dissolved in chloroform (10 mL), and 3-bromo-1,2-diaminobenzene (52 mg, 0.276 mmol) was accurately weighed and added. The mixture was reacted at room temperature for 12 h. After the reaction was complete, excess solvent was removed by vacuum distillation, and the mixture was subjected to silica gel column chromatography with stirring to obtain approximately 187 mg of compound 6-2, with a yield of 69.4%. MADLI-TOF-MS: 1347.13.

[0231] Synthesis of compound 6-3:

[0232] Compound 6-2 (175 mg, 0.13 mmol) was accurately weighed and dissolved in 1,2-dichloroethane (30 mL). Subsequent synthetic steps followed the synthetic route for compounds 1-3, yielding approximately 147 mg of compound 6-3, with a yield of 80.6%. MADLI-TOF-MS: 1402.79.

[0233] Synthesis of compound 6-4:

[0234] Compound 6-3 (112 mg, 0.08 mmol) and compound L-1 (31 mg, 0.04 mmol) were accurately weighed and dissolved in ultra-dry chlorobenzene (5 mL). Subsequent synthetic steps followed the synthetic route for compounds 1-4, yielding approximately 98 mg of compound 6-4, with a yield of 79.2%. MADLI-TOF-MS: 3091.57.

[0235] Synthesis of compound (59):

[0236] Compound 6-4 (93 mg, 0.03 mmol) and 5,6-difluoro-3-(dicyanomethylene)indone (55 mg, 0.24 mmol) were accurately weighed and dissolved in chloroform (15 mL). Subsequent synthetic steps followed the synthetic route of compound (6), yielding approximately 75 mg of compound (59), with a yield of 63.5%. MADLI-TOF-MS: 3939.28.

[0237] Dimeric acceptor synthesis Example 8: Synthesis of compound (66)

[0238]

[0239] Synthesis of compound 7-2:

[0240] Compound 1-1 (245 mg, 0.2 mmol) was accurately weighed and dissolved in ultradry THF (20 mL). Nitrogen was purged, and LiAlH4 (76 mg, 2.0 mmol) was added to the reaction mixture. Nitrogen was purged three times, and the mixture was refluxed for 24 h. After the reaction was complete, the mixture was cooled to room temperature, the reaction solution was quenched in water, and extracted with dichloromethane. The organic phase was dried over anhydrous MgSO4, and excess solvent was removed by vacuum distillation to obtain the crude product. The crude product was dissolved in chloroform (10 mL), and 3-bromo-4-fluoro-1,2-phenylenediamine (57 mg, 0.276 mmol) was accurately weighed and added. The mixture was reacted at room temperature for 12 h. After the reaction was complete, excess solvent was removed by vacuum distillation, and the mixture was subjected to silica gel column chromatography with stirring to obtain approximately 214 mg of compound 7-2, with a yield of 78.4%. MADLI-TOF-MS: 1365.23.

[0241] Synthesis of compound 7-3:

[0242] Compound 7-2 (177 mg, 0.13 mmol) was accurately weighed and dissolved in 1,2-dichloroethane (30 mL). Subsequent synthetic steps followed the synthetic route for compounds 1-3, yielding approximately 141 mg of compound 7-3, with a yield of 76.3%. MADLI-TOF-MS: 1421.39.

[0243] Synthesis of compound 7-4:

[0244] Compound 7-3 (114 mg, 0.08 mmol) and compound L-2 (26 mg, 0.04 mmol) were accurately weighed and dissolved in ultra-dry chlorobenzene (5 mL). Subsequent synthetic steps followed the synthetic route for compounds 1-4, yielding approximately 95 mg of compound 7-4, with a yield of 79.3%. MADLI-TOF-MS: 2994.62.

[0245] Synthesis of compound (66):

[0246] Compound 7-4 (90 mg, 0.03 mmol) and 5,6-difluoro-3-(dicyanomethylene)indone (55 mg, 0.24 mmol) were accurately weighed and dissolved in chloroform (15 mL). Subsequent synthetic steps followed the synthetic route of compound (6), yielding approximately 84 mg of compound (66), with a yield of 72.9%. MADLI-TOF-MS: 3843.16.

[0247] OPV Device Fabrication and Characterization Examples

[0248] This embodiment illustrates the fabrication and characterization of the OPV device provided by the present invention, but the present invention is not limited to the following embodiment.

[0249] Device Example 1:

[0250] refer to Figure 1 Device embodiment 1 includes a substrate 101, an anode layer 102, an anode buffer layer 103, a photoactive layer 104, a cathode buffer layer 105, and a cathode layer 106 stacked sequentially; wherein, the materials of the anode layer 102, the anode buffer layer 103, the photoactive layer 104, the cathode buffer layer 105, and the cathode layer 106 are, in, indium tin oxide (ITO) / PEDOT:PSS / photoactive layer material / PDINN / Ag, respectively.

[0251] The OPV device fabrication method includes the following steps:

[0252] (1) ITO substrate cleaning: Clean the ITO conductive glass with detergent, rinse it clean, and then ultrasonically clean it with deionized water, acetone and isopropanol for 15 minutes. Then dry it with nitrogen and treat it in a plasma cleaner for 5 minutes to further clean the surface and improve wettability.

[0253] (2) Preparation of anode buffer layer: PEDOT:PSS (CLEVIOSTM PVPAI4083) was spin-coated on the surface of conductive glass at a speed of 4000 rpm / min for 30 s, and then dried at 150℃ for 15 min to obtain the anode buffer layer.

[0254] (3) Preparation of photoactive layer: In a glove box (inert gas atmosphere), the photoactive layer solution is uniformly spin-coated onto the anode buffer layer at a speed of 1800-4000 rpm to obtain a photoactive material layer with a total thickness of about 100 nm.

[0255] Preparation of photoactive layer solution: The active layer donor material D18, the active layer acceptor material N3 and the dimer acceptor material compound (6) were dissolved in the organic solvent chloroform, and 0.5% by volume of 1-chloronaphthalene was added as an additive. The mass ratio of D18:N3:dimeric acceptor material compound (6) was 1:1.2:0.1, and the concentration of donor material D18 in chloroform was 4.5 mg / mL, thus obtaining the photoactive layer solution.

[0256]

[0257] (4) Preparation of cathode buffer layer: After annealing on a hot table at 80°C for 10 min, the cathode buffer layer material PDINN (PDINN is dissolved in methanol to prepare a solution with a concentration of 1 mg / mL) is uniformly spin-coated onto the photoactive layer at a spin speed of 3000-4000 rpm to obtain a cathode buffer layer with a thickness of about 10 nm.

[0258] (5) Cathode layer preparation: under high vacuum (1×10⁻⁶) -6 Ag is deposited onto the cathode buffer layer in millibars to form a cathode layer with a thickness of approximately 100 nm.

[0259] (6) Packaging: The device is encapsulated in a nitrogen glove box with UV-cured resin.

[0260] Device Examples 2-8

[0261] The preparation methods of device examples 2-8 are the same as those of device example 1. The difference lies in the selection of the acceptor material in the photoactive layer. Specifically, the dimer acceptor material compound (6) is replaced with compound (18), compound (20), compound (23), compound (33), compound (47), compound (59) and compound (66), respectively. See Table 10 for details.

[0262] Device Comparison Example 1

[0263] The preparation method of the device comparative example 1 is the same as that of the device example 1, except that the preparation method of the photoactive layer solution is different, as follows: the active layer donor material D18 and the active layer acceptor material N3 are dissolved in the organic solvent chloroform, and 0.5% by volume of 1-chloronaphthalene is added as an additive, wherein the mass ratio of D18:N3 is 1:1.3, and the total concentration of donor material D18 in chloroform is 4.5 mg / mL, thus obtaining the photoactive layer solution.

[0264] The organic photovoltaic devices were tested for performance. Under standard light irradiation using a solar simulator (AM 1.5G), the cell current-voltage curves were measured, and the photoelectric conversion efficiency was calculated, as shown in Table 10.

[0265] Table 10

[0266]

[0267]

[0268] As shown in the device characterization data in Table 10, applying the dimer acceptor material with silicon- or oxygen-containing flexible chains provided in this invention to organic photovoltaic devices can effectively improve the photoelectric conversion efficiency of the devices. This is because the non-fullerene acceptor of this invention is constructed through a central-linked approach, fully preserving the end-group structure and introducing suitable flexible chains, thereby improving the crystallinity and aggregation of the molecules. When used as a second acceptor material in the active layer, the blended film forms a more compact and ordered molecular stacking and a clear fibrous network structure, effectively promoting charge generation and transport while suppressing exciton recombination.

[0269] Obviously, the above embodiments are merely illustrative examples for clear explanation and are not intended to limit the implementation. Those skilled in the art will recognize that other variations or modifications can be made based on the above description. It is neither necessary nor possible to exhaustively list all possible implementations here. However, obvious variations or modifications derived therefrom are still within the scope of protection of this invention.

Claims

1. A dimer acceptor material, characterized in that, The dimer acceptor material has a structure as shown in general formula (I): in: L is selected from m is selected from any integer between 3 and 20; Each occurrence of X1 is independently selected from CR4R5, SiR6R7 or O, and L contains at least two SiR6R7 or at least one O. R4, R5, R6, and R7 are each independently selected from -H, -D, or alkyl groups having 1 to 10 carbon atoms; Each time Ar2 appears, it is independently selected from R. a Aromatic groups having 6-20 carbon atoms, substituted or unsubstituted, or containing R a Substituted or unsubstituted heteroaromatic groups having 5-20 ring atoms; R a Each time it appears, it is independently selected from -D, -F, -Cl, alkyl groups having 1-10 carbon atoms, or alkoxy groups having 1-10 carbon atoms; * indicates a connection point; Each time R3 appears, it is independently selected from -D, -F, -Cl, or an alkyl group having 1-10 carbon atoms, or an alkoxy group having 1-10 carbon atoms; r is selected from 0, 1, 2, or 3; Each time Z appears, it is independently selected from O, S, or Se; Each time R1 appears, it is independently selected from R. b Substituted or unsubstituted straight-chain or branched alkyl groups having 3-30 carbon atoms; R b Each occurrence is independently selected from one or a combination of at least two of the following: -D, -F, -Cl, vinyl, ethynyl, cycloalkyl having 3-30 carbon atoms, aromatic group having 6-20 carbon atoms, or heteroaromatic group having 5-20 ring atoms. Each occurrence of R2 is independently selected from -H, -D, alkyl groups having 1-30 carbon atoms, alkoxy groups having 1-30 carbon atoms, alkylthio groups having 1-30 carbon atoms, or groups influenced by R. c Aromatic groups having 6-20 carbon atoms, substituted or unsubstituted, or containing R c Substituted or unsubstituted heteroaromatic groups having 5-20 ring atoms; R c Each time it appears, it is independently selected from -D, -F, -Cl, alkyl groups having 1-30 carbon atoms, alkoxy groups having 1-30 carbon atoms, or alkylthio groups having 1-30 carbon atoms; Each time M appears, it is independently selected from O or C(CN)2; Each time Ar1 appears, it is independently selected from R. d Aromatic groups having 6-20 carbon atoms, substituted or unsubstituted, or containing R d Substituted or unsubstituted heteroaromatic groups having 5-20 ring atoms; R d Each occurrence is independently selected from -D, -F, -Cl, -Br, -I, -CF3, -CN, straight-chain alkyl with 1-10 carbon atoms, branched alkyl with 3-10 carbon atoms, straight-chain alkoxy with 1-10 carbon atoms, or branched alkoxy with 3-10 carbon atoms.

2. The dimer acceptor material according to claim 1, characterized in that, The dimer acceptor material is selected from structures shown as in general formula (II-1) or (II-2):

3. The dimer acceptor material according to claim 1 or 2, characterized in that, The L is selected from Where: a is selected from 1, 2, 3, 4, 5 or 6; b is selected from 1, 2, 3, 4, 5 or 6; c is selected from 3, 4, 5, 6, 7, 8, 9 or 10; Preferably, each occurrence of R6 and R7 is independently selected from methyl groups.

4. The dimer acceptor material according to claim 3, characterized in that, Each time Ar2 appears, it is independently selected from R. a Substituted or unsubstituted phenyl groups are subjected to R a Substituted or unsubstituted thiophene group, R a Substituted or unsubstituted furanyl, or R a Substituted or unsubstituted selenophene group; R a Each time it appears, it is independently selected from -D, -F, -Cl, alkyl groups having 1-10 carbon atoms, or alkoxy groups having 1-10 carbon atoms; Preferably, the Ar2 is selected from thiophene group.

5. The dimer acceptor material according to any one of claims 1-4, characterized in that: The L is selected from the following groups:

6. The dimer acceptor material according to claim 1 or 2, characterized in that, Each occurrence of R1 is independently selected from the subset of R. b Substituted or unsubstituted branched alkyl groups having 8-30 carbon atoms; R b Each occurrence is independently selected from one or a combination of at least two of the following: -D, -F, -Cl, vinyl, ethynyl, cycloalkyl having 3-10 carbon atoms, aromatic group having 6-10 carbon atoms, and heteroaromatic group having 5-10 ring atoms; Each occurrence of R2 is independently selected from -H, -D, alkyl groups having 1-20 carbon atoms, alkoxy groups having 1-20 carbon atoms, alkylthio groups having 1-20 carbon atoms, or groups affected by R. c Substituted or unsubstituted aromatic groups having 6-10 carbon atoms, or those modified by R c Substituted or unsubstituted heteroaromatic groups having 5-10 ring atoms; R c Each time it appears, it is independently selected from -D, -F, -Cl, alkyl groups having 1-20 carbon atoms, alkoxy groups having 1-20 carbon atoms, or alkylthio groups having 1-20 carbon atoms.

7. The dimer acceptor material according to claim 1 or 2, characterized in that, Each time Ar1 appears, it is independently selected from R. d Substituted or unsubstituted aromatic groups having 6-10 carbon atoms, or those modified by R d Substituted or unsubstituted heteroaromatic groups having 5-10 ring atoms; R d Each occurrence is independently selected from -D, -F, -Cl, -Br, -I, -CF3, -CN, straight-chain alkyl with 1-6 carbon atoms, branched alkyl with 3-6 carbon atoms, straight-chain alkoxy with 1-6 carbon atoms, or branched alkoxy with 3-6 carbon atoms; Preferably, each occurrence of Ar1 is independently selected from the following groups: # indicates a fusion site, which is selected from carbon atoms; Wherein: R8 is selected independently each time it appears from -H, -D, -F, -Cl, -Br, -I, -CF3, -CN, straight-chain alkyl with 1-6 carbon atoms, branched alkyl with 3-6 carbon atoms, straight-chain alkoxy with 1-6 carbon atoms, or branched alkoxy with 3-6 carbon atoms.

8. The dimer acceptor material according to claim 7, characterized in that, The dimer acceptor material is selected from structures represented by general formulas (III-1), (III-2), (III-3), (III-4), (III-5), (III-6), (III-7), (III-8), or (III-9):

9. A mixture, characterized in that, The mixture comprises a first receptor material and at least one other organic functional material; the first receptor material comprises a dimer receptor material as described in any one of claims 1-8; the other organic functional material is selected from photoactive layer donor materials and / or photoactive layer receptor materials.

10. An organic photovoltaic cell, characterized in that, The organic photovoltaic cell includes a cathode, an anode, and a photoactive layer located between the cathode and the anode, the photoactive layer comprising a dimer acceptor material as described in any one of claims 1-8, or a mixture as described in claim 9.

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